diff --git a/lib/data/provider/auth_fb.dart b/lib/data/provider/auth_fb.dart
index 15d9dc1..6062f1a 100644
--- a/lib/data/provider/auth_fb.dart
+++ b/lib/data/provider/auth_fb.dart
@@ -9,7 +9,7 @@ import 'package:fcs/domain/entities/user.dart';
 import 'package:fcs/domain/exceiptions/signin_exception.dart';
 import 'package:fcs/helpers/api_helper.dart';
 import 'package:fcs/helpers/firebase_helper.dart';
-import 'package:firebase_auth/firebase_auth.dart';
+import 'package:firebase_auth/firebase_auth.dart' as fb;
 import 'package:logging/logging.dart';
 
 class AuthFb {
@@ -18,17 +18,17 @@ class AuthFb {
   static final AuthFb instance = AuthFb._();
   AuthFb._();
 
-  StreamController<User> controller;
-  static final FirebaseAuth _fb = FirebaseAuth.instance;
-  static String _verificationId;
+  late StreamController<User?> controller;
+  static final fb.FirebaseAuth _fb = fb.FirebaseAuth.instance;
+  static String _verificationId = '';
 
   Future<fcs.AuthResult> sendSmsCodeToPhoneNumber(String phoneNumber) {
     Completer<fcs.AuthResult> completer = Completer();
     bool codeSentCompleted = false;
 
-    final PhoneVerificationCompleted verificationCompleted =
-        (AuthCredential credential) async {
-      AuthResult _authResult;
+    final fb.PhoneVerificationCompleted verificationCompleted =
+        (fb.AuthCredential credential) async {
+      fb.UserCredential _authResult;
       try {
         _authResult = await _fb.signInWithCredential(credential);
         print("PhoneVerificationCompleted :$_authResult");
@@ -48,23 +48,23 @@ class AuthFb {
           'Inside _sendCodeToPhoneNumber: signInWithPhoneNumber auto succeeded: ${_authResult.user}');
     };
 
-    final PhoneVerificationFailed verificationFailed =
-        (AuthException authException) async {
+    final fb.PhoneVerificationFailed verificationFailed =
+        (fb.FirebaseAuthException authException) async {
       print(
           'Phone number verification failed. Code: ${authException.code}. Message: ${authException.message}');
       completer.completeError(SigninException(
           "Phone number verification failed:${authException.message}"));
     };
 
-    final PhoneCodeSent codeSent =
-        (String verificationId, [int forceResendingToken]) async {
+    final fb.PhoneCodeSent codeSent =
+        (String verificationId, [int? forceResendingToken]) async {
       _verificationId = verificationId;
       print("codeSent  " + phoneNumber);
       codeSentCompleted = true;
       completer.complete(fcs.AuthResult(authStatus: AuthStatus.SMS_SENT));
     };
 
-    final PhoneCodeAutoRetrievalTimeout codeAutoRetrievalTimeout =
+    final fb.PhoneCodeAutoRetrievalTimeout codeAutoRetrievalTimeout =
         (String verificationId) {
       print("codeAutoRetrievalTimeout $verificationId ");
 
@@ -89,11 +89,11 @@ class AuthFb {
 
   Future<fcs.AuthResult> signInWithPhoneNumber(String smsCode) async {
     try {
-      final AuthCredential credential = PhoneAuthProvider.getCredential(
-        verificationId: _verificationId,
-        smsCode: smsCode,
-      );
-      AuthResult _authResult = await _fb.signInWithCredential(credential);
+      final fb.AuthCredential credential = fb.PhoneAuthProvider.credential(
+          verificationId: _verificationId, smsCode: smsCode);
+
+      fb.UserCredential _authResult =
+          await _fb.signInWithCredential(credential);
       if (_authResult == null) {
         throw SigninException("Sigin error!");
       }
@@ -105,19 +105,21 @@ class AuthFb {
   }
 
   Future<void> signout() async {
-    if (userListener != null) await userListener.cancel();
+    if (userListener != null) await userListener!.cancel();
     return _fb.signOut();
   }
 
   Future<void> _addUserToStream({bool refreshIdToken = false}) async {
-    FirebaseUser firebaseUser = await _fb.currentUser();
+    fb.User? firebaseUser = _fb.currentUser;
     if (firebaseUser == null) return null;
-    Map claims = await getClaims(refreshIdToken: refreshIdToken);
+    Map<dynamic, dynamic>? claims =
+        await getClaims(refreshIdToken: refreshIdToken);
 
     log.info("Claims:$claims");
+    if (claims == null) return;
 
     String cid = claims["cid"];
-    User user;
+    User? user;
     if (cid != null && cid != "") {
       user = await _getUserFromFirestore(cid);
     }
@@ -136,20 +138,20 @@ class AuthFb {
     controller.add(user);
   }
 
-  Future<User> _getUserFromFirestore(String userID) async {
-    DocumentSnapshot snap = await Firestore.instance
+  Future<User?> _getUserFromFirestore(String userID) async {
+    DocumentSnapshot snap = await FirebaseFirestore.instance
         .collection(user_collection)
-        .document(userID)
+        .doc(userID)
         .get();
     if (snap.exists) {
-      User user = User.fromMap(snap.data, snap.documentID);
+      User user = User.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       return user;
     }
     return null;
   }
 
   Future<bool> isLogin() async {
-    final FirebaseUser firebaseUser = await _fb.currentUser();
+    final fb.User? firebaseUser = _fb.currentUser;
     return Future.value(firebaseUser != null);
   }
 
@@ -193,48 +195,50 @@ class AuthFb {
   }
 
   Stream<Setting> settings() async* {
-    Stream<DocumentSnapshot> snapshot = Firestore.instance
+    Stream<DocumentSnapshot> snapshot = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(setting_doc_id)
+        .doc(setting_doc_id)
         .snapshots();
 
     await for (var snap in snapshot) {
-      Setting setting = Setting.fromMap(snap.data);
+      Setting setting = Setting.fromMap(snap.data() as Map<String, dynamic>);
       yield setting;
     }
   }
 
-  Future<String> _getCurrentUserID() async {
-    FirebaseUser firebaseUser = await _fb.currentUser();
+  Future<String?> _getCurrentUserID() async {
+    fb.User? firebaseUser = _fb.currentUser;
     if (firebaseUser == null) return null;
-    Map claims = await getClaims();
+    Map? claims = await getClaims();
+    if (claims == null) return null;
     String cid = claims["cid"];
     return cid;
   }
 
   Future<void> _startUserListener() async {
-    if (userListener != null) userListener.cancel();
-    String _userID = await _getCurrentUserID();
+    if (userListener != null) userListener!.cancel();
+    String? _userID = await _getCurrentUserID();
     if (_userID == null) {
       return;
     }
 
-    Stream<DocumentSnapshot> snapshot = Firestore.instance
+    Stream<DocumentSnapshot> snapshot = FirebaseFirestore.instance
         .collection(user_collection)
-        .document(_userID)
+        .doc(_userID)
         .snapshots();
     userListener = snapshot.listen((snap) async {
-      User user = User.fromMap(snap.data, snap.documentID);
+      User user = User.fromMap(snap.data() as Map<String, dynamic>, snap.id);
 
-      FirebaseUser firebaseUser = await _fb.currentUser();
+      fb.User? firebaseUser = _fb.currentUser;
       if (firebaseUser == null) {
-        userListener.cancel();
+        userListener?.cancel();
         return;
       }
       try {
         // get privilege from claim
-        IdTokenResult idToken = await firebaseUser.getIdToken(refresh: true);
-        String privileges = idToken.claims["pr"];
+        fb.IdTokenResult idToken = await firebaseUser.getIdTokenResult(true);
+
+        String privileges = idToken.claims?["pr"] ?? '';
         if (privileges != null && privileges != "") {
           user.privileges = privileges.split(":").toList();
         }
@@ -245,13 +249,13 @@ class AuthFb {
     });
   }
 
-  StreamSubscription<DocumentSnapshot> userListener;
-  Stream<User> user() {
+  StreamSubscription<DocumentSnapshot>? userListener;
+  Stream<User?> user() {
     // ignore: close_sinks
-    StreamSubscription<FirebaseUser> authListener;
+    StreamSubscription<fb.User?>? authListener;
 
     Future<void> _start() async {
-      authListener = _fb.onAuthStateChanged.listen((firebaseUser) async {
+      authListener = _fb.authStateChanges().listen((firebaseUser) {
         if (firebaseUser == null) {
           controller.add(null);
         } else {
@@ -263,10 +267,10 @@ class AuthFb {
 
     void _stop() {
       if (userListener != null) {
-        userListener.cancel();
+        userListener!.cancel();
       }
       if (authListener != null) {
-        authListener.cancel();
+        authListener!.cancel();
       }
     }
 
diff --git a/lib/data/provider/carton_data_provider.dart b/lib/data/provider/carton_data_provider.dart
index 7f74557..622b8c8 100644
--- a/lib/data/provider/carton_data_provider.dart
+++ b/lib/data/provider/carton_data_provider.dart
@@ -1,5 +1,4 @@
 import 'dart:async';
-import 'dart:convert';
 
 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:fcs/domain/constants.dart';
@@ -36,7 +35,7 @@ class CartonDataProvider {
   }
 
   Future<List<Carton>> searchCarton(String term) async {
-    if (term == null || term == '') return List();
+    if (term == null || term == '') return [];
 
     // var bytes = utf8.encode(term);
     // var base64Str = base64.encode(bytes);
@@ -45,7 +44,7 @@ class CartonDataProvider {
 
     try {
       String path = "/$cartons_collection";
-      var querySnap = await Firestore.instance
+      var querySnap = await FirebaseFirestore.instance
           .collection(path)
           .where("carton_number", isEqualTo: term)
           .where("carton_type",
@@ -53,13 +52,11 @@ class CartonDataProvider {
           .where("status", isEqualTo: carton_packed_status)
           .where("is_deleted", isEqualTo: false)
           .orderBy("user_name")
-          .getDocuments();
-      return querySnap.documents
-          .map((e) => Carton.fromMap(e.data, e.documentID))
-          .toList();
+          .get();
+      return querySnap.docs.map((e) => Carton.fromMap(e.data(), e.id)).toList();
     } catch (e) {
       log.warning("carton error:" + e.toString());
-      return null;
+      return [];
     }
   }
 }
diff --git a/lib/data/provider/package_data_provider.dart b/lib/data/provider/package_data_provider.dart
index e0d99a2..8183eaa 100644
--- a/lib/data/provider/package_data_provider.dart
+++ b/lib/data/provider/package_data_provider.dart
@@ -56,8 +56,8 @@ class PackageDataProvider {
         token: await getToken());
   }
 
-  Future<List<Package>> ftsSearchPackage(String term) async {
-    if (term == null || term == '') return List();
+  Future<List<Package>?> ftsSearchPackage(String term) async {
+    if (term == null || term == '') return [];
 
     var bytes = utf8.encode(term);
     var base64Str = base64.encode(bytes);
@@ -72,7 +72,7 @@ class PackageDataProvider {
           "/api/fts/$packages_collection/$escapePackage/$limit", "GET",
           url: Config.instance.reportURL, token: await getToken());
 
-      if (data == null) return List();
+      if (data == null) return [];
 
       data.forEach((p) {
         var package = Package.fromJson(p);
@@ -86,7 +86,7 @@ class PackageDataProvider {
   }
 
   Future<List<Package>> searchPackage(String term) async {
-    if (term == null || term == '') return List();
+    if (term == null || term == '') return [];
 
     List<Package> packages = [];
 
diff --git a/lib/data/provider/rate_data_provider.dart b/lib/data/provider/rate_data_provider.dart
index c8c416e..0ffc089 100644
--- a/lib/data/provider/rate_data_provider.dart
+++ b/lib/data/provider/rate_data_provider.dart
@@ -16,33 +16,33 @@ class RateDataProvider {
   static final RateDataProvider instance = RateDataProvider._();
   RateDataProvider._();
 
-  StreamController<Rate> controller;
+  late StreamController<Rate> controller;
   static Rate _rate = Rate();
 
   Stream<Rate> _rateStream() async* {
-    Stream<DocumentSnapshot> snapshot = Firestore.instance
+    Stream<DocumentSnapshot> snapshot = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .snapshots();
     await for (var snap in snapshot) {
-      Rate rate = Rate.fromMap(snap.data);
+      Rate rate = Rate.fromMap(snap.data() as Map<String, dynamic>);
       yield rate;
     }
   }
 
   Stream<List<CargoType>> _cargoTypeStream() async* {
     List<CargoType> cargoTypes = [];
-    Stream<QuerySnapshot> snapshots = Firestore.instance
+    Stream<QuerySnapshot> snapshots = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .collection(cargo_types_collection)
         .where("custom_duty", isEqualTo: false)
         .snapshots();
 
     await for (var snaps in snapshots) {
       cargoTypes = [];
-      cargoTypes = snaps.documents.map((snap) {
-        return CargoType.fromMap(snap.data, snap.documentID);
+      cargoTypes = snaps.docs.map((snap) {
+        return CargoType.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       }).toList();
 
       yield cargoTypes;
@@ -51,17 +51,17 @@ class RateDataProvider {
 
   Stream<List<CargoType>> _customDutiesStream() async* {
     List<CargoType> customDuries = [];
-    Stream<QuerySnapshot> snapshots = Firestore.instance
+    Stream<QuerySnapshot> snapshots = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .collection(cargo_types_collection)
         .where("custom_duty", isEqualTo: true)
         .snapshots();
 
     await for (var snaps in snapshots) {
       customDuries = [];
-      customDuries = snaps.documents.map((snap) {
-        return CargoType.fromMap(snap.data, snap.documentID);
+      customDuries = snaps.docs.map((snap) {
+        return CargoType.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       }).toList();
       yield customDuries;
     }
@@ -69,25 +69,26 @@ class RateDataProvider {
 
   Stream<List<DiscountByWeight>> _discountByWeightStream() async* {
     List<DiscountByWeight> discountByWeight = [];
-    Stream<QuerySnapshot> snapshots = Firestore.instance
+    Stream<QuerySnapshot> snapshots = FirebaseFirestore.instance
         .collection(config_collection)
-        .document(rate_doc_id)
+        .doc(rate_doc_id)
         .collection(discounts_by_weights_collection)
         .snapshots();
 
     await for (var snaps in snapshots) {
       discountByWeight = [];
-      discountByWeight = snaps.documents.map((snap) {
-        return DiscountByWeight.fromMap(snap.data, snap.documentID);
+      discountByWeight = snaps.docs.map((snap) {
+        return DiscountByWeight.fromMap(
+            snap.data() as Map<String, dynamic>, snap.id);
       }).toList();
       yield discountByWeight;
     }
   }
 
-  StreamSubscription<Rate> rateListener;
-  StreamSubscription<List<CargoType>> cargoListener;
-  StreamSubscription<List<CargoType>> customListener;
-  StreamSubscription<List<DiscountByWeight>> discountListener;
+  late StreamSubscription<Rate> rateListener;
+  late StreamSubscription<List<CargoType>> cargoListener;
+  late StreamSubscription<List<CargoType>> customListener;
+  late StreamSubscription<List<DiscountByWeight>> discountListener;
   Stream<Rate> rate() {
     Future<void> _start() async {
       rateListener = _rateStream().listen((rate) {
diff --git a/lib/data/provider/user_data_provider.dart b/lib/data/provider/user_data_provider.dart
index 99ec833..3fc8394 100644
--- a/lib/data/provider/user_data_provider.dart
+++ b/lib/data/provider/user_data_provider.dart
@@ -37,23 +37,23 @@ class UserDataProvider {
         payload: {"token": token}, token: await getToken());
   }
 
-  Future<User> findUser(String phoneNumber) async {
-    QuerySnapshot querySnap = await Firestore.instance
+  Future<User?> findUser(String phoneNumber) async {
+    QuerySnapshot querySnap = await FirebaseFirestore.instance
         .collection(user_collection)
         .where("phone_number", isEqualTo: phoneNumber)
         .limit(1)
-        .getDocuments();
+        .get();
 
-    if (querySnap.documents.length > 0) {
-      var snap = querySnap.documents.first;
-      User user = User.fromMap(snap.data, snap.documentID);
+    if (querySnap.docs.length > 0) {
+      var snap = querySnap.docs.first;
+      User user = User.fromMap(snap.data() as Map<String, dynamic>, snap.id);
       return user;
     }
     return null;
   }
 
   Future<List<User>> searchUser(String term) async {
-    if (term == null || term == '') return List();
+    if (term == null || term == '') return [];
 
     var bytes = utf8.encode(term);
     var base64Str = base64.encode(bytes);
@@ -68,7 +68,7 @@ class UserDataProvider {
           "/api/fts/$user_collection/$escapeBuyer/$limit", "GET",
           url: Config.instance.reportURL, token: await getToken());
 
-      if (data == null) return List();
+      if (data == null) return [];
 
       data.forEach((buyer) {
         var user = User.fromJson(buyer);
@@ -76,7 +76,7 @@ class UserDataProvider {
       });
     } catch (e) {
       log.warning("buyer error:" + e.toString());
-      return null;
+      // return null;
     }
     return users;
   }
diff --git a/lib/data/services/auth_imp.dart b/lib/data/services/auth_imp.dart
index 05b36ec..056907f 100644
--- a/lib/data/services/auth_imp.dart
+++ b/lib/data/services/auth_imp.dart
@@ -3,17 +3,16 @@ import 'package:fcs/domain/entities/auth_result.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/setting.dart';
 import 'package:fcs/domain/entities/user.dart';
-import 'package:flutter/material.dart';
 
 import 'auth_service.dart';
 
 class AuthServiceImp implements AuthService {
   AuthServiceImp({
-    @required this.authFb,
-    @required this.connectivity,
+    required this.authFb,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final AuthFb authFb;
 
   @override
@@ -32,7 +31,7 @@ class AuthServiceImp implements AuthService {
   }
 
   @override
-  Stream<User> getUserStream() {
+  Stream<User?> getUserStream() {
     return authFb.user();
   }
 
diff --git a/lib/data/services/auth_service.dart b/lib/data/services/auth_service.dart
index dad8ce7..a276495 100644
--- a/lib/data/services/auth_service.dart
+++ b/lib/data/services/auth_service.dart
@@ -11,6 +11,6 @@ abstract class AuthService {
   Future<void> updateProfileName(String newUserName);
   Future<void> updatePreferredCurrency(String currency);
   Future<bool> hasInvite();
-  Stream<User> getUserStream();
+  Stream<User?> getUserStream();
   Stream<Setting> getSetting();
 }
diff --git a/lib/data/services/carton_imp.dart b/lib/data/services/carton_imp.dart
index ba97084..402f48e 100644
--- a/lib/data/services/carton_imp.dart
+++ b/lib/data/services/carton_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/carton_data_provider.dart';
 import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
-import 'package:flutter/material.dart';
 
 import 'carton_service.dart';
 
 class CartonServiceImp implements CartonService {
   CartonServiceImp({
-    @required this.cartonDataProvider,
-    @required this.connectivity,
+    required this.cartonDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final CartonDataProvider cartonDataProvider;
 
   @override
diff --git a/lib/data/services/common_imp.dart b/lib/data/services/common_imp.dart
index 74e0654..cfc24e0 100644
--- a/lib/data/services/common_imp.dart
+++ b/lib/data/services/common_imp.dart
@@ -2,13 +2,12 @@ import 'package:fcs/data/provider/common_data_provider.dart';
 import 'package:fcs/domain/entities/discount.dart';
 import 'package:fcs/domain/entities/payment_method.dart';
 import 'package:fcs/domain/vo/message.dart';
-import 'package:flutter/material.dart';
 
 import 'common_service.dart';
 
 class CommonServiceImp implements CommonService {
   CommonServiceImp({
-    @required this.commonDataProvider,
+    required this.commonDataProvider,
   });
 
   final CommonDataProvider commonDataProvider;
diff --git a/lib/data/services/delivery_address_imp.dart b/lib/data/services/delivery_address_imp.dart
index 96d8a36..d60219a 100644
--- a/lib/data/services/delivery_address_imp.dart
+++ b/lib/data/services/delivery_address_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/delivery_address_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
-import 'package:flutter/material.dart';
 
 import 'delivery_address_service.dart';
 
 class DeliveryAddressImp implements DeliveryAddressService {
   DeliveryAddressImp({
-    @required this.connectivity,
-    @required this.deliveryAddressDataProvider,
+    required this.connectivity,
+    required this.deliveryAddressDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final DeliveryAddressDataProvider deliveryAddressDataProvider;
 
   @override
diff --git a/lib/data/services/fcs_shipment_imp.dart b/lib/data/services/fcs_shipment_imp.dart
index 6ffaafa..35e5071 100644
--- a/lib/data/services/fcs_shipment_imp.dart
+++ b/lib/data/services/fcs_shipment_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/fcs_shipment_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/fcs_shipment.dart';
-import 'package:flutter/material.dart';
 
 import 'fcs_shipment_service.dart';
 
 class FcsShipmentServiceImp implements FcsShipmentService {
   FcsShipmentServiceImp({
-    @required this.connectivity,
-    @required this.shipmentDataProvider,
+    required this.connectivity,
+    required this.shipmentDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final FcsShipmentDataProvider shipmentDataProvider;
 
   @override
diff --git a/lib/data/services/invoice_imp.dart b/lib/data/services/invoice_imp.dart
index c26dab4..de8e1d0 100644
--- a/lib/data/services/invoice_imp.dart
+++ b/lib/data/services/invoice_imp.dart
@@ -1,21 +1,17 @@
 import 'package:fcs/data/provider/invoice_data_provider.dart';
-import 'package:fcs/data/provider/shipment_data_provider.dart';
-import 'package:fcs/data/services/shipment_service.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/invoice.dart';
 import 'package:fcs/domain/entities/payment.dart';
-import 'package:fcs/domain/entities/shipment.dart';
-import 'package:flutter/material.dart';
 
 import 'invoice_service.dart';
 
 class InvoiceServiceImp implements InvoiceService {
   InvoiceServiceImp({
-    @required this.invoiceDataProvider,
-    @required this.connectivity,
+    required this.invoiceDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final InvoiceDataProvider invoiceDataProvider;
 
   @override
diff --git a/lib/data/services/package_imp.dart b/lib/data/services/package_imp.dart
index 75f0b56..f200147 100644
--- a/lib/data/services/package_imp.dart
+++ b/lib/data/services/package_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/package_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/package.dart';
-import 'package:flutter/material.dart';
 
 import 'package_service.dart';
 
 class PackageServiceImp implements PackageService {
   PackageServiceImp({
-    @required this.connectivity,
-    @required this.packageDataProvider,
+    required this.connectivity,
+    required this.packageDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final PackageDataProvider packageDataProvider;
 
   @override
@@ -30,7 +29,7 @@ class PackageServiceImp implements PackageService {
   }
 
   @override
-  Future<List<Package>> ftsSearchPackage(String term) {
+  Future<List<Package>?> ftsSearchPackage(String term) {
     return packageDataProvider.ftsSearchPackage(term);
   }
 
diff --git a/lib/data/services/package_service.dart b/lib/data/services/package_service.dart
index ca00c58..2d27585 100644
--- a/lib/data/services/package_service.dart
+++ b/lib/data/services/package_service.dart
@@ -7,7 +7,7 @@ abstract class PackageService {
   Future<void> deleteReceiving(Package package);
   Future<void> updateProcessing(Package package);
   Future<void> deleteProcessing(Package package);
-  Future<List<Package>> ftsSearchPackage(String term);
+  Future<List<Package>?> ftsSearchPackage(String term);
   Future<List<Package>> searchPackage(String term);
   Future<void> changeDeliveryAddress(String packageID, String deliveryID);
   Future<void> packageReturn(String packageID);
diff --git a/lib/data/services/rate_imp.dart b/lib/data/services/rate_imp.dart
index 6bea2ee..ad1d0e9 100644
--- a/lib/data/services/rate_imp.dart
+++ b/lib/data/services/rate_imp.dart
@@ -4,17 +4,16 @@ import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/discount_by_weight.dart';
 import 'package:fcs/domain/entities/custom_duty.dart';
 import 'package:fcs/domain/entities/rate.dart';
-import 'package:flutter/material.dart';
 
 import 'rate_service.dart';
 
 class RateServiceImp implements RateService {
   RateServiceImp({
-    @required this.rateDataProvider,
-    @required this.connectivity,
+    required this.rateDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final RateDataProvider rateDataProvider;
 
   @override
diff --git a/lib/data/services/services.dart b/lib/data/services/services.dart
index aee169b..b2e15d0 100644
--- a/lib/data/services/services.dart
+++ b/lib/data/services/services.dart
@@ -35,17 +35,18 @@ import 'user_service.dart';
 class Services {
   static final Services instance = Services._();
 
-  AuthService _authService;
-  UserService _userService;
-  PackageService _packageService;
-  MessagingService _messagingService;
-  CommonService _commonService;
-  FcsShipmentService _fcsShipmentService;
-  DeliveryAddressService _deliveryAddressService;
-  RateService _rateService;
-  ShipmentService _shipmentService;
-  CartonService _cartonService;
-  InvoiceService _invoiceService;
+  late AuthService _authService;
+  late UserService _userService;
+  late PackageService _packageService;
+  late MessagingService _messagingService;
+  late CommonService _commonService;
+  late FcsShipmentService _fcsShipmentService;
+  late DeliveryAddressService _deliveryAddressService;
+  late RateService _rateService;
+  late ShipmentService _shipmentService;
+  late CartonService _cartonService;
+  late InvoiceService _invoiceService;
+
   Services._() {
     _authService = AuthServiceImp(
       authFb: AuthFb.instance,
diff --git a/lib/data/services/shipment_imp.dart b/lib/data/services/shipment_imp.dart
index 8aeb11d..0b3a784 100644
--- a/lib/data/services/shipment_imp.dart
+++ b/lib/data/services/shipment_imp.dart
@@ -2,15 +2,14 @@ import 'package:fcs/data/provider/shipment_data_provider.dart';
 import 'package:fcs/data/services/shipment_service.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/shipment.dart';
-import 'package:flutter/material.dart';
 
 class ShipmentServiceImp implements ShipmentService {
   ShipmentServiceImp({
-    @required this.shipmentDataProvider,
-    @required this.connectivity,
+    required this.shipmentDataProvider,
+    required this.connectivity,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final ShipmentDataProvider shipmentDataProvider;
 
   @override
diff --git a/lib/data/services/user_imp.dart b/lib/data/services/user_imp.dart
index d3b7685..9b5305a 100644
--- a/lib/data/services/user_imp.dart
+++ b/lib/data/services/user_imp.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/data/provider/user_data_provider.dart';
 import 'package:fcs/domain/entities/connectivity.dart';
 import 'package:fcs/domain/entities/user.dart';
-import 'package:flutter/material.dart';
 
 import 'user_service.dart';
 
 class UserServiceImp implements UserService {
   UserServiceImp({
-    @required this.connectivity,
-    @required this.userDataProvider,
+    required this.connectivity,
+    required this.userDataProvider,
   });
 
-  final Connectivity connectivity;
+  final Connectivity? connectivity;
   final UserDataProvider userDataProvider;
 
   @override
@@ -30,7 +29,7 @@ class UserServiceImp implements UserService {
   }
 
   @override
-  Future<User> findUser(String phoneNumber) {
+  Future<User?> findUser(String phoneNumber) {
     return userDataProvider.findUser(phoneNumber);
   }
 
diff --git a/lib/data/services/user_service.dart b/lib/data/services/user_service.dart
index 168193d..0dd4297 100644
--- a/lib/data/services/user_service.dart
+++ b/lib/data/services/user_service.dart
@@ -4,7 +4,7 @@ abstract class UserService {
   Future<void> inviteUser(String userName, String phoneNumber);
   Future<void> deleteInvite(String phoneNumber);
   Future<void> acceptRequest(String userID);
-  Future<User> findUser(String phoneNumber);
+  Future<User?> findUser(String phoneNumber);
   Future<List<User>> searchUser(String term);
   Future<void> uploadMsgToken(String token);
   Future<void> removeMsgToken(String token);
diff --git a/lib/domain/entities/auth_result.dart b/lib/domain/entities/auth_result.dart
index dd989fd..5467733 100644
--- a/lib/domain/entities/auth_result.dart
+++ b/lib/domain/entities/auth_result.dart
@@ -1,9 +1,9 @@
 import 'auth_status.dart';
 
 class AuthResult {
-  AuthStatus authStatus;
-  String authErrorCode;
-  String authErrorMsg;
+  AuthStatus? authStatus;
+  String? authErrorCode;
+  String? authErrorMsg;
 
   AuthResult({this.authStatus, this.authErrorCode, this.authErrorMsg});
 }
diff --git a/lib/domain/entities/cargo_type.dart b/lib/domain/entities/cargo_type.dart
index 68ec494..0e165ea 100644
--- a/lib/domain/entities/cargo_type.dart
+++ b/lib/domain/entities/cargo_type.dart
@@ -1,28 +1,28 @@
 class CargoType {
-  String id;
-  String name;
+  String? id;
+  String? name;
   double rate;
   double weight;
   bool isChecked;
   int qty;
-  bool isCutomDuty;
+  bool? isCutomDuty;
   double customDutyFee;
-
-  double get calAmount => (calRate ?? 0) * (calWeight ?? 0);
-
   double calRate;
   double calWeight;
+
+  double get calAmount => calRate * calWeight;
+
   CargoType(
       {this.id,
       this.name,
-      this.rate,
-      this.weight,
-      this.calWeight,
-      this.calRate,
+      this.rate = 0,
+      this.weight = 0,
+      this.calWeight = 0,
+      this.calRate = 0,
       this.isChecked = false,
       this.qty = 0,
       this.isCutomDuty,
-      this.customDutyFee});
+      this.customDutyFee = 0});
 
   factory CargoType.fromMap(Map<String, dynamic> map, String id) {
     return CargoType(
@@ -52,7 +52,7 @@ class CargoType {
   }
 
   CargoType clone() {
-    return CargoType.fromMap(toMap(), this.id);
+    return CargoType.fromMap(toMap(), this.id!);
   }
 
   @override
@@ -63,7 +63,7 @@ class CargoType {
 
   @override
   String toString() {
-    return name;
+    return name ?? "";
   }
 
   bool isChangedForEdit(CargoType cargoType) {
diff --git a/lib/domain/entities/carton.dart b/lib/domain/entities/carton.dart
index 831adf2..22254ac 100644
--- a/lib/domain/entities/carton.dart
+++ b/lib/domain/entities/carton.dart
@@ -9,64 +9,64 @@ import 'cargo_type.dart';
 import 'package.dart';
 
 class Carton {
-  String id;
-  String shipmentID;
-  String shipmentNumber;
-  String senderID;
-  String senderFCSID;
-  String senderName;
+  String? id;
+  String? shipmentID;
+  String? shipmentNumber;
+  String? senderID;
+  String? senderFCSID;
+  String? senderName;
 
-  String boxNumber;
-  String status;
-  String cargoDesc;
-  String desc;
+  String? boxNumber;
+  String? status;
+  String? cargoDesc;
+  String? desc;
   double width;
   double height;
   double length;
-  int shipmentWeight;
-  bool isChecked;
-  bool isShipmentCarton;
-  String cartonType;
-  String fcsID;
-  String userName;
-  String userID;
-  String fcsShipmentID;
-  String fcsShipmentNumber;
-  String mixCartonID;
-  String mixCartonNumber;
-  String cartonSizeID;
-  String cartonSizeName;
-  double cartonWeight;
+  int? shipmentWeight;
+  bool? isChecked;
+  bool? isShipmentCarton;
+  String? cartonType;
+  String? fcsID;
+  String? userName;
+  String? userID;
+  String? fcsShipmentID;
+  String? fcsShipmentNumber;
+  String? mixCartonID;
+  String? mixCartonNumber;
+  String? cartonSizeID;
+  String? cartonSizeName;
+  double? cartonWeight;
 
   int rate;
   int weight;
-  String packageType;
-  String pickUpID;
-  List<String> photos;
-  String remark;
-  DateTime arrivedDate;
-  String cartonNumber;
+  String? packageType;
+  String? pickUpID;
+  List<String> photos = [];
+  String? remark;
+  DateTime? arrivedDate;
+  String? cartonNumber;
 
   List<String> packageIDs;
   List<Package> packages;
-  List<CargoType> cargoTypes;
+  List<CargoType> cargoTypes = [];
 
-  DeliveryAddress deliveryAddress;
-  Shipment shipment;
+  DeliveryAddress? deliveryAddress;
+  Shipment? shipment;
 
   //for mix box
-  String mixBoxType;
+  String? mixBoxType;
   List<Carton> mixCartons;
   List<String> mixCartonIDs;
 
-  int get amount => rate != null && weight != null ? rate * weight : 0;
+  int get amount => rate != null && weight != null ? (rate * weight) : 0;
 
   // String get packageNumber =>
   //     shipmentNumber + "-" + receiverNumber + " #" + boxNumber;
-  double get price => rate.toDouble() * weight;
 
-  double get actualWeight =>
-      cargoTypes == null ? 0 : cargoTypes.fold(0, (p, e) => e.weight + p);
+  double get actualWeight => cargoTypes == null
+      ? 0
+      : cargoTypes.fold(0, (p, e) => e.weight  + p);
 
   int getShipmentWeight(double volumetricRatio) {
     if (length == null ||
@@ -84,15 +84,15 @@ class Carton {
   /// getCargoTypeForCalWeight returns carton with shipment weight
   List<CargoType> getCargoTypeForCalWeight(double volumetricRatio) {
     // get shipment weight
-    double volume = (length ?? 0) * (width ?? 0) * (height ?? 0);
-    double sw = volume / volumetricRatio ?? 0;
+    double volume = length * width * height;
+    double sw = volume / volumetricRatio;
 
     // get actual weight
     double aw = cargoTypes.fold(0.0, (p, c) => p + c.weight);
     if (aw == 0 || sw == 0) return [];
 
     cargoTypes.forEach((e) {
-      double calWeight = aw > sw ? e.weight : e.weight / aw * sw;
+      double calWeight = aw > sw ? e.weight : (e.weight / aw) * sw;
       e.calWeight = calWeight;
     });
     return cargoTypes;
@@ -115,8 +115,8 @@ class Carton {
 
     double total = 0;
     cargoTypes.forEach((e) {
-      double r =
-          e.rate - (discountByWeight != null ? discountByWeight.discount : 0);
+      double r = e.rate -
+          (discountByWeight != null ? (discountByWeight.discount) : 0);
       double amount = e.weight * r;
       total += amount;
     });
@@ -134,9 +134,9 @@ class Carton {
       this.senderName,
       this.boxNumber,
       this.desc,
-      this.width,
-      this.height,
-      this.length,
+      this.width = 0,
+      this.height = 0,
+      this.length = 0,
       this.shipmentWeight,
       this.isChecked = false,
       this.cartonType,
@@ -151,13 +151,13 @@ class Carton {
       this.status,
       this.arrivedDate,
       this.cargoDesc,
-      this.shipmentHistory,
-      this.packages,
-      this.cargoTypes,
+      this.shipmentHistory = const [],
+      this.packages = const [],
+      this.cargoTypes = const [],
       this.cartonNumber,
       this.fcsShipmentID,
       this.fcsShipmentNumber,
-      this.packageIDs,
+      this.packageIDs = const [],
       this.mixCartonID,
       this.mixCartonNumber,
       this.isShipmentCarton = false,
@@ -165,14 +165,14 @@ class Carton {
       this.cartonSizeID,
       this.cartonSizeName,
       this.mixBoxType,
-      this.mixCartons,
-      this.mixCartonIDs,
+      this.mixCartons = const [],
+      this.mixCartonIDs = const [],
       this.cartonWeight});
 
   Map<String, dynamic> toMap() {
-    List _cargoTypes = cargoTypes?.map((c) => c.toMap())?.toList() ?? [];
-    List _packages = packages?.map((c) => c.toJson())?.toList();
-    List _mixCartons = mixCartons?.map((c) => c.toJson())?.toList();
+    List _cargoTypes = cargoTypes.map((c) => c.toMap()).toList();
+    List _packages = packages.map((c) => c.toJson()).toList();
+    List _mixCartons = mixCartons.map((c) => c.toJson()).toList();
     return {
       'id': id,
       'fcs_shipment_id': fcsShipmentID,
@@ -213,9 +213,9 @@ class Carton {
       shipmentNumber: map['shipment_number'],
       // receiverNumber: map['receiver_number'],
       boxNumber: map['box_number'],
-      length: double.tryParse(map['length']?.toString()),
-      width: double.tryParse(map['width']?.toString()),
-      height: double.tryParse(map['height']?.toString()),
+      length: double.tryParse(map['length'].toString()) ?? 0,
+      width: double.tryParse(map['width'].toString()) ?? 0,
+      height: double.tryParse(map['height'].toString()) ?? 0,
       userName: map['user_name'],
       fcsID: map['fcs_id'],
       cartonType: map['carton_type'],
@@ -242,8 +242,8 @@ class Carton {
 
   Map<String, dynamic> toJson() {
     List _cargoTypes = cargoTypes.map((c) => c.toMap()).toList();
-    List _packages = packages?.map((c) => c.toJson())?.toList();
-    List _mixCartons = mixCartons?.map((c) => c.toJson())?.toList();
+    List _packages = packages.map((c) => c.toJson()).toList();
+    List _mixCartons = mixCartons.map((c) => c.toJson()).toList();
     return {
       'id': id,
       'fcs_shipment_id': fcsShipmentID,
diff --git a/lib/domain/entities/carton_size.dart b/lib/domain/entities/carton_size.dart
index 7d9f494..e9cd28b 100644
--- a/lib/domain/entities/carton_size.dart
+++ b/lib/domain/entities/carton_size.dart
@@ -1,10 +1,11 @@
 class CartonSize {
-  String id;
-  String name;
+  String? id;
+  String? name;
   double length;
   double width;
   double height;
-  CartonSize({this.id, this.name, this.length, this.width, this.height});
+  CartonSize(
+      {this.id, this.name, this.length = 0, this.width = 0, this.height = 0});
 
   Map<String, dynamic> toMap() {
     return {
@@ -27,19 +28,10 @@ class CartonSize {
   }
 
   @override
-  bool operator ==(other) {
-    if (identical(this, other)) {
-      return true;
-    }
-    return other.id == this.id;
-  }
+  bool operator ==(Object other) => other is CartonSize && other.id == id;
 
   @override
-  int get hashCode {
-    int result = 17;
-    result = 37 * result + id.hashCode;
-    return result;
-  }
+  int get hashCode => id.hashCode;
 
   bool isChangedForEdit(CartonSize cartonSize) {
     return cartonSize.name != this.name ||
diff --git a/lib/domain/entities/custom_duty.dart b/lib/domain/entities/custom_duty.dart
index fb2a3aa..6f033f0 100644
--- a/lib/domain/entities/custom_duty.dart
+++ b/lib/domain/entities/custom_duty.dart
@@ -1,11 +1,15 @@
 class CustomDuty {
-  String id;
-  String productType;
-  String desc;
+  String? id;
+  String? productType;
+  String? desc;
   double fee;
   double shipmentRate;
   CustomDuty(
-      {this.id, this.productType, this.desc, this.fee, this.shipmentRate});
+      {this.id,
+      this.productType,
+      this.desc,
+      this.fee = 0,
+      this.shipmentRate = 0});
 
   factory CustomDuty.fromMap(Map<String, dynamic> map, String id) {
     return CustomDuty(
diff --git a/lib/domain/entities/customer.dart b/lib/domain/entities/customer.dart
index 0fb51e7..6606f28 100644
--- a/lib/domain/entities/customer.dart
+++ b/lib/domain/entities/customer.dart
@@ -1,10 +1,8 @@
-
-
 class Customer {
-  String id;
-  String name;
-  String phoneNumber;
-  String status;
+  String? id;
+  String? name;
+  String? phoneNumber;
+  String? status;
 
   Customer({
     this.id,
diff --git a/lib/domain/entities/discount.dart b/lib/domain/entities/discount.dart
index cb2bda0..144bb9d 100644
--- a/lib/domain/entities/discount.dart
+++ b/lib/domain/entities/discount.dart
@@ -1,9 +1,9 @@
 class Discount {
-  String id;
-  String code;
-  String customerId;
-  String customerName;
-  String status;
+  String? id;
+  String? code;
+  String? customerId;
+  String? customerName;
+  String? status;
   double amount;
 
   Discount({
@@ -11,7 +11,7 @@ class Discount {
     this.code,
     this.customerId,
     this.customerName,
-    this.amount,
+    this.amount = 0,
     this.status,
   });
 
diff --git a/lib/domain/entities/discount_by_weight.dart b/lib/domain/entities/discount_by_weight.dart
index 3ff9a1d..92d46f0 100644
--- a/lib/domain/entities/discount_by_weight.dart
+++ b/lib/domain/entities/discount_by_weight.dart
@@ -1,9 +1,9 @@
 class DiscountByWeight {
-  String id;
+  String? id;
   double weight;
   double discount;
 
-  DiscountByWeight({this.id, this.weight, this.discount});
+  DiscountByWeight({this.id, this.weight = 0, this.discount = 0});
 
   factory DiscountByWeight.fromMap(Map<String, dynamic> map, String id) {
     return DiscountByWeight(
diff --git a/lib/domain/entities/faq.dart b/lib/domain/entities/faq.dart
index fe20f07..7deae33 100644
--- a/lib/domain/entities/faq.dart
+++ b/lib/domain/entities/faq.dart
@@ -1,16 +1,17 @@
 class FAQ {
-  String id;
-  int sn;
-  String questionEng;
-  String questionMm;
-  String answerEng;
-  String answerMm;
-  String pageLinkLabelEng;
-  String pageLinkLabelMm;
-  String pageLink;
+  String? id;
+  int? sn;
+  String? questionEng;
+  String? questionMm;
+  String? answerEng;
+  String? answerMm;
+  String? pageLinkLabelEng;
+  String? pageLinkLabelMm;
+  String? pageLink;
 
-  String question(bool isEng) => isEng ? questionEng : questionMm;
-  String answer(bool isEng) => isEng ? answerEng : answerMm;
+  String question(bool isEng) =>
+      isEng ? (questionEng ?? "") : (questionMm ?? "");
+  String answer(bool isEng) => isEng ? (answerEng ?? "") : (answerMm ?? "");
 
   FAQ(
       {this.id,
diff --git a/lib/domain/entities/fcs_shipment.dart b/lib/domain/entities/fcs_shipment.dart
index 37e2c71..794e65e 100644
--- a/lib/domain/entities/fcs_shipment.dart
+++ b/lib/domain/entities/fcs_shipment.dart
@@ -3,17 +3,18 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 import '../constants.dart';
 
 class FcsShipment {
-  String id;
-  String shipmentNumber;
-  DateTime cutoffDate;
-  String shipType;
-  DateTime arrivalDate;
-  DateTime departureDate;
-  String consignee;
-  String port;
-  String destination;
-  String status;
-  String reportName;
+  String? id;
+  String? shipmentNumber;
+  DateTime? cutoffDate;
+  String? shipType;
+  DateTime? arrivalDate;
+  DateTime? departureDate;
+  String? consignee;
+  String? port;
+  String? destination;
+  String? status;
+  String? reportName;
+
   FcsShipment({
     this.id,
     this.shipmentNumber,
@@ -51,10 +52,10 @@ class FcsShipment {
     return {
       "id": id,
       'shipment_number': shipmentNumber,
-      'cutoff_date': cutoffDate?.toUtc()?.toIso8601String(),
+      'cutoff_date': cutoffDate?.toUtc().toIso8601String(),
       'shipment_type': shipType,
-      'arrival_date': arrivalDate?.toUtc()?.toIso8601String(),
-      'departure_date': departureDate?.toUtc()?.toIso8601String(),
+      'arrival_date': arrivalDate?.toUtc().toIso8601String(),
+      'departure_date': departureDate?.toUtc().toIso8601String(),
       'consignee': consignee,
       'port': port,
       'destination': destination,
diff --git a/lib/domain/entities/invoice.dart b/lib/domain/entities/invoice.dart
index b614fcc..a15e905 100644
--- a/lib/domain/entities/invoice.dart
+++ b/lib/domain/entities/invoice.dart
@@ -10,15 +10,15 @@ import 'package:fcs/domain/entities/rate.dart';
 import 'package:fcs/domain/entities/shipment.dart';
 
 class Invoice {
-  String id;
-  String invoiceNumber;
-  DateTime invoiceDate;
-  String fcsShipmentID;
-  String userID;
-  String fcsID;
-  String userName;
-  String phoneNumber;
-  String status;
+  String? id;
+  String? invoiceNumber;
+  DateTime? invoiceDate;
+  String? fcsShipmentID;
+  String? userID;
+  String? fcsID;
+  String? userName;
+  String? phoneNumber;
+  String? status;
 
   double handlingFee;
   double deliveryFee;
@@ -28,11 +28,11 @@ class Invoice {
   List<CustomDuty> customDuties;
   List<Carton> cartons;
   List<CargoType> cargoTypes;
-  List<Shipment> shipments;
+  List<Shipment?>? shipments;
   List<Payment> payments;
-  Discount discount;
-  PaymentMethod paymentMethod;
-  String invoiceURL;
+  Discount? discount;
+  PaymentMethod? paymentMethod;
+  String? invoiceURL;
 
   List<CargoType> getCargoTypes(Rate rate) {
     if (cargoTypes != null) return cargoTypes;
@@ -40,7 +40,7 @@ class Invoice {
     List<CargoType> _cargoTypes = [];
     double totalCalWeight = 0;
     cartons.forEach((carton) {
-      if (carton.isChecked) {
+      if (carton.isChecked ?? false) {
         var _cartonsTypes =
             carton.getCargoTypeForCalWeight(rate.volumetricRatio);
         _cartonsTypes.forEach((ct) {
@@ -68,15 +68,15 @@ class Invoice {
 
   double getTotal(Rate rate) {
     List<CargoType> cargoTypes = getCargoTypes(rate);
-    var total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
+    double total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
     return total;
   }
 
-  double get balance => (amount ?? 0) - (paidAmount ?? 0);
+  double get balance => amount - paidAmount;
 
   double getNetAmount(Rate rate) {
     List<CargoType> cargoTypes = getCargoTypes(rate);
-    var total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
+    double total = cargoTypes.fold(0.0, (p, c) => c.calAmount + p);
     total += getCustomFee();
     total += getDeliveryFee();
     total += getHandlingFee();
@@ -85,13 +85,13 @@ class Invoice {
   }
 
   double getHandlingFee() {
-    return shipments?.where((sh) => sh.isSelected ?? false)?.fold(0, (p, s) {
-      return p + (s?.handlingFee ?? 0) - (s?.paidHandlingFee ?? 0);
-    });
+    return shipments!
+        .where((sh) => sh!.isSelected)
+        .fold(0, (p, s) => p + (s!.handlingFee - s.paidHandlingFee));
   }
 
   double getTotalBalance(Rate rate) {
-    return getNetAmount(rate) - (paidAmount ?? 0);
+    return getNetAmount(rate) - paidAmount;
   }
 
   double getCustomFee() {
@@ -102,7 +102,7 @@ class Invoice {
     return deliveryFee == null ? 0 : deliveryFee;
   }
 
-  double getDiscount() => discount == null ? 0 : discount.amount;
+  double getDiscount() => discount == null ? 0 : discount!.amount;
 
   Invoice(
       {this.id,
@@ -111,19 +111,19 @@ class Invoice {
       this.fcsID,
       this.userName,
       this.phoneNumber,
-      this.amount,
-      this.paidAmount,
+      this.amount = 0,
+      this.paidAmount = 0,
       this.discount,
       this.status,
-      this.customDuties,
-      this.cartons,
-      this.cargoTypes,
-      this.handlingFee,
-      this.deliveryFee,
+      this.customDuties = const [],
+      this.cartons = const [],
+      this.cargoTypes = const [],
+      this.handlingFee = 0,
+      this.deliveryFee = 0,
       this.fcsShipmentID,
-      this.shipments,
+      this.shipments = const [],
       this.invoiceURL,
-      this.payments,
+      this.payments = const [],
       this.paymentMethod});
 
   factory Invoice.fromMap(Map<String, dynamic> map, String docID) {
@@ -153,7 +153,7 @@ class Invoice {
     return Invoice(
       id: docID,
       invoiceNumber: map['invoice_number'],
-      invoiceDate: invd?.toDate(),
+      invoiceDate: invd.toDate(),
       userName: map['user_name'],
       fcsID: map['fcs_id'],
       phoneNumber: map['phone_number'],
@@ -174,12 +174,12 @@ class Invoice {
 
   Map<String, dynamic> toMap() {
     List _cargoTypes = cargoTypes.map((c) => c.toMap()).toList();
-    List _customDuties = customDuties?.map((c) => c.toMap())?.toList();
-    List _cartons = cartons?.map((c) => c.toMap())?.toList() ?? [];
-    List _shipments = shipments?.map((s) => s.toMap())?.toList() ?? [];
+    List _customDuties = customDuties.map((c) => c.toMap()).toList();
+    List _cartons = cartons.map((c) => c.toMap()).toList();
+    List _shipments = shipments!.map((s) => s!.toMap()).toList();
     return {
       "id": id,
-      "invoice_date": invoiceDate?.toUtc()?.toIso8601String(),
+      "invoice_date": invoiceDate?.toUtc().toIso8601String(),
       "user_id": userID,
       "user_name": userName,
       "invoice_number": invoiceNumber,
diff --git a/lib/domain/entities/market.dart b/lib/domain/entities/market.dart
index 0b7ebec..f12c955 100644
--- a/lib/domain/entities/market.dart
+++ b/lib/domain/entities/market.dart
@@ -1,11 +1,8 @@
 class Market {
-  String id;
-  String name;
+  String? id;
+  String? name;
 
-  Market({
-    this.id,
-    this.name,
-  });
+  Market({this.id, this.name});
 
   Map<String, dynamic> toMap() {
     return {
diff --git a/lib/domain/entities/package.dart b/lib/domain/entities/package.dart
index 9eb3249..2df0c7d 100644
--- a/lib/domain/entities/package.dart
+++ b/lib/domain/entities/package.dart
@@ -5,72 +5,71 @@ import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/domain/vo/shipment_status.dart';
 
 class Package {
-  String id;
-  String trackingID;
-  String userID;
-  String fcsID;
-  String userName;
-  String phoneNumber;
-  DateTime currentStatusDate;
+  String? id;
+  String? trackingID;
+  String? userID;
+  String? fcsID;
+  String? userName;
+  String? phoneNumber;
+  DateTime? currentStatusDate;
   List<String> photoUrls;
   List<ShipmentStatus> shipmentHistory;
-  String desc;
+  String? desc;
 
-  String status;
-  String shipmentNumber;
-  String senderFCSID;
-  String senderName;
-  String senderPhoneNumber;
-  String boxNumber;
-  String cargoDesc;
-  String market;
+  String? status;
+  String? shipmentNumber;
+  String? senderFCSID;
+  String? senderName;
+  String? senderPhoneNumber;
+  String? boxNumber;
+  String? cargoDesc;
+  String? market;
   bool isChecked;
 
   int rate;
   int weight;
-  String packageType;
-  String pickUpID;
-  List<String> photos;
-  String remark;
-  DateTime arrivedDate;
-  DeliveryAddress deliveryAddress;
+  String? packageType;
+  String? pickUpID;
+  // List<String> photos;
+  String? remark;
+  DateTime? arrivedDate;
+  DeliveryAddress? deliveryAddress;
 
   //for packages in processing
-  List<File> photoFiles;
+  List<File?> photoFiles;
 
   int get amount => rate != null && weight != null ? rate * weight : 0;
 
   double get price => rate.toDouble() * weight;
 
-  Package({
-    this.id,
-    this.trackingID,
-    this.userID,
-    this.userName,
-    this.fcsID,
-    this.phoneNumber,
-    this.shipmentNumber,
-    this.senderFCSID,
-    this.senderName,
-    this.boxNumber,
-    this.rate,
-    this.weight,
-    this.packageType,
-    this.pickUpID,
-    this.remark,
-    this.status,
-    this.arrivedDate,
-    this.cargoDesc,
-    this.market,
-    this.shipmentHistory,
-    this.currentStatusDate,
-    this.photoUrls,
-    this.desc,
-    this.deliveryAddress,
-    this.isChecked = false,
-    this.photoFiles,
-    this.senderPhoneNumber
-  });
+  Package(
+      {this.id,
+      this.trackingID,
+      this.userID,
+      this.userName,
+      this.fcsID,
+      this.phoneNumber,
+      this.shipmentNumber,
+      this.senderFCSID,
+      this.senderName,
+      this.boxNumber,
+      this.rate = 0,
+      this.weight = 0,
+      this.packageType,
+      this.pickUpID,
+      this.remark,
+      this.status,
+      this.arrivedDate,
+      this.cargoDesc,
+      this.market,
+      this.shipmentHistory = const [],
+      this.currentStatusDate,
+      this.photoUrls = const [],
+      this.desc,
+      this.deliveryAddress,
+      this.isChecked = false,
+      this.photoFiles = const [],
+      this.senderPhoneNumber});
 
   factory Package.fromMap(Map<String, dynamic> map, String docID) {
     var _currentStatusDate = (map['status_date'] as Timestamp);
@@ -98,9 +97,7 @@ class Package {
         senderName: map['sender_name'],
         senderPhoneNumber: map['sender_phone_number'],
         deliveryAddress: _da,
-        currentStatusDate: _currentStatusDate != null
-            ? _currentStatusDate.toDate().toLocal()
-            : null,
+        currentStatusDate: _currentStatusDate.toDate().toLocal(),
         photoUrls: _photoUrls,
         shipmentHistory: _shipmentStatus);
   }
diff --git a/lib/domain/entities/payment.dart b/lib/domain/entities/payment.dart
index d30eebc..feaeaca 100644
--- a/lib/domain/entities/payment.dart
+++ b/lib/domain/entities/payment.dart
@@ -1,11 +1,11 @@
 import 'package:cloud_firestore/cloud_firestore.dart';
 
 class Payment {
-  String id;
-  String invoiceID;
-  DateTime paymentDate;
-  String paymentReceiptURL;
-  String status;
+  String? id;
+  String? invoiceID;
+  DateTime? paymentDate;
+  String? paymentReceiptURL;
+  String? status;
   double amount;
 
   Payment(
@@ -14,13 +14,13 @@ class Payment {
       this.paymentDate,
       this.paymentReceiptURL,
       this.status,
-      this.amount});
+      this.amount = 0});
 
   factory Payment.fromMap(Map<String, dynamic> map, String id) {
     var _paymentDate = (map['payment_date'] as Timestamp);
     return Payment(
       id: id,
-      paymentDate: _paymentDate?.toDate(),
+      paymentDate: _paymentDate.toDate(),
       paymentReceiptURL: map['payment_receipt_url'],
       status: map['status'],
       amount: map['amount']?.toDouble() ?? 0,
@@ -31,7 +31,7 @@ class Payment {
     return {
       "id": id,
       "invoice_id": invoiceID,
-      'payment_date': paymentDate?.toUtc()?.toIso8601String(),
+      'payment_date': paymentDate?.toUtc().toIso8601String(),
       'payment_receipt_url': paymentReceiptURL,
       'status': status,
       'amount': amount,
@@ -39,7 +39,7 @@ class Payment {
   }
 
   Payment clone() {
-    return Payment.fromMap(toMap(), this.id);
+    return Payment.fromMap(toMap(), this.id!);
   }
 
   @override
diff --git a/lib/domain/entities/payment_method.dart b/lib/domain/entities/payment_method.dart
index 50cf277..109ad16 100644
--- a/lib/domain/entities/payment_method.dart
+++ b/lib/domain/entities/payment_method.dart
@@ -1,11 +1,11 @@
 class PaymentMethod {
-  String id;
-  String name;
-  String accountName;
-  String account;
-  String phone;
-  String email;
-  String link;
+  String? id;
+  String? name;
+  String? accountName;
+  String? account;
+  String? phone;
+  String? email;
+  String? link;
 
   PaymentMethod(
       {this.id,
diff --git a/lib/domain/entities/processing.dart b/lib/domain/entities/processing.dart
index 0006183..0c1a165 100644
--- a/lib/domain/entities/processing.dart
+++ b/lib/domain/entities/processing.dart
@@ -1,15 +1,15 @@
 import 'package:fcs/domain/entities/package.dart';
 
 class Processing {
-  String id;
+  String? id;
   //for consignee
-  String userID;
-  String userName;
-  String userPhoneNumber;
+  String? userID;
+  String? userName;
+  String? userPhoneNumber;
   //for shipper
-  String fcsID;
-  String shipperName;
-  String shipperPhoneNumber;
+  String? fcsID;
+  String? shipperName;
+  String? shipperPhoneNumber;
 
   List<Package> packages;
 
@@ -21,7 +21,7 @@ class Processing {
       this.fcsID,
       this.shipperName,
       this.shipperPhoneNumber,
-      this.packages});
+      this.packages = const []});
 
   @override
   bool operator ==(Object other) => other is Processing && other.id == id;
diff --git a/lib/domain/entities/rate.dart b/lib/domain/entities/rate.dart
index f5682e1..54442e8 100644
--- a/lib/domain/entities/rate.dart
+++ b/lib/domain/entities/rate.dart
@@ -1,4 +1,3 @@
-
 import 'package:fcs/domain/entities/discount_by_weight.dart';
 
 import 'cargo_type.dart';
@@ -11,26 +10,23 @@ class Rate {
   double diffDiscountWeight;
   double diffWeightRate;
 
-  List<CargoType> cargoTypes;
-  List<CargoType> customDuties;
-  List<DiscountByWeight> discountByWeights;
+  List<CargoType> cargoTypes = [];
+  List<CargoType> customDuties = [];
+  List<DiscountByWeight> discountByWeights = [];
 
   DiscountByWeight getDiscountByWeight(double weight) {
     discountByWeights.sort((d1, d2) => d2.weight.compareTo(d1.weight));
-    return discountByWeights.firstWhere((e) => e.weight < weight,
-        orElse: () => null);
+    return discountByWeights.firstWhere((e) => e.weight < weight);
   }
 
-  CargoType get defaultCargoType => cargoTypes == null
-      ? null
-      : cargoTypes.firstWhere((e) => e.name == "General");
+  CargoType get defaultCargoType => cargoTypes.firstWhere((e) => e.name == "General");
 
   Rate(
-      {this.deliveryFee,
-      this.freeDeliveryWeight,
-      this.volumetricRatio,
-      this.diffDiscountWeight,
-      this.diffWeightRate});
+      {this.deliveryFee = 0,
+      this.freeDeliveryWeight = 0,
+      this.volumetricRatio = 0,
+      this.diffDiscountWeight = 0,
+      this.diffWeightRate = 0});
 
   factory Rate.fromMap(Map<String, dynamic> map) {
     return Rate(
diff --git a/lib/domain/entities/receipt.dart b/lib/domain/entities/receipt.dart
index 6fffbbe..70f59f5 100644
--- a/lib/domain/entities/receipt.dart
+++ b/lib/domain/entities/receipt.dart
@@ -1,9 +1,9 @@
 class Receipt {
-  String id;
-  int amount;
-  String date;
-  String status;
-  String fileUrl;
+  String? id;
+  int? amount = 0;
+  String? date;
+  String? status;
+  String? fileUrl;
 
   Receipt({this.id, this.amount, this.date, this.status, this.fileUrl});
 }
diff --git a/lib/domain/entities/setting.dart b/lib/domain/entities/setting.dart
index 8f594bb..dd85745 100644
--- a/lib/domain/entities/setting.dart
+++ b/lib/domain/entities/setting.dart
@@ -10,25 +10,24 @@ List<Day> dayLists = [
 
 class Setting {
   final int supportBuildNum;
-
   // contact page
-  String usaAddress;
-  String mmAddress;
-  String usaContactNumber;
-  String mmContactNumber;
-  String emailAddress;
-  String facebookLink;
-  bool inviteRequired;
-  String appUrl;
-  final String termsEng;
-  final String termsMm;
-  String about;
-  String courierWebsite;
+  String? usaAddress;
+  String? mmAddress;
+  String? usaContactNumber;
+  String? mmContactNumber;
+  String? emailAddress;
+  String? facebookLink;
+  bool? inviteRequired;
+  String? appUrl;
+  final String? termsEng;
+  final String? termsMm;
+  String? about;
+  String? courierWebsite;
 
   List<String> shipmentTypes;
 
   Setting(
-      {this.supportBuildNum,
+      {this.supportBuildNum = 1,
       this.usaAddress,
       this.mmAddress,
       this.usaContactNumber,
@@ -40,7 +39,7 @@ class Setting {
       this.termsEng,
       this.termsMm,
       this.about,
-      this.shipmentTypes,
+      this.shipmentTypes = const [],
       this.courierWebsite});
 
   factory Setting.fromMap(Map<String, dynamic> map) {
@@ -76,9 +75,9 @@ class Setting {
 }
 
 class Day {
-  int id;
-  String name;
-  bool isChecked = false;
+  int? id;
+  String? name;
+  bool? isChecked = false;
   Day({this.id, this.name, this.isChecked});
 
   @override
diff --git a/lib/domain/entities/shipment.dart b/lib/domain/entities/shipment.dart
index 7b837df..2d4cabc 100644
--- a/lib/domain/entities/shipment.dart
+++ b/lib/domain/entities/shipment.dart
@@ -4,35 +4,35 @@ import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
 
 class Shipment {
-  String id;
-  String shipmentNumber;
-  String shipmentType;
-  DeliveryAddress pickupAddress;
-  DateTime pickupDate;
-  String pickupTimeStart;
-  String pickupTimeEnd;
+  String? id;
+  String? shipmentNumber;
+  String? shipmentType;
+  DeliveryAddress? pickupAddress;
+  DateTime? pickupDate;
+  String? pickupTimeStart;
+  String? pickupTimeEnd;
 
-  String userName;
-  String userID;
-  String phoneNumber;
-  int numberOfPackage;
-  int weight;
-  double handlingFee;
-  double paidHandlingFee;
-  String address;
-  String status;
+  String? userName;
+  String? userID;
+  String? phoneNumber;
+  int numberOfPackage = 0;
+  int weight = 0;
+  double handlingFee = 0;
+  double paidHandlingFee = 0;
+  String? address;
+  String? status;
   bool isCourier;
   int radioIndex;
   List<Carton> boxes;
 
-  String pickupUserID;
-  String pickupUserName;
-  String pickupUserPhoneNumber;
+  String? pickupUserID;
+  String? pickupUserName;
+  String? pickupUserPhoneNumber;
 
-  String fcsShipmentID;
-  String fcsShipmentNumber;
-  String shipmentLabelUrl;
-  bool isSelected;
+  String? fcsShipmentID;
+  String? fcsShipmentNumber;
+  String? shipmentLabelUrl;
+  bool isSelected = false;
 
   Shipment(
       {this.id,
@@ -43,28 +43,28 @@ class Shipment {
       this.phoneNumber,
       this.pickupTimeStart,
       this.pickupTimeEnd,
-      this.numberOfPackage,
-      this.weight,
-      this.handlingFee,
-      this.paidHandlingFee,
+      this.numberOfPackage = 0,
+      this.weight = 0,
+      this.handlingFee = 0,
+      this.paidHandlingFee = 0,
       this.address,
       this.status,
       this.pickupDate,
       this.isCourier = false,
       this.radioIndex = 1,
-      this.pickupAddress,
+      required this.pickupAddress,
       this.pickupUserID,
       this.pickupUserName,
       this.pickupUserPhoneNumber,
       this.fcsShipmentID,
       this.fcsShipmentNumber,
       this.shipmentLabelUrl,
-      this.boxes});
+      this.boxes = const []});
 
-  int get last => DateTime.now().difference(pickupDate).inDays;
+  // int get last => DateTime.now().difference(pickupDate).inDays;
 
-  double get totalWeight => boxes?.fold(0, (p, e) => p + e.actualWeight);
-  int get totalCount => boxes?.length;
+  double get totalWeight => boxes.fold(0, (p, e) => p + e.actualWeight);
+  int get totalCount => boxes.length;
 
   bool get isPending => status == shipment_pending_status;
   bool get isAssigned => status == shipment_assigned_status;
@@ -100,15 +100,15 @@ class Shipment {
   }
 
   Map<String, dynamic> toMap() {
-    List _boxes = boxes?.map((l) => l.toMap())?.toList() ?? [];
+    List _boxes = boxes.map((l) => l.toMap()).toList();
 
     return {
       "id": id,
       'user_id': userID,
       'cartons': _boxes,
       'shipment_type': shipmentType,
-      'pickup_address': pickupAddress.toMap(),
-      "pickup_date": pickupDate?.toUtc()?.toIso8601String(),
+      'pickup_address': pickupAddress?.toMap(),
+      "pickup_date": pickupDate?.toUtc().toIso8601String(),
       'pickup_time_start': pickupTimeStart,
       'pickup_time_end': pickupTimeEnd,
       'pickup_user_id': pickupUserID,
diff --git a/lib/domain/entities/user.dart b/lib/domain/entities/user.dart
index 6ada508..0ad4100 100644
--- a/lib/domain/entities/user.dart
+++ b/lib/domain/entities/user.dart
@@ -9,18 +9,19 @@ DateFormat timeFormat = DateFormat("HH:mm");
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class User {
-  String id;
-  String name;
-  String phoneNumber;
-  String status;
-  String fcsID;
-  DateTime lastMessageTime;
-  String lastMessage;
+  String? id;
+  String? name;
+  String? phoneNumber;
+  String? status;
+  String? fcsID;
+  DateTime? lastMessageTime;
+  String? lastMessage;
   int userUnseenCount;
   int fcsUnseenCount;
-  String preferCurrency;
+  String? preferCurrency;
 
-  String get initial => name != null && name != "" ? name.substring(0, 1) : "?";
+  String get initial =>
+      name != null && name != "" ? name!.substring(0, 1) : "?";
 
   String get getLastMessage {
     var msg = lastMessage ?? "Say hi to $name";
@@ -31,27 +32,31 @@ class User {
   String get getLastMessageTime {
     if (lastMessageTime == null) return "";
     DateTime today = DateTime.now();
-    if (lastMessageTime.year == today.year &&
-        lastMessageTime.month == today.month &&
-        lastMessageTime.day == today.day) {
-      return timeFormat.format(lastMessageTime);
+    if (lastMessageTime!.year == today.year &&
+        lastMessageTime!.month == today.month &&
+        lastMessageTime!.day == today.day) {
+      return timeFormat.format(lastMessageTime!);
     } else {
-      return dateFormat.format(lastMessageTime);
+      return dateFormat.format(lastMessageTime!);
     }
   }
 
   String get getUserUnseenCount => userUnseenCount != null
-      ? userUnseenCount > 100 ? "99+" : userUnseenCount.toString()
+      ? userUnseenCount > 100
+          ? "99+"
+          : userUnseenCount.toString()
       : "0";
   String get getFcsUnseenCount => fcsUnseenCount != null
-      ? fcsUnseenCount > 100 ? "99+" : fcsUnseenCount.toString()
+      ? fcsUnseenCount > 100
+          ? "99+"
+          : fcsUnseenCount.toString()
       : "0";
 
   List<String> privileges = [];
 
-  String get phone => phoneNumber != null && phoneNumber.startsWith("959")
-      ? "0${phoneNumber.substring(2)}"
-      : phoneNumber;
+  String get phone => phoneNumber != null && phoneNumber!.startsWith("959")
+      ? "0${phoneNumber!.substring(2)}"
+      : phoneNumber!;
   bool get joined => status != null && status == user_joined_status;
   bool get invited => status != null && status == user_invited_status;
   bool get requested => status != null && status == user_requested_status;
@@ -64,11 +69,11 @@ class User {
       this.phoneNumber,
       this.fcsID,
       this.status,
-      this.privileges,
+      this.privileges = const [],
       this.lastMessage,
       this.lastMessageTime,
-      this.userUnseenCount,
-      this.fcsUnseenCount,
+      this.userUnseenCount = 0,
+      this.fcsUnseenCount = 0,
       this.preferCurrency});
 
   factory User.fromJson(Map<String, dynamic> json) {
diff --git a/lib/domain/exceiptions/server_exceptions.dart b/lib/domain/exceiptions/server_exceptions.dart
index a76ba67..7436d0b 100644
--- a/lib/domain/exceiptions/server_exceptions.dart
+++ b/lib/domain/exceiptions/server_exceptions.dart
@@ -1,12 +1,12 @@
 
 class ServerException  {
   @override
-  List<Object> get props => null;
+  List<Object>? get props => null;
 
   call() {
     return null;
   }
 
   @override
-  bool get stringify => null;
+  bool? get stringify => null;
 }
diff --git a/lib/domain/vo/contact.dart b/lib/domain/vo/contact.dart
index 5df67a2..2037ddf 100644
--- a/lib/domain/vo/contact.dart
+++ b/lib/domain/vo/contact.dart
@@ -1,12 +1,12 @@
 import 'package:fcs/domain/entities/setting.dart';
 
 class Contact {
-  String usaAddress;
-  String mmAddress;
-  String usaContactNumber;
-  String mmContactNumber;
-  String emailAddress;
-  String facebookLink;
+  String? usaAddress;
+  String? mmAddress;
+  String? usaContactNumber;
+  String? mmContactNumber;
+  String? emailAddress;
+  String? facebookLink;
 
   Contact({
     this.usaAddress,
diff --git a/lib/domain/vo/delivery_address.dart b/lib/domain/vo/delivery_address.dart
index 93e7960..b212ebc 100644
--- a/lib/domain/vo/delivery_address.dart
+++ b/lib/domain/vo/delivery_address.dart
@@ -1,13 +1,14 @@
 class DeliveryAddress {
-  String id;
-  String fullName;
-  String addressLine1;
-  String addressLine2;
-  String city;
-  String state;
-  String phoneNumber;
+  String? id;
+  String? fullName;
+  String? addressLine1;
+  String? addressLine2;
+  String? city;
+  String? state;
+  String? phoneNumber;
   bool isDefault;
-  String userID;
+  String? userID;
+
   DeliveryAddress(
       {this.id,
       this.fullName,
diff --git a/lib/domain/vo/message.dart b/lib/domain/vo/message.dart
index fc86b58..3417058 100644
--- a/lib/domain/vo/message.dart
+++ b/lib/domain/vo/message.dart
@@ -1,15 +1,15 @@
 import 'package:cloud_firestore/cloud_firestore.dart';
 
 class Message {
-  String id;
-  String message;
-  DateTime date;
-  String receiverID;
-  String receiverName;
-  String senderID;
-  String senderName;
-  String messageType;
-  String messageID;
+  String? id;
+  String? message;
+  DateTime? date;
+  String? receiverID;
+  String? receiverName;
+  String? senderID;
+  String? senderName;
+  String? messageType;
+  String? messageID;
 
   Message(
       {this.id,
@@ -21,11 +21,13 @@ class Message {
       this.senderName,
       this.messageType,
       this.messageID});
+
   bool fromToday() {
+    if (date == null) return false;
     var now = DateTime.now();
-    return date.day == now.day &&
-        date.month == now.month &&
-        date.year == now.year;
+    return date!.day == now.day &&
+        date!.month == now.month &&
+        date!.year == now.year;
   }
 
   Map<String, dynamic> toMap() {
@@ -36,9 +38,10 @@ class Message {
   }
 
   bool sameDay(Message another) {
-    return date.year == another.date.year &&
-        date.month == another.date.month &&
-        date.day == another.date.day;
+    if (date == null) return false;
+    return date!.year == another.date!.year &&
+        date!.month == another.date!.month &&
+        date!.day == another.date!.day;
   }
 
   factory Message.fromMap(Map<String, dynamic> map, String id) {
@@ -52,7 +55,7 @@ class Message {
       receiverName: map['receiver_name'],
       messageType: map['msg_type'],
       messageID: map['msg_id'],
-      date: date != null ? date.toDate() : null,
+      date: date.toDate(),
     );
   }
 }
diff --git a/lib/domain/vo/privilege.dart b/lib/domain/vo/privilege.dart
index 5b913b2..85907a2 100644
--- a/lib/domain/vo/privilege.dart
+++ b/lib/domain/vo/privilege.dart
@@ -1,20 +1,24 @@
 import 'package:fcs/domain/constants.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
 class Privilege {
   String id;
-  String name;
-  String desc;
-  bool sysAdminOnly = true;
-  bool isChecked = false;
+  String? name;
+  String? desc;
+  bool? sysAdminOnly = true;
+  bool? isChecked = false;
 
-  IconData iconData;
+  IconData? iconData;
 
   Privilege(
-      {this.id, this.name, this.desc, this.isChecked, this.sysAdminOnly}) {
+      {required this.id,
+      this.name,
+      this.desc,
+      this.isChecked,
+      this.sysAdminOnly}) {
     if (this.id == privilege_admin) {
       iconData = MaterialCommunityIcons.account_tie;
     } else if (this.id == privilege_support) {
diff --git a/lib/domain/vo/radio.dart b/lib/domain/vo/radio.dart
deleted file mode 100644
index ab1a7a1..0000000
--- a/lib/domain/vo/radio.dart
+++ /dev/null
@@ -1,5 +0,0 @@
-class RadioGroup {
-  String text;
-  int index;
-  RadioGroup({this.text, this.index});
-}
\ No newline at end of file
diff --git a/lib/domain/vo/shipment_status.dart b/lib/domain/vo/shipment_status.dart
index ed4549c..7783190 100644
--- a/lib/domain/vo/shipment_status.dart
+++ b/lib/domain/vo/shipment_status.dart
@@ -3,17 +3,21 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 class ShipmentStatus {
   String status;
   DateTime date;
-  bool done;
-  String staffId;
-  String staffName;
+  bool? done;
+  String? staffId;
+  String? staffName;
   ShipmentStatus(
-      {this.status, this.date, this.done, this.staffId, this.staffName});
+      {required this.status,
+      required this.date,
+      this.done,
+      this.staffId,
+      this.staffName});
 
   factory ShipmentStatus.fromMap(Map<String, dynamic> map) {
     var _date = (map['date'] as Timestamp);
     return ShipmentStatus(
         status: map['status'],
-        date: _date == null ? null : _date.toDate(),
+        date: _date.toDate(),
         done: map['done'],
         staffId: map['staff_id'],
         staffName: map['staff_name']);
diff --git a/lib/domain/vo/status.dart b/lib/domain/vo/status.dart
index e229726..a8b5b7b 100644
--- a/lib/domain/vo/status.dart
+++ b/lib/domain/vo/status.dart
@@ -1,8 +1,7 @@
-
 class Status {
-  String status;
-  String message;
-  String errorCode;
+  String? status;
+  String? message;
+  String? errorCode;
   Status(this.status, this.message);
 
   Status.fromJson(Map<String, dynamic> json) {
@@ -10,4 +9,4 @@ class Status {
     message = json['message'];
     errorCode = json['error_code'];
   }
-}
\ No newline at end of file
+}
diff --git a/lib/domain/vo/term.dart b/lib/domain/vo/term.dart
index b9c1086..9aa2c26 100644
--- a/lib/domain/vo/term.dart
+++ b/lib/domain/vo/term.dart
@@ -1,8 +1,8 @@
 import 'package:fcs/domain/entities/setting.dart';
 
 class Term {
-  String termEng;
-  String termMm;
+  String? termEng;
+  String? termMm;
 
   Term({this.termEng, this.termMm});
 
diff --git a/lib/helpers/api_helper.dart b/lib/helpers/api_helper.dart
index 06fca69..8eacdd2 100644
--- a/lib/helpers/api_helper.dart
+++ b/lib/helpers/api_helper.dart
@@ -20,8 +20,8 @@ Future<dynamic> requestAPI(
   String path,
   method, {
   dynamic payload,
-  String token,
-  String url,
+  String? token,
+  String? url,
 }) async {
   DevInfo devInfo = await DevInfo.getDevInfo();
 
@@ -33,7 +33,7 @@ Future<dynamic> requestAPI(
     headers["Token"] = token;
   }
   if (devInfo != null && devInfo.deviceID != null && deviceName != null) {
-    headers["Device"] = devInfo.deviceID + ":" + deviceName;
+    headers["Device"] = devInfo.deviceID??"" + ":" + deviceName;
   }
   headers["Project-ID"] = Config.instance.reportProjectID;
 
@@ -66,7 +66,7 @@ Future<dynamic> requestAPI(
 // request makes http request
 // if token is null
 Future<dynamic> requestDownloadAPI(String path, method,
-    {dynamic payload, String token, String url, String filePath}) async {
+    {dynamic payload, String? token, String? url, String? filePath}) async {
   DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
   AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
   String deviceName = "${androidInfo.model}(${androidInfo.id})";
@@ -81,7 +81,7 @@ Future<dynamic> requestDownloadAPI(String path, method,
     log.info("Path:$baseUrl$path");
     HttpClient client = new HttpClient();
     var _downloadData = StringBuffer();
-    var fileSave = new File(filePath);
+    var fileSave = new File(filePath!);
     var request = await client.getUrl(Uri.parse("$baseUrl$path"));
     request.headers.set("Project-ID", Config.instance.reportProjectID);
     request.headers
@@ -108,7 +108,7 @@ Future<dynamic> requestDownloadAPI(String path, method,
 // request makes http request
 // if token is null
 Future<dynamic> requestDownloadPDFAPI(String path, method,
-    {dynamic payload, String token, String url, String filePath}) async {
+    {dynamic payload, String? token, String? url, String? filePath}) async {
   DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
   AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
   String deviceName = "${androidInfo.model}(${androidInfo.id})";
@@ -123,7 +123,7 @@ Future<dynamic> requestDownloadPDFAPI(String path, method,
     log.info("Path:$baseUrl$path");
     HttpClient client = new HttpClient();
     // var _downloadData = StringBuffer();
-    var fileSave = new File(filePath);
+    var fileSave = new File(filePath!);
     var request = await client.getUrl(Uri.parse("$baseUrl$path"));
     request.headers.set("Project-ID", Config.instance.reportProjectID);
     if (token != null) {
@@ -135,7 +135,7 @@ Future<dynamic> requestDownloadPDFAPI(String path, method,
     request.headers.set("payload", escapePayload);
     var response = await request.close();
     print("headers:${response.headers}");
-    var _downloadData = List<int>();
+    List<int> _downloadData = [];
 
     response.listen((d) => _downloadData.addAll(d), onDone: () {
       fileSave.writeAsBytes(_downloadData);
@@ -155,10 +155,10 @@ typedef OnDownloadDone(File file);
 // if token is null
 Future<dynamic> requestDownload(String path, method,
     {dynamic payload,
-    String token,
-    String url,
-    String filePath,
-    OnDownloadDone onDownloadDone}) async {
+    required String token,
+    required String url,
+    required String filePath,
+    OnDownloadDone? onDownloadDone}) async {
   DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
   AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
   String deviceName = "${androidInfo.model}(${androidInfo.id})";
@@ -188,7 +188,7 @@ Future<dynamic> requestDownload(String path, method,
     // request.write(escapePayload);
     var response = await request.close();
     print("headers:${response.headers}");
-    var _downloadData = List<int>();
+    List<int> _downloadData = [];
     var cd = response.headers.value("content-disposition");
     String fileName = "download.csv";
     if (cd != null && cd.contains("filename=")) {
diff --git a/lib/helpers/dev_info.dart b/lib/helpers/dev_info.dart
index 255bf92..2d2c72d 100644
--- a/lib/helpers/dev_info.dart
+++ b/lib/helpers/dev_info.dart
@@ -2,13 +2,13 @@ import 'package:device_info/device_info.dart';
 import 'dart:io' show Platform;
 
 class DevInfo {
-  bool isAndroid;
-  bool isIOS;
-  String deviceID;
-  String id;
-  String model;
+  bool? isAndroid;
+  bool? isIOS;
+  String? deviceID;
+  String? id;
+  String? model;
 
-  static DevInfo _instance;
+  static DevInfo? _instance;
 
   static Future<DevInfo> getDevInfo() async {
     if (_instance != null) return Future.value(_instance);
@@ -18,14 +18,14 @@ class DevInfo {
 
     if (Platform.isAndroid) {
       AndroidDeviceInfo androidInfo = await deviceInfo.androidInfo;
-      _instance.deviceID = androidInfo.androidId;
-      _instance.id = androidInfo.id;
-      _instance.model = androidInfo.model;
+      _instance!.deviceID = androidInfo.androidId;
+      _instance!.id = androidInfo.id;
+      _instance!.model = androidInfo.model;
     } else if (Platform.isIOS) {
       IosDeviceInfo iosDeviceInfo = await deviceInfo.iosInfo;
-      _instance.deviceID = iosDeviceInfo.identifierForVendor;
-      _instance.id = iosDeviceInfo.utsname.release;
-      _instance.model = iosDeviceInfo.model;
+      _instance!.deviceID = iosDeviceInfo.identifierForVendor;
+      _instance!.id = iosDeviceInfo.utsname.release;
+      _instance!.model = iosDeviceInfo.model;
     }
     return Future.value(_instance);
   }
diff --git a/lib/helpers/firebase_helper.dart b/lib/helpers/firebase_helper.dart
index f9539e8..4014aa8 100644
--- a/lib/helpers/firebase_helper.dart
+++ b/lib/helpers/firebase_helper.dart
@@ -1,71 +1,82 @@
 import 'dart:io';
 
-import 'package:fcs/config.dart';
-import 'package:firebase_auth/firebase_auth.dart';
+import 'package:firebase_auth/firebase_auth.dart' as fb;
 import 'package:firebase_storage/firebase_storage.dart';
 import 'package:logging/logging.dart';
 import 'package:uuid/uuid.dart';
 
 final log = Logger('firebaseHelper');
 
-final FirebaseAuth auth = FirebaseAuth.instance;
+final fb.FirebaseAuth auth = fb.FirebaseAuth.instance;
 
 Future<String> getToken() async {
-  FirebaseUser firebaseUser = await auth.currentUser();
-  IdTokenResult token = await firebaseUser.getIdToken();
-  return token.token;
+  fb.User? firebaseUser = fb.FirebaseAuth.instance.currentUser;
+  String token = await firebaseUser?.getIdToken() ?? "";
+  return token;
 }
 
-Future<Map> getClaims({bool refreshIdToken = false}) async {
-  FirebaseUser firebaseUser = await auth.currentUser();
+Future<Map?> getClaims({bool refreshIdToken = false}) async {
+  fb.User? firebaseUser = auth.currentUser;
   if (firebaseUser == null) return null;
-  IdTokenResult idToken =
-      await firebaseUser.getIdToken(refresh: refreshIdToken);
+  fb.IdTokenResult idToken =
+      await firebaseUser.getIdTokenResult(refreshIdToken);
   return idToken.claims;
 }
 
 // returns list of url
-Future<List<String>> uploadFiles(String path, List<File> files,
-    {String fileName}) async {
+Future<List<String>> uploadFiles(String path, List<File?> files,
+    {String? fileName}) async {
   List<Future<String>> fu = [];
-  for (File f in files) {
+  for (File? f in files) {
     Future<String> u = uploadStorage(path, f);
     fu.add(u);
   }
   return Future.wait(fu);
 }
 
-Future<String> uploadStorage(String path, File file, {String fileName}) async {
+Future<String> uploadStorage(String path, File? file,
+    {String? fileName}) async {
   if (fileName == null) {
     fileName = Uuid().v4();
   }
-  StorageReference storageReference =
-      FirebaseStorage(storageBucket: Config.instance.bucketName)
-          .ref()
-          .child('$path/$fileName');
-  StorageUploadTask uploadTask = storageReference.putFile(file);
-  await uploadTask.onComplete;
-  String downloadUrl = await storageReference.getDownloadURL();
-  print("name:${await storageReference.getName()}");
-  print("bucket:${await storageReference.getBucket()}");
-  print("path:${await storageReference.getPath()}");
-  print("meta:${await storageReference.getMetadata()}");
+  if (file == null) {
+    return Future.value('');
+  }
+  Reference ref = FirebaseStorage.instance.ref().child('$path/$fileName');
+  UploadTask uploadTask = ref.putFile(file);
+  await uploadTask.resume();
+  String downloadUrl = await ref.getDownloadURL();
   return downloadUrl;
+  // StorageReference storageReference =
+  //     FirebaseStorage(storageBucket: Config.instance.bucketName)
+  //         .ref()
+  //         .child('$path/$fileName');
+  // StorageUploadTask uploadTask = storageReference.putFile(file);
+  // await uploadTask.onComplete;
+  // String downloadUrl = await storageReference.getDownloadURL();
+  // print("name:${await storageReference.getName()}");
+  // print("bucket:${await storageReference.getBucket()}");
+  // print("path:${await storageReference.getPath()}");
+  // print("meta:${await storageReference.getMetadata()}");
+  // return downloadUrl;
 }
 
-Future<void> deleteStorageFromUrls(List<String> urls) async {
+Future<void> deleteStorageFromUrls(List<String?> urls) async {
   if (urls == null) return;
   for (int i = 0; i < urls.length; i++) {
-    await deleteStorageFromUrl(urls[i]);
+    if (urls[i] == null) return;
+    await deleteStorageFromUrl(urls[i]!);
   }
 }
 
 Future<void> deleteStorageFromUrl(String url) async {
   try {
-    StorageReference storageReference =
-        await FirebaseStorage(storageBucket: Config.instance.bucketName)
-            .getReferenceFromUrl(url);
-    await storageReference.delete();
+    Reference ref = FirebaseStorage.instance.refFromURL(url);
+    await ref.delete();
+    // StorageReference storageReference =
+    //     await FirebaseStorage(storageBucket: Config.instance.bucketName)
+    //         .getReferenceFromUrl(url);
+    // await storageReference.delete();
   } catch (e) {
     log.warning("deleteStorage:$e");
   }
diff --git a/lib/helpers/network_connectivity.dart b/lib/helpers/network_connectivity.dart
index fe7c21d..4a7932d 100644
--- a/lib/helpers/network_connectivity.dart
+++ b/lib/helpers/network_connectivity.dart
@@ -11,7 +11,7 @@ class NetworkConnectivity {
   final log = Logger('NetworkConnectivity');
 
   static final NetworkConnectivity instance = NetworkConnectivity._internal();
-  static String hostName;
+  static String? hostName;
   NetworkConnectivity._internal() {
     _initialise();
     var uri = Uri.parse(Config.instance.apiURL);
@@ -38,7 +38,7 @@ class NetworkConnectivity {
     // lookup if connectivity is not none
     if (result != ConnectivityResult.none) {
       try {
-        final hostNameLookup = await InternetAddress.lookup(hostName);
+        final hostNameLookup = await InternetAddress.lookup(hostName ?? "");
         if (hostNameLookup.isNotEmpty &&
             hostNameLookup[0].rawAddress.isNotEmpty) {
           if (await checkHeartbeat()) {
diff --git a/lib/helpers/paginator.dart b/lib/helpers/paginator.dart
index cb89f15..240a8e3 100644
--- a/lib/helpers/paginator.dart
+++ b/lib/helpers/paginator.dart
@@ -13,7 +13,7 @@ class Paginator<T> {
   final log = Logger('Paginator');
 
   final int rowPerLoad;
-  DocumentSnapshot prev;
+  DocumentSnapshot? prev;
   bool ended = false;
   bool isLoading = false;
   List<T> values = [];
@@ -21,7 +21,7 @@ class Paginator<T> {
 
   Query pageQuery;
 
-  Paginator(this.pageQuery, {this.rowPerLoad = 20, this.toObj}) {
+  Paginator(this.pageQuery, {this.rowPerLoad = 20, required this.toObj}) {
     _clearState();
   }
 
@@ -36,27 +36,27 @@ class Paginator<T> {
     _clearState();
   }
 
-  Future<void> refresh({CallBack onFinished}) async {
+  Future<void> refresh({CallBack? onFinished}) async {
     _clearState();
     await load();
     if (onFinished != null) onFinished();
   }
 
-  Future<bool> load({CallBack onFinished}) async {
+  Future<bool?> load({CallBack? onFinished}) async {
     if (ended) return null;
     isLoading = true;
     Query _query =
-        prev != null ? pageQuery.startAfterDocument(prev) : pageQuery;
+        prev != null ? pageQuery.startAfterDocument(prev!) : pageQuery;
     try {
       await _query
           .limit(rowPerLoad)
-          .getDocuments(source: Source.server)
+          .get(GetOptions(source: Source.server))
           .then((QuerySnapshot snapshot) {
-        int count = snapshot.documents.length;
+        int count = snapshot.docs.length;
         ended = count < rowPerLoad;
-        prev = count > 0 ? snapshot.documents[count - 1] : prev;
-        snapshot.documents.forEach((e) {
-          values.add(toObj(e.data, e.documentID));
+        prev = count > 0 ? snapshot.docs[count - 1] : prev;
+        snapshot.docs.forEach((e) {
+          values.add(toObj(e.data() as Map<String, dynamic>, e.id));
         });
       });
     } catch (e) {
diff --git a/lib/helpers/shared_pref.dart b/lib/helpers/shared_pref.dart
index d2f26f8..e020232 100644
--- a/lib/helpers/shared_pref.dart
+++ b/lib/helpers/shared_pref.dart
@@ -7,17 +7,17 @@ class SharedPref {
   static final SharedPref instance = SharedPref._();
   SharedPref._();
 
-  static Future<bool> isFirstLaunch() async {
+  static Future<bool?> isFirstLaunch() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
     return prefs.getBool('first_launch');
   }
 
   static Future<void> finishFirstLaunch() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
-    return prefs.setBool('first_launch', false);
+    prefs.setBool('first_launch', false);
   }
 
-  static Future<String> getLang() async {
+  static Future<String?> getLang() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
     return prefs.getString('language');
   }
@@ -27,7 +27,7 @@ class SharedPref {
     prefs.setString('language', lang);
   }
 
-  static Future<bool> getStaffMode() async {
+  static Future<bool?> getStaffMode() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
     return prefs.getBool('staff_mode_on');
   }
@@ -41,7 +41,7 @@ class SharedPref {
     await _save("user", user.toJson());
   }
 
-  static Future<User> getUser() async {
+  static Future<User?> getUser() async {
     try {
       return User.fromJson(await _read("user"));
     } catch (e) {
@@ -57,7 +57,7 @@ class SharedPref {
     await _save("skipped_recovery_email", skipped);
   }
 
-  static Future<bool> getSkippedRecoverEmail() async {
+  static Future<bool?> getSkippedRecoverEmail() async {
     try {
       bool _skipped = await _read("skipped_recovery_email");
       return _skipped;
@@ -69,7 +69,7 @@ class SharedPref {
   static _read(String key) async {
     try {
       final prefs = await SharedPreferences.getInstance();
-      return json.decode(prefs.getString(key));
+      return json.decode(prefs.getString(key) ?? "");
     } catch (e) {
       print("Error:$e");
     }
diff --git a/lib/helpers/theme.dart b/lib/helpers/theme.dart
index e029208..e3ec100 100644
--- a/lib/helpers/theme.dart
+++ b/lib/helpers/theme.dart
@@ -20,8 +20,10 @@ const TextStyle labelStyleMM = TextStyle(
     fontFamily: "Myanmar3");
 const TextStyle subMenuStyle =
     TextStyle(fontSize: 14, color: Colors.white, fontWeight: FontWeight.w500);
-const TextStyle subMenuStyleMM =
-    TextStyle(fontSize: 14, color: Colors.white, fontWeight: FontWeight.w500,
+const TextStyle subMenuStyleMM = TextStyle(
+    fontSize: 14,
+    color: Colors.white,
+    fontWeight: FontWeight.w500,
     fontFamily: "Myanmar3");
 
 const TextStyle welcomeLabelStyle =
@@ -31,11 +33,10 @@ const TextStyle welcomeSubLabelStyle =
 const TextStyle siginButtonStyle =
     TextStyle(fontSize: 16, color: Colors.white, fontWeight: FontWeight.w500);
 
-
 TextStyle newLabelStyle(
-    {Color color,
-    double fontSize,
-    FontWeight fontWeight,
+    {Color? color,
+    double? fontSize,
+    FontWeight? fontWeight,
     bool underline = false}) {
   return TextStyle(
       fontSize: fontSize == null ? 14 : fontSize,
@@ -45,9 +46,9 @@ TextStyle newLabelStyle(
 }
 
 TextStyle newLabelStyleMM(
-    {Color color,
-    double fontSize,
-    FontWeight fontWeight,
+    {Color? color,
+    double? fontSize,
+    FontWeight? fontWeight,
     bool underline = false}) {
   return TextStyle(
       fontSize: fontSize == null ? 13 : fontSize,
@@ -59,8 +60,8 @@ TextStyle newLabelStyleMM(
 
 const TextStyle photoLabelStyle =
     TextStyle(color: Colors.black, fontSize: 13.0);
-const TextStyle photoLabelStyleMM = TextStyle(
-    color: Colors.black, fontSize: 13.0, fontFamily: "Myanmar3");
+const TextStyle photoLabelStyleMM =
+    TextStyle(color: Colors.black, fontSize: 13.0, fontFamily: "Myanmar3");
 const TextStyle textStyle =
     TextStyle(fontSize: 14, color: Colors.black87, fontWeight: FontWeight.w500);
 const TextStyle textStyleOdd = TextStyle(
diff --git a/lib/localization/app_translations.dart b/lib/localization/app_translations.dart
index 0c8cc59..f578c5a 100644
--- a/lib/localization/app_translations.dart
+++ b/lib/localization/app_translations.dart
@@ -6,14 +6,14 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart' show rootBundle;
 
 class AppTranslations {
-  Locale locale;
-  static Map<dynamic, dynamic> _localisedValues;
+  late Locale locale;
+  static late Map<dynamic, dynamic> _localisedValues;
 
   AppTranslations(Locale locale) {
     this.locale = locale;
   }
 
-  static AppTranslations of(BuildContext context) {
+  static AppTranslations? of(BuildContext context) {
     return Localizations.of<AppTranslations>(context, AppTranslations);
   }
 
@@ -27,7 +27,7 @@ class AppTranslations {
 
   get currentLanguage => locale.languageCode;
 
-  String text(String key, {List<String> translationVariables}) {
+  String text(String key, {List<String>? translationVariables}) {
     String value = _localisedValues[key];
     if (value == null) {
       return "$key not found";
diff --git a/lib/localization/app_translations_delegate.dart b/lib/localization/app_translations_delegate.dart
index 010d1ac..c90f302 100644
--- a/lib/localization/app_translations_delegate.dart
+++ b/lib/localization/app_translations_delegate.dart
@@ -15,7 +15,7 @@ class AppTranslationsDelegate extends LocalizationsDelegate<AppTranslations> {
 
   @override
   Future<AppTranslations> load(Locale locale) {
-    return AppTranslations.load(newLocale ?? locale);
+    return AppTranslations.load(newLocale);
   }
 
   @override
diff --git a/lib/localization/transalation.dart b/lib/localization/transalation.dart
index 634ae80..8a548b9 100644
--- a/lib/localization/transalation.dart
+++ b/lib/localization/transalation.dart
@@ -23,5 +23,5 @@ class Translation {
       supportedLanguagesCodes.map<Locale>((language) => Locale(language, ""));
 
   //function to be invoked when changing the language
-  LocaleChangeCallback? onLocaleChanged;
+  late LocaleChangeCallback onLocaleChanged;
 }
diff --git a/lib/pages/buying_instruction/buying_online.dart b/lib/pages/buying_instruction/buying_online.dart
index fc7efce..fbd8b53 100644
--- a/lib/pages/buying_instruction/buying_online.dart
+++ b/lib/pages/buying_instruction/buying_online.dart
@@ -1,6 +1,5 @@
 import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
-import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/widgets/display_text.dart';
 import 'package:fcs/pages/widgets/fcs_id_icon.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
@@ -15,7 +14,7 @@ class BuyingOnlinePage extends StatefulWidget {
 
 class _BuyingOnlinePagetate extends State<BuyingOnlinePage>
     with SingleTickerProviderStateMixin {
-  TabController _tabController;
+  late TabController _tabController;
 
   @override
   void initState() {
@@ -28,22 +27,22 @@ class _BuyingOnlinePagetate extends State<BuyingOnlinePage>
     MainModel mainModel = Provider.of<MainModel>(context);
 
     final phoneNumberBox = DisplayText(
-      text: mainModel.user.phone,
+      text: mainModel.user?.phone,
       labelTextKey: "contact.phone",
       iconData: Icons.location_on,
     );
     final nameBox = Center(
         child: Text(
-      mainModel.user.name,
+      mainModel.user?.name ?? "",
       style: TextStyle(fontSize: 18, color: primaryColor),
     ));
     final fcsIdBox = DisplayText(
-      text: mainModel.user.fcsID,
+      text: mainModel.user?.fcsID,
       labelTextKey: "customer.fcs.id",
       icon: FcsIDIcon(),
     );
     final shippingAddressBox = DisplayText(
-      text: mainModel.setting.usaAddress,
+      text: mainModel.setting?.usaAddress,
       labelTextKey: "profile.usa.shipping.address",
       iconData: Icons.location_on,
     );
diff --git a/lib/pages/carton/cargo_table.dart b/lib/pages/carton/cargo_table.dart
index 1abdf9c..9266868 100644
--- a/lib/pages/carton/cargo_table.dart
+++ b/lib/pages/carton/cargo_table.dart
@@ -6,10 +6,10 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
 class CargoTable extends StatefulWidget {
-  final List<CargoType> cargoTypes;
+  final List<CargoType>? cargoTypes;
 
   const CargoTable({
-    Key key,
+    Key? key,
     this.cargoTypes,
   }) : super(key: key);
 
@@ -58,13 +58,13 @@ class _CargoTableState extends State<CargoTable> {
       return [];
     }
     double total = 0;
-    var rows = widget.cargoTypes.map((c) {
+    var rows = widget.cargoTypes!.map((c) {
       total += c.weight;
       return MyDataRow(
         onSelectChanged: (bool selected) async {},
         cells: [
           MyDataCell(new Text(
-            c.name == null ? "" : c.name,
+            c.name ?? "",
             style: textStyle,
           )),
           MyDataCell(c.qty == null || c.qty == 0
diff --git a/lib/pages/carton/cargo_type_addtion.dart b/lib/pages/carton/cargo_type_addtion.dart
index 9cf3e11..0201e9b 100644
--- a/lib/pages/carton/cargo_type_addtion.dart
+++ b/lib/pages/carton/cargo_type_addtion.dart
@@ -35,7 +35,7 @@ class _CargoTypeAdditionState extends State<CargoTypeAddition> {
       p.isChecked = false;
       p.isCutomDuty = false;
       p.weight = 0;
-      p.qty = null;
+      p.qty = 0;
     });
     specialCargos.forEach((p) {
       p.isChecked = false;
@@ -69,12 +69,12 @@ class _CargoTypeAdditionState extends State<CargoTypeAddition> {
                   Checkbox(
                       value: c.isChecked,
                       activeColor: primaryColor,
-                      onChanged: (bool check) {
+                      onChanged: (bool? check) {
                         setState(() {
-                          c.isChecked = check;
+                          c.isChecked = check ?? false;
                         });
                       }),
-                  new Text(c.name, style: textStyle),
+                  new Text(c.name ?? '', style: textStyle),
                 ],
               ),
             ),
diff --git a/lib/pages/carton/cargo_type_editor.dart b/lib/pages/carton/cargo_type_editor.dart
index fb6376b..1d6572c 100644
--- a/lib/pages/carton/cargo_type_editor.dart
+++ b/lib/pages/carton/cargo_type_editor.dart
@@ -12,7 +12,7 @@ import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:provider/provider.dart';
 
 class CargoTypeEditor extends StatefulWidget {
-  final CargoType cargo;
+  final CargoType? cargo;
   CargoTypeEditor({this.cargo});
 
   @override
@@ -23,14 +23,14 @@ class _CargoTypeEditorState extends State<CargoTypeEditor> {
   TextEditingController _weightController = new TextEditingController();
 
   bool _isLoading = false;
-  CargoType _cargo;
+  CargoType? _cargo;
 
   @override
   void initState() {
     super.initState();
     if (widget.cargo != null) {
       _cargo = widget.cargo;
-      _weightController.text = _cargo.weight.toStringAsFixed(2);
+      _weightController.text = _cargo!.weight.toStringAsFixed(2);
     } else {
       _loadDefalut();
     }
@@ -67,7 +67,7 @@ class _CargoTypeEditorState extends State<CargoTypeEditor> {
       },
       labelKey: "cargo.type",
       iconData: Icons.text_format,
-      selectedValue: _cargo,
+      selectedValue: _cargo!,
       values: cargos,
     );
 
@@ -75,7 +75,7 @@ class _CargoTypeEditorState extends State<CargoTypeEditor> {
       context,
       getLocalString(context, 'box.cargo.save.btn'),
       callack: () {
-        _cargo.weight = double.tryParse(_weightController.text) ?? 0;
+        _cargo!.weight = double.tryParse(_weightController.text) ?? 0;
         Navigator.pop(context, _cargo);
       },
     );
diff --git a/lib/pages/carton/carton_cargo_table.dart b/lib/pages/carton/carton_cargo_table.dart
index d67eda5..cd02930 100644
--- a/lib/pages/carton/carton_cargo_table.dart
+++ b/lib/pages/carton/carton_cargo_table.dart
@@ -11,13 +11,13 @@ typedef OnRemove(CargoType cargoType);
 typedef OnUpdate(CargoType cargoType);
 
 class CargoTable extends StatefulWidget {
-  final List<CargoType> cargoTypes;
-  final bool isNew;
-  final OnRemove onRemove;
-  final OnUpdate onUpdate;
+  final List<CargoType>? cargoTypes;
+  final bool? isNew;
+  final OnRemove? onRemove;
+  final OnUpdate? onUpdate;
 
   const CargoTable(
-      {Key key, this.cargoTypes, this.isNew, this.onRemove, this.onUpdate})
+      {Key? key, this.cargoTypes, this.isNew, this.onRemove, this.onUpdate})
       : super(key: key);
 
   @override
@@ -26,14 +26,14 @@ class CargoTable extends StatefulWidget {
 
 class _CargoTableState extends State<CargoTable> {
   double totalWeight = 0;
-  List<CargoType> cargoTypes;
+  List<CargoType>? cargoTypes;
 
   @override
   void initState() {
     cargoTypes = widget.cargoTypes;
-    if (!widget.isNew) {
+    if (!widget.isNew!) {
       totalWeight =
-          cargoTypes.fold(0, (previous, current) => previous + current.weight);
+          cargoTypes!.fold(0, (previous, current) => previous + current.weight);
     }
 
     super.initState();
@@ -41,8 +41,8 @@ class _CargoTableState extends State<CargoTable> {
 
   @override
   Widget build(BuildContext context) {
-    print("Cargotypes:${cargoTypes.length}");
-    
+    print("Cargotypes:${cargoTypes!.length}");
+
     return SingleChildScrollView(
       scrollDirection: Axis.horizontal,
       child: MyDataTable(
@@ -80,18 +80,18 @@ class _CargoTableState extends State<CargoTable> {
     if (cargoTypes == null) {
       return [];
     }
-    var rows = cargoTypes.map((c) {
+    var rows = cargoTypes!.map((c) {
       return MyDataRow(
         onSelectChanged: (bool selected) async {},
         cells: [
           MyDataCell(
             new Text(
-              c.name == null ? "" : c.name,
+              c.name ?? '',
               style: textStyle,
             ),
           ),
           MyDataCell(
-            c.isCutomDuty
+            c.isCutomDuty!
                 ? GestureDetector(
                     onTap: () async {
                       String _t = await showDialog(
@@ -103,7 +103,7 @@ class _CargoTableState extends State<CargoTable> {
                       setState(() {
                         c.qty = int.tryParse(_t) ?? 0;
                       });
-                      if (widget.onUpdate != null) widget.onUpdate(c);
+                      if (widget.onUpdate != null) widget.onUpdate!(c);
                     },
                     child: Center(
                       child: Container(
@@ -153,7 +153,7 @@ class _CargoTableState extends State<CargoTable> {
                     if (c.weight != 0) {
                       _cal();
                     }
-                    if (widget.onUpdate != null) widget.onUpdate(c);
+                    if (widget.onUpdate != null) widget.onUpdate!(c);
                   },
                   child: Container(
                     padding: const EdgeInsets.all(7.0),
@@ -176,7 +176,7 @@ class _CargoTableState extends State<CargoTable> {
                           color: primaryColor,
                         ),
                         onPressed: () {
-                          if (widget.onRemove != null) widget.onRemove(c);
+                          if (widget.onRemove != null) widget.onRemove!(c);
                         })
               ],
             ),
@@ -237,26 +237,25 @@ class _CargoTableState extends State<CargoTable> {
   }
 
   _cal() {
-    var cargoType = autoCalWeight(cargoTypes, totalWeight);
+    var cargoType = autoCalWeight(cargoTypes!, totalWeight);
     if (cargoType == null) return;
 
     setState(() {
-      cargoTypes.remove(cargoType);
-      cargoTypes.add(cargoType);
+      cargoTypes!.remove(cargoType);
+      cargoTypes!.add(cargoType);
     });
 
     if (widget.onUpdate != null) {
-      widget.onUpdate(cargoType);
+      widget.onUpdate!(cargoType);
     }
   }
 }
 
-CargoType autoCalWeight(List<CargoType> cargoTypes, double total) {
-  if ((cargoTypes?.length ?? 0) == 0 || total == 0) return null;
+CargoType? autoCalWeight(List<CargoType> cargoTypes, double total) {
   List<CargoType> noWeight = cargoTypes.where((c) => c.weight == 0).toList();
   if (noWeight.length != 1) return null;
 
-  var _existing =
+  double _existing =
       cargoTypes.fold(0, (previous, current) => previous + current.weight);
 
   noWeight[0].weight = total - _existing;
diff --git a/lib/pages/carton/carton_cargo_table_old.dart b/lib/pages/carton/carton_cargo_table_old.dart
index 8e0d6f9..05378f2 100644
--- a/lib/pages/carton/carton_cargo_table_old.dart
+++ b/lib/pages/carton/carton_cargo_table_old.dart
@@ -1,23 +1,21 @@
 import 'package:fcs/domain/entities/cargo_type.dart';
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/my_data_table.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
-import 'cargo_type_editor.dart';
 import 'total_weight_edit.dart';
 
 typedef OnAdd(CargoType cargoType);
 typedef OnRemove(CargoType cargoType);
 
 class CargoTable extends StatefulWidget {
-  final List<CargoType> cargoTypes;
-  final OnAdd onAdd;
-  final OnRemove onRemove;
+  final List<CargoType>? cargoTypes;
+  final OnAdd? onAdd;
+  final OnRemove? onRemove;
 
-  const CargoTable({Key key, this.cargoTypes, this.onAdd, this.onRemove})
+  const CargoTable({Key? key, this.cargoTypes, this.onAdd, this.onRemove})
       : super(key: key);
 
   @override
@@ -67,7 +65,7 @@ class _CargoTableState extends State<CargoTable> {
     List<String> _types = [];
     double _total = 0;
 
-    var rows = widget.cargoTypes.map((c) {
+    var rows = widget.cargoTypes!.map((c) {
       _total += c.weight;
       return MyDataRow(
         onSelectChanged: (bool selected) async {},
@@ -75,7 +73,7 @@ class _CargoTableState extends State<CargoTable> {
           MyDataCell(Row(
             children: [
               new Text(
-                c.name == null ? "" : c.name,
+                c.name ?? "",
                 style: textStyle,
               ),
               new Text(
@@ -99,7 +97,7 @@ class _CargoTableState extends State<CargoTable> {
                           color: primaryColor,
                         ),
                         onPressed: () {
-                          if (widget.onRemove != null) widget.onRemove(c);
+                          if (widget.onRemove != null) widget.onRemove!(c);
                         })
               ],
             ),
@@ -127,7 +125,7 @@ class _CargoTableState extends State<CargoTable> {
                 alignment: Alignment.centerRight,
                 child: InkWell(
                   onTap: () async {
-                    double _t = await Navigator.of(context).push<double>(
+                    double? _t = await Navigator.of(context).push<double>(
                         CupertinoPageRoute(
                             builder: (context) =>
                                 TotalWeightEdit(totalWeight: totalWeight)));
@@ -135,21 +133,21 @@ class _CargoTableState extends State<CargoTable> {
                     setState(() {
                       totalWeight = _t;
                       this.remainingWeight = this.totalWeight - _total;
-                      widget.cargoTypes.forEach((c) {
+                      widget.cargoTypes!.forEach((c) {
                         if (c.qty == null) {
                           this._cargos.add(c);
                         }
                       });
                       this._cargos.forEach((c) {
-                        _list.add(c.name);
+                        _list.add(c.name!);
                       });
-                      widget.cargoTypes.forEach((c) {
-                        _types.add(c.name);
+                      widget.cargoTypes!.forEach((c) {
+                        _types.add(c.name!);
                       });
-                      if (this._cargos.length == widget.cargoTypes.length - 1) {
+                      if (this._cargos.length == widget.cargoTypes!.length - 1) {
                         _types.forEach((t) {
                           if (!_list.contains(t)) {
-                            widget.cargoTypes.forEach((c) {
+                            widget.cargoTypes!.forEach((c) {
                               if (c.name == t) {
                                 c.weight = this.remainingWeight;
                               }
diff --git a/lib/pages/carton/carton_editor.dart b/lib/pages/carton/carton_editor.dart
index e366bc3..e83d6b1 100644
--- a/lib/pages/carton/carton_editor.dart
+++ b/lib/pages/carton/carton_editor.dart
@@ -29,7 +29,7 @@ import 'package:fcs/pages/widgets/local_title.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 import 'cargo_type_addtion.dart';
 import 'carton_cargo_table.dart';
@@ -40,7 +40,7 @@ import 'package_carton_editor.dart';
 import 'widgets.dart';
 
 class CartonEditor extends StatefulWidget {
-  final Carton box;
+  final Carton? box;
   CartonEditor({this.box});
 
   @override
@@ -51,32 +51,32 @@ class _CartonEditorState extends State<CartonEditor> {
   TextEditingController _widthController = new TextEditingController();
   TextEditingController _heightController = new TextEditingController();
   TextEditingController _lengthController = new TextEditingController();
-  DeliveryAddress _deliveryAddress = new DeliveryAddress();
+  DeliveryAddress? _deliveryAddress = new DeliveryAddress();
   List<CargoType> _cargoTypes = [];
 
-  Carton _carton;
+  Carton? _carton;
   bool _isLoading = false;
-  bool _isNew;
-  User _user;
-  String _selectedCartonType;
+  bool _isNew = false;
+  User? _user;
+  String? _selectedCartonType;
 
   double volumetricRatio = 0;
   double shipmentWeight = 0;
-  FcsShipment _fcsShipment;
-  List<FcsShipment> _fcsShipments;
+  FcsShipment? _fcsShipment;
+  List<FcsShipment>? _fcsShipments;
   List<Carton> _cartons = [];
-  CartonSize selectedCatonSize;
+  CartonSize? selectedCatonSize;
 
   //for mix carton
   List<Carton> _mixCartons = [];
-  String _selectedMixBoxType;
+  String? _selectedMixBoxType;
 
   //for carton from cargos
-  User consignee;
-  User sender;
+  User? consignee;
+  User? sender;
   List<Carton> _cartonsFromCartons = [];
 
-  double totalWeight;
+  double? totalWeight;
 
   @override
   void initState() {
@@ -92,28 +92,28 @@ class _CartonEditorState extends State<CartonEditor> {
 
     if (widget.box != null) {
       _carton = widget.box;
-      _deliveryAddress = _carton.deliveryAddress;
-      _widthController.text = _carton.width.toString();
-      _heightController.text = _carton.height.toString();
-      _lengthController.text = _carton.length.toString();
-      _selectedCartonType = _carton.cartonType;
+      _deliveryAddress = _carton!.deliveryAddress;
+      _widthController.text = _carton!.width.toString();
+      _heightController.text = _carton!.height.toString();
+      _lengthController.text = _carton!.length.toString();
+      _selectedCartonType = _carton!.cartonType;
 
-      _cargoTypes = _carton.cargoTypes.map((e) => e.clone()).toList();
+      _cargoTypes = _carton!.cargoTypes.map((e) => e.clone()).toList();
 
       _isNew = false;
       _user = User(
-          id: _carton.userID, fcsID: _carton.fcsID, name: _carton.userName);
+          id: _carton!.userID, fcsID: _carton!.fcsID, name: _carton!.userName);
       consignee = User(
-          id: _carton.userID, fcsID: _carton.fcsID, name: _carton.userName);
+          id: _carton!.userID, fcsID: _carton!.fcsID, name: _carton!.userName);
       sender = User(
-          id: _carton.senderID,
-          fcsID: _carton.senderFCSID,
-          name: _carton.senderName);
-      _selectedMixBoxType = _carton.mixBoxType ?? "";
+          id: _carton!.senderID,
+          fcsID: _carton!.senderFCSID,
+          name: _carton!.senderName);
+      _selectedMixBoxType = _carton!.mixBoxType;
       this._mixCartons =
-          _carton.mixCartons == null ? [] : List.from(_carton.mixCartons);
-      bool isMixBox = _carton.cartonType == carton_mix_box;
-      bool isFromPackages = _carton.cartonType == carton_from_packages;
+          _carton!.mixCartons == null ? [] : List.from(_carton!.mixCartons);
+      bool isMixBox = _carton!.cartonType == carton_mix_box;
+      bool isFromPackages = _carton!.cartonType == carton_from_packages;
       if (isFromPackages) _loadPackages();
 
       if (!isMixBox) {
@@ -138,8 +138,8 @@ class _CartonEditorState extends State<CartonEditor> {
     FcsShipmentModel fcsShipmentModel =
         Provider.of<FcsShipmentModel>(context, listen: false);
     var fcsShipments = await fcsShipmentModel.getActiveFcsShipments();
-    var fcsShipment = fcsShipments
-        .firstWhere((e) => e.id == _carton.fcsShipmentID, orElse: () => null);
+    var fcsShipment =
+        fcsShipments.firstWhere((e) => e.id == _carton!.fcsShipmentID);
     setState(() {
       _fcsShipments = fcsShipments;
       _fcsShipment = fcsShipment;
@@ -151,9 +151,9 @@ class _CartonEditorState extends State<CartonEditor> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     List<Package> packages = await packageModel.getPackages(
-        _user.id, [package_processed_status, package_packed_status]);
+        _user!.id!, [package_processed_status, package_packed_status]);
     if (_isNew) {
-      String prevCompare;
+      String? prevCompare;
       packages.forEach((p) {
         String compare = (p.deliveryAddress?.fullName ?? "") +
             (p.deliveryAddress?.phoneNumber ?? "");
@@ -169,8 +169,8 @@ class _CartonEditorState extends State<CartonEditor> {
       });
     } else {
       packages.forEach((p) {
-        if (_carton.packages.contains(p)) {
-          p.isChecked = _carton.packages.firstWhere((cp) => cp == p).isChecked;
+        if (_carton!.packages.contains(p)) {
+          p.isChecked = _carton!.packages.firstWhere((cp) => cp == p).isChecked;
         } else {
           p.isChecked = false;
         }
@@ -178,7 +178,7 @@ class _CartonEditorState extends State<CartonEditor> {
     }
 
     setState(() {
-      _carton.packages = packages;
+      _carton!.packages = packages;
     });
     // _populateDeliveryAddress();
   }
@@ -195,9 +195,9 @@ class _CartonEditorState extends State<CartonEditor> {
   // }
 
   _calShipmentWeight() {
-    double l = double.parse(_lengthController.text, (s) => 0);
-    double w = double.parse(_widthController.text, (s) => 0);
-    double h = double.parse(_heightController.text, (s) => 0);
+    double l = double.parse(_lengthController.text);
+    double w = double.parse(_widthController.text);
+    double h = double.parse(_heightController.text);
     setState(() {
       shipmentWeight = l * w * h / volumetricRatio;
     });
@@ -206,9 +206,9 @@ class _CartonEditorState extends State<CartonEditor> {
   _getCartonSize() {
     var cartonSizeModel = Provider.of<CartonSizeModel>(context, listen: false);
     cartonSizeModel.cartonSizes.forEach((c) {
-      if (c.length == _carton.length &&
-          c.width == _carton.width &&
-          c.height == _carton.height) {
+      if (c.length == _carton!.length &&
+          c.width == _carton!.width &&
+          c.height == _carton!.height) {
         selectedCatonSize = CartonSize(
             id: c.id,
             name: c.name,
@@ -232,7 +232,7 @@ class _CartonEditorState extends State<CartonEditor> {
     bool isMixBox = _selectedCartonType == carton_mix_box;
 
     final shipmentBox = DisplayText(
-      text: _carton.fcsShipmentNumber,
+      text: _carton!.fcsShipmentNumber,
       labelTextKey: "box.fcs_shipment_num",
       iconData: Ionicons.ios_airplane,
     );
@@ -248,8 +248,8 @@ class _CartonEditorState extends State<CartonEditor> {
           labelKey: "shipment.pack.fcs.shipment",
           iconData: Ionicons.ios_airplane,
           display: (u) => u.shipmentNumber,
-          selectedValue: _fcsShipment,
-          values: _fcsShipments,
+          selectedValue: _fcsShipment!,
+          values: _fcsShipments!,
         ));
 
     final fcsIDBox = Container(
@@ -297,7 +297,7 @@ class _CartonEditorState extends State<CartonEditor> {
         readOnly: !_isNew,
         values: boxModel.cartonTypes,
         selectedValue: _selectedCartonType,
-        callback: (v) {
+        callback: (String? v) {
           setState(() {
             _selectedCartonType = v;
           });
@@ -337,7 +337,7 @@ class _CartonEditorState extends State<CartonEditor> {
                     value: e,
                     groupValue: _selectedMixBoxType,
                     activeColor: primaryColor,
-                    onChanged: (v) {
+                    onChanged: (String? v) {
                       setState(() {
                         _selectedMixBoxType = v;
                       });
@@ -407,7 +407,7 @@ class _CartonEditorState extends State<CartonEditor> {
             color: primaryColor,
           ),
           onPressed: () async {
-            List<CargoType> cargos = await Navigator.push<List<CargoType>>(
+            List<CargoType>? cargos = await Navigator.push<List<CargoType>>(
                 context,
                 CupertinoPageRoute(builder: (context) => CargoTypeAddition()));
             if (cargos == null) return;
@@ -462,7 +462,7 @@ class _CartonEditorState extends State<CartonEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: consignee != null ? consignee.fcsID : "",
+          text: consignee != null ? consignee!.fcsID : "",
           labelTextKey: "processing.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -477,7 +477,7 @@ class _CartonEditorState extends State<CartonEditor> {
     );
 
     final consigneeNameBox = DisplayText(
-      text: consignee != null ? consignee.name : "",
+      text: consignee != null ? consignee!.name : "",
       labelTextKey: "processing.consignee.name",
       maxLines: 2,
       iconData: Icons.person,
@@ -496,7 +496,7 @@ class _CartonEditorState extends State<CartonEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: sender != null ? sender.fcsID : "",
+          text: sender != null ? sender!.fcsID : "",
           labelTextKey: "processing.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -511,7 +511,7 @@ class _CartonEditorState extends State<CartonEditor> {
     );
 
     final shipperNamebox = DisplayText(
-      text: sender != null ? sender.name : "",
+      text: sender != null ? sender!.name : "",
       labelTextKey: "processing.shipper.name",
       maxLines: 2,
       iconData: Icons.person,
@@ -551,7 +551,7 @@ class _CartonEditorState extends State<CartonEditor> {
             children: [
               _isNew
                   ? Container()
-                  : Center(child: getCartonNumberStatus(context, _carton)),
+                  : Center(child: getCartonNumberStatus(context, _carton!)),
               LocalTitle(textKey: "box.type.title"),
               cartonTypeBox,
               LocalTitle(textKey: "box.shipment_info"),
@@ -572,7 +572,7 @@ class _CartonEditorState extends State<CartonEditor> {
                       isFromPackages ? namebox : Container(),
                       isFromPackages
                           ? CartonPackageTable(
-                              packages: _carton.packages,
+                              packages: _carton!.packages,
                               onSelect: (p, checked) {
                                 // if (checked &&
                                 //     _deliveryAddress != null &&
@@ -623,7 +623,7 @@ class _CartonEditorState extends State<CartonEditor> {
                               deliveryAddress: _deliveryAddress,
                               labelKey: "box.delivery_address",
                               onTap: () async {
-                                DeliveryAddress d =
+                                DeliveryAddress? d =
                                     await Navigator.push<DeliveryAddress>(
                                   context,
                                   CupertinoPageRoute(
@@ -631,8 +631,8 @@ class _CartonEditorState extends State<CartonEditor> {
                                           DeliveryAddressSelection(
                                               deliveryAddress: _deliveryAddress,
                                               user: User(
-                                                  id: _carton.userID,
-                                                  name: _carton.userName))),
+                                                  id: _carton!.userID,
+                                                  name: _carton!.userName))),
                                 );
                                 if (d == null) return;
                                 setState(() {
@@ -667,7 +667,7 @@ class _CartonEditorState extends State<CartonEditor> {
           bool isFromCartons = _selectedCartonType == carton_from_cartons;
           if (isFromPackages) {
             _loadPackages();
-            c.value.packages = _carton.packages;
+            c.value.packages = _carton!.packages;
             Carton _c = await Navigator.push(
               context,
               CupertinoPageRoute(
@@ -736,20 +736,20 @@ class _CartonEditorState extends State<CartonEditor> {
                     height: 1,
                     color: Colors.grey,
                   ),
-                  onChanged: (CartonSize newValue) {
+                  onChanged: (CartonSize? newValue) {
                     setState(() {
-                      if (newValue.name == MANAGE_CARTONSIZE) {
+                      if (newValue!.name == MANAGE_CARTONSIZE) {
                         selectedCatonSize = null;
                         _manageCartonSize();
                         return;
                       }
                       selectedCatonSize = newValue;
                       _widthController.text =
-                          selectedCatonSize.width.toString();
+                          selectedCatonSize!.width.toString();
                       _heightController.text =
-                          selectedCatonSize.height.toString();
+                          selectedCatonSize!.height.toString();
                       _lengthController.text =
-                          selectedCatonSize.length.toString();
+                          selectedCatonSize!.length.toString();
                     });
                   },
                   isExpanded: true,
@@ -789,8 +789,7 @@ class _CartonEditorState extends State<CartonEditor> {
 
   _updateCargo(CargoType cargo) {
     setState(() {
-      var _c =
-          _cargoTypes.firstWhere((e) => e.id == cargo.id, orElse: () => null);
+      var _c = _cargoTypes.firstWhere((e) => e.id == cargo.id);
       if (_c != null) {
         _c.weight = cargo.weight;
         _c.qty = cargo.qty;
@@ -827,30 +826,30 @@ class _CartonEditorState extends State<CartonEditor> {
     double h = double.parse(_heightController.text, (s) => 0);
 
     Carton carton = Carton();
-    carton.id = _carton.id;
-    carton.cartonType = _selectedCartonType;
-    carton.fcsShipmentID = _isNew ? _fcsShipment.id : _carton.fcsShipmentID;
+    carton.id = _carton!.id;
+    carton.cartonType = _selectedCartonType!;
+    carton.fcsShipmentID = _isNew ? _fcsShipment!.id : _carton!.fcsShipmentID;
     if (isFromPackages) {
-      carton.userID = _user?.id;
-      carton.fcsID = _user?.fcsID;
-      carton.userName = _user?.name;
-      carton.packages = _carton.packages.where((e) => e.isChecked).toList();
+      carton.userID = _user?.id ?? '';
+      carton.fcsID = _user?.fcsID ?? '';
+      carton.userName = _user?.name ?? '';
+      carton.packages = _carton!.packages.where((e) => e.isChecked).toList();
     }
 
     if (isFromCartons) {
-      carton.userID = consignee?.id;
-      carton.fcsID = consignee?.fcsID;
-      carton.userName = consignee?.name;
-      carton.senderID = sender?.id;
-      carton.senderFCSID = sender?.fcsID;
-      carton.senderName = sender?.name;
+      carton.userID = consignee?.id ?? "";
+      carton.fcsID = consignee?.fcsID ?? "";
+      carton.userName = consignee?.name ?? "";
+      carton.senderID = sender?.id ?? "";
+      carton.senderFCSID = sender?.fcsID ?? "";
+      carton.senderName = sender?.name ?? "";
     }
 
-    carton.cargoTypes = _carton.cargoTypes;
+    carton.cargoTypes = _carton!.cargoTypes;
     carton.length = l;
     carton.width = w;
     carton.height = h;
-    carton.deliveryAddress = _carton.deliveryAddress;
+    carton.deliveryAddress = _carton!.deliveryAddress;
 
     try {
       Carton _c = await Navigator.push(
@@ -864,7 +863,7 @@ class _CartonEditorState extends State<CartonEditor> {
       );
       if (_c == null) return;
       var cartonModel = Provider.of<CartonModel>(context, listen: false);
-      Carton _carton = await cartonModel.getCarton(_c.id);
+      Carton _carton = await cartonModel.getCarton(_c.id ?? "");
       if (isFromPackages) {
         _cartons.add(_carton);
       }
@@ -898,15 +897,15 @@ class _CartonEditorState extends State<CartonEditor> {
       showMsgDialog(context, "Error", "Please select FCS shipment");
       return;
     }
-    if ((this._mixCartons?.length ?? 0) == 0) {
+    if (this._mixCartons.length == 0) {
       showMsgDialog(context, "Error", "Expect at least one carton");
       return;
     }
     Carton carton = Carton();
-    carton.id = _carton.id;
-    carton.cartonType = _selectedCartonType;
-    carton.fcsShipmentID = _isNew ? _fcsShipment.id : _carton.fcsShipmentID;
-    carton.mixBoxType = _selectedMixBoxType;
+    carton.id = _carton!.id;
+    carton.cartonType = _selectedCartonType!;
+    carton.fcsShipmentID = _isNew ? _fcsShipment!.id : _carton!.fcsShipmentID;
+    carton.mixBoxType = _selectedMixBoxType!;
     carton.mixCartons = this._mixCartons;
     setState(() {
       _isLoading = true;
@@ -932,7 +931,7 @@ class _CartonEditorState extends State<CartonEditor> {
   _save() async {
     bool isFromPackages = _selectedCartonType == carton_from_packages;
     bool isFromCartons = _selectedCartonType == carton_from_cartons;
-    if ((_cargoTypes?.length ?? 0) == 0 && (isFromPackages || isFromCartons)) {
+    if (_cargoTypes.length == 0 && (isFromPackages || isFromCartons)) {
       showMsgDialog(context, "Error", "Expect at least one cargo type");
       return;
     }
@@ -940,9 +939,9 @@ class _CartonEditorState extends State<CartonEditor> {
       showMsgDialog(context, "Error", "Invalid cargo weight");
       return;
     }
-    double l = double.parse(_lengthController.text, (s) => 0);
-    double w = double.parse(_widthController.text, (s) => 0);
-    double h = double.parse(_heightController.text, (s) => 0);
+    double l = double.parse(_lengthController.text);
+    double w = double.parse(_widthController.text);
+    double h = double.parse(_heightController.text);
     if ((l <= 0 || w <= 0 || h <= 0) && (isFromPackages || isFromCartons)) {
       showMsgDialog(context, "Error", "Invalid dimension");
       return;
@@ -953,16 +952,16 @@ class _CartonEditorState extends State<CartonEditor> {
     }
 
     Carton carton = Carton();
-    carton.id = _carton.id;
-    carton.cartonType = _selectedCartonType;
-    carton.fcsShipmentID = _isNew ? _fcsShipment.id : _carton.fcsShipmentID;
+    carton.id = _carton!.id;
+    carton.cartonType = _selectedCartonType!;
+    carton.fcsShipmentID = _isNew ? _fcsShipment!.id : _carton!.fcsShipmentID;
     if (isFromPackages) {
-      carton.userID = _user?.id;
-      carton.packages = _carton.packages.where((e) => e.isChecked).toList();
+      carton.userID = _user?.id ?? "";
+      carton.packages = _carton!.packages.where((e) => e.isChecked).toList();
     }
     if (isFromCartons) {
-      carton.userID = consignee?.id;
-      carton.senderID = sender?.id;
+      carton.userID = consignee?.id ?? "";
+      carton.senderID = sender?.id ?? "";
     }
 
     carton.cargoTypes = _cargoTypes;
diff --git a/lib/pages/carton/carton_info.dart b/lib/pages/carton/carton_info.dart
index 522b548..68358c3 100644
--- a/lib/pages/carton/carton_info.dart
+++ b/lib/pages/carton/carton_info.dart
@@ -1,7 +1,5 @@
 import 'package:fcs/domain/constants.dart';
-import 'package:fcs/domain/entities/cargo_type.dart';
 import 'package:fcs/domain/entities/carton.dart';
-import 'package:fcs/domain/entities/carton_size.dart';
 import 'package:fcs/domain/entities/package.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/helpers/theme.dart';
@@ -19,7 +17,7 @@ import 'package:fcs/pages/widgets/local_title.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
@@ -33,7 +31,7 @@ import 'widgets.dart';
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class CartonInfo extends StatefulWidget {
-  final Carton box;
+  final Carton? box;
   CartonInfo({this.box});
 
   @override
@@ -42,22 +40,22 @@ class CartonInfo extends StatefulWidget {
 
 class _CartonInfoState extends State<CartonInfo> {
   bool _isLoading = false;
-  Carton _box;
-  DeliveryAddress _deliveryAddress = new DeliveryAddress();
+  Carton? _box;
+  DeliveryAddress? _deliveryAddress = new DeliveryAddress();
   TextEditingController _widthController = new TextEditingController();
   TextEditingController _heightController = new TextEditingController();
   TextEditingController _lengthController = new TextEditingController();
   TextEditingController _cartonSizeController = new TextEditingController();
   double volumetricRatio = 0;
   double shipmentWeight = 0;
-  String selectMixBoxType;
+  String? selectMixBoxType;
 
-  bool isMixBox;
-  bool isFromShipments;
-  bool isFromPackages;
-  bool isSmallBag;
-  bool isFromCartons;
-  bool isEdiable;
+  bool isMixBox = false;
+  bool isFromShipments = false;
+  bool isFromPackages = false;
+  bool isSmallBag = false;
+  bool isFromCartons = false;
+  bool isEdiable = false;
 
   @override
   void initState() {
@@ -77,31 +75,31 @@ class _CartonInfoState extends State<CartonInfo> {
   }
 
   _updateBoxData() {
-    _widthController.text = _box.width.toString();
-    _heightController.text = _box.height.toString();
-    _lengthController.text = _box.length.toString();
-    _cartonSizeController.text = _box.cartonSizeName ?? "";
-    _deliveryAddress = _box.deliveryAddress;
-    isMixBox = _box.cartonType == carton_mix_box;
-    isFromShipments = _box.cartonType == carton_from_shipments;
-    isFromPackages = _box.cartonType == carton_from_packages;
-    isSmallBag = _box.cartonType == carton_small_bag;
-    isFromCartons = _box.cartonType == carton_from_cartons;
+    _widthController.text = _box!.width.toString();
+    _heightController.text = _box!.height.toString();
+    _lengthController.text = _box!.length.toString();
+    _cartonSizeController.text = _box!.cartonSizeName ?? "";
+    _deliveryAddress = _box!.deliveryAddress;
+    isMixBox = _box!.cartonType == carton_mix_box;
+    isFromShipments = _box!.cartonType == carton_from_shipments;
+    isFromPackages = _box!.cartonType == carton_from_packages;
+    isSmallBag = _box!.cartonType == carton_small_bag;
+    isFromCartons = _box!.cartonType == carton_from_cartons;
 
     isEdiable = (isFromPackages || isMixBox || isFromCartons) &&
-        _box.status == carton_packed_status;
-    selectMixBoxType = _box.mixBoxType ?? "";
+        _box!.status == carton_packed_status;
+    selectMixBoxType = _box!.mixBoxType;
     getCartonSize();
   }
 
   getCartonSize() {
     var cartonSizeModel = Provider.of<CartonSizeModel>(context, listen: false);
     cartonSizeModel.cartonSizes.forEach((c) {
-      if (c.length == _box.length &&
-          c.width == _box.width &&
-          c.height == _box.height) {
+      if (c.length == _box!.length &&
+          c.width == _box!.width &&
+          c.height == _box!.height) {
         setState(() {
-          _cartonSizeController.text = c.name;
+          _cartonSizeController.text = c.name ?? "";
         });
       }
     });
@@ -110,43 +108,45 @@ class _CartonInfoState extends State<CartonInfo> {
   _loadPackages() async {
     if (!isFromPackages && !isSmallBag) return;
 
-    if (_box.cartonType == carton_from_packages && _box.userID == null) return;
+    if (_box!.cartonType == carton_from_packages && _box!.userID == null)
+      return;
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
-    List<Package> packages = await packageModel.getPackages(_box.userID, [
+    List<Package> packages =
+        await packageModel.getPackages(_box!.userID ?? "", [
       package_processed_status,
       package_packed_status,
       package_shipped_status,
       package_delivered_status
     ]);
-    packages = packages.where((p) => _box.packageIDs.contains(p.id)).toList();
+    packages = packages.where((p) => _box!.packageIDs.contains(p.id)).toList();
     packages.forEach((p) {
       p.isChecked = true;
     });
 
     setState(() {
-      _box.packages = packages;
+      _box!.packages = packages;
     });
   }
 
   _loadMixCartons() async {
-    if (_box.cartonType != carton_mix_box) return;
+    if (_box!.cartonType != carton_mix_box) return;
     CartonModel cartonModel = Provider.of<CartonModel>(context, listen: false);
     List<Carton> catons = [];
-    for (var id in _box.mixCartonIDs) {
+    for (var id in _box!.mixCartonIDs) {
       Carton c = await cartonModel.getCarton(id);
       catons.add(c);
     }
 
     setState(() {
-      _box.mixCartons = catons;
+      _box!.mixCartons = catons;
     });
   }
 
   _calShipmentWeight() {
-    double l = double.parse(_lengthController.text, (s) => 0);
-    double w = double.parse(_widthController.text, (s) => 0);
-    double h = double.parse(_heightController.text, (s) => 0);
+    double l = double.parse(_lengthController.text);
+    double w = double.parse(_widthController.text);
+    double h = double.parse(_heightController.text);
     setState(() {
       shipmentWeight = l * w * h / volumetricRatio;
     });
@@ -166,33 +166,34 @@ class _CartonInfoState extends State<CartonInfo> {
     final cartonTypeBox = LocalRadioButtons(
         readOnly: true,
         values: cartonModel.cartonTypesInfo,
-        selectedValue:
-            _box.isShipmentCarton ? carton_from_shipments : _box.cartonType);
+        selectedValue: (_box!.isShipmentCarton ?? false)
+            ? carton_from_shipments
+            : _box!.cartonType);
     final shipmentBox = DisplayText(
-      text: _box.fcsShipmentNumber,
+      text: _box!.fcsShipmentNumber,
       labelTextKey: "box.fcs_shipment_num",
       iconData: Ionicons.ios_airplane,
     );
     final fcsIDBox = DisplayText(
-      text: _box.fcsID == null ? "" : _box.fcsID,
+      text: _box!.fcsID == null ? "" : _box!.fcsID,
       labelTextKey: "box.fcs.id",
       icon: FcsIDIcon(),
     );
 
     final customerNameBox = DisplayText(
-      text: _box.userName == null ? "" : _box.userName,
+      text: _box!.userName == null ? "" : _box!.userName,
       labelTextKey: "box.name",
       iconData: Icons.person,
     );
 
     final consigneefcsIDBox = DisplayText(
-      text: _box.fcsID != null ? _box.fcsID : "",
+      text: _box!.fcsID != null ? _box!.fcsID : "",
       labelTextKey: "processing.fcs.id",
       icon: FcsIDIcon(),
     );
 
     final consigneeNameBox = DisplayText(
-      text: _box.userName != null ? _box.userName : "",
+      text: _box!.userName != null ? _box!.userName : "",
       labelTextKey: "processing.consignee.name",
       maxLines: 2,
       iconData: Icons.person,
@@ -211,7 +212,7 @@ class _CartonInfoState extends State<CartonInfo> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: _box.senderFCSID != null ? _box.senderFCSID : "",
+          text: _box!.senderFCSID,
           labelTextKey: "processing.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -219,7 +220,7 @@ class _CartonInfoState extends State<CartonInfo> {
     );
 
     final shipperNamebox = DisplayText(
-      text: _box.senderName != null ? _box.senderName : "",
+      text: _box!.senderName,
       labelTextKey: "processing.shipper.name",
       maxLines: 2,
       iconData: Icons.person,
@@ -269,10 +270,10 @@ class _CartonInfoState extends State<CartonInfo> {
       iconData: AntDesign.CodeSandbox,
     );
     final cargoTableBox = CargoTable(
-      cargoTypes: _box.cargoTypes,
+      cargoTypes: _box!.cargoTypes,
     );
     final mixCartonNumberBox = DisplayText(
-      text: _box.mixCartonNumber,
+      text: _box!.mixCartonNumber,
       labelTextKey: "box.mix.carton",
       iconData: MaterialCommunityIcons.package,
     );
@@ -300,7 +301,7 @@ class _CartonInfoState extends State<CartonInfo> {
                   color: primaryColor,
                 ),
               ),
-              Text(selectMixBoxType)
+              Text(selectMixBoxType ?? "")
             ],
           )
         ],
@@ -340,7 +341,7 @@ class _CartonInfoState extends State<CartonInfo> {
         body: Padding(
           padding: const EdgeInsets.all(10.0),
           child: ListView(shrinkWrap: true, children: <Widget>[
-            Center(child: getCartonNumberStatus(context, _box)),
+            Center(child: getCartonNumberStatus(context, _box!)),
             LocalTitle(textKey: "box.type.title"),
             cartonTypeBox,
             LocalTitle(textKey: "box.shipment_info"),
@@ -367,11 +368,11 @@ class _CartonInfoState extends State<CartonInfo> {
             isMixBox ? mixTypeBox : Container(),
             isMixBox ? LocalTitle(textKey: "box.mix_caton_title") : Container(),
             isMixBox
-                ? Column(children: _getCartons(context, _box.mixCartons))
+                ? Column(children: _getCartons(context, _box!.mixCartons))
                 : Container(),
             isFromPackages || isSmallBag
                 ? CartonPackageTable(
-                    packages: _box.packages,
+                    packages: _box!.packages,
                   )
                 : Container(),
             isMixBox ? Container() : LocalTitle(textKey: "box.cargo.type"),
@@ -408,14 +409,14 @@ class _CartonInfoState extends State<CartonInfo> {
   }
 
   _gotoEditor() async {
-    _box.mixCartons = _box.mixCartons;
-    bool updated = await Navigator.push<bool>(
+    _box!.mixCartons = _box!.mixCartons;
+    bool? updated = await Navigator.push<bool>(
       context,
       CupertinoPageRoute(builder: (context) => CartonEditor(box: _box)),
     );
     if (updated ?? false) {
       var cartonModel = Provider.of<CartonModel>(context, listen: false);
-      var c = await cartonModel.getCarton(widget.box.id);
+      var c = await cartonModel.getCarton(widget.box!.id ?? "");
       setState(() {
         _box = c;
         _loadPackages();
@@ -437,7 +438,7 @@ class _CartonInfoState extends State<CartonInfo> {
     });
     try {
       var cartonModel = Provider.of<CartonModel>(context, listen: false);
-      await cartonModel.deleteCarton(widget.box);
+      await cartonModel.deleteCarton(widget.box!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/carton/carton_list_row.dart b/lib/pages/carton/carton_list_row.dart
index 9c47368..8f61bb3 100644
--- a/lib/pages/carton/carton_list_row.dart
+++ b/lib/pages/carton/carton_list_row.dart
@@ -3,13 +3,13 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'carton_info.dart';
 
 class CartonListRow extends StatelessWidget {
   final Carton box;
-  CartonListRow({Key key, this.box}) : super(key: key);
+  CartonListRow({Key? key, required this.box}) : super(key: key);
 
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
@@ -71,14 +71,14 @@ class CartonListRow extends StatelessWidget {
               children: <Widget>[
                 Padding(
                   padding: const EdgeInsets.all(0),
-                  child: getStatus(box.status == null ? "" : box.status),
+                  child: getStatus(box.status ?? ""),
                 ),
                 Padding(
                   padding: const EdgeInsets.only(left: 8.0, top: 5, bottom: 5),
                   child: Row(
                     children: <Widget>[
                       new Text(
-                        "${box.cartonWeight?.toStringAsFixed(2) ?? ''} lb",
+                        "${box.cartonWeight?.toStringAsFixed(2)} lb",
                         style:
                             new TextStyle(fontSize: 15.0, color: Colors.grey),
                       ),
diff --git a/lib/pages/carton/carton_mix_table.dart b/lib/pages/carton/carton_mix_table.dart
index 86daa49..6d2cee4 100644
--- a/lib/pages/carton/carton_mix_table.dart
+++ b/lib/pages/carton/carton_mix_table.dart
@@ -8,10 +8,10 @@ import 'package:flutter/material.dart';
 typedef OnSelect = Function(Carton carton, bool checked);
 
 class CartonMixTable extends StatelessWidget {
-  final List<Carton> cartons;
-  final OnSelect onSelect;
+  final List<Carton>? cartons;
+  final OnSelect? onSelect;
 
-  const CartonMixTable({Key key, this.cartons, this.onSelect})
+  const CartonMixTable({Key? key, this.cartons, this.onSelect})
       : super(key: key);
 
   @override
@@ -32,21 +32,21 @@ class CartonMixTable extends StatelessWidget {
     );
 
     final rows = cartons == null
-        ? []
-        : cartons.asMap().entries.map((p) {
+        ? [Container()]
+        : cartons!.asMap().entries.map((p) {
             return Container(
-              color: p.value.isChecked
+              color: (p.value.isChecked ?? false)
                   ? Colors.grey.withOpacity(0.2)
-                  : Colors.grey[50].withOpacity(0.2),
+                  : Colors.grey.shade50.withOpacity(0.2),
               child: Container(
                 padding: EdgeInsets.only(
                     left: 0.0, right: 10.0, top: 3.0, bottom: 3.0),
                 decoration: BoxDecoration(
                   border: Border(
                     bottom: BorderSide(
-                        color: p.key == cartons.length - 1
+                        color: p.key == cartons!.length - 1
                             ? Colors.white
-                            : Colors.grey[350],
+                            : Colors.grey.shade300,
                         width: 1),
                   ),
                 ),
@@ -55,8 +55,8 @@ class CartonMixTable extends StatelessWidget {
                     Checkbox(
                         value: p.value.isChecked,
                         activeColor: primaryColor,
-                        onChanged: (bool check) {
-                          if (onSelect != null) onSelect(p.value, check);
+                        onChanged: (bool? check) {
+                          if (onSelect != null) onSelect!(p.value, check!);
                         }),
                     Expanded(
                         child: new Text(
@@ -64,7 +64,7 @@ class CartonMixTable extends StatelessWidget {
                       style: textStyle,
                     )),
                     new Text(
-                      p.value?.actualWeight?.toString() ?? "",
+                      p.value.actualWeight.toString(),
                       style: textStyle,
                     ),
                   ],
diff --git a/lib/pages/carton/carton_package_table.dart b/lib/pages/carton/carton_package_table.dart
index 07eb9f3..7850efa 100644
--- a/lib/pages/carton/carton_package_table.dart
+++ b/lib/pages/carton/carton_package_table.dart
@@ -8,10 +8,10 @@ import 'package:flutter/material.dart';
 typedef OnSelect = Function(Package package, bool checked);
 
 class CartonPackageTable extends StatelessWidget {
-  final List<Package> packages;
-  final OnSelect onSelect;
+  final List<Package>? packages;
+  final OnSelect? onSelect;
 
-  const CartonPackageTable({Key key, this.packages, this.onSelect})
+  const CartonPackageTable({Key? key, this.packages, this.onSelect})
       : super(key: key);
 
   @override
@@ -34,20 +34,20 @@ class CartonPackageTable extends StatelessWidget {
 
     final rows = packages == null
         ? [Container()]
-        : packages.asMap().entries.map((p) {
+        : packages!.asMap().entries.map((p) {
             return Container(
               color: p.value.isChecked
                   ? Colors.grey.withOpacity(0.2)
-                  : Colors.grey[50].withOpacity(0.2),
+                  : Colors.grey.shade50.withOpacity(0.2),
               child: Container(
                 padding: EdgeInsets.only(
                     left: 0.0, right: 10.0, top: 3.0, bottom: 3.0),
                 decoration: BoxDecoration(
                   border: Border(
                     bottom: BorderSide(
-                        color: p.key == packages.length - 1
+                        color: p.key == packages!.length - 1
                             ? Colors.white
-                            : Colors.grey[350],
+                            : Colors.grey.shade300,
                         width: 1),
                   ),
                 ),
@@ -62,15 +62,15 @@ class CartonPackageTable extends StatelessWidget {
                         : Checkbox(
                             value: p.value.isChecked,
                             activeColor: primaryColor,
-                            onChanged: (bool check) {
-                              if (onSelect != null) onSelect(p.value, check);
+                            onChanged: (bool? check) {
+                              if (onSelect != null) onSelect!(p.value, check!);
                             }),
                     Expanded(
                         child: Column(
                       crossAxisAlignment: CrossAxisAlignment.start,
                       children: [
                         Text(
-                          p.value.trackingID,
+                          p.value.trackingID ?? "",
                           style: textStyle,
                         ),
                         Text(
@@ -88,11 +88,11 @@ class CartonPackageTable extends StatelessWidget {
                         crossAxisAlignment: CrossAxisAlignment.start,
                         children: [
                           new Text(
-                            p.value?.desc ?? "",
+                            p.value.desc ?? "",
                             style: textStyle,
                           ),
                           new Text(
-                            "(${p.value?.market ?? ""})",
+                            "(${p.value.market})",
                             style: textStyle,
                           )
                         ],
diff --git a/lib/pages/carton/carton_row.dart b/lib/pages/carton/carton_row.dart
index 0c8eb21..970a3a2 100644
--- a/lib/pages/carton/carton_row.dart
+++ b/lib/pages/carton/carton_row.dart
@@ -2,15 +2,15 @@ import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 typedef OnRemove(Carton carton);
 
 class CartonRow extends StatelessWidget {
   final Carton box;
-  final OnRemove onRemove;
-  CartonRow({Key key, this.box, this.onRemove}) : super(key: key);
+  final OnRemove? onRemove;
+  CartonRow({Key? key, required this.box, this.onRemove}) : super(key: key);
 
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
@@ -20,7 +20,7 @@ class CartonRow extends StatelessWidget {
     return Container(
       decoration: BoxDecoration(
         border: Border(
-          bottom: BorderSide(color: Colors.grey[300]),
+          bottom: BorderSide(color: Colors.grey.shade300),
         ),
       ),
       child: Row(
@@ -75,7 +75,7 @@ class CartonRow extends StatelessWidget {
                         color: primaryColor,
                       ),
                       onPressed: () {
-                        if (onRemove != null) onRemove(box);
+                        if (onRemove != null) onRemove!(box);
                       }),
               box.actualWeight == 0
                   ? Container()
@@ -84,7 +84,7 @@ class CartonRow extends StatelessWidget {
                       child: Row(
                         children: <Widget>[
                           new Text(
-                            "${box.actualWeight?.toStringAsFixed(2) ?? ''} lb",
+                            "${box.actualWeight.toStringAsFixed(2)} lb",
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           ),
diff --git a/lib/pages/carton/input_text_border.dart b/lib/pages/carton/input_text_border.dart
index 58f2314..4c2eff7 100644
--- a/lib/pages/carton/input_text_border.dart
+++ b/lib/pages/carton/input_text_border.dart
@@ -3,10 +3,10 @@ import 'package:flutter/material.dart';
 typedef OnAdd(String value);
 
 class InputTextBorder extends StatelessWidget {
-  final OnAdd onAdd;
-  final TextEditingController controller;
+  final OnAdd? onAdd;
+  final TextEditingController? controller;
 
-  const InputTextBorder({Key key, this.onAdd, this.controller})
+  const InputTextBorder({Key? key, this.onAdd, this.controller})
       : super(key: key);
   @override
   Widget build(BuildContext context) {
@@ -14,7 +14,7 @@ class InputTextBorder extends StatelessWidget {
       textAlign: TextAlign.center,
       controller: controller,
       onChanged: (v) {
-        if (onAdd != null) onAdd(v);
+        if (onAdd != null) onAdd!(v);
       },
       keyboardType: TextInputType.number,
       decoration: new InputDecoration(
diff --git a/lib/pages/carton/model/carton_model.dart b/lib/pages/carton/model/carton_model.dart
index 24d3aeb..da5a7fb 100644
--- a/lib/pages/carton/model/carton_model.dart
+++ b/lib/pages/carton/model/carton_model.dart
@@ -3,9 +3,7 @@ import 'dart:async';
 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:fcs/data/services/services.dart';
 import 'package:fcs/domain/constants.dart';
-import 'package:fcs/domain/entities/cargo_type.dart';
 import 'package:fcs/domain/entities/carton.dart';
-import 'package:fcs/domain/vo/message.dart';
 import 'package:fcs/domain/vo/shipment_status.dart';
 import 'package:fcs/helpers/paginator.dart';
 import 'package:fcs/pages/main/model/base_model.dart';
@@ -14,19 +12,20 @@ import 'package:logging/logging.dart';
 
 class CartonModel extends BaseModel {
   List<Carton> _boxes = [];
-  PaginatorListener cartonsByFilter;
+  late PaginatorListener<Carton> cartonsByFilter;
 
   final log = Logger('CartonModel');
-  List<Carton> get boxes =>
-      _selectedIndex == 1 ? _boxes : List<Carton>.from(_delivered.values);
+  List<Carton> get boxes => _selectedIndex == 1
+      ? _boxes
+      : List<Carton>.from(_delivered?.values ?? []);
 
-  Paginator _delivered;
+  Paginator? _delivered;
   int _selectedIndex = 1;
   int _selectedIndexFilter = 1;
   bool isLoading = false;
 
-  StreamSubscription<QuerySnapshot> listener;
-  StreamSubscription<QuerySnapshot> cartonListener;
+  StreamSubscription<QuerySnapshot>? listener;
+  StreamSubscription<QuerySnapshot>? cartonListener;
   static List<ShipmentStatus> statusHistory = [
     ShipmentStatus(status: "Packed", date: DateTime(2020, 6, 1), done: true),
     ShipmentStatus(status: "Shipped", date: DateTime(2020, 6, 5), done: false),
@@ -87,22 +86,22 @@ class CartonModel extends BaseModel {
     notifyListeners();
   }
 
-  get selectedIndex => _selectedIndex;
-  get selectedIndexFilter => _selectedIndexFilter;
+  int get selectedIndex => _selectedIndex;
+  int get selectedIndexFilter => _selectedIndexFilter;
 
   initData() async {
     _selectedIndex = 1;
     _selectedIndexFilter = 1;
     _loadBoxes();
 
-    if (_delivered != null) _delivered.close();
+    if (_delivered != null) _delivered!.close();
     _delivered = _getDelivered();
-    _delivered.load();
+    _delivered!.load();
   }
 
   @override
   void privilegeChanged() {
-    if (user != null || !user.hasCarton()) {
+    if (user != null || !user!.hasCarton()) {
       _initData();
     }
   }
@@ -120,12 +119,12 @@ class CartonModel extends BaseModel {
   }
 
   Future<void> _loadBoxes() async {
-    if (user == null || !user.hasCarton()) return;
+    if (user == null || !user!.hasCarton()) return;
     String path = "/$cartons_collection/";
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     _boxes = [];
     try {
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("$path")
           .where("status",
               whereIn: [carton_packed_status, carton_shipped_status])
@@ -134,9 +133,10 @@ class CartonModel extends BaseModel {
           .snapshots()
           .listen((QuerySnapshot snapshot) {
             _boxes.clear();
-            _boxes = snapshot.documents.map((documentSnapshot) {
+            _boxes = snapshot.docs.map((documentSnapshot) {
               var s = Carton.fromMap(
-                  documentSnapshot.data, documentSnapshot.documentID);
+                  documentSnapshot.data() as Map<String, dynamic>,
+                  documentSnapshot.id);
               return s;
             }).toList();
             notifyListeners();
@@ -147,18 +147,18 @@ class CartonModel extends BaseModel {
   }
 
   Future<void> _loadCartonsByFilter(String orderName) async {
-    if (user == null || !user.hasCarton()) return null;
+    if (user == null || !user!.hasCarton()) return null;
     String path = "/$cartons_collection";
 
     try {
-      Query listenerQuery = Firestore.instance
+      Query listenerQuery = FirebaseFirestore.instance
           .collection("$path")
           .where("carton_type", whereIn: [
         carton_from_packages,
         carton_from_cartons
       ]).where("status", isEqualTo: carton_packed_status);
 
-      Query pageQuery = Firestore.instance
+      Query pageQuery = FirebaseFirestore.instance
           .collection("$path")
           .where("carton_type",
               whereIn: [carton_from_packages, carton_from_cartons])
@@ -172,10 +172,10 @@ class CartonModel extends BaseModel {
     }
   }
 
-  Paginator _getDelivered() {
-    if (user == null || !user.hasCarton()) return null;
+  Paginator? _getDelivered() {
+    if (user == null || !user!.hasCarton()) return null;
 
-    var pageQuery = Firestore.instance
+    var pageQuery = FirebaseFirestore.instance
         .collection("/$cartons_collection")
         .where("is_delivered", isEqualTo: true)
         .where("is_deleted", isEqualTo: false);
@@ -186,10 +186,10 @@ class CartonModel extends BaseModel {
   }
 
   Future<void> loadMore() async {
-    if (_delivered.ended || selectedIndex == 1) return;
+    if (_delivered == null && _delivered!.ended || selectedIndex == 1) return;
     isLoading = true;
     notifyListeners();
-    await _delivered.load(onFinished: () {
+    await _delivered!.load(onFinished: () {
       isLoading = false;
       notifyListeners();
     });
@@ -197,7 +197,7 @@ class CartonModel extends BaseModel {
 
   Future<void> refresh() async {
     if (selectedIndex == 1) return;
-    await _delivered.refresh(onFinished: () {
+    await _delivered?.refresh(onFinished: () {
       notifyListeners();
     });
   }
@@ -208,69 +208,62 @@ class CartonModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
-    if (cartonListener != null) await cartonListener.cancel();
-    if (_delivered != null) _delivered.close();
+    if (listener != null) await listener!.cancel();
+    if (cartonListener != null) await cartonListener!.cancel();
+    if (_delivered != null) _delivered!.close();
     if (cartonsByFilter != null) cartonsByFilter.close();
     _boxes = [];
   }
 
   Future<List<Carton>> getCartons(String shipmentID) async {
     String path = "/$cartons_collection";
-    var querySnap = await Firestore.instance
+    var querySnap = await FirebaseFirestore.instance
         .collection(path)
         .where("shipment_id", isEqualTo: shipmentID)
-        .getDocuments();
-    return querySnap.documents
-        .map((e) => Carton.fromMap(e.data, e.documentID))
-        .toList();
+        .get();
+    return querySnap.docs.map((e) => Carton.fromMap(e.data(), e.id)).toList();
   }
 
   Future<List<Carton>> getCartonsByFcsShipment(String fcsShipmentID) async {
     String path = "/$cartons_collection";
-    var querySnap = await Firestore.instance
+    var querySnap = await FirebaseFirestore.instance
         .collection(path)
         .where("fcs_shipment_id", isEqualTo: fcsShipmentID)
         .where("is_deleted", isEqualTo: false)
-        .getDocuments();
-    return querySnap.documents
-        .map((e) => Carton.fromMap(e.data, e.documentID))
-        .toList();
+        .get();
+    return querySnap.docs.map((e) => Carton.fromMap(e.data(), e.id)).toList();
   }
 
   Future<List<Carton>> getCartonsForInvoice(
       String fcsShipmentID, String userID) async {
     String path = "/$cartons_collection";
-    var querySnap = await Firestore.instance
+    var querySnap = await FirebaseFirestore.instance
         .collection(path)
         .where("fcs_shipment_id", isEqualTo: fcsShipmentID)
         .where("user_id", isEqualTo: userID)
         .where("is_deleted", isEqualTo: false)
         .where("is_invoiced", isEqualTo: false)
-        .getDocuments();
-    List<Carton> cartons = querySnap.documents
-        .map((e) => Carton.fromMap(e.data, e.documentID))
-        .toList();
+        .get();
+    List<Carton> cartons =
+        querySnap.docs.map((e) => Carton.fromMap(e.data(), e.id)).toList();
     return cartons;
   }
 
   Future<List<Carton>> getMixCartonsByFcsShipment(String fcsShipmentID) async {
     String path = "/$cartons_collection";
-    var querySnap = await Firestore.instance
+    var querySnap = await FirebaseFirestore.instance
         .collection(path)
         .where("fcs_shipment_id", isEqualTo: fcsShipmentID)
         .where("carton_type", isEqualTo: carton_mix_box)
         .where("is_deleted", isEqualTo: false)
-        .getDocuments();
-    return querySnap.documents
-        .map((e) => Carton.fromMap(e.data, e.documentID))
-        .toList();
+        .get();
+    return querySnap.docs.map((e) => Carton.fromMap(e.data(), e.id)).toList();
   }
 
   Future<Carton> getCarton(String id) async {
     String path = "/$cartons_collection";
-    var snap = await Firestore.instance.collection(path).document(id).get();
-    return Carton.fromMap(snap.data, snap.documentID);
+    var snap = await FirebaseFirestore.instance.collection(path).doc(id).get();
+    return Carton.fromMap(snap.data() as Map<String, dynamic>, snap.id);
   }
 
   Future<Carton> createCarton(Carton carton) {
diff --git a/lib/pages/carton/package_carton_editor.dart b/lib/pages/carton/package_carton_editor.dart
index 87f48e4..2d52b7d 100644
--- a/lib/pages/carton/package_carton_editor.dart
+++ b/lib/pages/carton/package_carton_editor.dart
@@ -8,12 +8,9 @@ import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/carton_size/carton_size_list.dart';
 import 'package:fcs/pages/carton_size/model/carton_size_model.dart';
-import 'package:fcs/pages/delivery_address/model/delivery_address_model.dart';
 import 'package:fcs/pages/main/util.dart';
-import 'package:fcs/pages/rates/model/shipment_rate_model.dart';
 import 'package:fcs/pages/widgets/defalut_delivery_address.dart';
 import 'package:fcs/pages/widgets/delivery_address_selection.dart';
-import 'package:fcs/pages/widgets/display_text.dart';
 import 'package:fcs/pages/widgets/length_picker.dart';
 import 'package:fcs/pages/widgets/local_button.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
@@ -21,7 +18,7 @@ import 'package:fcs/pages/widgets/local_title.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 import 'cargo_type_addtion.dart';
@@ -29,9 +26,9 @@ import 'carton_cargo_table.dart';
 import 'model/carton_model.dart';
 
 class PackageCartonEditor extends StatefulWidget {
-  final Carton carton;
-  final bool isNew;
-  final User consignee;
+  final Carton? carton;
+  final bool? isNew;
+  final User? consignee;
   PackageCartonEditor({this.carton, this.isNew, this.consignee});
 
   @override
@@ -43,13 +40,13 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
   TextEditingController _widthCtl = new TextEditingController();
   TextEditingController _heightCtl = new TextEditingController();
 
-  Carton _carton;
+  Carton? _carton;
   bool _isLoading = false;
-  DeliveryAddress _deliveryAddress = new DeliveryAddress();
+  DeliveryAddress? _deliveryAddress = new DeliveryAddress();
   List<CargoType> _cargoTypes = [];
-  CartonSize selectedCatonSize;
-  bool isFromPackages;
-  bool isFromCartons;
+  CartonSize? selectedCatonSize;
+  bool isFromPackages = false;
+  bool isFromCartons = false;
 
   @override
   void initState() {
@@ -59,19 +56,19 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
 
   _load() {
     _carton = widget.carton;
-    isFromPackages = _carton.cartonType == carton_from_packages;
-    isFromCartons = _carton.cartonType == carton_from_cartons;
+    isFromPackages = _carton!.cartonType == carton_from_packages;
+    isFromCartons = _carton!.cartonType == carton_from_cartons;
 
-    if (widget.isNew) {
+    if (widget.isNew!) {
       _lengthCtl.text = "0";
       _widthCtl.text = "0";
       _heightCtl.text = "0";
     } else {
-      _cargoTypes = widget.carton.cargoTypes.map((e) => e.clone()).toList();
-      _lengthCtl.text = _carton.length.toString();
-      _widthCtl.text = _carton.width.toString();
-      _heightCtl.text = _carton.height.toString();
-      _deliveryAddress = _carton.deliveryAddress;
+      _cargoTypes = widget.carton!.cargoTypes.map((e) => e.clone()).toList();
+      _lengthCtl.text = _carton!.length.toString();
+      _widthCtl.text = _carton!.width.toString();
+      _heightCtl.text = _carton!.height.toString();
+      _deliveryAddress = _carton!.deliveryAddress;
       _getCartonSize();
     }
   }
@@ -79,9 +76,9 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
   _getCartonSize() {
     var cartonSizeModel = Provider.of<CartonSizeModel>(context, listen: false);
     cartonSizeModel.cartonSizes.forEach((c) {
-      if (c.length == _carton.length &&
-          c.width == _carton.width &&
-          c.height == _carton.height) {
+      if (c.length == _carton!.length &&
+          c.width == _carton!.width &&
+          c.height == _carton!.height) {
         selectedCatonSize = CartonSize(
             id: c.id,
             name: c.name,
@@ -122,7 +119,7 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
       ],
     );
     final createBtn = LocalButton(
-      textKey: widget.isNew ? "box.new_carton_btn" : "box.cargo.save.btn",
+      textKey: widget.isNew! ? "box.new_carton_btn" : "box.cargo.save.btn",
       callBack: _creatCarton,
     );
 
@@ -134,11 +131,10 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
             color: primaryColor,
           ),
           onPressed: () async {
-            List<CargoType> cargos = await Navigator.push<List<CargoType>>(
+            List<CargoType>? cargos = await Navigator.push<List<CargoType>>(
                 context,
                 CupertinoPageRoute(builder: (context) => CargoTypeAddition()));
             if (cargos == null) return;
-            if (cargos == null) return;
             setState(() {
               _cargoTypes.addAll(
                   cargos.where((e) => !_cargoTypes.contains(e)).toList());
@@ -168,7 +164,7 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
           backgroundColor: Colors.white,
           title: LocalText(
             context,
-            widget.isNew ? "boxes.create.title" : "box.edit.title",
+            widget.isNew! ? "boxes.create.title" : "box.edit.title",
             fontSize: 20,
             color: primaryColor,
           ),
@@ -187,13 +183,14 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
                   deliveryAddress: _deliveryAddress,
                   labelKey: "box.delivery_address",
                   onTap: () async {
-                    DeliveryAddress d = await Navigator.push<DeliveryAddress>(
+                    DeliveryAddress? d = await Navigator.push<DeliveryAddress>(
                       context,
                       CupertinoPageRoute(
                           builder: (context) => DeliveryAddressSelection(
                                 deliveryAddress: _deliveryAddress,
                                 user: User(
-                                    id: _carton.userID, name: _carton.userName),
+                                    id: _carton!.userID,
+                                    name: _carton!.userName),
                               )),
                     );
                     if (d == null) return;
@@ -245,17 +242,17 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
                     height: 1,
                     color: Colors.grey,
                   ),
-                  onChanged: (CartonSize newValue) {
+                  onChanged: (CartonSize? newValue) {
                     setState(() {
-                      if (newValue.name == MANAGE_CARTONSIZE) {
+                      if (newValue!.name == MANAGE_CARTONSIZE) {
                         selectedCatonSize = null;
                         _manageCartonSize();
                         return;
                       }
                       selectedCatonSize = newValue;
-                      _widthCtl.text = selectedCatonSize.width.toString();
-                      _heightCtl.text = selectedCatonSize.height.toString();
-                      _lengthCtl.text = selectedCatonSize.length.toString();
+                      _widthCtl.text = selectedCatonSize!.width.toString();
+                      _heightCtl.text = selectedCatonSize!.height.toString();
+                      _lengthCtl.text = selectedCatonSize!.length.toString();
                     });
                   },
                   isExpanded: true,
@@ -295,8 +292,7 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
 
   _updateCargo(CargoType cargo) {
     setState(() {
-      var _c =
-          _cargoTypes.firstWhere((e) => e.id == cargo.id, orElse: () => null);
+      var _c = _cargoTypes.firstWhere((e) => e.id == cargo.id);
       if (_c != null) {
         _c.weight = cargo.weight;
         _c.qty = cargo.qty;
@@ -305,13 +301,13 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
   }
 
   _creatCarton() async {
-    if ((_cargoTypes?.length ?? 0) == 0) {
+    if (_cargoTypes.length == 0) {
       showMsgDialog(context, "Error", "Expect at least one cargo type");
       return;
     }
-    double l = double.parse(_lengthCtl.text, (s) => 0);
-    double w = double.parse(_widthCtl.text, (s) => 0);
-    double h = double.parse(_heightCtl.text, (s) => 0);
+    double l = double.parse(_lengthCtl.text);
+    double w = double.parse(_widthCtl.text);
+    double h = double.parse(_heightCtl.text);
     if ((l <= 0 || w <= 0 || h <= 0)) {
       showMsgDialog(context, "Error", "Invalid dimension");
       return;
@@ -322,22 +318,22 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
     }
 
     Carton carton = Carton();
-    carton.id = _carton.id;
-    carton.cartonType = _carton.cartonType;
-    carton.fcsShipmentID = _carton.fcsShipmentID;
+    carton.id = _carton!.id;
+    carton.cartonType = _carton!.cartonType;
+    carton.fcsShipmentID = _carton!.fcsShipmentID;
     carton.cargoTypes = _cargoTypes;
     if (isFromPackages) {
-      carton.userID = _carton.userID;
-      carton.packages = _carton.packages.where((e) => e.isChecked).toList();
+      carton.userID = _carton!.userID;
+      carton.packages = _carton!.packages.where((e) => e.isChecked).toList();
     }
 
     if (isFromCartons) {
-      carton.userID = _carton.userID;
-      carton.fcsID = _carton.fcsID;
-      carton.userName = _carton.userName;
-      carton.senderID = _carton.senderID;
-      carton.senderFCSID = _carton.senderFCSID;
-      carton.senderName = _carton.senderName;
+      carton.userID = _carton!.userID;
+      carton.fcsID = _carton!.fcsID;
+      carton.userName = _carton!.userName;
+      carton.senderID = _carton!.senderID;
+      carton.senderFCSID = _carton!.senderFCSID;
+      carton.senderName = _carton!.senderName;
     }
 
     carton.length = l;
@@ -350,12 +346,12 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
     try {
       CartonModel cartonModel =
           Provider.of<CartonModel>(context, listen: false);
-      if (widget.isNew) {
+      if (widget.isNew!) {
         Carton _c = await cartonModel.createCarton(carton);
         Navigator.pop(context, _c);
       } else {
         await cartonModel.updateCarton(carton);
-        Carton _c = await cartonModel.getCarton(_carton.id);
+        Carton _c = await cartonModel.getCarton(_carton!.id!);
         Navigator.pop(context, _c);
       }
     } catch (e) {
diff --git a/lib/pages/carton/total_weight_edit.dart b/lib/pages/carton/total_weight_edit.dart
index 614e0d5..21632f3 100644
--- a/lib/pages/carton/total_weight_edit.dart
+++ b/lib/pages/carton/total_weight_edit.dart
@@ -10,9 +10,9 @@ import 'package:fcs/pages/main/util.dart';
 typedef void ProfileCallback();
 
 class TotalWeightEdit extends StatefulWidget {
-  final double totalWeight;
+  final double? totalWeight;
 
-  const TotalWeightEdit({Key key, this.totalWeight}) : super(key: key);
+  const TotalWeightEdit({Key? key, this.totalWeight}) : super(key: key);
   @override
   _TotalWeightEditState createState() => _TotalWeightEditState();
 }
@@ -24,7 +24,7 @@ class _TotalWeightEditState extends State<TotalWeightEdit> {
   @override
   void initState() {
     super.initState();
-    totalController.text = widget.totalWeight.toStringAsFixed(2);
+    totalController.text = widget.totalWeight!.toStringAsFixed(2);
   }
 
   @override
diff --git a/lib/pages/carton/widgets.dart b/lib/pages/carton/widgets.dart
index 3e9a50c..c690008 100644
--- a/lib/pages/carton/widgets.dart
+++ b/lib/pages/carton/widgets.dart
@@ -10,14 +10,14 @@ Widget getCartonNumberStatus(BuildContext context, Carton carton) {
       LocalText(
         context,
         '',
-        text: carton.cartonNumber ?? "",
+        text: carton.cartonNumber ,
         color: primaryColor,
         fontSize: 18,
         fontWeight: FontWeight.bold,
       ),
       Padding(
         padding: const EdgeInsets.only(left: 8.0),
-        child: Chip(label: Text(carton.status ?? "")),
+        child: Chip(label: Text(carton.status??"")),
       ),
     ],
   );
diff --git a/lib/pages/carton_search/carton_list_row.dart b/lib/pages/carton_search/carton_list_row.dart
index 427a32e..563084e 100644
--- a/lib/pages/carton_search/carton_list_row.dart
+++ b/lib/pages/carton_search/carton_list_row.dart
@@ -1,45 +1,32 @@
 import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 
 import 'carton_search.dart';
 
-class CartonListRow extends StatefulWidget {
-  final CallbackCartonSelect callbackCartonSelect;
+class CartonListRow extends StatelessWidget {
+  final CallbackCartonSelect? callbackCartonSelect;
   final Carton carton;
 
   // const CartonListRow({this.carton, this.callbackCartonSelect});
-  CartonListRow(
-      {Key key, this.carton, this.callbackCartonSelect})
+  CartonListRow({Key? key, required this.carton, this.callbackCartonSelect})
       : super(key: key);
 
-  @override
-  _CartonListRowState createState() => _CartonListRowState();
-}
-
-class _CartonListRowState extends State<CartonListRow> {
   final double dotSize = 15.0;
-  Carton _carton;
-  @override
-  void initState() {
-    super.initState();
-    this._carton = widget.carton;
-  }
 
   @override
   Widget build(BuildContext context) {
     return Container(
       decoration: BoxDecoration(
         border: Border(
-          bottom: BorderSide(color: Colors.grey[300]),
+          bottom: BorderSide(color: Colors.grey.shade300),
         ),
       ),
       child: InkWell(
         onTap: () {
           Navigator.pop(context);
-          if (widget.callbackCartonSelect != null)
-            widget.callbackCartonSelect(widget.carton);
+          if (callbackCartonSelect != null) callbackCartonSelect!(carton);
         },
         child: Row(
           children: <Widget>[
@@ -64,7 +51,7 @@ class _CartonListRowState extends State<CartonListRow> {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              _carton.cartonNumber ?? "",
+                              carton.cartonNumber ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -72,7 +59,7 @@ class _CartonListRowState extends State<CartonListRow> {
                           Padding(
                             padding: const EdgeInsets.only(left: 10.0, top: 10),
                             child: new Text(
-                              _carton.userName ?? "",
+                              carton.userName ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.grey),
                             ),
@@ -86,7 +73,7 @@ class _CartonListRowState extends State<CartonListRow> {
                       child: Row(
                         children: <Widget>[
                           new Text(
-                            "${_carton.cartonWeight?.toStringAsFixed(2) ?? ''} lb",
+                            "${carton.cartonWeight?.toStringAsFixed(2)} lb",
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           ),
diff --git a/lib/pages/carton_search/carton_search.dart b/lib/pages/carton_search/carton_search.dart
index 87cc1c9..07c2215 100644
--- a/lib/pages/carton_search/carton_search.dart
+++ b/lib/pages/carton_search/carton_search.dart
@@ -10,7 +10,7 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/popupmenu.dart';
 import 'package:fcs/pagination/paginator_listview.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:provider/provider.dart';
 
@@ -18,15 +18,15 @@ import 'carton_list_row.dart';
 
 typedef CallbackCartonSelect(Carton carton);
 
-Future<Carton> searchCarton(BuildContext context,
-        {CallbackCartonSelect callbackCartonSelect}) async =>
+Future<Carton?> searchCarton(BuildContext context,
+        {CallbackCartonSelect? callbackCartonSelect}) async =>
     await showSearch<Carton>(
       context: context,
       delegate: PartSearchDelegate(callbackCartonSelect: callbackCartonSelect),
     );
 
 class PartSearchDelegate extends SearchDelegate<Carton> {
-  final CallbackCartonSelect callbackCartonSelect;
+  final CallbackCartonSelect? callbackCartonSelect;
   PartSearchDelegate({this.callbackCartonSelect});
 
   @override
@@ -38,10 +38,10 @@ class PartSearchDelegate extends SearchDelegate<Carton> {
     return theme.copyWith(
       inputDecorationTheme: InputDecorationTheme(
           hintStyle: TextStyle(
-              color: theme.primaryTextTheme.caption.color, fontSize: 14)),
+              color: theme.primaryTextTheme.caption!.color, fontSize: 14)),
       textTheme: theme.textTheme.copyWith(
-          title: theme.textTheme.title.copyWith(
-              color: theme.primaryTextTheme.title.color, fontSize: 16)),
+          title: theme.textTheme.title!.copyWith(
+              color: theme.primaryTextTheme.title!.color, fontSize: 16)),
       primaryColor: primaryColor,
     );
   }
@@ -85,7 +85,7 @@ class PartSearchDelegate extends SearchDelegate<Carton> {
   Widget buildLeading(BuildContext context) {
     return IconButton(
       icon: Icon(Icons.arrow_back),
-      onPressed: () => close(context, null),
+      onPressed: () => close(context, new Carton()),
     );
   }
 
@@ -96,7 +96,7 @@ class PartSearchDelegate extends SearchDelegate<Carton> {
         future: cartonModel.searchCarton(query),
         builder: (context, AsyncSnapshot<List<Carton>> snapshot) {
           if (snapshot.hasData) {
-            if (snapshot.data.length == 0) {
+            if (snapshot.data!.length == 0) {
               return Container(
                 child: Center(
                   child: Text(
@@ -109,7 +109,7 @@ class PartSearchDelegate extends SearchDelegate<Carton> {
             return Container(
               padding: EdgeInsets.only(top: 15),
               child: ListView(
-                children: snapshot.data
+                children: snapshot.data!
                     .map((u) => CartonListRow(
                           key: ValueKey(u.id),
                           carton: u,
@@ -158,20 +158,20 @@ class PartSearchDelegate extends SearchDelegate<Carton> {
   }
 
   _scan(BuildContext context) async {
-    PermissionStatus permission =
-        await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
-    if (permission != PermissionStatus.granted) {
-      Map<PermissionGroup, PermissionStatus> permissions =
-          await PermissionHandler()
-              .requestPermissions([PermissionGroup.camera]);
-      if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
-        showMsgDialog(context, "Error", "Camera permission is not granted");
-        return null;
-      }
-    }
+    // PermissionStatus permission =
+    //     await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
+    // if (permission != PermissionStatus.granted) {
+    //   Map<PermissionGroup, PermissionStatus> permissions =
+    //       await PermissionHandler()
+    //           .requestPermissions([PermissionGroup.camera]);
+    //   if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
+    //     showMsgDialog(context, "Error", "Camera permission is not granted");
+    //     return null;
+    //   }
+    // }
 
     try {
-      String barcode = await scanBarcode();
+      String? barcode = await scanBarcode();
       if (barcode != null) {
         query = barcode;
         showResults(context);
diff --git a/lib/pages/carton_size/carton_size_editor.dart b/lib/pages/carton_size/carton_size_editor.dart
index 0b3662b..b9a21c1 100644
--- a/lib/pages/carton_size/carton_size_editor.dart
+++ b/lib/pages/carton_size/carton_size_editor.dart
@@ -7,13 +7,13 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 import 'model/carton_size_model.dart';
 
 class CartonSizeEditor extends StatefulWidget {
-  final CartonSize cartonSize;
+  final CartonSize? cartonSize;
   CartonSizeEditor({this.cartonSize});
 
   @override
@@ -27,8 +27,8 @@ class _CartonSizeEditorState extends State<CartonSizeEditor> {
   TextEditingController _lengthController = new TextEditingController();
 
   bool _isLoading = false;
-  CartonSize _cartonSize;
-  bool _isNew;
+  CartonSize? _cartonSize;
+  bool _isNew = false;
 
   @override
   void initState() {
@@ -36,10 +36,10 @@ class _CartonSizeEditorState extends State<CartonSizeEditor> {
     if (widget.cartonSize != null) {
       _cartonSize = widget.cartonSize;
       _isNew = false;
-      _nameController.text = _cartonSize.name;
-      _widthController.text = _cartonSize.width.toString();
-      _heightController.text = _cartonSize.height.toString();
-      _lengthController.text = _cartonSize.length.toString();
+      _nameController.text = _cartonSize!.name ?? "";
+      _widthController.text = _cartonSize!.width.toString();
+      _heightController.text = _cartonSize!.height.toString();
+      _lengthController.text = _cartonSize!.length.toString();
     } else {
       _lengthController.text = "12";
       _widthController.text = "12";
@@ -110,7 +110,7 @@ class _CartonSizeEditorState extends State<CartonSizeEditor> {
             await cartonSizeModel.addCartonSize(_cartonSize);
           } else {
             CartonSize _cartonSize = CartonSize(
-                id: widget.cartonSize.id,
+                id: widget.cartonSize!.id,
                 name: _nameController.text,
                 length: l,
                 width: w,
@@ -184,7 +184,7 @@ class _CartonSizeEditorState extends State<CartonSizeEditor> {
       CartonSize _cartonSize = CartonSize(
           name: _nameController.text, length: l, width: w, height: h);
 
-      return widget.cartonSize.isChangedForEdit(_cartonSize);
+      return widget.cartonSize!.isChangedForEdit(_cartonSize);
     }
   }
 }
diff --git a/lib/pages/carton_size/carton_size_list.dart b/lib/pages/carton_size/carton_size_list.dart
index 2341edb..e396f11 100644
--- a/lib/pages/carton_size/carton_size_list.dart
+++ b/lib/pages/carton_size/carton_size_list.dart
@@ -40,7 +40,7 @@ class _CartonSizeListState extends State<CartonSizeList> {
                   crossAxisAlignment: CrossAxisAlignment.start,
                   children: [
                     new Text(
-                      p.name,
+                      p.name ?? "",
                       style: TextStyle(fontSize: 15.0),
                     ),
                     Padding(
@@ -135,7 +135,7 @@ class _CartonSizeListState extends State<CartonSizeList> {
     CartonSizeModel cartonSizeModel =
         Provider.of<CartonSizeModel>(context, listen: false);
     try {
-      await cartonSizeModel.deleteCartonSize(cartonSize.id);
+      await cartonSizeModel.deleteCartonSize(cartonSize.id!);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
     } finally {
diff --git a/lib/pages/carton_size/model/carton_size_model.dart b/lib/pages/carton_size/model/carton_size_model.dart
index d9e9c1b..c104453 100644
--- a/lib/pages/carton_size/model/carton_size_model.dart
+++ b/lib/pages/carton_size/model/carton_size_model.dart
@@ -13,7 +13,7 @@ class CartonSizeModel extends BaseModel {
   List<CartonSize> cartonSizes = [];
   final log = Logger('CartonSizeModel');
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   List<CartonSize> get getCartonSizes {
     var _cartonSizes = new List<CartonSize>.from(cartonSizes);
@@ -27,17 +27,18 @@ class CartonSizeModel extends BaseModel {
 
   Future<void> _loadCartonSizes() async {
     try {
-      if (listener != null) listener.cancel();
+      if (listener != null) listener!.cancel();
 
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection(
               "/$config_collection/$setting_doc_id/$carton_sizes_collection")
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         cartonSizes.clear();
-        cartonSizes = snapshot.documents.map((documentSnapshot) {
+        cartonSizes = snapshot.docs.map((documentSnapshot) {
           var c = CartonSize.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+              documentSnapshot.data() as Map<String, dynamic>,
+              documentSnapshot.id);
           return c;
         }).toList();
         notifyListeners();
@@ -49,7 +50,7 @@ class CartonSizeModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     cartonSizes = [];
   }
 
diff --git a/lib/pages/chat/bubble.dart b/lib/pages/chat/bubble.dart
index 9a99de3..dabed50 100644
--- a/lib/pages/chat/bubble.dart
+++ b/lib/pages/chat/bubble.dart
@@ -2,7 +2,6 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/package/package_info.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/widgets/fcs_id_icon.dart';
-import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 
@@ -14,18 +13,18 @@ typedef CallbackOnViewDetail();
 class Bubble extends StatelessWidget {
   Bubble(
       {this.message,
-      this.date,
-      this.delivered,
-      this.isMine,
+      required this.date,
+      required this.delivered,
+      required this.isMine,
       this.sender,
-      this.isSystem,
-      this.isCustomer,
-      this.showDate,
+      required this.isSystem,
+      required this.isCustomer,
+      required this.showDate,
       this.callbackOnViewDetail});
 
-  final CallbackOnViewDetail callbackOnViewDetail;
+  final CallbackOnViewDetail? callbackOnViewDetail;
   final DateTime date;
-  final String message, sender;
+  final String? message, sender;
   final bool delivered, isMine, isSystem, isCustomer, showDate;
 
   @override
@@ -84,7 +83,7 @@ class Bubble extends StatelessWidget {
                                     fontWeight: FontWeight.bold)))
                       ]
                     : [
-                        Text(isCustomer ? "FCS Team" : sender,
+                        Text(isCustomer ? "FCS Team" : sender ?? "",
                             style: TextStyle(
                               color: Colors.black38,
                               fontSize: 10.0,
@@ -102,8 +101,8 @@ class Bubble extends StatelessWidget {
       children: <Widget>[
         Padding(
             padding: EdgeInsets.only(right: 48.0),
-            child: Text(message,
-                style: hasUnicode(message)
+            child: Text(message ?? "",
+                style: hasUnicode(message ?? "")
                     ? newLabelStyleMM(color: primaryColor)
                     : newLabelStyle(color: primaryColor))),
         Positioned(
@@ -130,6 +129,6 @@ class Bubble extends StatelessWidget {
   }
 
   _viewDetail() {
-    if (callbackOnViewDetail != null) callbackOnViewDetail();
+    if (callbackOnViewDetail != null) callbackOnViewDetail!();
   }
 }
diff --git a/lib/pages/chat/message_detail.dart b/lib/pages/chat/message_detail.dart
index c1209e7..d1b7144 100644
--- a/lib/pages/chat/message_detail.dart
+++ b/lib/pages/chat/message_detail.dart
@@ -21,14 +21,17 @@ import 'package:provider/provider.dart';
 import 'bubble.dart';
 
 class MessageDetail extends StatelessWidget {
-  final String receiverName;
-  final String receiverID;
+  final String? receiverName;
+  final String? receiverID;
   final MessageModel messageModel;
   final TextEditingController textEditingController = TextEditingController();
   final ScrollController listScrollController = ScrollController();
 
   MessageDetail(
-      {Key key, this.messageModel, this.receiverName, this.receiverID})
+      {Key? key,
+      required this.messageModel,
+      this.receiverName,
+      this.receiverID})
       : super(key: key) {
     listScrollController.addListener(() {
       if (listScrollController.offset >=
@@ -44,7 +47,7 @@ class MessageDetail extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    String userID = Provider.of<MessageModel>(context).user.id;
+    String userID = Provider.of<MessageModel>(context).user?.id ?? "";
 
     return Scaffold(
       appBar: AppBar(
@@ -96,8 +99,8 @@ class MessageDetail extends StatelessWidget {
   Widget buildBubble(Message msg, String userID, bool showDate,
       CallbackOnViewDetail callback) {
     return Bubble(
-      message: msg.message,
-      date: msg.date,
+      message: msg.message ?? "",
+      date: msg.date!,
       delivered: true,
       sender: msg.senderName,
       isMine: msg.senderID == userID || msg.receiverID == receiverID,
@@ -117,8 +120,8 @@ class MessageDetail extends StatelessWidget {
             child: Container(
               child: TextField(
                 onSubmitted: (value) {
-                  Provider.of<MessageModel>(context, listen: false)
-                      .sendMessage(textEditingController.text, receiverID);
+                  Provider.of<MessageModel>(context, listen: false).sendMessage(
+                      textEditingController.text, receiverID ?? "");
                   textEditingController.text = "";
                 },
                 style: TextStyle(color: primaryColor, fontSize: 15.0),
@@ -152,8 +155,8 @@ class MessageDetail extends StatelessWidget {
               child: IconButton(
                 icon: Icon(Icons.send),
                 onPressed: () {
-                  Provider.of<MessageModel>(context, listen: false)
-                      .sendMessage(textEditingController.text, receiverID);
+                  Provider.of<MessageModel>(context, listen: false).sendMessage(
+                      textEditingController.text, receiverID ?? "");
                   textEditingController.text = "";
                 },
                 color: primaryColor,
@@ -165,7 +168,8 @@ class MessageDetail extends StatelessWidget {
       ),
       width: double.infinity,
       decoration: BoxDecoration(
-          border: Border(top: BorderSide(color: Colors.grey[700], width: 0.5)),
+          border:
+              Border(top: BorderSide(color: Colors.grey.shade700, width: 0.5)),
           color: Colors.white),
     );
   }
@@ -176,7 +180,7 @@ class MessageDetail extends StatelessWidget {
         message.messageID != "") {
       PackageModel packageModel =
           Provider.of<PackageModel>(context, listen: false);
-      Package p = await packageModel.getPackage(message.messageID);
+      Package p = await packageModel.getPackage(message.messageID!);
       if (p == null) return;
       Navigator.push<bool>(context,
           CupertinoPageRoute(builder: (context) => PackageInfo(package: p)));
@@ -186,7 +190,7 @@ class MessageDetail extends StatelessWidget {
         message.messageID != "") {
       MainModel mainModel = Provider.of<MainModel>(context, listen: false);
 
-      if (mainModel.user.isCustomer()) {
+      if (mainModel.user?.isCustomer() ?? false) {
         Navigator.push<bool>(
             context, CupertinoPageRoute(builder: (context) => Profile()));
       } else {
@@ -202,7 +206,7 @@ class MessageDetail extends StatelessWidget {
         message.messageID != "") {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      Shipment s = await shipmentModel.getShipment(message.messageID);
+      Shipment s = await shipmentModel.getShipment(message.messageID!);
       if (s == null) return;
       await Navigator.push<bool>(
           context,
diff --git a/lib/pages/chat/model/message_model.dart b/lib/pages/chat/model/message_model.dart
index 447a325..64535ef 100644
--- a/lib/pages/chat/model/message_model.dart
+++ b/lib/pages/chat/model/message_model.dart
@@ -10,44 +10,46 @@ import 'package:logging/logging.dart';
 class MessageModel extends BaseModel {
   final log = Logger('MessageModel');
 
-  List<Message> messages;
+  List<Message> messages = [];
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     messages = [];
   }
 
-  Query query;
-  DocumentSnapshot prevSnap;
-  bool isEnded;
-  bool isLoading;
-  String userID;
-  StreamSubscription<QuerySnapshot> listener;
+  late Query query;
+  DocumentSnapshot? prevSnap;
+  late bool isEnded;
+  late bool isLoading;
+  String? userID;
+  StreamSubscription<QuerySnapshot>? listener;
 
   static const int rowPerLoad = 20;
-  void initQuery(String userID) {
+  void initQuery(String? userID) {
+    if (userID == null) return;
     this.messages = [];
     this.userID = userID;
     this.prevSnap = null;
-    query = Firestore.instance
+    query = FirebaseFirestore.instance
         .collection("$user_collection/$userID/$messages_collection")
         .orderBy('date', descending: true);
     load();
   }
 
   Future<void> load() async {
+    if (prevSnap == null) return;
     Query _query =
-        prevSnap != null ? query.startAfterDocument(prevSnap) : query;
+        prevSnap != null ? query.startAfterDocument(prevSnap!) : query;
     QuerySnapshot snapshot =
-        await _query.limit(rowPerLoad).getDocuments(source: Source.server);
+        await _query.limit(rowPerLoad).get(GetOptions(source: Source.server));
 
-    int count = snapshot.documents.length;
+    int count = snapshot.docs.length;
     isEnded = count < rowPerLoad;
-    prevSnap = count > 0 ? snapshot.documents[count - 1] : prevSnap;
+    prevSnap = count > 0 ? snapshot.docs[count - 1] : prevSnap;
 
-    snapshot.documents.forEach((e) {
-      messages.add(Message.fromMap(e.data, e.documentID));
+    snapshot.docs.forEach((e) {
+      messages.add(Message.fromMap(e.data() as Map<String, dynamic>, e.id));
       if (messages.length == 1) {
         _initListener(e);
       }
@@ -56,20 +58,22 @@ class MessageModel extends BaseModel {
   }
 
   void _initListener(DocumentSnapshot snap) {
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
 
-    listener = Firestore.instance
+    listener = FirebaseFirestore.instance
         .collection("$user_collection/$userID/$messages_collection")
         .endBeforeDocument(snap)
         .orderBy('date', descending: true)
         .snapshots(includeMetadataChanges: true)
         .listen((qs) {
-      qs.documentChanges.forEach((c) {
+      qs.docChanges.forEach((c) {
         switch (c.type) {
           case DocumentChangeType.added:
             log.info("added!! $c");
             messages.insert(
-                0, Message.fromMap(c.document.data, c.document.documentID));
+                0,
+                Message.fromMap(
+                    c.doc.data() as Map<String, dynamic>, c.doc.id));
             notifyListeners();
             break;
           case DocumentChangeType.modified:
diff --git a/lib/pages/contact/contact_editor.dart b/lib/pages/contact/contact_editor.dart
index 5a7cf50..8092c2f 100644
--- a/lib/pages/contact/contact_editor.dart
+++ b/lib/pages/contact/contact_editor.dart
@@ -1,6 +1,5 @@
 import 'package:fcs/domain/vo/contact.dart';
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/localization/app_translations.dart';
 import 'package:fcs/pages/contact/model/contact_model.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/widgets/input_text.dart';
@@ -14,7 +13,7 @@ import 'package:provider/provider.dart';
 import 'widgets.dart';
 
 class ContactEditor extends StatefulWidget {
-  final Contact contact;
+  final Contact? contact;
   const ContactEditor({this.contact});
   @override
   _ContactEditorState createState() => _ContactEditorState();
@@ -29,22 +28,23 @@ class _ContactEditorState extends State<ContactEditor> {
   TextEditingController _facebook = new TextEditingController();
 
   bool _isLoading = false;
-  bool isNew;
+  bool isNew = false;
 
+  Contact? _contact;
   @override
   void initState() {
+    if (widget.contact != null) _contact = widget.contact!;
     super.initState();
-    if (widget.contact != null) {
-      isNew = false;
-      _usaPhone.text = widget.contact.usaContactNumber;
-      _mmPhone.text = widget.contact.mmContactNumber;
-      _usaAddress.text = widget.contact.usaAddress;
-      _mmAddress.text = widget.contact.mmAddress;
-      _email.text = widget.contact.emailAddress;
-      _facebook.text = widget.contact.facebookLink;
-    } else {
-      isNew = true;
-    }
+    isNew = widget.contact == null;
+  }
+
+  initContact() {
+    _usaPhone.text = _contact?.usaContactNumber ?? '';
+    _mmPhone.text = _contact?.mmContactNumber ?? '';
+    _usaAddress.text = _contact?.usaAddress ?? '';
+    _mmAddress.text = _contact?.mmAddress ?? '';
+    _email.text = _contact?.emailAddress ?? '';
+    _facebook.text = _contact?.facebookLink ?? '';
   }
 
   @override
@@ -136,14 +136,17 @@ class _ContactEditorState extends State<ContactEditor> {
       _isLoading = true;
     });
     try {
-      widget.contact.usaContactNumber = _usaPhone.text;
-      widget.contact.mmContactNumber = _mmPhone.text;
-      widget.contact.usaAddress = _usaAddress.text;
-      widget.contact.mmAddress = _mmAddress.text;
-      widget.contact.emailAddress = _email.text;
-      widget.contact.facebookLink = _facebook.text;
-      var contactModel = Provider.of<ContactModel>(context, listen: false);
-      await contactModel.saveContact(widget.contact);
+      _contact?.usaContactNumber = _usaPhone.text;
+      _contact?.mmContactNumber = _mmPhone.text;
+      _contact?.usaAddress = _usaAddress.text;
+      _contact?.mmAddress = _mmAddress.text;
+      _contact?.emailAddress = _email.text;
+      _contact?.facebookLink = _facebook.text;
+      if (this._contact != null) {
+        var contactModel = Provider.of<ContactModel>(context, listen: false);
+        await contactModel.saveContact(_contact!);
+      }
+
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/contact/contact_page.dart b/lib/pages/contact/contact_page.dart
index 404b2ac..f0c1fae 100644
--- a/lib/pages/contact/contact_page.dart
+++ b/lib/pages/contact/contact_page.dart
@@ -1,7 +1,6 @@
 import 'package:fcs/domain/entities/setting.dart';
 import 'package:fcs/domain/vo/contact.dart';
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/localization/app_translations.dart';
 import 'package:fcs/pages/contact/contact_editor.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
@@ -22,7 +21,8 @@ class ContactPage extends StatefulWidget {
 class _ContactPageState extends State<ContactPage> {
   @override
   Widget build(BuildContext context) {
-    Setting setting = Provider.of<MainModel>(context).setting;
+    Setting? setting = Provider.of<MainModel>(context).setting;
+    if (setting == null) return Container();
     bool isEditable = context.select((MainModel m) => m.contactEditable());
 
     return Scaffold(
@@ -62,14 +62,14 @@ class _ContactPageState extends State<ContactPage> {
         children: [
           itemTitle(context, "contact.callus"),
           contactItem(context, setting.usaContactNumber, CupertinoIcons.phone,
-              onTap: () => _call(setting.usaContactNumber),
+              onTap: () => _call(setting.usaContactNumber ?? ""),
               labelKey: "contact.usa.phone"),
           contactItem(
             context,
             setting.mmContactNumber,
             CupertinoIcons.phone,
             onTap: () => _call(
-              setting.mmContactNumber,
+              setting.mmContactNumber ?? "",
             ),
             labelKey: "contact.mm.phone",
           ),
@@ -91,7 +91,7 @@ class _ContactPageState extends State<ContactPage> {
             context,
             setting.emailAddress,
             CupertinoIcons.mail,
-            onTap: () => _email(setting.emailAddress),
+            onTap: () => _email(setting.emailAddress ?? ""),
             labelKey: "contact.fcs.email",
           ),
           itemTitle(context, "contact.visitus"),
@@ -99,7 +99,7 @@ class _ContactPageState extends State<ContactPage> {
             context,
             setting.facebookLink,
             FontAwesomeIcons.facebook,
-            onTap: () => _opencontactItem(setting.facebookLink),
+            onTap: () => _opencontactItem(setting.facebookLink ?? ""),
             labelKey: "contact.facebook",
           ),
         ],
diff --git a/lib/pages/contact/widgets.dart b/lib/pages/contact/widgets.dart
index 40a78f6..f8f38b8 100644
--- a/lib/pages/contact/widgets.dart
+++ b/lib/pages/contact/widgets.dart
@@ -7,25 +7,25 @@ Widget itemTitle(BuildContext context, String textKey) {
   return Padding(
     padding: const EdgeInsets.only(left: 18.0, top: 25, bottom: 5),
     child: Text(
-      AppTranslations.of(context).text(textKey),
+      AppTranslations.of(context)!.text(textKey),
       style: TextStyle(
           fontWeight: FontWeight.bold, fontSize: 18, color: Colors.black),
     ),
   );
 }
 
-Widget subItemTitle(BuildContext context, String textKey, {IconData iconData}) {
+Widget subItemTitle(BuildContext context, String textKey, {IconData? iconData}) {
   return Padding(
     padding: const EdgeInsets.only(left: 0, top: 0, bottom: 0),
     child: Row(
       children: [
         Icon(
-          iconData,
+          iconData, 
           color: primaryColor,
         ),
         SizedBox(width: 10),
         Text(
-          AppTranslations.of(context).text(textKey),
+          AppTranslations.of(context)!.text(textKey),
           style: TextStyle(
               fontWeight: FontWeight.w700, fontSize: 15, color: primaryColor),
         ),
@@ -34,8 +34,8 @@ Widget subItemTitle(BuildContext context, String textKey, {IconData iconData}) {
   );
 }
 
-Widget contactItem(BuildContext context, String text, IconData iconData,
-    {Function() onTap, String labelKey}) {
+Widget contactItem(BuildContext context, String? text, IconData iconData,
+    {Function()? onTap, String? labelKey}) {
   return Material(
     child: Padding(
       padding: const EdgeInsets.only(left: 18.0, bottom: 10, right: 18),
diff --git a/lib/pages/customer/customer_editor.dart b/lib/pages/customer/customer_editor.dart
index e3df283..c85a44f 100644
--- a/lib/pages/customer/customer_editor.dart
+++ b/lib/pages/customer/customer_editor.dart
@@ -14,7 +14,7 @@ import 'package:provider/provider.dart';
 typedef void FindCallBack();
 
 class CustomerEditor extends StatefulWidget {
-  final User customer;
+  final User? customer;
   const CustomerEditor({this.customer});
   @override
   _CustomerEditorState createState() => _CustomerEditorState();
@@ -34,17 +34,17 @@ class _CustomerEditorState extends State<CustomerEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: widget.customer.phoneNumber,
+          text: widget.customer!.phoneNumber,
           labelTextKey: "customer.phone",
           iconData: Icons.phone,
         )),
         IconButton(
             icon: Icon(Icons.open_in_new, color: primaryColor),
-            onPressed: () => call(context, widget.customer.phoneNumber)),
+            onPressed: () => call(context, widget.customer?.phoneNumber ?? "")),
       ],
     );
 
-    final enabled = widget.customer.status != user_disabled_status;
+    final enabled = widget.customer!.status != user_disabled_status;
     final enableBox = LocalButton(
       textKey: enabled ? "customer.disable.btn" : "customer.enable.btn",
       iconData: enabled ? Icons.lock : Icons.lock_open,
@@ -68,7 +68,7 @@ class _CustomerEditorState extends State<CustomerEditor> {
                 onPressed: () => Navigator.of(context).pop(),
               ),
               title: Text(
-                widget.customer.name,
+                widget.customer?.name ?? "",
                 style: TextStyle(
                   fontSize: 20,
                   color: primaryColor,
@@ -81,26 +81,26 @@ class _CustomerEditorState extends State<CustomerEditor> {
                 children: <Widget>[
                   phoneNumberBox,
                   DisplayText(
-                    text: widget.customer.fcsID,
+                    text: widget.customer!.fcsID,
                     labelTextKey: "customer.fcs.id",
                     icon: FcsIDIcon(),
                   ),
                   DisplayText(
-                    text: widget.customer.status,
+                    text: widget.customer!.status,
                     labelTextKey: "customer.status",
                     iconData: Icons.add_alarm,
                   ),
                   SizedBox(
                     height: 20,
                   ),
-                  widget.customer.requested
+                  widget.customer!.requested
                       ? fcsButton(
                           context,
                           getLocalString(
                               context, "customer.invitation.request.confirm"),
                           callack: _add)
                       : Container(),
-                  widget.customer.joined || widget.customer.disabled
+                  widget.customer!.joined || widget.customer!.disabled
                       ? enableBox
                       : Container()
                 ],
@@ -119,7 +119,7 @@ class _CustomerEditorState extends State<CustomerEditor> {
       CustomerModel customerModel =
           Provider.of<CustomerModel>(context, listen: false);
       try {
-        await customerModel.acceptRequest(widget.customer.id);
+        await customerModel.acceptRequest(widget.customer?.id ?? "");
         Navigator.pop(context);
       } catch (e) {
         showMsgDialog(context, "Error", e.toString());
@@ -139,7 +139,7 @@ class _CustomerEditorState extends State<CustomerEditor> {
     CustomerModel customerModel =
         Provider.of<CustomerModel>(context, listen: false);
     try {
-      await customerModel.enableUser(widget.customer, enabled);
+      await customerModel.enableUser(widget.customer!, enabled);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/customer/customer_list.dart b/lib/pages/customer/customer_list.dart
index a1fbd72..09c4cba 100644
--- a/lib/pages/customer/customer_list.dart
+++ b/lib/pages/customer/customer_list.dart
@@ -125,7 +125,7 @@ class _CustomerListState extends State<CustomerList> {
                             Padding(
                               padding: const EdgeInsets.only(top: 2.0),
                               child: new Text(
-                                customer.name,
+                                customer.name ?? "",
                                 style: new TextStyle(
                                     fontSize: 20.0, color: primaryColor),
                               ),
@@ -171,7 +171,7 @@ class _CustomerListState extends State<CustomerList> {
               children: [
                 Padding(
                   padding: const EdgeInsets.only(right: 5),
-                  child: _status(customer.status),
+                  child: _status(customer.status ?? ""),
                 ),
                 Padding(
                   padding: const EdgeInsets.only(right: 5),
@@ -222,22 +222,22 @@ class _CustomerListState extends State<CustomerList> {
                 )))
         .then((value) {
       if (customer.fcsUnseenCount > 0) {
-        messageModel.seenMessages(customer.id, false);
+        messageModel.seenMessages(customer.id ?? "", false);
       }
     });
     if (customer.fcsUnseenCount > 0) {
-      messageModel.seenMessages(customer.id, false);
+      messageModel.seenMessages(customer.id ?? "", false);
     }
   }
 
   _share(User user) async {
     MainModel mainModel = Provider.of<MainModel>(context, listen: false);
-    String appUrl = mainModel.setting.appUrl;
-    final RenderBox box = context.findRenderObject();
+    String appUrl = mainModel.setting?.appUrl ?? "";
+    final RenderBox? box = context.findRenderObject() as RenderBox;
     await Share.share(
         "Join us on FCS Logistics App. Here is the link:\n $appUrl\n" +
             user.share,
         subject: "Invitation to FCS Logistics App",
-        sharePositionOrigin: box.localToGlobal(Offset.zero) & box.size);
+        sharePositionOrigin: box!.localToGlobal(Offset.zero) & box.size);
   }
 }
diff --git a/lib/pages/customer/invitation_create.dart b/lib/pages/customer/invitation_create.dart
index af2e2ed..e2bb37a 100644
--- a/lib/pages/customer/invitation_create.dart
+++ b/lib/pages/customer/invitation_create.dart
@@ -19,7 +19,7 @@ class _InvitationCreateState extends State<InvitationCreate> {
   TextEditingController _phoneController = new TextEditingController();
 
   bool _isLoading = false;
-  String dialCode;
+  late String dialCode;
 
   @override
   void initState() {
@@ -85,7 +85,7 @@ class _InvitationCreateState extends State<InvitationCreate> {
                   ),
                   Container(
                     decoration: BoxDecoration(
-                        border: Border.all(color: Colors.grey[400], width: 1),
+                        border: Border.all(color: Colors.grey.shade400, width: 1),
                         borderRadius: BorderRadius.all(Radius.circular(12.0))),
                     child: CountryCodePicker(
                       onChanged: _countryChange,
@@ -140,7 +140,7 @@ class _InvitationCreateState extends State<InvitationCreate> {
 
   _countryChange(CountryCode countryCode) {
     setState(() {
-      dialCode = countryCode.dialCode;
+      dialCode = countryCode.dialCode!;
     });
   }
 
diff --git a/lib/pages/customer/invitation_editor.dart b/lib/pages/customer/invitation_editor.dart
index 837f704..fe2f946 100644
--- a/lib/pages/customer/invitation_editor.dart
+++ b/lib/pages/customer/invitation_editor.dart
@@ -11,7 +11,7 @@ import 'package:provider/provider.dart';
 typedef void FindCallBack();
 
 class InvitationEditor extends StatefulWidget {
-  final User customer;
+  final User? customer;
   const InvitationEditor({this.customer});
   @override
   _InvitationEditorState createState() => _InvitationEditorState();
@@ -31,13 +31,13 @@ class _InvitationEditorState extends State<InvitationEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: widget.customer.phoneNumber,
+          text: widget.customer!.phoneNumber,
           labelTextKey: getLocalString(context, "customer.phone"),
           iconData: Icons.phone,
         )),
         IconButton(
             icon: Icon(Icons.open_in_new, color: primaryColor),
-            onPressed: () => call(context, widget.customer.phoneNumber)),
+            onPressed: () => call(context, widget.customer?.phoneNumber ?? "")),
       ],
     );
 
@@ -57,7 +57,7 @@ class _InvitationEditorState extends State<InvitationEditor> {
               onPressed: () => Navigator.of(context).pop(),
             ),
             title: Text(
-              widget.customer.name,
+              widget.customer?.name ?? "",
               style: TextStyle(fontSize: 20, color: primaryColor),
             ),
           ),
@@ -87,7 +87,7 @@ class _InvitationEditorState extends State<InvitationEditor> {
       CustomerModel customerModel =
           Provider.of<CustomerModel>(context, listen: false);
       try {
-        await customerModel.deleteInvite(widget.customer.phoneNumber);
+        await customerModel.deleteInvite(widget.customer?.phoneNumber ?? "");
         Navigator.pop(context);
       } catch (e) {
         showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/customer/model/customer_model.dart b/lib/pages/customer/model/customer_model.dart
index 1413f3a..a82c24b 100644
--- a/lib/pages/customer/model/customer_model.dart
+++ b/lib/pages/customer/model/customer_model.dart
@@ -12,8 +12,8 @@ class CustomerModel extends BaseModel {
 
   List<User> customers = [];
   List<User> invitations = [];
-  StreamSubscription<QuerySnapshot> customerListener;
-  StreamSubscription<QuerySnapshot> invitationListener;
+  late StreamSubscription<QuerySnapshot>? customerListener;
+  late StreamSubscription<QuerySnapshot>? invitationListener;
 
   @override
   void privilegeChanged() {
@@ -24,8 +24,8 @@ class CustomerModel extends BaseModel {
 
   @override
   logout() async {
-    if (customerListener != null) customerListener.cancel();
-    if (invitationListener != null) invitationListener.cancel();
+    if (customerListener != null) customerListener!.cancel();
+    if (invitationListener != null) invitationListener!.cancel();
     customers = [];
     invitations = [];
   }
@@ -43,21 +43,22 @@ class CustomerModel extends BaseModel {
   }
 
   Future<void> _loadCustomer() async {
-    if (user == null || !user.hasCustomers()) return;
+    if (user == null && !user!.hasCustomers()) return;
 
     try {
-      if (customerListener != null) customerListener.cancel();
+      if (customerListener != null) customerListener!.cancel();
 
-      customerListener = Firestore.instance
+      customerListener = FirebaseFirestore.instance
           .collection("/$user_collection")
           .where("is_sys_admin", isEqualTo: false)
           .orderBy("message_time", descending: true)
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         customers.clear();
-        customers = snapshot.documents.map((documentSnapshot) {
-          var user =
-              User.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+        customers = snapshot.docs.map((documentSnapshot) {
+          var user = User.fromMap(
+              documentSnapshot.data() as Map<String, dynamic>,
+              documentSnapshot.id);
           return user;
         }).toList();
         notifyListeners();
@@ -68,19 +69,20 @@ class CustomerModel extends BaseModel {
   }
 
   Future<void> _loadInvitations() async {
-    if (user == null || !user.hasCustomers()) return;
+    if (user == null && !user!.hasCustomers()) return;
 
     try {
-      if (invitationListener != null) invitationListener.cancel();
+      if (invitationListener != null) invitationListener!.cancel();
 
-      invitationListener = Firestore.instance
+      invitationListener = FirebaseFirestore.instance
           .collection("/$invitations_collection")
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         invitations.clear();
-        invitations = snapshot.documents.map((documentSnapshot) {
-          var user =
-              User.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+        invitations = snapshot.docs.map((documentSnapshot) {
+          var user = User.fromMap(
+              documentSnapshot.data() as Map<String, dynamic>,
+              documentSnapshot.id);
           return user;
         }).toList();
         notifyListeners();
@@ -90,23 +92,22 @@ class CustomerModel extends BaseModel {
     }
   }
 
-  Future<User> getUser(String id) async {
+  Future<User> getUser(String? id) async {
     String path = "/$user_collection";
-    var snap = await Firestore.instance.collection(path).document(id).get();
-    return User.fromMap(snap.data, snap.documentID);
+    var snap = await FirebaseFirestore.instance.collection(path).doc(id).get();
+    return User.fromMap(snap.data() as Map<String, dynamic>, snap.id);
   }
 
   Future<List<User>> getInvoiceUsers(String fcsShipmentID) async {
     List<User> users = [];
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection(
               "/$fcs_shipment_collection/$fcsShipmentID/$user_collection")
           .where("pending_invoice_carton_count", isGreaterThan: 0)
-          .getDocuments(source: Source.server);
-      users = snaps.documents.map((documentSnapshot) {
-        var user =
-            User.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+          .get(GetOptions(source: Source.server));
+      users = snaps.docs.map((documentSnapshot) {
+        var user = User.fromMap(documentSnapshot.data(), documentSnapshot.id);
         return user;
       }).toList();
     } catch (e) {
@@ -116,6 +117,6 @@ class CustomerModel extends BaseModel {
   }
 
   Future<void> enableUser(User user, bool enabled) {
-    return Services.instance.userService.enableUser(user.id, enabled);
+    return Services.instance.userService.enableUser(user.id ?? "", enabled);
   }
 }
diff --git a/lib/pages/delivery/delivery_info.dart b/lib/pages/delivery/delivery_info.dart
index f9fecd2..fef0d5e 100644
--- a/lib/pages/delivery/delivery_info.dart
+++ b/lib/pages/delivery/delivery_info.dart
@@ -22,14 +22,14 @@ import 'package:fcs/pages/widgets/local_title.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class DeliveryInfo extends StatefulWidget {
-  final Carton box;
+  final Carton? box;
   DeliveryInfo({this.box});
 
   @override
@@ -38,8 +38,8 @@ class DeliveryInfo extends StatefulWidget {
 
 class _DeliveryInfoState extends State<DeliveryInfo> {
   bool _isLoading = false;
-  Carton _box;
-  String _selectedCartonType;
+  late Carton _box;
+  late String _selectedCartonType;
   List<Package> _packages = [];
   List<Carton> _mixBoxes = [];
   Carton _selectedShipmentBox = new Carton();
@@ -51,17 +51,17 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
   double volumetricRatio = 0;
   double shipmentWeight = 0;
 
-  bool isMixBox;
-  bool isFromShipments;
-  bool isFromPackages;
-  bool isSmallBag;
-  bool isEdiable;
+  late bool isMixBox;
+  late bool isFromShipments;
+  late bool isFromPackages;
+  late bool isSmallBag;
+  late bool isEdiable;
 
   @override
   void initState() {
     super.initState();
-    _box = widget.box;
-    _selectedCartonType = _box.cartonType;
+    if (widget.box != null) _box = widget.box!;
+    _selectedCartonType = _box.cartonType ?? '';
 
     //for shipment weight
     volumetricRatio = Provider.of<ShipmentRateModel>(context, listen: false)
@@ -80,7 +80,7 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
     _heightController.text = _box.height.toString();
     _lengthController.text = _box.length.toString();
     _cargoTypes = _box.cargoTypes;
-    _deliveryAddress = _box.deliveryAddress;
+    _deliveryAddress = _box.deliveryAddress!;
     isMixBox = _box.cartonType == carton_mix_box;
     isFromShipments = _box.cartonType == carton_from_shipments;
     isFromPackages = _box.cartonType == carton_from_packages;
@@ -96,7 +96,7 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
     if (_box.cartonType == carton_from_packages && _box.userID == null) return;
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
-    List<Package> packages = await packageModel.getPackages(_box.userID, [
+    List<Package> packages = await packageModel.getPackages(_box.userID!, [
       package_processed_status,
       package_packed_status,
       package_shipped_status,
@@ -135,21 +135,22 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
     final cartonTypeBox = LocalRadioButtons(
         readOnly: true,
         values: cartonModel.cartonTypesInfo,
-        selectedValue:
-            _box.isShipmentCarton ? carton_from_shipments : _box.cartonType);
+        selectedValue: (_box.isShipmentCarton ?? false)
+            ? carton_from_shipments
+            : _box.cartonType);
     final shipmentBox = DisplayText(
       text: _box.fcsShipmentNumber,
       labelTextKey: "box.fcs_shipment_num",
       iconData: Ionicons.ios_airplane,
     );
     final fcsIDBox = DisplayText(
-      text: _box.fcsID == null ? "" : _box.fcsID,
+      text: _box.fcsID,
       labelTextKey: "box.fcs.id",
       icon: FcsIDIcon(),
     );
 
     final customerNameBox = DisplayText(
-      text: _box.userName == null ? "" : _box.userName,
+      text: _box.userName,
       labelTextKey: "box.name",
       iconData: Icons.person,
     );
@@ -173,13 +174,11 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
         children: <Widget>[
           Expanded(
               child: new Text(
-            _selectedShipmentBox.shipmentNumber == null
-                ? ""
-                : _selectedShipmentBox.shipmentNumber,
+            _selectedShipmentBox.shipmentNumber ?? "",
             style: textStyle,
           )),
           new Text(
-            _selectedShipmentBox.desc == null ? "" : _selectedShipmentBox.desc,
+            _selectedShipmentBox.desc ?? "",
             style: textStyle,
           ),
         ],
@@ -216,7 +215,7 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
     );
 
     final shipmentWeightBox = DisplayText(
-      text: shipmentWeight != null ? shipmentWeight.toStringAsFixed(0) : "",
+      text: shipmentWeight.toStringAsFixed(0),
       labelTextKey: "box.shipment_weight",
       iconData: MaterialCommunityIcons.weight,
     );
@@ -302,7 +301,7 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
     });
     try {
       var deliveryModel = Provider.of<DeliveryModel>(context, listen: false);
-      await deliveryModel.deliver(widget.box);
+      await deliveryModel.deliver(this._box);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/delivery/delivery_list_row.dart b/lib/pages/delivery/delivery_list_row.dart
index 16bdcac..c77f115 100644
--- a/lib/pages/delivery/delivery_list_row.dart
+++ b/lib/pages/delivery/delivery_list_row.dart
@@ -3,14 +3,14 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 import 'delivery_info.dart';
 
 class DeliveryListRow extends StatelessWidget {
-  final Carton box;
-  DeliveryListRow({Key key, this.box}) : super(key: key);
+  final Carton? box;
+  DeliveryListRow({Key? key, this.box}) : super(key: key);
 
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
@@ -19,10 +19,11 @@ class DeliveryListRow extends StatelessWidget {
   Widget build(BuildContext context) {
     return InkWell(
       onTap: () {
-        Navigator.push(
-          context,
-          CupertinoPageRoute(builder: (context) => DeliveryInfo(box: box)),
-        );
+        if (box != null)
+          Navigator.push(
+            context,
+            CupertinoPageRoute(builder: (context) => DeliveryInfo(box: box!)),
+          );
       },
       child: Container(
         padding: EdgeInsets.only(left: 15, right: 15),
@@ -48,7 +49,7 @@ class DeliveryListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              box.cartonNumber ?? "",
+                              box?.cartonNumber ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -56,7 +57,7 @@ class DeliveryListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 10.0, top: 10),
                             child: new Text(
-                              box.userName ?? "",
+                              box?.userName ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.grey),
                             ),
@@ -72,14 +73,14 @@ class DeliveryListRow extends StatelessWidget {
               children: <Widget>[
                 Padding(
                   padding: const EdgeInsets.all(0),
-                  child: getStatus(box.status == null ? "" : box.status),
+                  child: getStatus(box?.status ?? ''),
                 ),
                 Padding(
                   padding: const EdgeInsets.only(left: 8.0, top: 5, bottom: 5),
                   child: Row(
                     children: <Widget>[
                       new Text(
-                        "${box.actualWeight?.toString() ?? ''} lb",
+                        "${box?.actualWeight.toString() ?? ''} lb",
                         style:
                             new TextStyle(fontSize: 15.0, color: Colors.grey),
                       ),
diff --git a/lib/pages/delivery/model/delivery_model.dart b/lib/pages/delivery/model/delivery_model.dart
index b200684..235f820 100644
--- a/lib/pages/delivery/model/delivery_model.dart
+++ b/lib/pages/delivery/model/delivery_model.dart
@@ -14,18 +14,18 @@ class DeliveryModel extends BaseModel {
   List<Carton> get cartons =>
       _selectedIndex == 1 ? _cartons : List<Carton>.from(_delivered.values);
 
-  Paginator _delivered;
+  late Paginator _delivered;
   int _selectedIndex = 1;
   bool isLoading = false;
   List<Carton> _cartons = [];
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   set selectedIndex(int index) {
     _selectedIndex = index;
     notifyListeners();
   }
 
-  get selectedIndex => _selectedIndex;
+  int get selectedIndex => _selectedIndex;
 
   initData() {
     _selectedIndex = 1;
@@ -37,12 +37,12 @@ class DeliveryModel extends BaseModel {
   }
 
   Future<void> _loadCartons() async {
-    if (user == null || !user.hasDeliveries()) return;
+    if (user == null || !user!.hasDeliveries()) return;
     String path = "/$cartons_collection/";
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     _cartons = [];
     try {
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("$path")
           .where("status", isEqualTo: carton_shipped_status)
           .where("carton_type", whereIn: [
@@ -55,9 +55,9 @@ class DeliveryModel extends BaseModel {
           .snapshots()
           .listen((QuerySnapshot snapshot) {
             _cartons.clear();
-            _cartons = snapshot.documents.map((documentSnapshot) {
+            _cartons = snapshot.docs.map((documentSnapshot) {
               var s = Carton.fromMap(
-                  documentSnapshot.data, documentSnapshot.documentID);
+                  documentSnapshot.data as Map<String, dynamic>, documentSnapshot.id);
               return s;
             }).toList();
             notifyListeners();
@@ -68,9 +68,9 @@ class DeliveryModel extends BaseModel {
   }
 
   Paginator _getDelivered() {
-    if (user == null || !user.hasDeliveries()) return null;
+    if (user == null || !user!.hasDeliveries()) throw "No Privilege";
 
-    var pageQuery = Firestore.instance
+    var pageQuery = FirebaseFirestore.instance
         .collection("/$cartons_collection")
         .where("is_delivered", isEqualTo: true)
         .where("status", whereIn: [carton_delivered_status]).where("is_deleted",
@@ -105,7 +105,7 @@ class DeliveryModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     if (_delivered != null) _delivered.close();
     _cartons = [];
   }
diff --git a/lib/pages/delivery_address/delivery_address_editor.dart b/lib/pages/delivery_address/delivery_address_editor.dart
index 812e0db..aa84ba2 100644
--- a/lib/pages/delivery_address/delivery_address_editor.dart
+++ b/lib/pages/delivery_address/delivery_address_editor.dart
@@ -7,13 +7,13 @@ import 'package:fcs/pages/widgets/input_text.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
-import 'package:flutter_icons/flutter_icons.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 class DeliveryAddressEditor extends StatefulWidget {
-  final DeliveryAddress deliveryAddress;
-  final User user;
+  final DeliveryAddress? deliveryAddress;
+  final User? user;
   DeliveryAddressEditor({this.deliveryAddress, this.user});
 
   @override
@@ -38,13 +38,13 @@ class _DeliveryAddressEditorState extends State<DeliveryAddressEditor> {
     super.initState();
     if (widget.deliveryAddress != null) {
       _isNew = false;
-      _deliveryAddress = widget.deliveryAddress;
-      _nameController.text = _deliveryAddress.fullName;
-      _address1Controller.text = _deliveryAddress.addressLine1;
-      _address2Controller.text = _deliveryAddress.addressLine2;
-      _cityController.text = _deliveryAddress.city;
-      _stateController.text = _deliveryAddress.state;
-      _phoneController.text = _deliveryAddress.phoneNumber;
+      _deliveryAddress = widget.deliveryAddress!;
+      _nameController.text = _deliveryAddress.fullName ?? "";
+      _address1Controller.text = _deliveryAddress.addressLine1 ?? "";
+      _address2Controller.text = _deliveryAddress.addressLine2 ?? "";
+      _cityController.text = _deliveryAddress.city ?? "";
+      _stateController.text = _deliveryAddress.state ?? "";
+      _phoneController.text = _deliveryAddress.phoneNumber?? "";
     } else {
       _cityController.text = "Yangon";
       _stateController.text = "Yangon";
@@ -198,7 +198,7 @@ class _DeliveryAddressEditorState extends State<DeliveryAddressEditor> {
       return;
     }
     if (widget.user != null) {
-      deliveryAddress.userID = widget.user.id;
+      deliveryAddress.userID = widget.user!.id;
     }
     setState(() {
       _isLoading = true;
@@ -224,7 +224,7 @@ class _DeliveryAddressEditorState extends State<DeliveryAddressEditor> {
       return;
     }
     if (widget.user != null) {
-      deliveryAddress.userID = widget.user.id;
+      deliveryAddress.userID = widget.user!.id;
     }
     setState(() {
       _isLoading = true;
@@ -255,7 +255,7 @@ class _DeliveryAddressEditorState extends State<DeliveryAddressEditor> {
       DeliveryAddressModel deliveryAddressModel =
           Provider.of<DeliveryAddressModel>(context, listen: false);
       if (widget.user != null) {
-        _deliveryAddress.userID = widget.user.id;
+        _deliveryAddress.userID = widget.user!.id;
       }
       await deliveryAddressModel.deleteDeliveryAddress(_deliveryAddress);
       Navigator.pop(context, true);
@@ -278,7 +278,7 @@ class _DeliveryAddressEditorState extends State<DeliveryAddressEditor> {
           _stateController.text != "Yangon";
     } else {
       DeliveryAddress deliveryAddress = _getPayload();
-      return widget.deliveryAddress.isChangedForEdit(deliveryAddress);
+      return this._deliveryAddress.isChangedForEdit(deliveryAddress);
     }
   }
 }
diff --git a/lib/pages/delivery_address/delivery_address_list.dart b/lib/pages/delivery_address/delivery_address_list.dart
index c8455ba..480e5b6 100644
--- a/lib/pages/delivery_address/delivery_address_list.dart
+++ b/lib/pages/delivery_address/delivery_address_list.dart
@@ -13,9 +13,9 @@ import 'model/delivery_address_model.dart';
 
 class DeliveryAddressList extends StatefulWidget {
   final bool isAdminCreation;
-  final DeliveryAddress deliveryAddress;
+  final DeliveryAddress? deliveryAddress;
   const DeliveryAddressList(
-      {Key key, this.isAdminCreation = false, this.deliveryAddress})
+      {Key? key, this.isAdminCreation = false,  this.deliveryAddress})
       : super(key: key);
   @override
   _DeliveryAddressListState createState() => _DeliveryAddressListState();
@@ -85,7 +85,7 @@ class _DeliveryAddressListState extends State<DeliveryAddressList> {
             padding: const EdgeInsets.all(10.0),
             child: Icon(Icons.check,
                 color: widget.isAdminCreation
-                    ? widget.deliveryAddress.id == deliveryAddress.id
+                    ? widget.deliveryAddress?.id == deliveryAddress.id
                         ? primaryColor
                         : Colors.black26
                     : deliveryAddress.isDefault
diff --git a/lib/pages/delivery_address/delivery_address_row.dart b/lib/pages/delivery_address/delivery_address_row.dart
index e596213..c6e248c 100644
--- a/lib/pages/delivery_address/delivery_address_row.dart
+++ b/lib/pages/delivery_address/delivery_address_row.dart
@@ -3,15 +3,15 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 
 typedef SelectionCallback(DeliveryAddress deliveryAddress);
 
 class DeliveryAddressRow extends StatelessWidget {
   final DeliveryAddress deliveryAddress;
-  final SelectionCallback selectionCallback;
+  final SelectionCallback? selectionCallback;
   const DeliveryAddressRow(
-      {Key key, this.deliveryAddress, this.selectionCallback})
+      {Key? key, required this.deliveryAddress, this.selectionCallback})
       : super(key: key);
 
   @override
@@ -19,7 +19,7 @@ class DeliveryAddressRow extends StatelessWidget {
     return InkWell(
       onTap: selectionCallback == null
           ? null
-          : () => this.selectionCallback(deliveryAddress),
+          : () => this.selectionCallback!(deliveryAddress),
       child: Row(
         children: <Widget>[
           Expanded(
@@ -54,8 +54,8 @@ class DeliveryAddressRow extends StatelessWidget {
     );
   }
 
-  Widget line(BuildContext context, String text,
-      {IconData iconData, Color color, double fontSize}) {
+  Widget line(BuildContext context, String? text,
+      {IconData? iconData, Color? color, double? fontSize}) {
     return Row(
       children: [
         iconData == null
@@ -69,7 +69,7 @@ class DeliveryAddressRow extends StatelessWidget {
             context,
             text ?? "",
             fontSize: fontSize ?? 14,
-            color: color,
+            color: color ?? Colors.grey,
           ),
         ),
       ],
diff --git a/lib/pages/delivery_address/model/delivery_address_model.dart b/lib/pages/delivery_address/model/delivery_address_model.dart
index a344c82..0ccbf33 100644
--- a/lib/pages/delivery_address/model/delivery_address_model.dart
+++ b/lib/pages/delivery_address/model/delivery_address_model.dart
@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'package:barcode_scan2/gen/protos/protos.pb.dart';
 import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:fcs/data/services/services.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
@@ -10,13 +11,13 @@ class DeliveryAddressModel extends BaseModel {
   final log = Logger('FcsShipmentModel');
   List<DeliveryAddress> deliveryAddresses = [];
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   DeliveryAddress get defalutAddress =>
-      deliveryAddresses.firstWhere((e) => e.isDefault, orElse: () => null);
+      deliveryAddresses.firstWhere((e) => e.isDefault, orElse: () => DeliveryAddress());
 
   DeliveryAddress getLocalDeliveryAddress(String id) =>
-      deliveryAddresses.firstWhere((e) => e.id == id, orElse: () => null);
+      deliveryAddresses.firstWhere((e) => e.id == id, orElse: () => DeliveryAddress());
 
   @override
   void privilegeChanged() {
@@ -26,26 +27,26 @@ class DeliveryAddressModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     deliveryAddresses = [];
   }
 
   Future<void> _loadDeliveryAddresses() async {
     if (user == null) return;
     String path = "$delivery_address_collection/";
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     deliveryAddresses = [];
     try {
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection('users')
-          .document("${user.id}")
+          .doc("${user!.id}")
           .collection("$path")
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         deliveryAddresses.clear();
-        deliveryAddresses = snapshot.documents.map((documentSnapshot) {
+        deliveryAddresses = snapshot.docs.map((documentSnapshot) {
           var s = DeliveryAddress.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+              documentSnapshot.data as Map<String,dynamic>, documentSnapshot.id);
           return s;
         }).toList();
         notifyListeners();
@@ -56,9 +57,9 @@ class DeliveryAddressModel extends BaseModel {
   }
 
   Future<DeliveryAddress> getDeliveryAddress(String id) async {
-    String path = "/$user_collection/${user.id}/$delivery_address_collection";
-    var snap = await Firestore.instance.collection(path).document(id).get();
-    return DeliveryAddress.fromMap(snap.data, snap.documentID);
+    String path = "/$user_collection/${user!.id}/$delivery_address_collection";
+    var snap = await FirebaseFirestore.instance.collection(path).doc(id).get();
+    return DeliveryAddress.fromMap(snap.data as Map<String,dynamic>, snap.id);
   }
 
   void initUser(user) {
@@ -87,14 +88,14 @@ class DeliveryAddressModel extends BaseModel {
 
   Future<List<DeliveryAddress>> getDeliveryAddresses(String userID) async {
     String path = "$delivery_address_collection/";
-    var querySnap = await Firestore.instance
+    var querySnap = await FirebaseFirestore.instance
         .collection('users')
-        .document("$userID")
+        .doc("$userID")
         .collection("$path")
         .orderBy("full_name")
-        .getDocuments();
-    return querySnap.documents
-        .map((e) => DeliveryAddress.fromMap(e.data, e.documentID))
+        .get();
+    return querySnap.docs
+        .map((e) => DeliveryAddress.fromMap(e.data as Map<String,dynamic>, e.id))
         .toList();
   }
 }
diff --git a/lib/pages/discount/discount_editor.dart b/lib/pages/discount/discount_editor.dart
index d967cb5..3b66baf 100644
--- a/lib/pages/discount/discount_editor.dart
+++ b/lib/pages/discount/discount_editor.dart
@@ -1,24 +1,22 @@
 import 'package:fcs/domain/entities/discount.dart';
-import 'package:fcs/domain/entities/user.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/localization/app_translations.dart';
 import 'package:fcs/pages/discount/model/discount_model.dart';
 import 'package:fcs/pages/main/util.dart';
-import 'package:fcs/pages/rates/model/shipment_rate_model.dart';
 import 'package:fcs/pages/user_search/user_serach.dart';
 import 'package:fcs/pages/widgets/display_text.dart';
 import 'package:fcs/pages/widgets/input_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:provider/provider.dart';
 
 class DiscountEditor extends StatefulWidget {
-  final Discount discount;
+  final Discount? discount;
 
-  const DiscountEditor({Key key, this.discount}) : super(key: key);
+  const DiscountEditor({Key? key, this.discount}) : super(key: key);
   @override
   _DiscountEditorState createState() => _DiscountEditorState();
 }
@@ -38,12 +36,12 @@ class _DiscountEditorState extends State<DiscountEditor> {
   void initState() {
     super.initState();
     if (widget.discount != null) {
-      _discount = widget.discount;
-      _codeController.text = _discount.code;
+      _discount = widget.discount!;
+      _codeController.text = _discount.code ?? "";
       _amountController.text = _discount.amount.toStringAsFixed(2);
-      _statusController.text = _discount.status;
-      customerName = widget.discount.customerName;
-      customerId = widget.discount.customerId;
+      _statusController.text = _discount.status ?? '';
+      customerName = _discount.customerName ?? "";
+      customerId = _discount.customerId ?? "";
     } else {
       _isNew = true;
     }
@@ -71,7 +69,7 @@ class _DiscountEditorState extends State<DiscountEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: customerName != null ? customerName : "",
+          text: customerName,
           labelTextKey: "discount.name",
           iconData: Feather.user,
         )),
@@ -79,8 +77,8 @@ class _DiscountEditorState extends State<DiscountEditor> {
             icon: Icon(Icons.search, color: primaryColor),
             onPressed: () => searchUser(context, onUserSelect: (u) {
                   setState(() {
-                    customerId = u.id;
-                    customerName = u.name;
+                    customerId = u.id ?? "";
+                    customerName = u.name ?? "";
                   });
                 },popPage: true)),
       ],
@@ -93,7 +91,7 @@ class _DiscountEditorState extends State<DiscountEditor> {
           appBar: AppBar(
             centerTitle: true,
             title: Text(
-              AppTranslations.of(context).text("discount.form"),
+              AppTranslations.of(context)!.text("discount.form"),
             ),
             leading: new IconButton(
               icon: new Icon(CupertinoIcons.back),
@@ -162,7 +160,7 @@ class _DiscountEditorState extends State<DiscountEditor> {
       if (_isNew) {
         await discountModel.addDiscount(_discount);
       } else {
-        _discount.id = widget.discount.id;
+        _discount.id = this._discount.id;
         await discountModel.updateDiscount(_discount);
       }
       Navigator.pop(context);
@@ -186,7 +184,7 @@ class _DiscountEditorState extends State<DiscountEditor> {
     });
     try {
       var discountModel = Provider.of<DiscountModel>(context, listen: false);
-      await discountModel.deleteDiscount(widget.discount);
+      await discountModel.deleteDiscount(_discount);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -208,7 +206,7 @@ class _DiscountEditorState extends State<DiscountEditor> {
           customerName: customerName,
           customerId: customerId,
           amount: double.parse(_amountController.text));
-      return widget.discount.isChangedForEdit(_discount);
+      return widget.discount!.isChangedForEdit(_discount);
     }
   }
 }
diff --git a/lib/pages/discount/discount_list.dart b/lib/pages/discount/discount_list.dart
index ca2845a..466f800 100644
--- a/lib/pages/discount/discount_list.dart
+++ b/lib/pages/discount/discount_list.dart
@@ -16,7 +16,7 @@ import 'discount_editor.dart';
 class DiscountList extends StatefulWidget {
   final bool selectionMode;
 
-  const DiscountList({Key key, this.selectionMode = false}) : super(key: key);
+  const DiscountList({Key? key, this.selectionMode = false}) : super(key: key);
   @override
   _DiscountListState createState() => _DiscountListState();
 }
@@ -62,7 +62,7 @@ class _DiscountListState extends State<DiscountList> {
         appBar: AppBar(
           centerTitle: true,
           title: Text(
-            AppTranslations.of(context).text("discount.title"),
+            AppTranslations.of(context)!.text("discount.title"),
           ),
           leading: new IconButton(
             icon: new Icon(CupertinoIcons.back),
diff --git a/lib/pages/discount/discount_list_row.dart b/lib/pages/discount/discount_list_row.dart
index 868905d..b2702b2 100644
--- a/lib/pages/discount/discount_list_row.dart
+++ b/lib/pages/discount/discount_list_row.dart
@@ -5,15 +5,15 @@ import 'package:fcs/pages/discount/discount_editor.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 typedef OnSelect(Discount discount);
 
 class DiscountListRow extends StatelessWidget {
-  final OnSelect onSelect;
-  final Discount discount;
-  DiscountListRow({Key key, this.discount, this.onSelect}) : super(key: key);
+  final OnSelect? onSelect;
+  final Discount? discount;
+  DiscountListRow({Key? key, this.discount, this.onSelect}) : super(key: key);
 
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
 
@@ -21,8 +21,8 @@ class DiscountListRow extends StatelessWidget {
   Widget build(BuildContext context) {
     return InkWell(
       onTap: () {
-        if (onSelect != null) {
-          onSelect(discount);
+        if (onSelect != null && discount != null) {
+        onSelect!(discount!);
         }
       },
       child: Container(
@@ -49,7 +49,7 @@ class DiscountListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              discount.code ?? "",
+                              discount?.code ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -57,7 +57,7 @@ class DiscountListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 10.0, top: 10),
                             child: new Text(
-                              discount.customerName ?? "",
+                              discount?.customerName ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.grey),
                             ),
@@ -73,14 +73,14 @@ class DiscountListRow extends StatelessWidget {
               children: <Widget>[
                 Padding(
                   padding: const EdgeInsets.all(0),
-                  child: Text(discount.status),
+                  child: Text(discount?.status ?? ''),
                 ),
                 Padding(
                   padding: const EdgeInsets.only(left: 8.0, top: 5, bottom: 5),
                   child: Row(
                     children: <Widget>[
                       new Text(
-                        "${discount.amount.toStringAsFixed(2) ?? ''}",
+                        "${discount?.amount.toStringAsFixed(2) ?? ''}",
                         style:
                             new TextStyle(fontSize: 15.0, color: Colors.grey),
                       ),
diff --git a/lib/pages/discount/model/discount_model.dart b/lib/pages/discount/model/discount_model.dart
index 5a25660..df50e03 100644
--- a/lib/pages/discount/model/discount_model.dart
+++ b/lib/pages/discount/model/discount_model.dart
@@ -11,13 +11,13 @@ import 'package:logging/logging.dart';
 class DiscountModel extends BaseModel {
   final log = Logger('DiscountModel');
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   List<Discount> _discounts = [];
   List<Discount> get discounts =>
       _selectedIndex == 1 ? _discounts : List<Discount>.from(_used.values);
 
-  Paginator _used;
+  late Paginator _used;
   bool isLoading = false;
   int _selectedIndex = 1;
   set selectedIndex(int index) {
@@ -25,14 +25,12 @@ class DiscountModel extends BaseModel {
     notifyListeners();
   }
 
-  get selectedIndex => _selectedIndex;
+  int get selectedIndex => _selectedIndex;
 
   initData() {
     _selectedIndex = 1;
     _load();
-
-    if (_used != null) _used.close();
-    _used = _getUsed();
+    if (_getUsed() != null) _used = _getUsed();
     _used.load();
   }
 
@@ -42,16 +40,16 @@ class DiscountModel extends BaseModel {
   }
 
   _load() {
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     try {
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("/$discounts_collection")
           .orderBy("code", descending: false)
           .snapshots()
           .listen((snaps) {
         _discounts.clear();
-        snaps.documents.forEach((d) {
-          _discounts.add(Discount.fromMap(d.data, d.documentID));
+        snaps.docs.forEach((d) {
+          _discounts.add(Discount.fromMap(d.data as Map<String,dynamic>, d.id));
         });
         notifyListeners();
       });
@@ -61,9 +59,9 @@ class DiscountModel extends BaseModel {
   }
 
   Paginator _getUsed() {
-    if (user == null || !user.hasFcsShipments()) return null;
+    if (user == null || !user!.hasFcsShipments()) throw "No Privilege";
 
-    var pageQuery = Firestore.instance
+    var pageQuery = FirebaseFirestore.instance
         .collection("/$discounts_collection")
         .where("status", isEqualTo: fcs_shipment_shipped_status)
         .orderBy("code", descending: false);
@@ -73,17 +71,17 @@ class DiscountModel extends BaseModel {
     return paginator;
   }
 
-  Future<List<Discount>> getDiscount(String userID) async {
+  Future<List<Discount?>?> getDiscount(String userID) async {
     String path = "/$discounts_collection";
     try {
-      var q = Firestore.instance
+      var q = FirebaseFirestore.instance
           .collection("$path")
           .where("customer_id", isEqualTo: userID)
           .where("status", isEqualTo: "available");
-      var snaps = await q.getDocuments(source: Source.server);
-      List<Discount> discounts = snaps.documents.map((snap) {
+      var snaps = await q.get(const GetOptions(source: Source.server));
+    var discounts = snaps.docs.map((snap) {
         if (snap.exists) {
-          var s = Discount.fromMap(snap.data, snap.documentID);
+          var s = Discount.fromMap(snap.data as Map<String,dynamic>, snap.id);
           return s;
         }
       }).toList();
@@ -113,7 +111,7 @@ class DiscountModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     if (_used != null) _used.close();
 
     _discounts = [];
@@ -128,6 +126,6 @@ class DiscountModel extends BaseModel {
   }
 
   Future<void> deleteDiscount(Discount discount) async {
-    return Services.instance.commonService.deleteDiscount(discount.id);
+    return Services.instance.commonService.deleteDiscount(discount.id!);
   }
 }
diff --git a/lib/pages/faq/faq_detail_page.dart b/lib/pages/faq/faq_detail_page.dart
index 8a4124f..d2bd99c 100644
--- a/lib/pages/faq/faq_detail_page.dart
+++ b/lib/pages/faq/faq_detail_page.dart
@@ -13,14 +13,14 @@ import 'package:provider/provider.dart';
 
 class FAQDetailPage extends StatefulWidget {
   final FAQ faq;
-  const FAQDetailPage({this.faq});
+  const FAQDetailPage({required this.faq});
   @override
   _FAQDetailPageState createState() => _FAQDetailPageState();
 }
 
 class _FAQDetailPageState extends State<FAQDetailPage> {
   bool _isLoading = false;
-  FAQ faq;
+  FAQ faq = new FAQ();
 
   intState() {
     super.initState();
@@ -28,7 +28,8 @@ class _FAQDetailPageState extends State<FAQDetailPage> {
 
   @override
   Widget build(BuildContext context) {
-    faq = context.select((FAQModel m) => m.getFAQ(widget.faq.id));
+    if(widget.faq.id != null)
+    faq = context.select((FAQModel m) => m.getFAQ(widget.faq.id!));
     if (faq == null) return Text("Deleted");
 
     bool isEditable = context.select((MainModel m) => m.faqEditable());
diff --git a/lib/pages/faq/faq_edit_page.dart b/lib/pages/faq/faq_edit_page.dart
index 73045be..d56471c 100644
--- a/lib/pages/faq/faq_edit_page.dart
+++ b/lib/pages/faq/faq_edit_page.dart
@@ -10,13 +10,13 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 const info = "Select additional page";
 
 class FAQEditor extends StatefulWidget {
-  final FAQ faq;
+  final FAQ? faq;
   const FAQEditor({this.faq});
   @override
   _FAQEditorState createState() => _FAQEditorState();
@@ -35,20 +35,22 @@ class _FAQEditorState extends State<FAQEditor> {
   bool _isLoading = false;
   bool _isNew = false;
   String _pageLink = info;
+  FAQ _faq = new FAQ();
 
   @override
   void initState() {
     super.initState();
     _isNew = widget.faq == null;
     if (widget.faq != null) {
-      _sn.text = widget.faq.sn.toString();
-      _engQ.text = widget.faq.questionEng;
-      _mmQ.text = widget.faq.questionMm;
-      _engA.text = widget.faq.answerEng;
-      _mmA.text = widget.faq.answerMm;
-      _pageLabelEng.text = widget.faq.pageLinkLabelEng;
-      _pageLabelMm.text = widget.faq.pageLinkLabelMm;
-      _pageLink = widget.faq.pageLink;
+      _faq = widget.faq!;
+      _sn.text = _faq.sn.toString();
+      _engQ.text = _faq.questionEng ?? "";
+      _mmQ.text = _faq.questionMm ?? '';
+      _engA.text = _faq.answerEng ?? '';
+      _mmA.text = _faq.answerMm ?? '';
+      _pageLabelEng.text = _faq.pageLinkLabelEng ?? "";
+      _pageLabelMm.text = _faq.pageLinkLabelMm ?? "";
+      _pageLink = _faq.pageLink ?? '';
     }
   }
 
@@ -89,7 +91,8 @@ class _FAQEditorState extends State<FAQEditor> {
         height: 2,
         color: primaryColor,
       ),
-      onChanged: (String newValue) {
+      onChanged: (String? newValue) {
+        if(newValue != null)
         setState(() {
           _pageLink = newValue;
         });
@@ -211,7 +214,7 @@ class _FAQEditorState extends State<FAQEditor> {
       if (_isNew) {
         await faqModel.addFAQ(_faq);
       } else {
-        _faq.id = widget.faq.id;
+        _faq.id = this._faq.id;
         await faqModel.updateFAQ(_faq);
       }
       Navigator.pop(context);
@@ -234,7 +237,7 @@ class _FAQEditorState extends State<FAQEditor> {
     });
     try {
       FAQModel faqModel = Provider.of<FAQModel>(context, listen: false);
-      await faqModel.deleteFAQ(widget.faq);
+      await faqModel.deleteFAQ(this._faq);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/faq/faq_list_page.dart b/lib/pages/faq/faq_list_page.dart
index 2c5ae2d..1e8bc36 100644
--- a/lib/pages/faq/faq_list_page.dart
+++ b/lib/pages/faq/faq_list_page.dart
@@ -1,14 +1,12 @@
 import 'package:fcs/domain/constants.dart';
 import 'package:fcs/domain/entities/faq.dart';
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/localization/app_translations.dart';
 import 'package:fcs/pages/buying_instruction/buying_online.dart';
 import 'package:fcs/pages/faq/faq_edit_page.dart';
 import 'package:fcs/pages/main/model/language_model.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
 import 'package:fcs/pages/payment_methods/payment_method_page.dart';
 import 'package:fcs/pages/rates/shipment_rates.dart';
-import 'package:fcs/pages/widgets/bottom_up_page_route.dart';
 import 'package:fcs/pages/widgets/fcs_expansion_tile.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:flutter/cupertino.dart';
@@ -26,8 +24,8 @@ class FAQListPage extends StatefulWidget {
 
 class _FAQListPageState extends State<FAQListPage>
     with SingleTickerProviderStateMixin {
-  AnimationController _controller;
-  Animation<double> _iconTurns;
+  AnimationController? _controller;
+  Animation<double>? _iconTurns;
 
   @override
   void initState() {
@@ -35,7 +33,7 @@ class _FAQListPageState extends State<FAQListPage>
     _controller = AnimationController(duration: _kExpand, vsync: this);
     var _halfTween = Tween<double>(begin: 0.0, end: 0.5);
     var _easeInTween = CurveTween(curve: Curves.easeIn);
-    _iconTurns = _controller.drive(_halfTween.chain(_easeInTween));
+    _iconTurns = _controller?.drive(_halfTween.chain(_easeInTween));
   }
 
   @override
@@ -139,7 +137,7 @@ class _FAQListPageState extends State<FAQListPage>
     );
   }
 
-  Widget _pageLink(String linkPage, String text) {
+  Widget _pageLink(String? linkPage, String? text) {
     return linkPage == null || linkPage == "" || text == null || text == ""
         ? Container()
         : Row(
diff --git a/lib/pages/faq/model/faq_model.dart b/lib/pages/faq/model/faq_model.dart
index ece61b7..cc43d41 100644
--- a/lib/pages/faq/model/faq_model.dart
+++ b/lib/pages/faq/model/faq_model.dart
@@ -12,22 +12,22 @@ class FAQModel extends BaseModel {
   List<FAQ> faqs = [];
 
   FAQ getFAQ(String id) {
-    return faqs.firstWhere((e) => e.id == id, orElse: () => null);
+    return faqs.firstWhere((e) => e.id == id, orElse: () => FAQ());
   }
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   FAQModel() {
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     try {
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("/faqs")
           .orderBy("sn", descending: false)
           .snapshots()
           .listen((snaps) {
         faqs.clear();
-        snaps.documents.forEach((d) {
-          faqs.add(FAQ.fromMap(d.data, d.documentID));
+        snaps.docs.forEach((d) {
+          faqs.add(FAQ.fromMap(d.data as Map<String,dynamic>, d.id));
         });
         notifyListeners();
       });
diff --git a/lib/pages/faq/widgets.dart b/lib/pages/faq/widgets.dart
index ba1c60a..a954882 100644
--- a/lib/pages/faq/widgets.dart
+++ b/lib/pages/faq/widgets.dart
@@ -7,14 +7,14 @@ Widget itemTitle(BuildContext context, String textKey) {
   return Padding(
     padding: const EdgeInsets.only(left: 18.0, top: 15, bottom: 0),
     child: Text(
-      AppTranslations.of(context).text(textKey),
+      AppTranslations.of(context)!.text(textKey),
       style: TextStyle(
           fontWeight: FontWeight.bold, fontSize: 18, color: Colors.black),
     ),
   );
 }
 
-Widget subItemTitle(BuildContext context, String textKey, {IconData iconData}) {
+Widget subItemTitle(BuildContext context, String textKey, {IconData? iconData}) {
   return Padding(
     padding: const EdgeInsets.only(left: 0, top: 0, bottom: 0),
     child: Row(
@@ -25,7 +25,7 @@ Widget subItemTitle(BuildContext context, String textKey, {IconData iconData}) {
         ),
         SizedBox(width: 10),
         Text(
-          AppTranslations.of(context).text(textKey),
+          AppTranslations.of(context)!.text(textKey),
           style: TextStyle(
               fontWeight: FontWeight.w700, fontSize: 15, color: primaryColor),
         ),
@@ -35,7 +35,7 @@ Widget subItemTitle(BuildContext context, String textKey, {IconData iconData}) {
 }
 
 Widget contactItem(BuildContext context, String text, IconData iconData,
-    {Function() onTap, String labelKey}) {
+    {Function()? onTap, String? labelKey}) {
   return Material(
     child: Padding(
       padding: const EdgeInsets.only(left: 18.0, bottom: 10, right: 18),
diff --git a/lib/pages/fcs_shipment/fcs_shipment_editor.dart b/lib/pages/fcs_shipment/fcs_shipment_editor.dart
index 82feb2e..0a48598 100644
--- a/lib/pages/fcs_shipment/fcs_shipment_editor.dart
+++ b/lib/pages/fcs_shipment/fcs_shipment_editor.dart
@@ -12,7 +12,7 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
@@ -20,7 +20,7 @@ import 'package:provider/provider.dart';
 import '../main/util.dart';
 
 class FcsShipmentEditor extends StatefulWidget {
-  final FcsShipment shipment;
+  final FcsShipment? shipment;
   FcsShipmentEditor({this.shipment});
 
   @override
@@ -40,7 +40,7 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
 
   FcsShipment _shipment = new FcsShipment();
   bool _isLoading = false;
-  String _currentShipmentType;
+  String? _currentShipmentType;
   bool _isNew = false;
 
   @override
@@ -48,20 +48,23 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
     super.initState();
     _isNew = widget.shipment == null;
     if (widget.shipment != null) {
-      _shipment = widget.shipment;
-      _shipmentNumberController.text = _shipment.shipmentNumber;
-      _cutoffDateController.text = dateFormatter.format(_shipment.cutoffDate);
-      _arrivalDateController.text = dateFormatter.format(_shipment.arrivalDate);
+      _shipment = widget.shipment!;
+      _shipmentNumberController.text = _shipment.shipmentNumber ?? "";
+      if(_shipment.cutoffDate != null)
+      _cutoffDateController.text = dateFormatter.format(_shipment.cutoffDate!);
+      if(_shipment.arrivalDate != null)
+      _arrivalDateController.text = dateFormatter.format(_shipment.arrivalDate!);
+      if(_shipment.departureDate != null)
       _departureDateControler.text =
-          dateFormatter.format(_shipment.departureDate);
-      _statusController.text = _shipment.status;
+          dateFormatter.format(_shipment.departureDate!);
+      _statusController.text = _shipment.status ?? "";
       _currentShipmentType = _shipment.shipType;
-      _consigneeController.text = _shipment.consignee;
-      _portController.text = _shipment.port;
-      _destinationController.text = _shipment.destination;
+      _consigneeController.text = _shipment.consignee ?? "";
+      _portController.text = _shipment.port ?? "";
+      _destinationController.text = _shipment.destination ?? "";
     } else {
       var mainModel = Provider.of<MainModel>(context, listen: false);
-      _currentShipmentType = mainModel.setting.shipmentTypes[0];
+      _currentShipmentType = mainModel.setting!.shipmentTypes[0];
     }
   }
 
@@ -143,13 +146,13 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
                   labelStyle: languageModel.isEng
                       ? newLabelStyle(color: Colors.black54, fontSize: 20)
                       : newLabelStyleMM(color: Colors.black54, fontSize: 20),
-                  labelText: AppTranslations.of(context)
+                  labelText: AppTranslations.of(context)!
                       .text('FCSshipment.shipment_type'),
                   icon: Icon(Ionicons.ios_airplane, color: primaryColor)),
-              items: mainModel.setting.shipmentTypes
+              items: mainModel.setting!.shipmentTypes
                   .map((e) => DropdownMenuItem(child: Text(e), value: e))
                   .toList(),
-              onChanged: (selected) => {
+              onChanged: (String? selected) => {
                 setState(() {
                   _currentShipmentType = selected;
                 })
@@ -188,7 +191,7 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
     FcsShipment fcsShipment = FcsShipment();
     fcsShipment.id = _shipment.id;
     fcsShipment.shipmentNumber = _shipmentNumberController.text;
-    fcsShipment.shipType = _currentShipmentType;
+    fcsShipment.shipType = _currentShipmentType!;
     fcsShipment.consignee = _consigneeController.text;
     fcsShipment.port = _portController.text;
     fcsShipment.destination = _destinationController.text;
@@ -197,9 +200,9 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
       var arrivalDate = _arrivalDateController.text;
       // var depDate = _departureDateControler.text;
       fcsShipment.cutoffDate =
-          cutoffDate == "" ? null : dateFormatter.parse(cutoffDate);
+          (cutoffDate == "" ? null : dateFormatter.parse(cutoffDate))!;
       fcsShipment.arrivalDate =
-          arrivalDate == "" ? null : dateFormatter.parse(arrivalDate);
+          (arrivalDate == "" ? null : dateFormatter.parse(arrivalDate))!;
       // fcsShipment.departureDate =
       //     depDate == "" ? null : dateFormatter.parse(depDate);
     } catch (e) {
@@ -285,10 +288,10 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
           _consigneeController.text != "" ||
           _portController.text != "" ||
           _destinationController.text != "" ||
-          _currentShipmentType != mainModel.setting.shipmentTypes[0];
+          _currentShipmentType != mainModel.setting!.shipmentTypes[0];
     } else {
       FcsShipment fcsShipment = _getPayload();
-      return widget.shipment.isChangedForEdit(fcsShipment);
+      return widget.shipment!.isChangedForEdit(fcsShipment);
     }
   }
 }
diff --git a/lib/pages/fcs_shipment/fcs_shipment_info.dart b/lib/pages/fcs_shipment/fcs_shipment_info.dart
index 091fe30..ffd7723 100644
--- a/lib/pages/fcs_shipment/fcs_shipment_info.dart
+++ b/lib/pages/fcs_shipment/fcs_shipment_info.dart
@@ -11,7 +11,7 @@ import 'package:fcs/pages/widgets/popupmenu.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
@@ -19,7 +19,7 @@ import 'package:provider/provider.dart';
 import 'fcs_shipment_editor.dart';
 
 class FcsShipmentInfo extends StatefulWidget {
-  final FcsShipment fcsShipment;
+  final FcsShipment? fcsShipment;
   FcsShipmentInfo({this.fcsShipment});
 
   @override
@@ -28,7 +28,7 @@ class FcsShipmentInfo extends StatefulWidget {
 
 class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
-  FcsShipment _fcsShipment;
+  FcsShipment? _fcsShipment;
   bool _isLoading = false;
   TextEditingController _shipmentNumberController = new TextEditingController();
   TextEditingController _cutoffDateController = new TextEditingController();
@@ -48,17 +48,20 @@ class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
   }
 
   _load() {
-    _shipmentNumberController.text = _fcsShipment.shipmentNumber;
-    _cutoffDateController.text = dateFormatter.format(_fcsShipment.cutoffDate);
+    _shipmentNumberController.text = _fcsShipment!.shipmentNumber ?? "";
+    if(_fcsShipment!.cutoffDate != null)
+    _cutoffDateController.text = dateFormatter.format(_fcsShipment!.cutoffDate!);
+  if(_fcsShipment!.arrivalDate != null)
     _arrivalDateController.text =
-        dateFormatter.format(_fcsShipment.arrivalDate);
+        dateFormatter.format(_fcsShipment!.arrivalDate!);
+        if(_fcsShipment!.departureDate != null)
     _departureDateControler.text =
-        dateFormatter.format(_fcsShipment.departureDate);
-    _shipmentTypeControler.text = _fcsShipment.shipType;
-    _consigneeController.text = _fcsShipment.consignee;
-    _portController.text = _fcsShipment.port;
-    _destinationController.text = _fcsShipment.destination;
-    _statusController.text = _fcsShipment.status;
+        dateFormatter.format(_fcsShipment!.departureDate!);
+    _shipmentTypeControler.text = _fcsShipment!.shipType ?? "";
+    _consigneeController.text = _fcsShipment!.consignee ?? "";
+    _portController.text = _fcsShipment!.port ?? "";
+    _destinationController.text = _fcsShipment!.destination ?? "";
+    _statusController.text = _fcsShipment!.status ?? "";
   }
 
   @override
@@ -166,7 +169,7 @@ class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
                   portBox,
                   destinationBox,
                   statusBox,
-                  _fcsShipment.status == fcs_shipment_confirmed_status
+                  _fcsShipment!.status == fcs_shipment_confirmed_status
                       ? shipBtn
                       : Container(),
                   SizedBox(
@@ -182,14 +185,16 @@ class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
   }
 
   _edit() async {
-    bool updated = await Navigator.push<bool>(
+    var f;
+    bool? updated = await Navigator.push<bool>(
       context,
       CupertinoPageRoute(
           builder: (context) => FcsShipmentEditor(shipment: _fcsShipment)),
     );
     if (updated ?? false) {
       var shipmentModel = Provider.of<FcsShipmentModel>(context, listen: false);
-      var f = await shipmentModel.getFcsShipment(_fcsShipment.id);
+      if(_fcsShipment != null && _fcsShipment!.id != null )
+       f = await shipmentModel.getFcsShipment(_fcsShipment!.id!);
       setState(() {
         _fcsShipment = f;
       });
@@ -238,7 +243,7 @@ class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
     try {
       FcsShipmentModel fcsShipmentModel =
           Provider.of<FcsShipmentModel>(context, listen: false);
-      await fcsShipmentModel.ship(_fcsShipment);
+      await fcsShipmentModel.ship(_fcsShipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -264,11 +269,11 @@ class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
       } else if (id == 4) {
         reportName = "manifest";
       }
-      _fcsShipment.reportName = reportName;
+      _fcsShipment!.reportName = reportName;
 
       FcsShipmentModel fcsShipmentModel =
           Provider.of<FcsShipmentModel>(context, listen: false);
-      String url = await fcsShipmentModel.report(_fcsShipment);
+      String url = await fcsShipmentModel.report(_fcsShipment!);
       Navigator.of(context).push(CupertinoPageRoute(
           builder: (context) => PDFScreen(
                 title: "",
diff --git a/lib/pages/fcs_shipment/fcs_shipment_list_row.dart b/lib/pages/fcs_shipment/fcs_shipment_list_row.dart
index 020b304..b16e410 100644
--- a/lib/pages/fcs_shipment/fcs_shipment_list_row.dart
+++ b/lib/pages/fcs_shipment/fcs_shipment_list_row.dart
@@ -3,14 +3,14 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'fcs_shipment_info.dart';
 
 class FcsShipmentListRow extends StatelessWidget {
-  final FcsShipment shipment;
+  final FcsShipment? shipment;
   final dateFormatter = new DateFormat('dd MMM yyyy');
-  FcsShipmentListRow({Key key, this.shipment}) : super(key: key);
+  FcsShipmentListRow({Key? key, this.shipment}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -43,9 +43,7 @@ class FcsShipmentListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              shipment.shipmentNumber == null
-                                  ? ''
-                                  : shipment.shipmentNumber,
+                              shipment?.shipmentNumber ?? '',
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -53,7 +51,7 @@ class FcsShipmentListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 10.0, top: 10),
                             child: new Text(
-                              dateFormatter.format(shipment.cutoffDate),
+                              dateFormatter.format(shipment!.cutoffDate!),
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.grey),
                             ),
@@ -67,7 +65,7 @@ class FcsShipmentListRow extends StatelessWidget {
             ),
             Padding(
               padding: const EdgeInsets.all(0),
-              child: getStatus(shipment.status),
+              child: getStatus(shipment!.status ?? ''),
             ),
           ],
         ),
diff --git a/lib/pages/fcs_shipment/model/fcs_shipment_model.dart b/lib/pages/fcs_shipment/model/fcs_shipment_model.dart
index aaf40a4..45d2141 100644
--- a/lib/pages/fcs_shipment/model/fcs_shipment_model.dart
+++ b/lib/pages/fcs_shipment/model/fcs_shipment_model.dart
@@ -11,13 +11,13 @@ import 'package:logging/logging.dart';
 class FcsShipmentModel extends BaseModel {
   final log = Logger('FcsShipmentModel');
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
   List<FcsShipment> _fcsShipments = [];
   List<FcsShipment> get fcsShipments => _selectedIndex == 1
       ? _fcsShipments
       : List<FcsShipment>.from(_shipped.values);
 
-  Paginator _shipped;
+  late Paginator _shipped;
   bool isLoading = false;
   int _selectedIndex = 1;
   set selectedIndex(int index) {
@@ -25,7 +25,7 @@ class FcsShipmentModel extends BaseModel {
     notifyListeners();
   }
 
-  get selectedIndex => _selectedIndex;
+ int get selectedIndex => _selectedIndex;
 
   @override
   void privilegeChanged() {
@@ -43,12 +43,12 @@ class FcsShipmentModel extends BaseModel {
   }
 
   Future<void> _loadFcsShipments() async {
-    if (user == null || !user.hasFcsShipments()) return;
+    if (user == null || !user!.hasFcsShipments()) throw "No Privilege";
     String path = "/$fcs_shipment_collection/";
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     _fcsShipments = [];
     try {
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("$path")
           .where("status", isEqualTo: fcs_shipment_confirmed_status)
           .where("is_deleted", isEqualTo: false)
@@ -56,9 +56,9 @@ class FcsShipmentModel extends BaseModel {
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         _fcsShipments.clear();
-        _fcsShipments = snapshot.documents.map((documentSnapshot) {
+        _fcsShipments = snapshot.docs.map((documentSnapshot) {
           var s = FcsShipment.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+              documentSnapshot.data as Map<String,dynamic>, documentSnapshot.id);
           return s;
         }).toList();
         notifyListeners();
@@ -69,9 +69,9 @@ class FcsShipmentModel extends BaseModel {
   }
 
   Paginator _getShipped() {
-    if (user == null || !user.hasFcsShipments()) return null;
+    if (user == null || !user!.hasFcsShipments()) throw "No Privilege";
 
-    var pageQuery = Firestore.instance
+    var pageQuery = FirebaseFirestore.instance
         .collection("/$fcs_shipment_collection")
         .where("status", isEqualTo: fcs_shipment_shipped_status)
         .where("is_deleted", isEqualTo: false)
@@ -102,13 +102,13 @@ class FcsShipmentModel extends BaseModel {
   Future<List<FcsShipment>> getActiveFcsShipments() async {
     List<FcsShipment> fcsShipments = [];
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection("/$fcs_shipment_collection")
           .where("status", isEqualTo: fcs_shipment_confirmed_status)
-          .getDocuments(source: Source.server);
-      fcsShipments = snaps.documents.map((documentSnapshot) {
+          .get(const GetOptions(source: Source.server));
+      fcsShipments = snaps.docs.map((documentSnapshot) {
         var fcs = FcsShipment.fromMap(
-            documentSnapshot.data, documentSnapshot.documentID);
+            documentSnapshot.data as Map<String,dynamic>, documentSnapshot.id);
         return fcs;
       }).toList();
     } catch (e) {
@@ -117,13 +117,13 @@ class FcsShipmentModel extends BaseModel {
     return fcsShipments;
   }
 
-  Future<FcsShipment> getFcsShipment(String id) async {
+  Future<FcsShipment?> getFcsShipment(String id) async {
     try {
-      var snap = await Firestore.instance
+      var snap = await FirebaseFirestore.instance
           .collection("/$fcs_shipment_collection")
-          .document(id)
-          .get(source: Source.server);
-      var fcs = FcsShipment.fromMap(snap.data, snap.documentID);
+          .doc(id)
+          .get(const GetOptions(source: Source.server));
+      var fcs = FcsShipment.fromMap(snap.data as Map<String,dynamic>, snap.id);
 
       return fcs;
     } catch (e) {
@@ -135,13 +135,13 @@ class FcsShipmentModel extends BaseModel {
   Future<List<FcsShipment>> getInvoiceFcsShipments() async {
     List<FcsShipment> fcsShipments = [];
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection("/$fcs_shipment_collection")
           .where("pending_invoice_user_count", isGreaterThan: 0)
-          .getDocuments(source: Source.server);
-      fcsShipments = snaps.documents.map((documentSnapshot) {
+          .get(const GetOptions(source: Source.server));
+      fcsShipments = snaps.docs.map((documentSnapshot) {
         var fcs = FcsShipment.fromMap(
-            documentSnapshot.data, documentSnapshot.documentID);
+            documentSnapshot.data as Map<String,dynamic>, documentSnapshot.id);
         return fcs;
       }).toList();
     } catch (e) {
@@ -156,7 +156,7 @@ class FcsShipmentModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     if (_shipped != null) _shipped.close();
     _fcsShipments = [];
   }
diff --git a/lib/pages/invoice/box_addition.dart b/lib/pages/invoice/box_addition.dart
index 5429589..805979f 100644
--- a/lib/pages/invoice/box_addition.dart
+++ b/lib/pages/invoice/box_addition.dart
@@ -8,7 +8,7 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 class BoxAddition extends StatefulWidget {
-  final Carton box;
+  final Carton? box;
   BoxAddition({this.box});
 
   @override
@@ -23,7 +23,7 @@ class _BoxAdditionState extends State<BoxAddition> {
   void initState() {
     super.initState();
     if (widget.box != null) {
-      _box = widget.box;
+      _box = widget.box!;
     }
   }
 
@@ -45,7 +45,7 @@ class _BoxAdditionState extends State<BoxAddition> {
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("box.edit.title")),
+          title: Text(AppTranslations.of(context)!.text("box.edit.title")),
         ),
         body: Card(
           child: Column(
@@ -54,7 +54,7 @@ class _BoxAdditionState extends State<BoxAddition> {
                   child: Padding(
                 padding: const EdgeInsets.all(10.0),
                 child: ListView(children: <Widget>[
-                  DropdownButtonFormField(
+                  DropdownButtonFormField<Object>(
                     decoration: InputDecoration(
                         fillColor: Colors.white,
                         labelText: 'Box Number',
diff --git a/lib/pages/invoice/editor/invoice_carton_table.dart b/lib/pages/invoice/editor/invoice_carton_table.dart
index 77f05ec..6faf7c8 100644
--- a/lib/pages/invoice/editor/invoice_carton_table.dart
+++ b/lib/pages/invoice/editor/invoice_carton_table.dart
@@ -9,11 +9,11 @@ import 'package:flutter/material.dart';
 typedef OnSelect = Function(Carton carton, bool checked);
 
 class InvoiceCartonTable extends StatelessWidget {
-  final List<Carton> cartons;
-  final OnSelect onSelect;
-  final Rate rate;
+  final List<Carton>? cartons;
+  final OnSelect? onSelect;
+  final Rate? rate;
 
-  const InvoiceCartonTable({Key key, this.cartons, this.onSelect, this.rate})
+  const InvoiceCartonTable({Key? key, this.cartons, this.onSelect, this.rate})
       : super(key: key);
 
   @override
@@ -36,27 +36,27 @@ class InvoiceCartonTable extends StatelessWidget {
 
     final rows = cartons == null
         ? [Container()]
-        : cartons.asMap().entries.map((p) {
+        : cartons!.asMap().entries.map((p) {
             return Container(
-              color: p.value.isChecked
+              color: p.value.isChecked!
                   ? Colors.grey.withOpacity(0.2)
-                  : Colors.grey[50].withOpacity(0.2),
+                  : Colors.grey.shade50.withOpacity(0.2),
               child: Container(
                 padding: EdgeInsets.only(
                     left: 0.0, right: 10.0, top: 3.0, bottom: 3.0),
                 decoration: BoxDecoration(
                   border: Border(
                     bottom: BorderSide(
-                        color: p.key == cartons.length - 1
+                        color: p.key == cartons!.length - 1
                             ? Colors.white
-                            : Colors.grey[350],
+                            : Colors.grey.shade300,
                         width: 1),
                   ),
                 ),
                 child: Row(
                   children: <Widget>[
                     onSelect == null
-                        ? p.value.isChecked
+                        ? p.value.isChecked!
                             ? SizedBox(
                                 child: Icon(Icons.check, color: primaryColor),
                                 width: 30)
@@ -64,15 +64,15 @@ class InvoiceCartonTable extends StatelessWidget {
                         : Checkbox(
                             value: p.value.isChecked,
                             activeColor: primaryColor,
-                            onChanged: (bool check) {
-                              if (onSelect != null) onSelect(p.value, check);
+                            onChanged: (bool? check) {
+                              if (onSelect != null) onSelect!(p.value, check!);
                             }),
                     Expanded(
                         child: Column(
                       crossAxisAlignment: CrossAxisAlignment.start,
                       children: [
                         Text(
-                          p.value.cartonNumber,
+                          p.value.cartonNumber!,
                           style: textStyle,
                         ),
                       ],
@@ -82,15 +82,15 @@ class InvoiceCartonTable extends StatelessWidget {
                         crossAxisAlignment: CrossAxisAlignment.start,
                         children: [
                           new Text(
-                            "${p.value?.length ?? ""} x ${p.value?.width ?? ""} x ${p.value?.height ?? ""}",
+                            "${p.value.length} x ${p.value.width} x ${p.value.height}",
                             style: textStyle,
                           ),
                           new Text(
-                            "${p.value?.getShipmentWeight(rate.volumetricRatio)?.toStringAsFixed(2) ?? "0"} lb",
+                            "${p.value.getShipmentWeight(rate!.volumetricRatio).toStringAsFixed(2)} lb",
                             style: textStyle,
                           ),
                           new Text(
-                            "${p.value?.actualWeight?.toStringAsFixed(2) ?? "0"} lb (Actual)",
+                            "${p.value.actualWeight.toStringAsFixed(2)} lb (Actual)",
                             style: textStyle,
                           ),
                         ],
diff --git a/lib/pages/invoice/editor/invoice_discount_list.dart b/lib/pages/invoice/editor/invoice_discount_list.dart
index 13ad897..a86a056 100644
--- a/lib/pages/invoice/editor/invoice_discount_list.dart
+++ b/lib/pages/invoice/editor/invoice_discount_list.dart
@@ -6,10 +6,10 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
 class InvoiceDiscountList extends StatelessWidget {
-  final List<Discount> discounts;
+  final List<Discount?>? discounts;
 
   const InvoiceDiscountList({
-    Key key,
+    Key? key,
     this.discounts,
   }) : super(key: key);
 
@@ -63,19 +63,19 @@ class InvoiceDiscountList extends StatelessWidget {
     if (discounts == null) {
       return [];
     }
-    var rows = discounts.map((c) {
+    var rows = discounts!.map((c) {
       return MyDataRow(
         onSelectChanged: (value) => Navigator.pop(context, c),
         cells: [
           MyDataCell(new Text(
-            c.code ?? "",
+            c?.code ?? '',
             style: textStyle,
           )),
           MyDataCell(
             Row(
               mainAxisAlignment: MainAxisAlignment.end,
               children: [
-                Text(c.amount?.toStringAsFixed(2) ?? "0", style: textStyle),
+                Text(c?.amount.toStringAsFixed(2) ?? "", style: textStyle),
               ],
             ),
           ),
diff --git a/lib/pages/invoice/editor/invoice_editor.dart b/lib/pages/invoice/editor/invoice_editor.dart
index 16f3420..99b5143 100644
--- a/lib/pages/invoice/editor/invoice_editor.dart
+++ b/lib/pages/invoice/editor/invoice_editor.dart
@@ -31,15 +31,15 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class InvoiceEditor extends StatefulWidget {
-  final Invoice invoice;
-  final User customer;
-  final FcsShipment fcsShipment;
+  final Invoice? invoice;
+  final User? customer;
+  final FcsShipment? fcsShipment;
   InvoiceEditor({this.invoice, this.customer, this.fcsShipment});
 
   @override
@@ -49,10 +49,10 @@ class InvoiceEditor extends StatefulWidget {
 class _InvoiceEditorState extends State<InvoiceEditor> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
 
-  Invoice _invoice;
+  Invoice? _invoice;
   bool _isLoading = false;
-  bool _isNew;
-  User _user;
+  bool _isNew = false;
+  User? _user;
 
   bool _showCartons = false;
   @override
@@ -91,36 +91,36 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
   _loadCartons() async {
     CartonModel cartonModel = Provider.of<CartonModel>(context, listen: false);
     List<Carton> cartons = await cartonModel.getCartonsForInvoice(
-        widget.fcsShipment.id, widget.customer.id);
+        widget.fcsShipment!.id!, widget.customer!.id!);
     cartons.forEach((c) {
       c.isChecked = true;
     });
     setState(() {
-      _invoice.cartons = cartons;
+      _invoice!.cartons = cartons;
     });
   }
 
   _loadShipments() async {
     ShipmentModel shipmentModel =
         Provider.of<ShipmentModel>(context, listen: false);
-    List<Shipment> shipments = await shipmentModel.getShipmentWithHandlingFee(
-        widget.fcsShipment.id, widget.customer.id);
-    shipments.forEach((s) {
-      s.isSelected = true;
+    List<Shipment?>? shipments = await shipmentModel.getShipmentWithHandlingFee(
+        widget.fcsShipment!.id!, widget.customer!.id!);
+    shipments!.forEach((s) {
+      s!.isSelected = true;
     });
     setState(() {
-      _invoice.shipments = shipments;
+      _invoice!.shipments = shipments;
     });
   }
 
-  List<Discount> discounts = [];
+  List<Discount?> discounts = [];
   _loadDiscount() async {
     DiscountModel discountModel =
         Provider.of<DiscountModel>(context, listen: false);
-    discounts = await discountModel.getDiscount(widget.customer.id);
+    discounts = (await discountModel.getDiscount(widget.customer!.id!))!;
     if (discounts != null && discounts.length > 0) {
       setState(() {
-        _invoice.discount = discounts.first;
+        _invoice!.discount = discounts.first;
       });
     }
   }
@@ -146,7 +146,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
         iconData: Icons.av_timer,
         labelTextKey: 'invoice.status');
     final cartonTable = InvoiceCartonTable(
-      cartons: _invoice.cartons,
+      cartons: _invoice!.cartons,
       rate: rate,
       onSelect: (c, checked) {
         setState(() {
@@ -157,30 +157,30 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
     final paymentTypesBox = LocalDropdown<PaymentMethod>(
       callback: (v) {
         setState(() {
-          _invoice.paymentMethod = v;
+          _invoice!.paymentMethod = v;
         });
       },
       labelKey: "invoice.payment_method",
       iconData: FontAwesome.money,
       display: (u) => u.name,
-      selectedValue: _invoice.paymentMethod,
+      selectedValue: _invoice!.paymentMethod,
       values: paymentMethodModel.paymentMethods,
     );
     final invoiceTableBox = InvoiceTable(
-      invoice: _invoice,
+      invoice: _invoice!,
       rate: rate,
       deliveryFeeSelected: (selected) {
         setState(() {
           if (selected) {
-            _invoice.deliveryFee = rate.deliveryFee;
+            _invoice!.deliveryFee = rate.deliveryFee;
           } else {
-            _invoice.deliveryFee = 0;
+            _invoice!.deliveryFee = 0;
           }
         });
       },
       discountSelected: (discount) {
         setState(() {
-          _invoice.discount = discount;
+          _invoice!.discount = discount;
         });
       },
       onRemove: (i) {
@@ -189,12 +189,12 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
         }
         if (i.invoiceDataType == InvoiceDataType.DiscountDataType) {
           setState(() {
-            _invoice.discount = null;
+            _invoice!.discount = new Discount();
           });
         }
         if (i.invoiceDataType == InvoiceDataType.DeliveryFeeType) {
           setState(() {
-            _invoice.deliveryFee = 0;
+            _invoice!.deliveryFee = 0;
           });
         }
         if (i.invoiceDataType == InvoiceDataType.HandlingFeeType) {
@@ -254,7 +254,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
           Shipment shipment = await Navigator.of(context).push(
               CupertinoPageRoute(
                   builder: (context) =>
-                      InvoiceHandlingFeeList(shipments: _invoice.shipments)));
+                      InvoiceHandlingFeeList(shipments: _invoice!.shipments)));
           _addShipment(shipment);
         } else if (p.id == 3) {
           Discount discount =
@@ -264,12 +264,12 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
                       )));
           if (discount != null) {
             setState(() {
-              _invoice.discount = discount;
+              _invoice!.discount = discount;
             });
           }
         } else if (p.id == 4) {
           setState(() {
-            _invoice.deliveryFee = rate.deliveryFee;
+            _invoice!.deliveryFee = rate.deliveryFee;
           });
         }
       },
@@ -281,7 +281,7 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
         Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
-            Text(dateFormatter.format(_invoice.invoiceDate)),
+            Text(dateFormatter.format(_invoice!.invoiceDate!)),
             SizedBox(
               height: 10,
             ),
@@ -371,8 +371,8 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
   _addCustom(CustomDuty customDuty) {
     if (customDuty == null) return;
     setState(() {
-      _invoice.customDuties.remove(customDuty);
-      _invoice.customDuties.add(customDuty);
+      _invoice!.customDuties.remove(customDuty);
+      _invoice!.customDuties.add(customDuty);
     });
   }
 
@@ -380,8 +380,8 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
     if (shipment == null) return;
     shipment.isSelected = true;
     setState(() {
-      _invoice.shipments.remove(shipment);
-      _invoice.shipments.add(shipment);
+      _invoice!.shipments!.remove(shipment);
+      _invoice!.shipments!.add(shipment);
     });
   }
 
@@ -389,30 +389,30 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
     if (shipment == null) return;
     shipment.isSelected = false;
     setState(() {
-      _invoice.shipments.remove(shipment);
-      _invoice.shipments.add(shipment);
+      _invoice!.shipments!.remove(shipment);
+      _invoice!.shipments!.add(shipment);
     });
   }
 
   _removeCustom(CustomDuty customDuty) {
     setState(() {
-      _invoice.customDuties.remove(customDuty);
+      _invoice!.customDuties.remove(customDuty);
     });
   }
 
   _save() async {
     var rateModel = Provider.of<ShipmentRateModel>(context, listen: false);
-    double amount = _invoice.getNetAmount(rateModel.rate);
-    if (_invoice.paymentMethod == null) {
+    double amount = _invoice!.getNetAmount(rateModel.rate);
+    if (_invoice!.paymentMethod == null) {
       showMsgDialog(context, "Error", "Payment method required");
       return;
     }
-    List<CargoType> cargoTypes = _invoice.getCargoTypes(rateModel.rate);
+    List<CargoType> cargoTypes = _invoice!.getCargoTypes(rateModel.rate);
     if (cargoTypes == null || cargoTypes.length == 0) {
       showMsgDialog(context, "Error", "Expected at least one cargo type");
       return;
     }
-    if ((amount ?? 0) <= 0) {
+    if ((amount ) <= 0) {
       showMsgDialog(context, "Error", "Expected positive amount");
       return;
     }
@@ -428,18 +428,18 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
       Invoice invoice = Invoice();
       invoice.cargoTypes = cargoTypes;
       invoice.amount = amount;
-      invoice.handlingFee = _invoice.getHandlingFee();
-      invoice.cartons = _invoice.cartons.where((c) => c.isChecked).toList();
+      invoice.handlingFee = _invoice!.getHandlingFee();
+      invoice.cartons = _invoice!.cartons.where((c) => c.isChecked!).toList();
       invoice.shipments =
-          _invoice.shipments.where((s) => s.isSelected).toList();
-      invoice.discount = _invoice.discount;
-      invoice.deliveryFee = _invoice.deliveryFee;
+          _invoice!.shipments!.where((s) => s!.isSelected).toList();
+      invoice.discount = _invoice!.discount;
+      invoice.deliveryFee = _invoice!.deliveryFee;
 
-      invoice.userID = widget.customer.id;
-      invoice.fcsShipmentID = widget.fcsShipment.id;
-      invoice.invoiceDate = _invoice.invoiceDate;
-      invoice.paymentMethod = _invoice.paymentMethod;
-      invoice.customDuties = _invoice.customDuties;
+      invoice.userID = widget.customer!.id;
+      invoice.fcsShipmentID = widget.fcsShipment!.id;
+      invoice.invoiceDate = _invoice!.invoiceDate;
+      invoice.paymentMethod = _invoice!.paymentMethod;
+      invoice.customDuties = _invoice!.customDuties;
 
       await invoiceModel.createInvoice(invoice);
       Navigator.pop(context, true);
diff --git a/lib/pages/invoice/editor/invoice_handling_fee_list.dart b/lib/pages/invoice/editor/invoice_handling_fee_list.dart
index 9e1af8b..75d6462 100644
--- a/lib/pages/invoice/editor/invoice_handling_fee_list.dart
+++ b/lib/pages/invoice/editor/invoice_handling_fee_list.dart
@@ -9,12 +9,12 @@ typedef OnAdd(Shipment shipment);
 typedef OnRemove(Shipment shipment);
 
 class InvoiceHandlingFeeList extends StatelessWidget {
-  final List<Shipment> shipments;
-  final OnAdd onAdd;
-  final OnRemove onRemove;
+  final List<Shipment?>? shipments;
+  final OnAdd? onAdd;
+  final OnRemove? onRemove;
 
   const InvoiceHandlingFeeList(
-      {Key key, this.shipments, this.onAdd, this.onRemove})
+      {Key? key, this.shipments, this.onAdd, this.onRemove})
       : super(key: key);
 
   @override
@@ -67,20 +67,19 @@ class InvoiceHandlingFeeList extends StatelessWidget {
     if (shipments == null) {
       return [];
     }
-    var rows = shipments.map((c) {
+    var rows = shipments!.map((c) {
       return MyDataRow(
         onSelectChanged: (value) => Navigator.pop(context, c),
         cells: [
           MyDataCell(new Text(
-            c.shipmentNumber ?? "",
+            c!.shipmentNumber!,
             style: textStyle,
           )),
           MyDataCell(
             Row(
               mainAxisAlignment: MainAxisAlignment.end,
               children: [
-                Text(c.handlingFee?.toStringAsFixed(2) ?? "0",
-                    style: textStyle),
+                Text(c.handlingFee.toStringAsFixed(2), style: textStyle),
                 onRemove == null
                     ? SizedBox(
                         width: 50,
@@ -91,7 +90,7 @@ class InvoiceHandlingFeeList extends StatelessWidget {
                           color: primaryColor,
                         ),
                         onPressed: () {
-                          if (onRemove != null) onRemove(c);
+                          if (onRemove != null) onRemove!(c);
                         })
               ],
             ),
diff --git a/lib/pages/invoice/invoice_customer_list.dart b/lib/pages/invoice/invoice_customer_list.dart
index dfa7a61..3df5226 100644
--- a/lib/pages/invoice/invoice_customer_list.dart
+++ b/lib/pages/invoice/invoice_customer_list.dart
@@ -11,9 +11,9 @@ import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class InvoiceCustomerList extends StatefulWidget {
-  final FcsShipment fcsShipment;
+  final FcsShipment? fcsShipment;
 
-  const InvoiceCustomerList({Key key, this.fcsShipment}) : super(key: key);
+  const InvoiceCustomerList({Key? key, this.fcsShipment}) : super(key: key);
 
   @override
   _InvoiceCustomerListState createState() => _InvoiceCustomerListState();
@@ -33,7 +33,7 @@ class _InvoiceCustomerListState extends State<InvoiceCustomerList> {
   _load() async {
     CustomerModel customerModel =
         Provider.of<CustomerModel>(context, listen: false);
-    var users = await customerModel.getInvoiceUsers(widget.fcsShipment.id);
+    var users = await customerModel.getInvoiceUsers(widget.fcsShipment!.id!);
     setState(() {
       _users = users;
     });
@@ -88,7 +88,7 @@ class _InvoiceCustomerListState extends State<InvoiceCustomerList> {
                   customer: customer,
                   fcsShipment: widget.fcsShipment,
                 )));
-        if (created ?? false) {
+        if (created) {
           _load();
         }
       },
@@ -125,7 +125,7 @@ class _InvoiceCustomerListState extends State<InvoiceCustomerList> {
                             Padding(
                               padding: const EdgeInsets.only(top: 2.0),
                               child: new Text(
-                                customer.name,
+                                customer.name!,
                                 style: new TextStyle(
                                     fontSize: 20.0, color: primaryColor),
                               ),
@@ -133,7 +133,7 @@ class _InvoiceCustomerListState extends State<InvoiceCustomerList> {
                             Padding(
                               padding: const EdgeInsets.only(top: 2.0),
                               child: new Text(
-                                customer.phoneNumber,
+                                customer.phoneNumber!,
                                 style: new TextStyle(
                                     fontSize: 15.0, color: Colors.grey),
                               ),
diff --git a/lib/pages/invoice/invoice_info.dart b/lib/pages/invoice/invoice_info.dart
index 8681798..d9980ec 100644
--- a/lib/pages/invoice/invoice_info.dart
+++ b/lib/pages/invoice/invoice_info.dart
@@ -20,8 +20,8 @@ import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class InvoiceInfo extends StatefulWidget {
-  final Invoice invoice;
-  final bool forCustomer;
+  final Invoice? invoice;
+  final bool? forCustomer;
   InvoiceInfo({this.invoice, this.forCustomer});
 
   @override
@@ -31,16 +31,16 @@ class InvoiceInfo extends StatefulWidget {
 class _InvoiceInfoState extends State<InvoiceInfo> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
 
-  Invoice _invoice;
+  Invoice? _invoice;
   bool _isLoading = false;
 
   bool _showCartons = false;
   @override
   void initState() {
     super.initState();
-    _invoice = widget.invoice;
-    _invoice.shipments?.forEach((s) {
-      s.isSelected = true;
+    _invoice = widget.invoice!;
+    _invoice!.shipments!.forEach((s) {
+      s!.isSelected = true;
     });
     _loadCartons();
   }
@@ -54,7 +54,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
       cartons.add(_carton);
     }
     setState(() {
-      _invoice.cartons = cartons;
+      _invoice!.cartons = cartons;
     });
   }
 
@@ -65,31 +65,31 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
 
   @override
   Widget build(BuildContext context) {
-    bool isCanceled = _invoice.status == invoice_cancel_status;
-    bool isPaid = _invoice.status == invoice_paid_status;
+    bool isCanceled = _invoice!.status == invoice_cancel_status;
+    bool isPaid = _invoice!.status == invoice_paid_status;
     var rateModel = Provider.of<ShipmentRateModel>(context);
     var rate = rateModel.rate;
 
     final cartonTable = InvoiceCartonTable(
-      cartons: _invoice.cartons,
+      cartons: _invoice!.cartons,
       rate: rate,
     );
 
     final invoiceTableBox = InvoiceTable(
-      invoice: _invoice,
+      invoice: _invoice!,
       rate: rate,
       deliveryFeeSelected: (selected) {
         setState(() {
           if (selected) {
-            _invoice.deliveryFee = rate.deliveryFee;
+            _invoice!.deliveryFee = rate.deliveryFee;
           } else {
-            _invoice.deliveryFee = 0;
+            _invoice!.deliveryFee = 0;
           }
         });
       },
       discountSelected: (discount) {
         setState(() {
-          _invoice.discount = discount;
+          _invoice!.discount = discount;
         });
       },
     );
@@ -118,7 +118,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
         Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
-            Text(dateFormatter.format(_invoice.invoiceDate)),
+            Text(dateFormatter.format(_invoice!.invoiceDate!)),
             SizedBox(
               height: 5,
             ),
@@ -140,7 +140,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
     );
     final paymentMethodBox = DisplayText(
       labelTextKey: "invoice.payment_method",
-      text: _invoice.paymentMethod.name,
+      text: _invoice!.paymentMethod!.name,
     );
 
     final cancelBtn = LocalButton(
@@ -166,7 +166,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
           padding: const EdgeInsets.all(8.0),
           child: ListView(
             children: <Widget>[
-              getInvoiceStatus(context, _invoice),
+              getInvoiceStatus(context, _invoice!),
               headerBox,
               _showCartons ? cartonTable : Container(),
               _showCartons
@@ -183,7 +183,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
               SizedBox(
                 height: 10,
               ),
-              isCanceled || isPaid || widget.forCustomer
+              isCanceled || isPaid || widget.forCustomer!
                   ? Container()
                   : cancelBtn,
             ],
@@ -206,7 +206,7 @@ class _InvoiceInfoState extends State<InvoiceInfo> {
       InvoiceModel invoiceModel =
           Provider.of<InvoiceModel>(context, listen: false);
 
-      await invoiceModel.cancelInvoice(_invoice);
+      await invoiceModel.cancelInvoice(_invoice!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/invoice/invoice_list.dart b/lib/pages/invoice/invoice_list.dart
index 6222180..cbb5ce3 100644
--- a/lib/pages/invoice/invoice_list.dart
+++ b/lib/pages/invoice/invoice_list.dart
@@ -12,9 +12,9 @@ import 'package:provider/provider.dart';
 import 'invoice_list_row.dart';
 
 class InvoiceList extends StatefulWidget {
-  final bool forCustomer;
+  final bool? forCustomer;
 
-  const InvoiceList({Key key, this.forCustomer}) : super(key: key);
+  const InvoiceList({Key? key, this.forCustomer}) : super(key: key);
   @override
   _InvoiceListState createState() => _InvoiceListState();
 }
@@ -29,13 +29,13 @@ class _InvoiceListState extends State<InvoiceList> {
     _controller.addListener(() async {
       if (_controller.position.pixels == _controller.position.maxScrollExtent) {
         Provider.of<InvoiceModel>(context, listen: false)
-            .loadMore(isCustomer: widget.forCustomer);
+            .loadMore(isCustomer: widget.forCustomer!);
       }
     });
 
     InvoiceModel invoiceModel =
         Provider.of<InvoiceModel>(context, listen: false);
-    invoiceModel.initData(widget.forCustomer, true, false);
+    invoiceModel.initData(widget.forCustomer!, true, false);
   }
 
   @override
@@ -66,13 +66,13 @@ class _InvoiceListState extends State<InvoiceList> {
         invoiceModel.selectedIndex = p.id;
         if (p.id == 2) {
           Provider.of<InvoiceModel>(context, listen: false)
-              .initData(widget.forCustomer, false, true);
+              .initData(widget.forCustomer!, false, true);
         } else if (p.id == 3) {
           Provider.of<InvoiceModel>(context, listen: false)
-              .initData(widget.forCustomer, true, false);
+              .initData(widget.forCustomer!, true, false);
         } else {
           Provider.of<InvoiceModel>(context, listen: false)
-              .initData(widget.forCustomer, true, false);
+              .initData(widget.forCustomer!, true, false);
         }
       }),
     );
@@ -93,7 +93,7 @@ class _InvoiceListState extends State<InvoiceList> {
                   color: Colors.white, fontSize: 20),
               actions: <Widget>[popupMenu],
             ),
-            floatingActionButton: widget.forCustomer
+            floatingActionButton: widget.forCustomer!
                 ? null
                 : FloatingActionButton.extended(
                     onPressed: () {
diff --git a/lib/pages/invoice/invoice_list_row.dart b/lib/pages/invoice/invoice_list_row.dart
index bc68360..2022362 100644
--- a/lib/pages/invoice/invoice_list_row.dart
+++ b/lib/pages/invoice/invoice_list_row.dart
@@ -12,9 +12,9 @@ import '../widgets/pdf_screen.dart';
 
 class InvoiceListRow extends StatelessWidget {
   final dateFormatter = new DateFormat('dd MMM yyyy');
-  final Invoice invoice;
-  final bool forCustomer;
-  InvoiceListRow({Key key, this.invoice, this.forCustomer}) : super(key: key);
+  final Invoice? invoice;
+  final bool? forCustomer;
+  InvoiceListRow({Key? key, this.invoice, this.forCustomer}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -22,8 +22,8 @@ class InvoiceListRow extends StatelessWidget {
       onTap: () {
         Navigator.of(context).push(CupertinoPageRoute(
             builder: (context) => PDFScreen(
-                  title: invoice.invoiceNumber,
-                  url: invoice.invoiceURL,
+                  title: invoice!.invoiceNumber,
+                  url: invoice!.invoiceURL,
                 )));
       },
       child: Row(
@@ -48,17 +48,19 @@ class InvoiceListRow extends StatelessWidget {
                         crossAxisAlignment: CrossAxisAlignment.start,
                         children: <Widget>[
                           new Text(
-                            invoice.invoiceNumber ?? "",
+                            invoice!.invoiceNumber ?? "",
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.black),
                           ),
                           new Text(
-                            invoice.status ?? "",
+                            invoice!.status ?? "",
                             style: new TextStyle(
                                 fontSize: 13.0, color: primaryColor),
                           ),
                           new Text(
-                            dateFormatter.format(invoice.invoiceDate),
+                            invoice!.invoiceDate != null
+                                ? dateFormatter.format(invoice!.invoiceDate!)
+                                : '',
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           )
@@ -70,7 +72,7 @@ class InvoiceListRow extends StatelessWidget {
               ),
             ),
           ),
-          invoice.status == invoice_issued_status
+          invoice!.status == invoice_issued_status
               ? Padding(
                   padding: const EdgeInsets.only(left: 10.0),
                   child: InkWell(
diff --git a/lib/pages/invoice/invoice_shipment_list_row.dart b/lib/pages/invoice/invoice_shipment_list_row.dart
index eb66ce6..a08a362 100644
--- a/lib/pages/invoice/invoice_shipment_list_row.dart
+++ b/lib/pages/invoice/invoice_shipment_list_row.dart
@@ -2,7 +2,7 @@ import 'package:fcs/domain/entities/fcs_shipment.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 import '../main/util.dart';
@@ -11,8 +11,8 @@ import 'invoice_customer_list.dart';
 typedef OnSelect(FcsShipment fcsShipment);
 
 class InvoiceShipmentListRow extends StatefulWidget {
-  final OnSelect onSelect;
-  final FcsShipment fcsShipment;
+  final OnSelect? onSelect;
+  final FcsShipment? fcsShipment;
   const InvoiceShipmentListRow({this.fcsShipment, this.onSelect});
 
   @override
@@ -28,7 +28,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
   void initState() {
     super.initState();
     if (widget.fcsShipment != null) {
-      _fcsShipment = widget.fcsShipment;
+      _fcsShipment = widget.fcsShipment!;
     }
   }
 
@@ -38,7 +38,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
       padding: EdgeInsets.only(left: 15, right: 15),
       child: InkWell(
         onTap: () {
-          if (widget.onSelect != null) widget.onSelect(widget.fcsShipment);
+          if (widget.onSelect != null) widget.onSelect!(widget.fcsShipment!);
         },
         child: Row(
           children: <Widget>[
@@ -64,7 +64,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
                             child: new Text(
                               _fcsShipment.shipmentNumber == null
                                   ? ''
-                                  : _fcsShipment.shipmentNumber,
+                                  : _fcsShipment.shipmentNumber!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -72,7 +72,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
                           Padding(
                             padding: const EdgeInsets.only(left: 10.0, top: 10),
                             child: new Text(
-                              dateFormatter.format(_fcsShipment.cutoffDate),
+                              dateFormatter.format(_fcsShipment.cutoffDate!),
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.grey),
                             ),
@@ -86,7 +86,7 @@ class _InvoiceShipmentListRowState extends State<InvoiceShipmentListRow> {
             ),
             Padding(
               padding: const EdgeInsets.all(0),
-              child: getStatus(_fcsShipment.status),
+              child: getStatus(_fcsShipment.status??"")
             ),
           ],
         ),
diff --git a/lib/pages/invoice/invoice_table.dart b/lib/pages/invoice/invoice_table.dart
index b25c222..77812dd 100644
--- a/lib/pages/invoice/invoice_table.dart
+++ b/lib/pages/invoice/invoice_table.dart
@@ -23,11 +23,11 @@ enum InvoiceDataType {
 
 class InvoiceTableRow {
   final dynamic data;
-  final String id;
-  final InvoiceDataType invoiceDataType;
-  final String desc;
-  final String rate;
-  final String amount;
+  final String? id;
+  final InvoiceDataType? invoiceDataType;
+  final String? desc;
+  final String? rate;
+  final String? amount;
 
   InvoiceTableRow(
       {this.id,
@@ -39,14 +39,14 @@ class InvoiceTableRow {
 }
 
 class InvoiceTable extends StatelessWidget {
-  final Invoice invoice;
-  final Rate rate;
-  final OnDiscountSelected discountSelected;
-  final OnDeliveryFeeSelected deliveryFeeSelected;
-  final OnRemove onRemove;
+  final Invoice? invoice;
+  final Rate? rate;
+  final OnDiscountSelected? discountSelected;
+  final OnDeliveryFeeSelected? deliveryFeeSelected;
+  final OnRemove? onRemove;
 
   const InvoiceTable(
-      {Key key,
+      {Key? key,
       this.invoice,
       this.discountSelected,
       this.deliveryFeeSelected,
@@ -61,7 +61,7 @@ class InvoiceTable extends StatelessWidget {
   List<InvoiceTableRow> getTableRows() {
     List<InvoiceTableRow> tableRows = [];
     // add cargo types
-    List<CargoType> _cargoTypes = invoice.getCargoTypes(rate) ?? [];
+    List<CargoType> _cargoTypes = invoice!.getCargoTypes(rate!);
     _cargoTypes.forEach((c) {
       tableRows.add(InvoiceTableRow(
           invoiceDataType: InvoiceDataType.CargoDataType,
@@ -70,16 +70,16 @@ class InvoiceTable extends StatelessWidget {
               "${c.calWeight.toStringAsFixed(2)} x ${c.calRate.toStringAsFixed(2)}",
           amount: "${c.calAmount.toStringAsFixed(2)}"));
     });
-    invoice.shipments.where((ss) => (ss.isSelected ?? false)).forEach((s) {
+    invoice!.shipments!.where((ss) => (ss!.isSelected )).forEach((s) {
       tableRows.add(InvoiceTableRow(
           data: s,
           invoiceDataType: InvoiceDataType.HandlingFeeType,
-          desc: "Handling fee\n${s.shipmentNumber}",
+          desc: "Handling fee\n${s!.shipmentNumber}",
           rate: "",
           amount: "${s.handlingFee.toStringAsFixed(2)}"));
     });
     // // add custom fee
-    invoice.customDuties.forEach((c) {
+    invoice!.customDuties.forEach((c) {
       tableRows.add(InvoiceTableRow(
           data: c,
           invoiceDataType: InvoiceDataType.CustomFeeDataType,
@@ -89,22 +89,22 @@ class InvoiceTable extends StatelessWidget {
     });
     // // add delivery fee
     tableRows.add(InvoiceTableRow(
-        data: invoice.deliveryFee == null || invoice.deliveryFee == 0
+        data: invoice!.deliveryFee == null || invoice!.deliveryFee == 0
             ? null
-            : invoice.deliveryFee,
+            : invoice!.deliveryFee,
         invoiceDataType: InvoiceDataType.DeliveryFeeType,
         desc: "Delivery fee",
         rate: "",
-        amount: "${invoice?.deliveryFee?.toStringAsFixed(2) ?? '0'}"));
+        amount: "${invoice?.deliveryFee.toStringAsFixed(2) ?? '0'}"));
 
     // // add discounts
-    if (invoice.discount != null) {
+    if (invoice!.discount != null) {
       tableRows.add(InvoiceTableRow(
-          data: invoice.discount,
+          data: invoice!.discount,
           invoiceDataType: InvoiceDataType.DiscountDataType,
           desc: "Discount\n${invoice?.discount?.code ?? ""}",
           rate: "",
-          amount: "(${invoice?.discount?.amount?.toStringAsFixed(2) ?? ''})"));
+          amount: "(${invoice?.discount?.amount.toStringAsFixed(2) ?? ''})"));
     }
 
     return tableRows;
@@ -132,7 +132,7 @@ class InvoiceTable extends StatelessWidget {
                     r.data == null || onRemove == null
                         ? Container()
                         : InkWell(
-                            onTap: () => onRemove(r),
+                            onTap: () => onRemove!(r),
                             child: Icon(
                               Icons.remove_circle,
                               color: Colors.black45,
@@ -217,7 +217,7 @@ class InvoiceTable extends StatelessWidget {
               ),
               SizedBox(width: 20),
               Text(
-                '\$ ${invoice.getNetAmount(rate).toStringAsFixed(2)}',
+                '\$ ${invoice!.getNetAmount(rate!).toStringAsFixed(2)}',
                 style: TextStyle(fontSize: 14, fontWeight: FontWeight.bold),
                 textAlign: TextAlign.end,
               )
diff --git a/lib/pages/invoice/model/invoice_model.dart b/lib/pages/invoice/model/invoice_model.dart
index f8f7758..e1d82ab 100644
--- a/lib/pages/invoice/model/invoice_model.dart
+++ b/lib/pages/invoice/model/invoice_model.dart
@@ -15,14 +15,14 @@ import 'package:path/path.dart' as Path;
 class InvoiceModel extends BaseModel {
   final log = Logger('InvoiceModel');
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot<Map<String, dynamic>>>? listener;
 
   List<Invoice> _invoices = [];
 
   List<Invoice> get invoices =>
       _selectedIndex == 1 ? _invoices : List<Invoice>.from(_paginator.values);
 
-  Paginator _paginator;
+  late Paginator _paginator;
 
   bool endOfPaidInvoices = false;
   bool isLoading = false;
@@ -33,7 +33,7 @@ class InvoiceModel extends BaseModel {
     notifyListeners();
   }
 
-  get selectedIndex => _selectedIndex;
+  int get selectedIndex => _selectedIndex;
 
   @override
   void privilegeChanged() {
@@ -52,26 +52,26 @@ class InvoiceModel extends BaseModel {
 
   Future<void> _loadInvoices(bool forCustomer) async {
     if (user == null) return;
-    if (!forCustomer && !user.hasInvoices()) return;
+    if (!forCustomer && !user!.hasInvoices()) return;
     String path = "/$invoices_collection";
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     _invoices = [];
 
     try {
-      var q = Firestore.instance
+      var q = FirebaseFirestore.instance
           .collection("$path")
           .where("status", isEqualTo: invoice_issued_status)
           .where("is_deleted", isEqualTo: false);
 
       if (forCustomer) {
-        q = q.where("user_id", isEqualTo: user.id);
+        q = q.where("user_id", isEqualTo: user!.id);
       }
 
       listener = q.snapshots().listen((QuerySnapshot snapshot) {
         _invoices.clear();
-        _invoices = snapshot.documents.map((documentSnapshot) {
-          var s = Invoice.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+        _invoices = snapshot.docs.map((documentSnapshot) {
+          var s = Invoice.fromMap(documentSnapshot.data as Map<String, dynamic>,
+              documentSnapshot.id);
           return s;
         }).toList();
         notifyListeners();
@@ -83,13 +83,13 @@ class InvoiceModel extends BaseModel {
 
   Paginator _getPaginator(bool isCustomer, bool isCanceled, bool isPaid) {
     if (!isCustomer) {
-      if (user == null || !(user.hasInvoices())) throw "No privilege";
+      if (user == null || !(user!.hasInvoices())) throw "No privilege";
     }
-    var pageQuery = Firestore.instance
+    var pageQuery = FirebaseFirestore.instance
         .collection("/$invoices_collection")
         .where("is_deleted", isEqualTo: false);
     if (isCustomer) {
-      pageQuery = pageQuery.where("user_id", isEqualTo: user.id);
+      pageQuery = pageQuery.where("user_id", isEqualTo: user!.id);
     }
     if (isCanceled) {
       pageQuery = pageQuery.where("status", isEqualTo: invoice_cancel_status);
@@ -105,7 +105,7 @@ class InvoiceModel extends BaseModel {
     return paginator;
   }
 
-  Future<void> loadMore({bool isCustomer}) async {
+  Future<void> loadMore({bool? isCustomer}) async {
     if (_paginator.ended || _selectedIndex == 1)
       return; // when paid menu is not selected return
     isLoading = true;
@@ -116,7 +116,7 @@ class InvoiceModel extends BaseModel {
     });
   }
 
-  Future<void> refresh({bool isCustomer}) async {
+  Future<void> refresh({bool? isCustomer}) async {
     if (_selectedIndex == 1) return; // when paid menu is not selected return
     await _paginator.refresh(onFinished: () {
       notifyListeners();
@@ -129,17 +129,17 @@ class InvoiceModel extends BaseModel {
 
   logout() async {
     if (_paginator != null) _paginator.close();
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     _invoices = [];
   }
 
-  Future<Invoice> getInvoice(String id) async {
+  Future<Invoice?> getInvoice(String id) async {
     String path = "/$invoices_collection";
     try {
-      var ref = Firestore.instance.collection("$path").document(id);
-      var snap = await ref.get(source: Source.server);
+      var ref = FirebaseFirestore.instance.collection("$path").doc(id);
+      var snap = await ref.get(const GetOptions(source: Source.server));
       if (snap.exists) {
-        var s = Invoice.fromMap(snap.data, snap.documentID);
+        var s = Invoice.fromMap(snap.data as Map<String, dynamic>, snap.id);
         return s;
       }
     } catch (e) {
@@ -149,7 +149,7 @@ class InvoiceModel extends BaseModel {
   }
 
   Future<void> pay(Payment payment, File file) async {
-    String path = Path.join(receipt_labels_files_path, user.id);
+    String path = Path.join(receipt_labels_files_path, user!.id);
     String url = await uploadStorage(path, file);
     payment.paymentReceiptURL = url;
     return Services.instance.invoiceService.pay(payment);
diff --git a/lib/pages/invoice/payment/payment_page.dart b/lib/pages/invoice/payment/payment_page.dart
index 680bec1..c17e966 100644
--- a/lib/pages/invoice/payment/payment_page.dart
+++ b/lib/pages/invoice/payment/payment_page.dart
@@ -20,8 +20,8 @@ import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class PaymentPage extends StatefulWidget {
-  final Invoice invoice;
-  final bool forCustomer;
+  final Invoice? invoice;
+  final bool? forCustomer;
   PaymentPage({this.invoice, this.forCustomer});
 
   @override
@@ -35,24 +35,24 @@ class _PaymentPageState extends State<PaymentPage> {
   Invoice _invoice = new Invoice();
   bool _isLoading = false;
 
-  bool isNew;
-  File _file;
-  bool _hasBalance;
+  bool isNew = false;
+  File? _file;
+  bool _hasBalance = false;
 
   @override
   void initState() {
     super.initState();
-    _invoice = widget.invoice;
-    _hasBalance = widget.invoice.balance > 0;
+    _invoice = widget.invoice!;
+    _hasBalance = widget.invoice!.balance > 0;
     _loadInvoice();
   }
 
   _loadInvoice() async {
     InvoiceModel invoiceModel =
         Provider.of<InvoiceModel>(context, listen: false);
-    Invoice i = await invoiceModel.getInvoice(_invoice.id);
+    Invoice? i = await invoiceModel.getInvoice(_invoice.id!);
     setState(() {
-      _invoice = i;
+      _invoice = i!;
     });
   }
 
@@ -97,7 +97,7 @@ class _PaymentPageState extends State<PaymentPage> {
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("pm_.title")),
+          title: Text(AppTranslations.of(context)!.text("pm_.title")),
         ),
         body: ListView(
           padding: const EdgeInsets.all(10.0),
@@ -129,76 +129,74 @@ class _PaymentPageState extends State<PaymentPage> {
   getCustomFeeRows(BuildContext context) {
     List<Widget> dataRow = [];
 
-    dataRow = _invoice?.payments?.map((p) {
-          return Container(
-            decoration: BoxDecoration(
-                border: Border(bottom: BorderSide(color: Colors.grey))),
-            padding: const EdgeInsets.only(
-                left: 5.0, right: 5.0, top: 5.0, bottom: 5.0),
-            child: Row(
-              children: [
-                Expanded(
-                    flex: 1,
+    dataRow = _invoice.payments.map((p) {
+      return Container(
+        decoration: BoxDecoration(
+            border: Border(bottom: BorderSide(color: Colors.grey))),
+        padding:
+            const EdgeInsets.only(left: 5.0, right: 5.0, top: 5.0, bottom: 5.0),
+        child: Row(
+          children: [
+            Expanded(
+                flex: 1,
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Padding(
+                      padding: const EdgeInsets.only(left: 8.0),
+                      child: Text(
+                          '${p.paymentDate != null ? dateFormatter.format(p.paymentDate!) : ""}'),
+                    ),
+                    SizedBox(
+                      height: 5,
+                    ),
+                    LocalImagePicker(
+                      key: ValueKey(p.id),
+                      enabled: false,
+                      initialImgUrl: p.paymentReceiptURL!,
+                      title: "Receipt",
+                      color: primaryColor,
+                    )
+                  ],
+                )),
+            Expanded(
+                flex: 1,
+                child: Center(
                     child: Column(
-                      crossAxisAlignment: CrossAxisAlignment.start,
-                      children: [
-                        Padding(
-                          padding: const EdgeInsets.only(left: 8.0),
-                          child: Text(
-                              '${p.paymentDate != null ? dateFormatter.format(p.paymentDate) : ""}'),
-                        ),
-                        SizedBox(
-                          height: 5,
-                        ),
-                        LocalImagePicker(
-                          key: ValueKey(p.id),
-                          enabled: false,
-                          initialImgUrl: p.paymentReceiptURL,
-                          title: "Receipt",
-                          color: primaryColor,
-                        )
-                      ],
-                    )),
-                Expanded(
+                  children: [Text('\$ ${p.amount}'), Text('${p.status}')],
+                ))),
+            widget.forCustomer!
+                ? Container()
+                : Expanded(
                     flex: 1,
-                    child: Center(
-                        child: Column(
-                      children: [Text('\$ ${p.amount}'), Text('${p.status}')],
-                    ))),
-                widget.forCustomer
-                    ? Container()
-                    : Expanded(
-                        flex: 1,
-                        child: Row(
-                          mainAxisAlignment: MainAxisAlignment.center,
-                          children: p.status == payment_pending_status
-                              ? [
-                                  InkWell(
-                                    onTap: () => _confirm(p),
-                                    child: Padding(
-                                      padding: const EdgeInsets.all(8.0),
-                                      child: Icon(
-                                        Icons.check,
-                                        color: primaryColor,
-                                      ),
-                                    ),
+                    child: Row(
+                      mainAxisAlignment: MainAxisAlignment.center,
+                      children: p.status == payment_pending_status
+                          ? [
+                              InkWell(
+                                onTap: () => _confirm(p),
+                                child: Padding(
+                                  padding: const EdgeInsets.all(8.0),
+                                  child: Icon(
+                                    Icons.check,
+                                    color: primaryColor,
                                   ),
-                                  InkWell(
-                                    onTap: () => _cancel(p),
-                                    child: Padding(
-                                      padding: const EdgeInsets.all(8.0),
-                                      child: Icon(Icons.close,
-                                          color: primaryColor),
-                                    ),
-                                  ),
-                                ]
-                              : [],
-                        )),
-              ],
-            ),
-          );
-        })?.toList() ??
-        [];
+                                ),
+                              ),
+                              InkWell(
+                                onTap: () => _cancel(p),
+                                child: Padding(
+                                  padding: const EdgeInsets.all(8.0),
+                                  child: Icon(Icons.close, color: primaryColor),
+                                ),
+                              ),
+                            ]
+                          : [],
+                    )),
+          ],
+        ),
+      );
+    }).toList();
 
     dataRow.insert(
         0,
@@ -217,7 +215,7 @@ class _PaymentPageState extends State<PaymentPage> {
                   child: Text('Amount',
                       textAlign: TextAlign.center,
                       style: TextStyle(color: Colors.grey))),
-              widget.forCustomer
+              widget.forCustomer!
                   ? Container()
                   : Expanded(
                       flex: 1,
@@ -250,11 +248,11 @@ class _PaymentPageState extends State<PaymentPage> {
                   flex: 1,
                   child: Center(
                       child: Text(
-                          '\$ ${widget.invoice.balance.toStringAsFixed(2)}',
+                          '\$ ${widget.invoice!.balance.toStringAsFixed(2)}',
                           textAlign: TextAlign.center,
                           style: TextStyle(
                               fontWeight: FontWeight.bold, fontSize: 16.0)))),
-              widget.forCustomer
+              widget.forCustomer!
                   ? Container()
                   : Expanded(
                       flex: 1,
@@ -279,7 +277,7 @@ class _PaymentPageState extends State<PaymentPage> {
   }
 
   _updatePayment(Payment payment) async {
-    payment.invoiceID = widget.invoice.id;
+    payment.invoiceID = widget.invoice!.id;
     setState(() {
       _isLoading = true;
     });
@@ -314,7 +312,7 @@ class _PaymentPageState extends State<PaymentPage> {
     try {
       InvoiceModel invoiceModel =
           Provider.of<InvoiceModel>(context, listen: false);
-      await invoiceModel.pay(payment, _file);
+      await invoiceModel.pay(payment, _file!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/invoice/payment/payment_page_edit.dart b/lib/pages/invoice/payment/payment_page_edit.dart
index f751dc3..098a354 100644
--- a/lib/pages/invoice/payment/payment_page_edit.dart
+++ b/lib/pages/invoice/payment/payment_page_edit.dart
@@ -20,7 +20,7 @@ import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class PaymentPageEdit extends StatefulWidget {
-  final Receipt receipt;
+  final Receipt? receipt;
   PaymentPageEdit({this.receipt});
 
   @override
@@ -33,14 +33,14 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
 
   Receipt _receipt = new Receipt();
   bool _isLoading = false;
-  File _file;
+  File? _file;
 
-  bool isNew;
+  bool isNew = false;
 
   @override
   void initState() {
     if (widget.receipt != null) {
-      _receipt = widget.receipt;
+      _receipt = widget.receipt!;
     }
     super.initState();
   }
@@ -154,7 +154,7 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("pm_.title")),
+          title: Text(AppTranslations.of(context)!.text("pm_.title")),
         ),
         body: Padding(
           padding: const EdgeInsets.all(8.0),
@@ -185,11 +185,11 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
       return initialImage();
     } else {
       Widget _widget;
-      if (widget.receipt.fileUrl == null) {
+      if (widget.receipt!.fileUrl == null) {
         _widget = initialImage();
       } else {
         _widget = InkWell(
-          child: Image.asset(widget.receipt.fileUrl, fit: BoxFit.cover),
+          child: Image.asset(widget.receipt!.fileUrl!, fit: BoxFit.cover),
           onTap: () {},
         );
       }
@@ -209,13 +209,13 @@ class _PaymentPageEditState extends State<PaymentPageEdit> {
 
   Widget enableUpload(BuildContext context) {
     return InkWell(
-      child: Image.file(_file, fit: BoxFit.cover),
+      child: Image.file(_file!, fit: BoxFit.cover),
       onTap: () {
         Navigator.push(
             context,
             MaterialPageRoute(
                 builder: (context) =>
-                    ShowImage(imageFile: _file, url: null, fileName: 'image')));
+                    ShowImage(imageFile: _file!, url: '', fileName: 'image')));
       },
     );
   }
diff --git a/lib/pages/main/home_page.dart b/lib/pages/main/home_page.dart
index 48080c8..1e1b88d 100644
--- a/lib/pages/main/home_page.dart
+++ b/lib/pages/main/home_page.dart
@@ -36,7 +36,7 @@ import 'package:fcs/pages/widgets/right_left_page_rout.dart';
 import 'package:fcs/pages/widgets/task_button.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:logging/logging.dart';
@@ -84,7 +84,7 @@ class _HomePageState extends State<HomePage> {
   }
 
   _loadStaffMode(bool isCustomer) async {
-    bool staffMode = await SharedPref.getStaffMode();
+    bool? staffMode = await SharedPref.getStaffMode();
     setState(() {
       if (isCustomer) {
         isFcs[0] = false;
@@ -94,7 +94,7 @@ class _HomePageState extends State<HomePage> {
     });
   }
 
-  String notiUserID, notiUserName;
+  late String notiUserID, notiUserName;
   _showNotiContent(Map<String, dynamic> message) {
     try {
       Map<String, dynamic> map = Map<String, dynamic>.from(message["data"]);
@@ -117,12 +117,12 @@ class _HomePageState extends State<HomePage> {
     if (mainModel.isLogin()) {
       timer.cancel();
       bool isCustomer = mainModel.isCustomer();
-      String receiverID = isCustomer ? mainModel.user.id : notiUserID;
-      String receiverName = isCustomer ? mainModel.user.name : notiUserName;
+      String? receiverID = isCustomer ? mainModel.user?.id : notiUserID;
+      String? receiverName = isCustomer ? mainModel.user?.name : notiUserName;
       MessageModel messageModel =
           Provider.of<MessageModel>(context, listen: false);
       messageModel.initQuery(receiverID);
-      User user = mainModel.user;
+      User user = mainModel.user!;
       if (!isCustomer) {
         CustomerModel customerModel =
             Provider.of<CustomerModel>(context, listen: false);
@@ -133,15 +133,15 @@ class _HomePageState extends State<HomePage> {
           MaterialPageRoute(
               builder: (context) => MessageDetail(
                     messageModel: messageModel,
-                    receiverID: receiverID,
-                    receiverName: receiverName,
+                    receiverID: receiverID ?? "",
+                    receiverName: receiverName ?? "",
                   ))).then((value) {
         if (user.userUnseenCount > 0) {
-          messageModel.seenMessages(user.id, true);
+          messageModel.seenMessages(user.id ?? "", true);
         }
       });
       if (user.userUnseenCount > 0) {
-        messageModel.seenMessages(user.id, true);
+        messageModel.seenMessages(user.id ?? "", true);
       }
     }
   }
@@ -151,7 +151,7 @@ class _HomePageState extends State<HomePage> {
         new AndroidInitializationSettings('@mipmap/ic_launcher');
     var initializationSettingsIOS = new IOSInitializationSettings();
     var initializationSettings = new InitializationSettings(
-        initializationSettingsAndroid, initializationSettingsIOS);
+        android: initializationSettingsAndroid, iOS: initializationSettingsIOS);
     _flutterLocalNotificationsPlugin.initialize(initializationSettings);
   }
 
@@ -179,13 +179,15 @@ class _HomePageState extends State<HomePage> {
         'your channel id', 'your channel name', 'your channel description',
         playSound: true,
         enableVibration: true,
-        importance: Importance.Max,
-        priority: Priority.High);
+        importance: Importance.max,
+        priority: Priority.high);
+
     // @formatter:on
     var platformChannelSpecificsIos =
         new IOSNotificationDetails(presentSound: true);
     var platformChannelSpecifics = new NotificationDetails(
-        platformChannelSpecificsAndroid, platformChannelSpecificsIos);
+        android: platformChannelSpecificsAndroid,
+        iOS: platformChannelSpecificsIos);
 
     new Future.delayed(Duration.zero, () {
       _flutterLocalNotificationsPlugin.show(
@@ -204,7 +206,7 @@ class _HomePageState extends State<HomePage> {
 
   @override
   Widget build(BuildContext context) {
-    User user = Provider.of<MainModel>(context).user;
+    User? user = Provider.of<MainModel>(context).user;
 
     if (user == null) {
       Future.microtask(
@@ -280,18 +282,18 @@ class _HomePageState extends State<HomePage> {
       ))
           .then((value) {
         if (user.userUnseenCount > 0) {
-          messageModel.seenMessages(user.id, true);
+          messageModel.seenMessages(user.id ?? "", true);
         }
       });
       if (user.userUnseenCount > 0) {
-        messageModel.seenMessages(user.id, true);
+        messageModel.seenMessages(user.id ?? "", true);
       }
     });
     final notiBtn = badgeCounter(notiBtnOrg, user.userUnseenCount);
 
     final staffBtn = TaskButton(
       "staff.title",
-      icon: MaterialCommunityIcons.worker,
+      icon: MaterialCommunityIcons.account_tie,
       btnCallback: () => Navigator.of(context).push<void>(CupertinoPageRoute(
         builder: (context) => StaffList(),
       )),
@@ -350,7 +352,7 @@ class _HomePageState extends State<HomePage> {
       selectedColor: Colors.white,
       color: Colors.blue,
       children: <Widget>[
-        Icon(MaterialCommunityIcons.worker),
+        Icon(MaterialCommunityIcons.account_tie),
       ],
       onPressed: (i) => this.setState(() {
         isFcs[0] = !isFcs[0];
@@ -531,7 +533,7 @@ class _HomePageState extends State<HomePage> {
       String term = _searchCtl.text;
       if (term == null || term.trim() == "") return;
       var packageModel = Provider.of<PackageModel>(context, listen: false);
-      Package package = await packageModel.lookupPackage(term);
+      Package? package = await packageModel.lookupPackage(term);
       if (package == null) {
         showMsgDialog(context, "Not found", "Tracking ID - '$term' not found!");
         return;
diff --git a/lib/pages/main/initial_language_selection.dart b/lib/pages/main/initial_language_selection.dart
index 7d6a018..7ce4cfe 100644
--- a/lib/pages/main/initial_language_selection.dart
+++ b/lib/pages/main/initial_language_selection.dart
@@ -3,7 +3,6 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/localization/transalation.dart';
 import 'package:fcs/pages/main/model/language_model.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
-import 'package:fcs/pages/signin/signin_page.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/material.dart';
@@ -27,9 +26,9 @@ class _InitialLanguageSelectionPageState
     languagesList[1]: languageCodesList[1],
   };
 
-  String selectedLanguage;
-  int selectedIndex;
-  bool _isLoading;
+  String selectedLanguage = 'en';
+  late int selectedIndex;
+  bool _isLoading = false;
 
   @override
   void initState() {
@@ -102,8 +101,8 @@ class _InitialLanguageSelectionPageState
                                   ? BoxDecoration()
                                   : BoxDecoration(
                                       border: Border(
-                                        bottom:
-                                            BorderSide(color: Colors.grey[300]),
+                                        bottom: BorderSide(
+                                            color: Colors.grey.shade300),
                                       ),
                                     ),
                               child: ListTile(
@@ -134,7 +133,7 @@ class _InitialLanguageSelectionPageState
                                     child: Radio(
                                       value: key,
                                       groupValue: selectedIndex,
-                                      onChanged: (int i) =>
+                                      onChanged: (int? i) =>
                                           _select(key, language),
                                       activeColor: primaryColor,
                                     ),
diff --git a/lib/pages/main/model/base_model.dart b/lib/pages/main/model/base_model.dart
index a0b82d0..a5cbc4f 100644
--- a/lib/pages/main/model/base_model.dart
+++ b/lib/pages/main/model/base_model.dart
@@ -6,9 +6,9 @@ import 'package:fcs/helpers/api_helper.dart';
 import 'main_model.dart';
 
 abstract class BaseModel extends ChangeNotifier {
-  User user;
-  Setting setting;
-  MainModel mainModel;
+  User? user;
+  Setting? setting;
+  MainModel? mainModel;
 
   void initUser(User user) async {
     this.user = user;
@@ -16,7 +16,7 @@ abstract class BaseModel extends ChangeNotifier {
 
   void privilegeChanged() {}
 
-  void initSetting(Setting setting) async {
+  void initSetting(Setting? setting) async {
     this.setting = setting;
   }
 
@@ -32,8 +32,8 @@ abstract class BaseModel extends ChangeNotifier {
     String path,
     method, {
     dynamic payload,
-    String token,
-    String url,
+    required String token,
+    String? url,
   }) async {
     return await requestAPI(path, method,
         payload: payload, token: token, url: url);
diff --git a/lib/pages/main/model/language_model.dart b/lib/pages/main/model/language_model.dart
index b6bd04c..5be6d4e 100644
--- a/lib/pages/main/model/language_model.dart
+++ b/lib/pages/main/model/language_model.dart
@@ -5,7 +5,7 @@ import 'package:flutter/painting.dart';
 import 'base_model.dart';
 
 class LanguageModel extends BaseModel {
-  String language;
+  late String language;
   bool get isEng => this.language == "English";
   List<bool> get currentState => isEng ? [true, false] : [false, true];
 
diff --git a/lib/pages/main/model/main_model.dart b/lib/pages/main/model/main_model.dart
index 5f2180e..67a963b 100644
--- a/lib/pages/main/model/main_model.dart
+++ b/lib/pages/main/model/main_model.dart
@@ -15,16 +15,16 @@ class MainModel extends ChangeNotifier {
   final log = Logger('MainModel');
   List<BaseModel> models = [];
 
-  String messagingToken;
-  User user;
-  PackageInfo packageInfo;
+  String? messagingToken;
+  User? user;
+  PackageInfo? packageInfo;
 
   set setMessaginToken(token) {
     this.messagingToken = token;
     uploadMsgToken();
   }
 
-  Setting setting;
+  Setting? setting;
 
   bool isLoaded = false;
   bool isOnline = false;
@@ -42,23 +42,23 @@ class MainModel extends ChangeNotifier {
   }
 
   bool faqEditable() {
-    return this.user != null && this.user.hasSupport();
+    return this.user != null && this.user!.hasSupport();
   }
 
   bool rateEditable() {
-    return this.user != null && this.user.hasSupport();
+    return this.user != null && this.user!.hasSupport();
   }
 
   bool paymentMethodsEditable() {
-    return this.user != null && this.user.hasSupport();
+    return this.user != null && this.user!.hasSupport();
   }
 
   bool termEditable() {
-    return this.user != null && this.user.hasSupport();
+    return this.user != null && this.user!.hasSupport();
   }
 
   bool contactEditable() {
-    return this.user != null && this.user.hasSupport();
+    return this.user != null && this.user!.hasSupport();
   }
 
   bool isLogin() {
@@ -66,32 +66,31 @@ class MainModel extends ChangeNotifier {
   }
 
   bool isCustomer() {
-    return user != null && user.isCustomer();
+    return user != null && user!.isCustomer();
   }
 
   bool isSysAdmin() {
-    return this.user != null && this.user.hasSysAdmin();
+    return this.user != null && this.user!.hasSysAdmin();
   }
 
   bool isAdmin() {
-    return this.user != null && this.user.hasAdmin();
+    return this.user != null && this.user!.hasAdmin();
   }
 
   // userListener should never be closed
-  StreamSubscription<User> userListener;
+  StreamSubscription<User?>? userListener;
   _init() async {
     await _listenSetting();
-    this.isFirstLaunch = await SharedPref.isFirstLaunch();
-    this.isFirstLaunch = this.isFirstLaunch ?? true;
+    this.isFirstLaunch = await SharedPref.isFirstLaunch() ?? true;
     this.packageInfo = await PackageInfo.fromPlatform();
 
-    if (userListener != null) userListener.cancel();
+    if (userListener != null) userListener!.cancel();
     userListener =
         Services.instance.authService.getUserStream().listen((_user) {
       if (_user != null) {
         models.forEach((m) => m.initUser(_user));
         // call diffPrivileges if privilege changed or first time login
-        if (this.user == null || _user.diffPrivileges(this.user)) {
+        if (this.user == null || _user.diffPrivileges(this.user!)) {
           models.forEach((m) => m.privilegeChanged());
         }
         if (this.user == null) {
@@ -124,7 +123,7 @@ class MainModel extends ChangeNotifier {
 
   bool isSupport() {
     if (packageInfo == null || setting == null) return false;
-    return int.parse(packageInfo.buildNumber) >= setting.supportBuildNum;
+    return int.parse(packageInfo!.buildNumber) >= setting!.supportBuildNum;
   }
 
   Future<AuthResult> sendSms(String phoneNumber) {
@@ -137,14 +136,14 @@ class MainModel extends ChangeNotifier {
     return authResult;
   }
 
-  Future<void> uploadMsgToken() {
+  Future<void>? uploadMsgToken() {
     if (messagingToken == null || user == null) return null;
-    return Services.instance.userService.uploadMsgToken(messagingToken);
+    return Services.instance.userService.uploadMsgToken(messagingToken!);
   }
 
-  Future<void> removeMsgToken() {
+  Future<void>? removeMsgToken() {
     if (messagingToken == null || user == null) return null;
-    return Services.instance.userService.removeMsgToken(messagingToken);
+    return Services.instance.userService.removeMsgToken(messagingToken!);
   }
 
   Future<void> signout() async {
diff --git a/lib/pages/main/splash_page.dart b/lib/pages/main/splash_page.dart
index eb5edfb..e719e5b 100644
--- a/lib/pages/main/splash_page.dart
+++ b/lib/pages/main/splash_page.dart
@@ -18,7 +18,7 @@ class _SplashScreenState extends State<SplashScreen> {
   bool _loaded = false;
   bool _isSupport = false;
   bool _isOnline = true;
-  Timer timer;
+  late Timer timer;
 
   startTime() async {
     var _duration = new Duration(milliseconds: 3000);
diff --git a/lib/pages/main/util.dart b/lib/pages/main/util.dart
index a6ccd3f..277bfe1 100644
--- a/lib/pages/main/util.dart
+++ b/lib/pages/main/util.dart
@@ -33,7 +33,7 @@ Future showMsgDialog(BuildContext context, String title, String msg) {
 
 Future<void> showConfirmDialog(
     BuildContext context, String translationKey, ok(),
-    {List<String> translationVariables}) async {
+    {List<String>? translationVariables}) async {
   await showDialog(
       context: context,
       builder: (_) {
@@ -42,7 +42,7 @@ Future<void> showConfirmDialog(
             child: LocalText(
               context,
               translationKey,
-              translationVariables: translationVariables,
+              translationVariables: translationVariables!,
               color: primaryColor,
             ),
           ),
@@ -54,7 +54,7 @@ Future<void> showConfirmDialog(
                 FlatButton(
                     color: Colors.grey[300],
                     child: Text(
-                      AppTranslations.of(context).text('btn.cancel'),
+                      AppTranslations.of(context)!.text('btn.cancel'),
                       style: Provider.of<LanguageModel>(context).isEng
                           ? TextStyle()
                           : TextStyle(fontFamily: 'Myanmar3'),
@@ -67,7 +67,7 @@ Future<void> showConfirmDialog(
                 ),
                 FlatButton(
                     color: primaryColor,
-                    child: Text(AppTranslations.of(context).text('btn.ok'),
+                    child: Text(AppTranslations.of(context)!.text('btn.ok'),
                         style: Provider.of<LanguageModel>(context).isEng
                             ? TextStyle(
                                 color: Colors.white,
@@ -188,7 +188,7 @@ Widget getStatus(String status) {
                                               ],
                                             )
                                           : Text(
-                                              status ?? "",
+                                              status,
                                               style: TextStyle(
                                                   color: primaryColor,
                                                   fontSize: 18,
@@ -230,10 +230,10 @@ Widget phoneWidget(BuildContext context, String phone) {
 }
 
 Widget fcsInput(String label, IconData iconData,
-    {TextEditingController controller,
-    String value,
+    {required TextEditingController controller,
+    required String value,
     bool autoFocus = false,
-    TextInputType textInputType}) {
+    TextInputType? textInputType}) {
   return TextFormField(
       initialValue: value,
       controller: controller,
@@ -257,7 +257,7 @@ Widget fcsInput(String label, IconData iconData,
 }
 
 Widget fcsInputReadOnly(String label, IconData iconData,
-    {TextEditingController controller, String value}) {
+    {required TextEditingController controller, required String value}) {
   return TextFormField(
       initialValue: value,
       controller: controller,
@@ -279,7 +279,7 @@ Widget fcsInputReadOnly(String label, IconData iconData,
 }
 
 Widget fcsDropDown(String label, IconData iconData,
-    {TextEditingController controller}) {
+    {required TextEditingController controller}) {
   return Row(
     children: <Widget>[
       Padding(
@@ -308,7 +308,7 @@ Widget _dropDown() {
       height: 2,
       color: primaryColor,
     ),
-    onChanged: (String newValue) {},
+    onChanged: (String? newValue) {},
     items: <String>['Ko Nge', 'Two', 'Free', 'Four']
         .map<DropdownMenuItem<String>>((String value) {
       return DropdownMenuItem<String>(
@@ -320,7 +320,7 @@ Widget _dropDown() {
 }
 
 Widget fcsButton(BuildContext context, String text,
-    {Function callack, IconData iconData}) {
+    {Function? callack, IconData? iconData}) {
   var languageModel = Provider.of<LanguageModel>(context);
 
   var style = languageModel.isEng
@@ -344,7 +344,7 @@ Widget fcsButton(BuildContext context, String text,
         minWidth: 900.0,
         height: 100.0,
         child: FlatButton(
-          onPressed: callack,
+          onPressed: callack == null ? null : () => callack(),
           child: Row(
             mainAxisAlignment: MainAxisAlignment.center,
             children: [
@@ -367,11 +367,11 @@ Widget fcsButton(BuildContext context, String text,
 }
 
 String getLocalString(BuildContext context, String key) {
-  return AppTranslations.of(context).text(key);
+  return AppTranslations.of(context)!.text(key);
 }
 
 void showToast(GlobalKey key, String text) {
-  final ScaffoldState scaffold = key.currentState;
+  final ScaffoldState scaffold = key.currentState as ScaffoldState;
   scaffold.showSnackBar(
     SnackBar(
       content: Text(text),
diff --git a/lib/pages/main/welcome_page.dart b/lib/pages/main/welcome_page.dart
index df39162..c7ca5e5 100644
--- a/lib/pages/main/welcome_page.dart
+++ b/lib/pages/main/welcome_page.dart
@@ -24,7 +24,7 @@ typedef BtnCallback();
 class _WelcomePageState extends State<WelcomePage> {
   final log = Logger('_HomePageWelcomeState');
 
-  String pin;
+  late String pin;
   List<bool> isSelected = [true, false];
 
   @override
diff --git a/lib/pages/market/market_editor.dart b/lib/pages/market/market_editor.dart
index 9ab9717..9efdd9e 100644
--- a/lib/pages/market/market_editor.dart
+++ b/lib/pages/market/market_editor.dart
@@ -35,7 +35,7 @@ class _MarketEditorState extends State<MarketEditor> {
         children: <Widget>[
           Expanded(
             child: new Text(
-              p.name,
+              p.name ?? "",
               style: TextStyle(
                 fontSize: 15.0,
               ),
@@ -61,7 +61,8 @@ class _MarketEditorState extends State<MarketEditor> {
           appBar: AppBar(
             centerTitle: true,
             leading: new IconButton(
-              icon: new Icon(CupertinoIcons.back, color: primaryColor, size: 30),
+              icon:
+                  new Icon(CupertinoIcons.back, color: primaryColor, size: 30),
               onPressed: () => Navigator.of(context).pop(),
             ),
             shadowColor: Colors.transparent,
@@ -116,7 +117,7 @@ class _MarketEditorState extends State<MarketEditor> {
     });
     MarketModel marketModel = Provider.of<MarketModel>(context, listen: false);
     try {
-      await marketModel.deleteMarket(market.id);
+      await marketModel.deleteMarket(market.id!);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
     } finally {
@@ -150,37 +151,39 @@ class _MarketEditorState extends State<MarketEditor> {
   _showDialog(BuildContext context) async {
     await showDialog<String>(
       context: context,
-      child: new AlertDialog(
-        contentPadding: const EdgeInsets.all(16.0),
-        content: new Row(
-          children: <Widget>[
-            new Expanded(
-              child: InputText(
-                labelTextKey: "market.edit.name",
-                controller: _marketNameCtl,
-                autoFocus: true,
-              ),
-            )
+      builder: (BuildContext context) {
+        return new AlertDialog(
+          contentPadding: const EdgeInsets.all(16.0),
+          content: new Row(
+            children: <Widget>[
+              new Expanded(
+                child: InputText(
+                  labelTextKey: "market.edit.name",
+                  controller: _marketNameCtl,
+                  autoFocus: true,
+                ),
+              )
+            ],
+          ),
+          actions: <Widget>[
+            new FlatButton(
+                child: LocalText(context, "btn.cancel", color: primaryColor),
+                onPressed: () {
+                  Navigator.pop(context);
+                }),
+            new FlatButton(
+                child: LocalText(
+                  context,
+                  "btn.save",
+                  color: primaryColor,
+                ),
+                onPressed: () {
+                  Navigator.pop(context);
+                  _add();
+                })
           ],
-        ),
-        actions: <Widget>[
-          new FlatButton(
-              child: LocalText(context, "btn.cancel", color: primaryColor),
-              onPressed: () {
-                Navigator.pop(context);
-              }),
-          new FlatButton(
-              child: LocalText(
-                context,
-                "btn.save",
-                color: primaryColor,
-              ),
-              onPressed: () {
-                Navigator.pop(context);
-                _add();
-              })
-        ],
-      ),
+        );
+      },
     );
   }
 }
diff --git a/lib/pages/market/model/market_model.dart b/lib/pages/market/model/market_model.dart
index c97cbdb..658d2c0 100644
--- a/lib/pages/market/model/market_model.dart
+++ b/lib/pages/market/model/market_model.dart
@@ -9,7 +9,7 @@ import 'package:logging/logging.dart';
 
 class MarketModel extends BaseModel {
   final log = Logger('MarketModel');
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
   List<Market> markets = [];
 
   MarketModel() {
@@ -18,16 +18,16 @@ class MarketModel extends BaseModel {
 
   Future<void> _loadMarkets() async {
     try {
-      if (listener != null) listener.cancel();
+      if (listener != null) listener!.cancel();
 
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("/$config_collection/$setting_doc_id/$markets_collection")
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         markets.clear();
-        markets = snapshot.documents.map((documentSnapshot) {
+        markets = snapshot.docs.map((documentSnapshot) {
           var user = Market.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+              documentSnapshot.data as Map<String, dynamic>, documentSnapshot.id);
           return user;
         }).toList();
         notifyListeners();
diff --git a/lib/pages/package/model/package_model.dart b/lib/pages/package/model/package_model.dart
index f826ceb..380f9b7 100644
--- a/lib/pages/package/model/package_model.dart
+++ b/lib/pages/package/model/package_model.dart
@@ -16,9 +16,9 @@ import 'package:path/path.dart' as Path;
 class PackageModel extends BaseModel {
   final log = Logger('PackageModel');
 
-  PaginatorListener packages;
-  PaginatorListener customerPackages;
-  PaginatorListener activePackages;
+  late PaginatorListener<Package> packages;
+  late PaginatorListener<Package> customerPackages;
+  late PaginatorListener<Package> activePackages;
 
   bool isLoading = false;
   int _menuSelectedIndex = 1;
@@ -32,7 +32,7 @@ class PackageModel extends BaseModel {
     notifyListeners();
   }
 
-  get menuSelectedIndex => _menuSelectedIndex;
+  int get menuSelectedIndex => _menuSelectedIndex;
 
   void privilegeChanged() {
     if (user != null) {
@@ -70,15 +70,16 @@ class PackageModel extends BaseModel {
 
   Future<void> _loadPackages(bool isDelivered) async {
     if (user == null) return;
-    if (!((user.hasPackages() || user.hasReceiving() || user.hasProcessing())))
-      return;
+    if (!((user!.hasPackages() ||
+        user!.hasReceiving() ||
+        user!.hasProcessing()))) return;
     String path = "/$packages_collection";
 
     try {
-      Query listenerQuery = Firestore.instance
+      Query listenerQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered);
-      Query pageQuery = Firestore.instance
+      Query pageQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered);
 
@@ -94,14 +95,14 @@ class PackageModel extends BaseModel {
     String path = "/$packages_collection";
 
     try {
-      Query listenerQuery = Firestore.instance
+      Query listenerQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered)
-          .where("user_id", isEqualTo: user.id);
-      Query pageQuery = Firestore.instance
+          .where("user_id", isEqualTo: user!.id);
+      Query pageQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: isDelivered)
-          .where("user_id", isEqualTo: user.id)
+          .where("user_id", isEqualTo: user!.id)
           .orderBy("update_time", descending: true);
 
       customerPackages.refresh(
@@ -113,15 +114,16 @@ class PackageModel extends BaseModel {
 
   Future<void> _loadActivePackages() async {
     if (user == null) return;
-    if (!((user.hasPackages() || user.hasReceiving() || user.hasProcessing())))
-      return;
+    if (!((user!.hasPackages() ||
+        user!.hasReceiving() ||
+        user!.hasProcessing()))) return;
     String path = "/$packages_collection";
 
     try {
-      Query listenerQuery = Firestore.instance
+      Query listenerQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: false);
-      Query pageQuery = Firestore.instance
+      Query pageQuery = FirebaseFirestore.instance
           .collection(path)
           .where("is_delivered", isEqualTo: false);
 
@@ -133,14 +135,15 @@ class PackageModel extends BaseModel {
     }
   }
 
-  Future<Package> getPackage(String id) async {
+  Future<Package?> getPackage(String id) async {
     if (user == null) return null;
     String path = "/$packages_collection";
     try {
       DocumentSnapshot snap =
-          await Firestore.instance.collection("$path").document(id).get();
+          await FirebaseFirestore.instance.collection("$path").doc(id).get();
       if (snap.exists) {
-        var package = Package.fromMap(snap.data, snap.documentID);
+        var package =
+            Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
         return package;
       }
     } catch (e) {
@@ -149,18 +152,19 @@ class PackageModel extends BaseModel {
     return null;
   }
 
-  Future<Package> getPackageByTrackingID(String trackingID) async {
+  Future<Package?> getPackageByTrackingID(String trackingID) async {
     if (user == null) return null;
     String path = "/$packages_collection";
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection("$path")
           .where("tracking_id", isEqualTo: trackingID)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      if (snaps.documents.length == 1) {
-        var snap = snaps.documents[0];
-        var package = Package.fromMap(snap.data, snap.documentID);
+          .get(const GetOptions(source: Source.server));
+      if (snaps.docs.length == 1) {
+        var snap = snaps.docs[0];
+        var package =
+            Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
         return package;
       }
     } catch (e) {
@@ -169,35 +173,37 @@ class PackageModel extends BaseModel {
     return null;
   }
 
-  Future<Package> lookupPackage(String trackingID) async {
+  Future<Package?> lookupPackage(String trackingID) async {
     if (user == null) return null;
     String path = "/$packages_collection";
 
     try {
-      var qsnap = await Firestore.instance
+      var qsnap = await FirebaseFirestore.instance
           .collection("$path")
           .where("tracking_id", isEqualTo: trackingID)
           .where("has_user_id", isEqualTo: false)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      if (qsnap.documents.length > 0) {
-        var snap = qsnap.documents[0];
+          .get(const GetOptions(source: Source.server));
+      if (qsnap.docs.length > 0) {
+        var snap = qsnap.docs[0];
         if (snap.exists) {
-          var package = Package.fromMap(snap.data, snap.documentID);
+          var package =
+              Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
           return package;
         }
       }
 
-      qsnap = await Firestore.instance
+      qsnap = await FirebaseFirestore.instance
           .collection("$path")
           .where("tracking_id", isEqualTo: trackingID)
-          .where("user_id", isEqualTo: user.id)
+          .where("user_id", isEqualTo: user!.id)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      if (qsnap.documents.length > 0) {
-        var snap = qsnap.documents[0];
+          .get(const GetOptions(source: Source.server));
+      if (qsnap.docs.length > 0) {
+        var snap = qsnap.docs[0];
         if (snap.exists) {
-          var package = Package.fromMap(snap.data, snap.documentID);
+          var package =
+              Package.fromMap(snap.data as Map<String, dynamic>, snap.id);
           return package;
         }
       }
@@ -210,15 +216,15 @@ class PackageModel extends BaseModel {
   Future<List<Package>> getPackages(String userID, List<String> status) async {
     List<Package> packages = [];
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection("/$packages_collection")
           .where("status", whereIn: status)
           .where("user_id", isEqualTo: userID)
           .where("is_deleted", isEqualTo: false)
-          .getDocuments(source: Source.server);
-      packages = snaps.documents.map((documentSnapshot) {
-        var p =
-            Package.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+          .get(const GetOptions(source: Source.server));
+      packages = snaps.docs.map((documentSnapshot) {
+        var p = Package.fromMap(
+            documentSnapshot.data as Map<String, dynamic>, documentSnapshot.id);
         return p;
       }).toList();
     } catch (e) {
@@ -235,26 +241,26 @@ class PackageModel extends BaseModel {
     Future<List<Package>> packages =
         Services.instance.packageService.searchPackage(term);
 
-    Future<List<Package>> packagesFTS =
+    Future<List<Package>?> packagesFTS =
         Services.instance.packageService.ftsSearchPackage(term);
     // Package pkg = await getPackageByTrackingID(term);
     // if (pkg != null && !packages.contains(pkg)) {
     //   packages.insert(0, pkg);
     // }
     List<Package> pkgs = await packages;
-    List<Package> ftsPkgs = await packagesFTS;
-    pkgs.addAll(ftsPkgs);
+    List<Package>? ftsPkgs = await packagesFTS;
+    pkgs.addAll(ftsPkgs!);
     final seen = Set<Package>();
     return pkgs.where((e) => seen.add(e)).toList();
   }
 
   Future<void> createPackages(User user, List<Package> packages) {
     return Services.instance.packageService
-        .createPackages(packages, user.fcsID);
+        .createPackages(packages, user.fcsID!);
   }
 
   Future<void> createReceiving(
-      User user, Package package, List<File> files) async {
+      User user, Package package, List<File?> files) async {
     if (user != null) {
       package.fcsID = user.fcsID;
     }
@@ -282,22 +288,21 @@ class PackageModel extends BaseModel {
     }
   }
 
-  Future<void> updateReceiving(User user, Package package, List<File> files,
-      List<String> deletedUrls) async {
+  Future<void> updateReceiving(User user, Package package, List<File?> files,
+      List<String?> deletedUrls) async {
     if (user != null) {
       package.fcsID = user.fcsID;
     }
     if (deletedUrls != null) {
-      for (String url in deletedUrls) {
+      for (String? url in deletedUrls) {
         package.photoUrls.remove(url);
       }
     }
 
     List<String> uploadedURL = [];
     if (files != null) {
-      var count = (package.photoUrls?.length ?? 0) +
-          files.length -
-          (deletedUrls?.length ?? 0);
+      var count =
+          (package.photoUrls.length) + files.length - (deletedUrls.length);
 
       if (count > uploadPhotoLimit)
         throw Exception("Exceed number of file upload");
@@ -327,18 +332,17 @@ class PackageModel extends BaseModel {
   }
 
   Future<void> updateProcessing(
-      Package package, List<File> files, List<String> deletedUrls) async {
+      Package package, List<File?> files, List<String?> deletedUrls) async {
     if (deletedUrls != null) {
-      for (String url in deletedUrls) {
+      for (String? url in deletedUrls) {
         package.photoUrls.remove(url);
       }
     }
 
     List<String> uploadedURL = [];
     if (files != null) {
-      var count = (package.photoUrls?.length ?? 0) +
-          files.length -
-          (deletedUrls?.length ?? 0);
+      var count =
+          (package.photoUrls.length) + files.length - (deletedUrls.length);
 
       if (count > uploadPhotoLimit)
         throw Exception("Exceed number of file upload");
@@ -370,10 +374,10 @@ class PackageModel extends BaseModel {
   Future<void> changeDeliveryAddress(
       Package package, DeliveryAddress deliveryAddress) {
     return Services.instance.packageService
-        .changeDeliveryAddress(package.id, deliveryAddress.id);
+        .changeDeliveryAddress(package.id!, deliveryAddress.id!);
   }
 
   Future<void> packageReturn(Package package) {
-    return Services.instance.packageService.packageReturn(package.id);
+    return Services.instance.packageService.packageReturn(package.id!);
   }
 }
diff --git a/lib/pages/package/package_editor.dart b/lib/pages/package/package_editor.dart
index 0f488f3..9afa78b 100644
--- a/lib/pages/package/package_editor.dart
+++ b/lib/pages/package/package_editor.dart
@@ -14,12 +14,12 @@ import 'package:fcs/pages/widgets/multi_img_file.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class PackageEditorPage extends StatefulWidget {
-  final Package package;
+  final Package? package;
   PackageEditorPage({this.package});
 
   @override
@@ -30,17 +30,17 @@ class _PackageEditorPageState extends State<PackageEditorPage> {
   TextEditingController _remarkCtl = new TextEditingController();
   TextEditingController _descCtl = new TextEditingController();
 
-  Package _package;
+  Package? _package;
   bool _isLoading = false;
 
   @override
   void initState() {
     super.initState();
-    _package = widget.package;
-    selectedMarket = _package.market ?? "";
-    _descCtl.text = _package.desc;
-    _remarkCtl.text = _package.remark;
-    multiImgController.setImageUrls = _package.photoUrls;
+    _package = widget.package!;
+    selectedMarket = _package!.market;
+    _descCtl.text = _package!.desc!;
+    _remarkCtl.text = _package!.remark!;
+    multiImgController.setImageUrls = _package!.photoUrls;
   }
 
   final DateFormat dateFormat = DateFormat("d MMM yyyy");
@@ -51,17 +51,17 @@ class _PackageEditorPageState extends State<PackageEditorPage> {
   @override
   Widget build(BuildContext context) {
     final trackingIdBox = DisplayText(
-      text: _package.trackingID,
+      text: _package != null ? _package!.trackingID : "",
       labelTextKey: "package.tracking.id",
       iconData: MaterialCommunityIcons.barcode_scan,
     );
     final statusBox = DisplayText(
-      text: _package.status,
+      text: _package != null ? _package!.status : "",
       labelTextKey: "package.edit.status",
       iconData: AntDesign.exclamationcircleo,
     );
     final customerNameBox = DisplayText(
-      text: _package.userName,
+      text: _package != null ? _package!.userName : "",
       labelTextKey: "package.create.name",
       iconData: Icons.perm_identity,
     );
@@ -154,13 +154,13 @@ class _PackageEditorPageState extends State<PackageEditorPage> {
     );
   }
 
-  String selectedMarket;
+  String? selectedMarket;
   Widget marketDropdown() {
     List<Market> _markets = Provider.of<MarketModel>(context).markets;
-    List<String> markets = _markets.map((e) => e.name).toList();
+    List<String?> markets = _markets.map((e) => e.name).toList();
     markets.insert(0, MANAGE_MARKET);
     if (!markets.contains(selectedMarket)) {
-      markets.insert(0, selectedMarket);
+      markets.insert(0, selectedMarket!);
     }
 
     return Row(
@@ -183,7 +183,7 @@ class _PackageEditorPageState extends State<PackageEditorPage> {
               height: 1,
               color: Colors.grey,
             ),
-            onChanged: (String newValue) {
+            onChanged: (String? newValue) {
               setState(() {
                 if (newValue == MANAGE_MARKET) {
                   selectedMarket = null;
@@ -194,7 +194,7 @@ class _PackageEditorPageState extends State<PackageEditorPage> {
               });
             },
             isExpanded: true,
-            items: markets.map<DropdownMenuItem<String>>((String value) {
+            items: markets.map<DropdownMenuItem<String>>((String? value) {
               return DropdownMenuItem<String>(
                 value: value,
                 child: Text(value ?? "",
@@ -229,9 +229,9 @@ class _PackageEditorPageState extends State<PackageEditorPage> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     try {
-      _package.desc = _descCtl.text;
-      _package.remark = _remarkCtl.text;
-      _package.market = selectedMarket;
+      _package!.desc = _descCtl.text;
+      _package!.remark = _remarkCtl.text;
+      _package!.market = selectedMarket!;
       // await packageModel.completeProcessing(_package,
       //     multiImgController.getAddedFile, multiImgController.getDeletedUrl);
       Navigator.pop(context);
diff --git a/lib/pages/package/package_info.dart b/lib/pages/package/package_info.dart
index 3e32a2d..cb755e6 100644
--- a/lib/pages/package/package_info.dart
+++ b/lib/pages/package/package_info.dart
@@ -18,7 +18,7 @@ import 'package:fcs/pages/widgets/progress.dart';
 import 'package:fcs/pages/widgets/status_tree.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
@@ -27,7 +27,7 @@ final DateFormat dateFormat = DateFormat("d MMM yyyy");
 class PackageInfo extends StatefulWidget {
   final isCustomer;
   final isSearchResult;
-  final Package package;
+  final Package? package;
 
   PackageInfo(
       {this.package, this.isSearchResult = false, this.isCustomer = false});
@@ -38,23 +38,23 @@ class PackageInfo extends StatefulWidget {
 
 class _PackageInfoState extends State<PackageInfo> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
-  Package _package;
+  Package? _package;
   bool _isLoading = false;
   MultiImgController multiImgController = MultiImgController();
 
   @override
   void initState() {
     super.initState();
-    initPackage(widget.package);
+    initPackage(widget.package!);
   }
 
   initPackage(Package pkg) async {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
-    Package package = await packageModel.getPackageByTrackingID(pkg.trackingID);
+    Package? package = await packageModel.getPackageByTrackingID(pkg.trackingID!);
     setState(() {
       _package = package;
-      multiImgController.setImageUrls = package.photoUrls;
+      multiImgController.setImageUrls = package!.photoUrls;
     });
   }
 
@@ -65,7 +65,7 @@ class _PackageInfoState extends State<PackageInfo> {
 
   @override
   Widget build(BuildContext context) {
-    String id = Provider.of<MainModel>(context).user.id;
+    String? id = Provider.of<MainModel>(context).user!.id;
     bool owner = _package?.userID == id;
     bool canChangeDeliveryAddress =
         _package?.status == package_received_status ||
@@ -113,21 +113,21 @@ class _PackageInfoState extends State<PackageInfo> {
       callBack: _return,
     );
     final deliveryAddressBox = DefaultDeliveryAddress(
-      deliveryAddress: _package?.deliveryAddress,
+      deliveryAddress: _package!.deliveryAddress,
       labelKey: "package.delivery.address",
       onTap: owner && canChangeDeliveryAddress
           ? () async {
-              DeliveryAddress d = await Navigator.push<DeliveryAddress>(
+              DeliveryAddress? d = await Navigator.push<DeliveryAddress>(
                 context,
                 CupertinoPageRoute(
                     builder: (context) => DeliveryAddressSelection(
-                        deliveryAddress: _package.deliveryAddress,
+                        deliveryAddress: _package!.deliveryAddress,
                         user: mainModel.user)),
               );
               if (d == null) return;
               _changeDeliverayAddress(d);
             }
-          : null,
+          : () {},
     );
 
     return LocalProgress(
@@ -159,7 +159,7 @@ class _PackageInfoState extends State<PackageInfo> {
                   widget.isSearchResult ? Container() : fcsIDBox,
                   widget.isSearchResult ? Container() : customerNameBox,
                   widget.isSearchResult ? Container() : marketBox,
-                  _package == null || _package.photoUrls.length == 0
+                  _package == null || _package!.photoUrls.length == 0
                       ? Container()
                       : img,
                   widget.isSearchResult ? Container() : descBox,
@@ -172,8 +172,8 @@ class _PackageInfoState extends State<PackageInfo> {
                   widget.isSearchResult
                       ? Container()
                       : StatusTree(
-                          shipmentHistory: _package?.shipmentHistory,
-                          currentStatus: _package?.status),
+                          shipmentHistory: _package!.shipmentHistory,
+                          currentStatus: _package!.status),
                   SizedBox(
                     height: 20,
                   )
@@ -197,11 +197,11 @@ class _PackageInfoState extends State<PackageInfo> {
         Provider.of<DeliveryAddressModel>(context, listen: false);
 
     try {
-      await packageModel.changeDeliveryAddress(_package, deliveryAddress);
+      await packageModel.changeDeliveryAddress(_package!, deliveryAddress);
       var da =
-          await deliveryAddressModel.getDeliveryAddress(deliveryAddress.id);
+          await deliveryAddressModel.getDeliveryAddress(deliveryAddress.id!);
       setState(() {
-        _package.deliveryAddress = da;
+        _package!.deliveryAddress = da;
       });
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -223,7 +223,7 @@ class _PackageInfoState extends State<PackageInfo> {
     try {
       PackageModel packageModel =
           Provider.of<PackageModel>(context, listen: false);
-      await packageModel.packageReturn(_package);
+      await packageModel.packageReturn(_package!);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/package/package_list.dart b/lib/pages/package/package_list.dart
index c28ce22..e806ead 100644
--- a/lib/pages/package/package_list.dart
+++ b/lib/pages/package/package_list.dart
@@ -16,7 +16,7 @@ import 'package:provider/provider.dart';
 class PackageList extends StatefulWidget {
   final bool forCustomer;
 
-  const PackageList({Key key, this.forCustomer = true}) : super(key: key);
+  const PackageList({Key? key, this.forCustomer = true}) : super(key: key);
   @override
   _PackageListState createState() => _PackageListState();
 }
@@ -97,7 +97,7 @@ class _PackageListState extends State<PackageList> {
 
   _searchCallback(Package package) async {
     var packageModel = Provider.of<PackageModel>(context, listen: false);
-    Package _package = await packageModel.getPackage(package.id);
+    Package? _package = await packageModel.getPackage(package.id!);
     if (_package == null) return;
     Navigator.push(
       context,
diff --git a/lib/pages/package/package_list_row.dart b/lib/pages/package/package_list_row.dart
index 76c8297..a613c26 100644
--- a/lib/pages/package/package_list_row.dart
+++ b/lib/pages/package/package_list_row.dart
@@ -4,28 +4,31 @@ import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/package/package_info.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 typedef CallbackPackageSelect(Package package);
 
 class PackageListRow extends StatelessWidget {
   final bool isCustomer;
-  final Package package;
-  final CallbackPackageSelect callbackPackageSelect;
+  final Package? package;
+  final CallbackPackageSelect? callbackPackageSelect;
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
 
   PackageListRow(
-      {Key key, this.package, this.callbackPackageSelect, this.isCustomer})
+      {Key? key,
+      this.package,
+      this.callbackPackageSelect,
+      this.isCustomer = false})
       : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return InkWell(
-      onTap: () {        
+      onTap: () {
         if (callbackPackageSelect != null) {
-          callbackPackageSelect(package);
+          callbackPackageSelect!(package!);
           return;
         }
         Navigator.push(
@@ -57,7 +60,9 @@ class PackageListRow extends StatelessWidget {
                               Padding(
                                 padding: const EdgeInsets.only(left: 8.0),
                                 child: new Text(
-                                  package.id == null ? '' : package.trackingID,
+                                  package!.id == null
+                                      ? ''
+                                      : package!.trackingID!,
                                   style: new TextStyle(
                                       fontSize: 15.0, color: Colors.black),
                                 ),
@@ -65,7 +70,9 @@ class PackageListRow extends StatelessWidget {
                               Padding(
                                 padding: const EdgeInsets.only(left: 8.0),
                                 child: new Text(
-                                  package.market == null ? '' : package.market,
+                                  package!.market == null
+                                      ? ''
+                                      : package!.market!,
                                   style: new TextStyle(
                                       fontSize: 15.0, color: Colors.black),
                                 ),
@@ -81,12 +88,14 @@ class PackageListRow extends StatelessWidget {
                   children: <Widget>[
                     Padding(
                       padding: const EdgeInsets.all(3.0),
-                      child: getStatus(package.status),
+                      child: getStatus(package!.status??""),
                     ),
                     Padding(
                       padding: const EdgeInsets.all(0),
                       child: new Text(
-                        dateFormat.format(package.currentStatusDate),
+                        package!.currentStatusDate != null
+                            ? dateFormat.format(package!.currentStatusDate!)
+                            : '',
                         style:
                             new TextStyle(fontSize: 15.0, color: Colors.grey),
                       ),
diff --git a/lib/pages/package/package_new.dart b/lib/pages/package/package_new.dart
index 54360eb..1b33c1d 100644
--- a/lib/pages/package/package_new.dart
+++ b/lib/pages/package/package_new.dart
@@ -26,7 +26,7 @@ class PackageNew extends StatefulWidget {
 
 class _PackageNewState extends State<PackageNew> {
   bool _isLoading = false;
-  User user;
+  User? user;
 
   List<Package> packages = [];
 
@@ -41,7 +41,7 @@ class _PackageNewState extends State<PackageNew> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: user != null ? user.fcsID : "",
+          text: user != null ? user!.fcsID : "",
           labelTextKey: "package.create.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -55,12 +55,12 @@ class _PackageNewState extends State<PackageNew> {
       ],
     );
     final namebox = DisplayText(
-      text: user != null ? user.name : "",
+      text: user != null ? user!.name : "",
       labelTextKey: "package.create.name",
       iconData: Icons.person,
     );
     final phoneNumberBox = DisplayText(
-      text: user != null ? user.phoneNumber : "",
+      text: user != null ? user!.phoneNumber : "",
       labelTextKey: "package.create.phone",
       iconData: Icons.phone,
     );
@@ -144,8 +144,8 @@ class _PackageNewState extends State<PackageNew> {
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-                Text(packages[index].market ?? ""),
-                Text(packages[index].trackingID),
+                Text(packages[index].market!),
+                Text(packages[index].trackingID!),
                 // DisplayText(
                 //   labelText: "Tracking ID",
                 //   text: packages[index].trackingID,
@@ -170,7 +170,7 @@ class _PackageNewState extends State<PackageNew> {
   }
 
   _addPackage() async {
-    Package package = await Navigator.push<Package>(
+    Package? package = await Navigator.push<Package>(
       context,
       CupertinoPageRoute(builder: (context) => TrackingIDPage()),
     );
@@ -197,7 +197,7 @@ class _PackageNewState extends State<PackageNew> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     try {
-      await packageModel.createPackages(user, packages);
+      await packageModel.createPackages(user!, packages);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/package/tracking_id_page.dart b/lib/pages/package/tracking_id_page.dart
index 26db8ae..6cdd773 100644
--- a/lib/pages/package/tracking_id_page.dart
+++ b/lib/pages/package/tracking_id_page.dart
@@ -1,4 +1,3 @@
-import 'package:barcode_scan/barcode_scan.dart';
 import 'package:fcs/domain/entities/market.dart';
 import 'package:fcs/domain/entities/package.dart';
 import 'package:fcs/helpers/theme.dart';
@@ -12,7 +11,7 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:provider/provider.dart';
 
@@ -20,7 +19,7 @@ const MANAGE_MARKET = "Manage Market";
 const SELECT_MARKET = "Select Market";
 
 class TrackingIDPage extends StatefulWidget {
-  const TrackingIDPage({Key key}) : super(key: key);
+  const TrackingIDPage({Key? key}) : super(key: key);
   @override
   _TrackingIDPageState createState() => _TrackingIDPageState();
 }
@@ -85,10 +84,10 @@ class _TrackingIDPageState extends State<TrackingIDPage> {
     );
   }
 
-  String selectedMarket;
+  String? selectedMarket;
   Widget dropDown() {
     List<Market> _markets = Provider.of<MarketModel>(context).markets;
-    List<String> markets = _markets.map((e) => e.name).toList();
+    List<String?> markets = _markets.map((e) => e.name).toList();
     markets.insert(0, MANAGE_MARKET);
     markets.insert(0, SELECT_MARKET);
 
@@ -112,7 +111,7 @@ class _TrackingIDPageState extends State<TrackingIDPage> {
               height: 1,
               color: Colors.grey,
             ),
-            onChanged: (String newValue) {
+            onChanged: (String? newValue) {
               setState(() {
                 if (newValue == MANAGE_MARKET) {
                   selectedMarket = null;
@@ -127,10 +126,10 @@ class _TrackingIDPageState extends State<TrackingIDPage> {
               });
             },
             isExpanded: true,
-            items: markets.map<DropdownMenuItem<String>>((String value) {
+            items: markets.map<DropdownMenuItem<String>>((String? value) {
               return DropdownMenuItem<String>(
                 value: value,
-                child: Text(value,
+                child: Text(value ?? "",
                     overflow: TextOverflow.ellipsis,
                     style: TextStyle(
                         color: value == MANAGE_MARKET
@@ -147,25 +146,25 @@ class _TrackingIDPageState extends State<TrackingIDPage> {
   _manageMarket() {
     Navigator.push<Package>(
       context,
-     CupertinoPageRoute(builder: (context) => MarketEditor()),
+      CupertinoPageRoute(builder: (context) => MarketEditor()),
     );
   }
 
   _scan() async {
-    PermissionStatus permission =
-        await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
-    if (permission != PermissionStatus.granted) {
-      Map<PermissionGroup, PermissionStatus> permissions =
-          await PermissionHandler()
-              .requestPermissions([PermissionGroup.camera]);
-      if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
-        showMsgDialog(context, "Error", "Camera permission is not granted");
-        return null;
-      }
-    }
+    // PermissionStatus permission =
+    //     await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
+    // if (permission != PermissionStatus.granted) {
+    //   Map<PermissionGroup, PermissionStatus> permissions =
+    //       await PermissionHandler()
+    //           .requestPermissions([PermissionGroup.camera]);
+    //   if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
+    //     showMsgDialog(context, "Error", "Camera permission is not granted");
+    //     return null;
+    //   }
+    // }
 
     try {
-      String barcode = await scanBarcode();
+      String? barcode = await scanBarcode();
       if (barcode != null) {
         setState(() {
           _transcationIDCtl.text = barcode;
@@ -179,6 +178,6 @@ class _TrackingIDPageState extends State<TrackingIDPage> {
   _select() {
     if (_transcationIDCtl.text == "" && selectedMarket == null) return;
     Navigator.pop(context,
-        Package(trackingID: _transcationIDCtl.text, market: selectedMarket));
+        Package(trackingID: _transcationIDCtl.text, market: selectedMarket!));
   }
 }
diff --git a/lib/pages/package_search/package_serach.dart b/lib/pages/package_search/package_serach.dart
index 2ee5ccf..566b46c 100644
--- a/lib/pages/package_search/package_serach.dart
+++ b/lib/pages/package_search/package_serach.dart
@@ -1,4 +1,3 @@
-import 'package:barcode_scan/barcode_scan.dart';
 import 'package:fcs/domain/entities/package.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/util.dart';
@@ -6,12 +5,12 @@ import 'package:fcs/pages/package/model/package_model.dart';
 import 'package:fcs/pages/package/package_list_row.dart';
 import 'package:fcs/pages/widgets/barcode_scanner.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:provider/provider.dart';
 
-Future<Package> searchPackage(BuildContext context,
-        {CallbackPackageSelect callbackPackageSelect}) async =>
+Future<Package?> searchPackage(BuildContext context,
+        {CallbackPackageSelect? callbackPackageSelect}) async =>
     await showSearch<Package>(
       context: context,
       delegate:
@@ -19,7 +18,7 @@ Future<Package> searchPackage(BuildContext context,
     );
 
 class PackageSearchDelegate extends SearchDelegate<Package> {
-  final CallbackPackageSelect callbackPackageSelect;
+  final CallbackPackageSelect? callbackPackageSelect;
 
   PackageSearchDelegate({this.callbackPackageSelect});
 
@@ -32,10 +31,10 @@ class PackageSearchDelegate extends SearchDelegate<Package> {
     return theme.copyWith(
       inputDecorationTheme: InputDecorationTheme(
           hintStyle: TextStyle(
-              color: theme.primaryTextTheme.caption.color, fontSize: 14)),
+              color: theme.primaryTextTheme.caption!.color, fontSize: 14)),
       textTheme: theme.textTheme.copyWith(
-          title: theme.textTheme.title.copyWith(
-              color: theme.primaryTextTheme.title.color, fontSize: 16)),
+          title: theme.textTheme.title!.copyWith(
+              color: theme.primaryTextTheme.title!.color, fontSize: 16)),
       primaryColor: primaryColor,
     );
   }
@@ -59,7 +58,7 @@ class PackageSearchDelegate extends SearchDelegate<Package> {
   Widget buildLeading(BuildContext context) {
     return IconButton(
       icon: Icon(Icons.arrow_back),
-      onPressed: () => close(context, null),
+      onPressed: () => close(context, new Package()),
     );
   }
 
@@ -70,7 +69,7 @@ class PackageSearchDelegate extends SearchDelegate<Package> {
         future: packageModel.searchPackage(query),
         builder: (context, AsyncSnapshot<List<Package>> snapshot) {
           if (snapshot.hasData) {
-            if (snapshot.data.length == 0) {
+            if (snapshot.data!.length == 0) {
               return Container(
                 child: Center(
                   child: Text(
@@ -83,7 +82,7 @@ class PackageSearchDelegate extends SearchDelegate<Package> {
             return Container(
               padding: EdgeInsets.only(top: 15),
               child: ListView(
-                children: snapshot.data
+                children: snapshot.data!
                     .map((u) => PackageListRow(
                           package: u,
                           callbackPackageSelect: callbackPackageSelect,
@@ -124,17 +123,17 @@ class PackageSearchDelegate extends SearchDelegate<Package> {
   }
 
   _scan(BuildContext context) async {
-    PermissionStatus permission =
-        await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
-    if (permission != PermissionStatus.granted) {
-      Map<PermissionGroup, PermissionStatus> permissions =
-          await PermissionHandler()
-              .requestPermissions([PermissionGroup.camera]);
-      if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
-        showMsgDialog(context, "Error", "Camera permission is not granted");
-        return null;
-      }
-    }
+    // PermissionStatus permission =
+    //     await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
+    // if (permission != PermissionStatus.granted) {
+    //   Map<PermissionGroup, PermissionStatus> permissions =
+    //       await PermissionHandler()
+    //           .requestPermissions([PermissionGroup.camera]);
+    //   if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
+    //     showMsgDialog(context, "Error", "Camera permission is not granted");
+    //     return null;
+    //   }
+    // }
 
     try {
       // PickedFile pickedFile =
@@ -148,7 +147,7 @@ class PackageSearchDelegate extends SearchDelegate<Package> {
       // Barcode bc = barcodes.firstWhere((element) => true);
       // String barcode;
       // if (bc != null) barcode = bc.rawValue;
-      String barcode = await scanBarcode();
+      String? barcode = await scanBarcode();
       if (barcode != null) {
         query = barcode;
         showResults(context);
diff --git a/lib/pages/payment_methods/model/payment_method_model.dart b/lib/pages/payment_methods/model/payment_method_model.dart
index 25d9f11..229bd9f 100644
--- a/lib/pages/payment_methods/model/payment_method_model.dart
+++ b/lib/pages/payment_methods/model/payment_method_model.dart
@@ -12,21 +12,22 @@ class PaymentMethodModel extends BaseModel {
   List<PaymentMethod> paymentMethods = [];
 
   PaymentMethod getPaymentMethod(String id) {
-    return paymentMethods.firstWhere((e) => e.id == id, orElse: () => null);
+    return paymentMethods.firstWhere((e) => e.id == id);
   }
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   PaymentMethodModel() {
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     try {
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("/payment_methods")
           .snapshots()
           .listen((snaps) {
         paymentMethods.clear();
-        snaps.documents.forEach((d) {
-          paymentMethods.add(PaymentMethod.fromMap(d.data, d.documentID));
+        snaps.docs.forEach((d) {
+          paymentMethods
+              .add(PaymentMethod.fromMap(d.data as Map<String, dynamic>, d.id));
         });
         notifyListeners();
       });
diff --git a/lib/pages/payment_methods/payment_method_editor.dart b/lib/pages/payment_methods/payment_method_editor.dart
index 9118cdf..9699db7 100644
--- a/lib/pages/payment_methods/payment_method_editor.dart
+++ b/lib/pages/payment_methods/payment_method_editor.dart
@@ -8,20 +8,20 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 class PaymentMethodEditor extends StatefulWidget {
-  final PaymentMethod paymentMethod;
+  final PaymentMethod? paymentMethod;
 
-  const PaymentMethodEditor({Key key, this.paymentMethod}) : super(key: key);
+  const PaymentMethodEditor({Key? key, this.paymentMethod}) : super(key: key);
   @override
   _PaymentMethodEditorState createState() => _PaymentMethodEditorState();
 }
 
 class _PaymentMethodEditorState extends State<PaymentMethodEditor> {
   bool _isLoading = false;
-  PaymentMethod _paymentMethod;
+  PaymentMethod? _paymentMethod;
   TextEditingController _nameController = new TextEditingController();
   TextEditingController _accountNameController = new TextEditingController();
   TextEditingController _accountNumberController = new TextEditingController();
@@ -29,7 +29,7 @@ class _PaymentMethodEditorState extends State<PaymentMethodEditor> {
   TextEditingController _phoneController = new TextEditingController();
   TextEditingController _linkController = new TextEditingController();
 
-  bool isNew;
+  late bool isNew;
 
   @override
   void initState() {
@@ -38,12 +38,12 @@ class _PaymentMethodEditorState extends State<PaymentMethodEditor> {
 
     if (widget.paymentMethod != null) {
       _paymentMethod = widget.paymentMethod;
-      _nameController.text = _paymentMethod.name;
-      _accountNameController.text = _paymentMethod.accountName;
-      _accountNumberController.text = _paymentMethod.account;
-      _mailController.text = _paymentMethod.email;
-      _phoneController.text = _paymentMethod.phone;
-      _linkController.text = _paymentMethod.link;
+      _nameController.text = _paymentMethod!.name!;
+      _accountNameController.text = _paymentMethod!.accountName!;
+      _accountNumberController.text = _paymentMethod!.account!;
+      _mailController.text = _paymentMethod!.email!;
+      _phoneController.text = _paymentMethod!.phone!;
+      _linkController.text = _paymentMethod!.link!;
     } else {
       _paymentMethod = new PaymentMethod();
       _nameController.text = '';
@@ -179,7 +179,7 @@ class _PaymentMethodEditorState extends State<PaymentMethodEditor> {
     });
     try {
       PaymentMethod pm = PaymentMethod(
-          id: _paymentMethod.id,
+          id: _paymentMethod!.id,
           name: _nameController.text,
           accountName: _accountNameController.text,
           account: _accountNumberController.text,
@@ -208,7 +208,7 @@ class _PaymentMethodEditorState extends State<PaymentMethodEditor> {
     });
     try {
       await Provider.of<PaymentMethodModel>(context, listen: false)
-          .deletePaymentMethod(_paymentMethod.id);
+          .deletePaymentMethod(_paymentMethod!.id!);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/payment_methods/payment_method_page.dart b/lib/pages/payment_methods/payment_method_page.dart
index b03e94a..0fb95e2 100644
--- a/lib/pages/payment_methods/payment_method_page.dart
+++ b/lib/pages/payment_methods/payment_method_page.dart
@@ -12,7 +12,7 @@ import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 class PaymentMethodPage extends StatefulWidget {
@@ -84,13 +84,13 @@ class _PaymentMethodPageState extends State<PaymentMethodPage> {
   }
 
   _item(PaymentMethod method, bool isEditable) {
-    final accountName = _itemRow(method.accountName, "pm.account.name",
+    final accountName = _itemRow(method.accountName!, "pm.account.name",
         iconData: MaterialCommunityIcons.bank);
-    final accountNumber = _itemRow(method.account, "pm.account.no",
+    final accountNumber = _itemRow(method.account!, "pm.account.no",
         iconData: MaterialCommunityIcons.checkbook);
-    final phone = _itemRow(method.phone, "pm.phone", iconData: Icons.phone);
-    final email = _itemRow(method.email, "pm.email", iconData: Icons.mail);
-    final link = _itemRow(method.link, "pm.link", iconData: Icons.link);
+    final phone = _itemRow(method.phone!, "pm.phone", iconData: Icons.phone);
+    final email = _itemRow(method.email!, "pm.email", iconData: Icons.mail);
+    final link = _itemRow(method.link!, "pm.link", iconData: Icons.link);
 
     return InkWell(
       onTap: isEditable
@@ -110,7 +110,7 @@ class _PaymentMethodPageState extends State<PaymentMethodPage> {
           Padding(
             padding: const EdgeInsets.all(8.0),
             child: Text(
-              method.name,
+              method.name!,
               style: TextStyle(
                   color: primaryColor,
                   fontWeight: FontWeight.bold,
@@ -127,7 +127,7 @@ class _PaymentMethodPageState extends State<PaymentMethodPage> {
     );
   }
 
-  _itemRow(String text, String labelKey, {IconData iconData}) {
+  _itemRow(String text, String labelKey, {IconData? iconData}) {
     return text == null || text == ""
         ? Container()
         : Row(
@@ -153,7 +153,7 @@ class _PaymentMethodPageState extends State<PaymentMethodPage> {
   }
 
   void _showToast(String title) {
-    final ScaffoldState scaffold = key.currentState;
+    final ScaffoldState scaffold = key.currentState as ScaffoldState;
     scaffold.showSnackBar(
       SnackBar(
         content: Text('copied "$title" data to clipboard'),
diff --git a/lib/pages/processing/model/processing_model.dart b/lib/pages/processing/model/processing_model.dart
index e5782c8..0977245 100644
--- a/lib/pages/processing/model/processing_model.dart
+++ b/lib/pages/processing/model/processing_model.dart
@@ -11,7 +11,7 @@ class ProcessingModel extends BaseModel {
   List<Processing> processings = [];
   final log = Logger('ProcessingModel');
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   void initUser(user) {
     super.initUser(user);
@@ -19,12 +19,12 @@ class ProcessingModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
 
     processings = [];
   }
 
-  Future<void> createProcessing(Processing processing) {}
+  Future<void> createProcessing(Processing processing) async {}
 
-  Future<void> updateProcessing(Processing processing) {}
+  Future<void> updateProcessing(Processing processing) async {}
 }
diff --git a/lib/pages/processing/package_editor.dart b/lib/pages/processing/package_editor.dart
index 17a7292..458e3dc 100644
--- a/lib/pages/processing/package_editor.dart
+++ b/lib/pages/processing/package_editor.dart
@@ -18,14 +18,14 @@ import 'package:fcs/pages/widgets/multi_img_file.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:provider/provider.dart';
 
 class PackageEditor extends StatefulWidget {
-  final Package package;
-  final User consignee;
-  final User sender;
+  final Package? package;
+  final User? consignee;
+  final User? sender;
   PackageEditor({this.package, this.consignee, this.sender});
 
   @override
@@ -38,20 +38,20 @@ class _PackageEditorState extends State<PackageEditor> {
 
   bool _isLoading = false;
   MultiImgController multiImgController = MultiImgController();
-  Package _package;
+  Package? _package;
 
   @override
   void initState() {
     super.initState();
     _package = Package();
-    _loadPackageData(null);
+    _loadPackageData(widget.package!.id!);
   }
 
   _loadPackageData(String id) async {
     if (id != null) {
       PackageModel packageModel =
           Provider.of<PackageModel>(context, listen: false);
-      Package package = await packageModel.getPackage(id);
+      Package? package = await packageModel.getPackage(id);
       if (package != null) {
         if (package.status != package_received_status) {
           showMsgDialog(context, "Error",
@@ -64,10 +64,10 @@ class _PackageEditorState extends State<PackageEditor> {
       }
     }
     setState(() {
-      selectedMarket = _package.market ?? "";
-      _descCtl.text = _package.desc;
-      _remarkCtl.text = _package.remark;
-      multiImgController.setImageUrls = _package.photoUrls;
+      selectedMarket = _package!.market ?? "";
+      _descCtl.text = _package!.desc!;
+      _remarkCtl.text = _package!.remark!;
+      multiImgController.setImageUrls = _package!.photoUrls;
     });
   }
 
@@ -77,14 +77,14 @@ class _PackageEditorState extends State<PackageEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: _package.trackingID,
+          text: _package!.trackingID != null ? _package!.trackingID : "",
           labelTextKey: "processing.tracking.id",
           iconData: MaterialCommunityIcons.barcode_scan,
         )),
         IconButton(
             icon: Icon(Icons.search, color: primaryColor),
             onPressed: () => searchPackage(context, callbackPackageSelect: (u) {
-                  _loadPackageData(u.id);
+                  _loadPackageData(u.id!);
                   Navigator.pop(context);
                 })),
       ],
@@ -174,13 +174,13 @@ class _PackageEditorState extends State<PackageEditor> {
     );
   }
 
-  String selectedMarket;
+  String? selectedMarket;
   Widget marketDropdown() {
     List<Market> _markets = Provider.of<MarketModel>(context).markets;
-    List<String> markets = _markets.map((e) => e.name).toList();
+    List<String?> markets = _markets.map((e) => e.name).toList();
     markets.insert(0, MANAGE_MARKET);
     if (!markets.contains(selectedMarket)) {
-      markets.insert(0, selectedMarket);
+      markets.insert(0, selectedMarket!);
     }
 
     return Row(
@@ -210,7 +210,7 @@ class _PackageEditorState extends State<PackageEditor> {
                   height: 1,
                   color: Colors.grey,
                 ),
-                onChanged: (String newValue) {
+                onChanged: (String? newValue) {
                   setState(() {
                     if (newValue == MANAGE_MARKET) {
                       selectedMarket = null;
@@ -221,7 +221,7 @@ class _PackageEditorState extends State<PackageEditor> {
                   });
                 },
                 isExpanded: true,
-                items: markets.map<DropdownMenuItem<String>>((String value) {
+                items: markets.map<DropdownMenuItem<String>>((String? value) {
                   return DropdownMenuItem<String>(
                     value: value,
                     child: Text(value ?? "",
@@ -254,14 +254,15 @@ class _PackageEditorState extends State<PackageEditor> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     try {
-      _package.market = selectedMarket;
-      _package.desc = _descCtl.text;
-      _package.remark = _remarkCtl.text;
-      _package.photoFiles = multiImgController.getUpdatedFile;
-      _package.fcsID = widget.consignee.fcsID;
-      _package.senderFCSID = widget.sender?.fcsID;
+      _package!.market = selectedMarket!;
+      _package!.desc = _descCtl.text;
+      _package!.remark = _remarkCtl.text;
+      _package!.photoFiles = multiImgController.getUpdatedFile;
+      _package!.fcsID = widget.consignee!.fcsID;
+      _package!.senderFCSID =
+          widget.sender!.fcsID != null ? widget.sender!.fcsID : "";
 
-      await packageModel.updateProcessing(_package,
+      await packageModel.updateProcessing(_package!,
           multiImgController.getAddedFile, multiImgController.getDeletedUrl);
 
       Navigator.pop<Package>(context, _package);
diff --git a/lib/pages/processing/processing_edit_editor.dart b/lib/pages/processing/processing_edit_editor.dart
index 9c3678f..4751134 100644
--- a/lib/pages/processing/processing_edit_editor.dart
+++ b/lib/pages/processing/processing_edit_editor.dart
@@ -17,12 +17,12 @@ import 'package:fcs/pages/widgets/multi_img_file.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class ProcessingEditEditor extends StatefulWidget {
-  final Package package;
+  final Package? package;
   ProcessingEditEditor({this.package});
 
   @override
@@ -33,22 +33,22 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
   TextEditingController _remarkCtl = new TextEditingController();
   TextEditingController _descCtl = new TextEditingController();
 
-  Package _package;
-  User _user;
+  Package? _package;
+  User? _user;
   bool _isLoading = false;
 
   @override
   void initState() {
     super.initState();
     _package = widget.package;
-    selectedMarket = _package.market ?? "";
-    _descCtl.text = _package.desc;
-    _remarkCtl.text = _package.remark;
-    multiImgController.setImageUrls = _package.photoUrls;
+    selectedMarket = _package!.market ?? "";
+    _descCtl.text = _package!.desc!;
+    _remarkCtl.text = _package!.remark!;
+    multiImgController.setImageUrls = _package!.photoUrls;
     _user = User(
-        fcsID: _package.fcsID ?? "",
-        name: _package.userName ?? "",
-        phoneNumber: _package.phoneNumber ?? "");
+        fcsID: _package!.fcsID ?? "",
+        name: _package!.userName ?? "",
+        phoneNumber: _package!.phoneNumber ?? "");
   }
 
   final DateFormat dateFormat = DateFormat("d MMM yyyy");
@@ -62,7 +62,7 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: _user.fcsID,
+          text: _user!.fcsID,
           labelTextKey: "processing.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -76,18 +76,18 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
       ],
     );
     final namebox = DisplayText(
-      text: _user.name,
+      text: _user!.name,
       labelTextKey: "processing.name",
       iconData: Icons.person,
     );
     final phoneNumberBox = DisplayText(
-      text: _user.phoneNumber,
+      text: _user!.phoneNumber,
       labelTextKey: "processing.phone",
       iconData: Icons.phone,
     );
 
     final trackingIdBox = DisplayText(
-      text: _package.trackingID,
+      text: _package!.trackingID,
       labelTextKey: "processing.tracking.id",
       iconData: MaterialCommunityIcons.barcode_scan,
     );
@@ -159,13 +159,13 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
     );
   }
 
-  String selectedMarket;
+  String? selectedMarket;
   Widget marketDropdown() {
     List<Market> _markets = Provider.of<MarketModel>(context).markets;
-    List<String> markets = _markets.map((e) => e.name).toList();
+    List<String?> markets = _markets.map((e) => e.name).toList();
     markets.insert(0, MANAGE_MARKET);
     if (!markets.contains(selectedMarket)) {
-      markets.insert(0, selectedMarket);
+      markets.insert(0, selectedMarket!);
     }
 
     return Padding(
@@ -197,7 +197,7 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
                     height: 1,
                     color: Colors.grey,
                   ),
-                  onChanged: (String newValue) {
+                  onChanged: (String? newValue) {
                     setState(() {
                       if (newValue == MANAGE_MARKET) {
                         selectedMarket = null;
@@ -208,7 +208,7 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
                     });
                   },
                   isExpanded: true,
-                  items: markets.map<DropdownMenuItem<String>>((String value) {
+                  items: markets.map<DropdownMenuItem<String>>((String? value) {
                     return DropdownMenuItem<String>(
                       value: value,
                       child: Text(value ?? "",
@@ -236,7 +236,7 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
   }
 
   _completeProcessing() async {
-    if (_user.fcsID == null || _user.fcsID == "") {
+    if (_user!.fcsID == null || _user!.fcsID == "") {
       showMsgDialog(context, "Error", "Expected FCS-ID");
       return;
     }
@@ -246,11 +246,11 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     try {
-      _package.fcsID = _user.fcsID;
-      _package.desc = _descCtl.text;
-      _package.remark = _remarkCtl.text;
-      _package.market = selectedMarket;
-      await packageModel.updateProcessing(_package,
+      _package!.fcsID = _user!.fcsID;
+      _package!.desc = _descCtl.text;
+      _package!.remark = _remarkCtl.text;
+      _package!.market = selectedMarket!;
+      await packageModel.updateProcessing(_package!,
           multiImgController.getAddedFile, multiImgController.getDeletedUrl);
       Navigator.pop(context);
     } catch (e) {
@@ -264,20 +264,20 @@ class _ProcessingEditEditorState extends State<ProcessingEditEditor> {
 
   isDataChanged() {
     if (isNew) {
-      return _user.fcsID != "" ||
+      return _user!.fcsID != "" ||
           selectedMarket != null ||
           _descCtl.text != "" ||
           _remarkCtl.text != "" ||
           multiImgController.getAddedFile.isNotEmpty;
     } else {
       var _package = Package(
-          trackingID: widget.package.trackingID,
-          fcsID: _user.fcsID,
-          market: selectedMarket,
+          trackingID: widget.package!.trackingID,
+          fcsID: _user!.fcsID,
+          market: selectedMarket!,
           desc: _descCtl.text,
           remark: _remarkCtl.text,
-          photoUrls: widget.package.photoUrls);
-      return widget.package.isChangedForEditProcessing(_package) ||
+          photoUrls: widget.package!.photoUrls);
+      return widget.package!.isChangedForEditProcessing(_package) ||
           multiImgController.getAddedFile.isNotEmpty ||
           multiImgController.getDeletedUrl.isNotEmpty;
     }
diff --git a/lib/pages/processing/processing_editor.dart b/lib/pages/processing/processing_editor.dart
index 3618af4..3ae2505 100644
--- a/lib/pages/processing/processing_editor.dart
+++ b/lib/pages/processing/processing_editor.dart
@@ -11,14 +11,14 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 import 'model/processing_model.dart';
 import 'package_editor.dart';
 
 class ProcesingEditor extends StatefulWidget {
-  final Processing processing;
+  final Processing? processing;
   const ProcesingEditor({this.processing});
   @override
   _ProcesingEditorState createState() => _ProcesingEditorState();
@@ -27,9 +27,9 @@ class ProcesingEditor extends StatefulWidget {
 class _ProcesingEditorState extends State<ProcesingEditor> {
   Processing processing = Processing();
   bool _isLoading = false;
-  bool _isNew;
-  User consignee;
-  User sender;
+  late bool _isNew;
+  User? consignee;
+  User? sender;
   List<Package> packages = [];
 
   @override
@@ -37,7 +37,7 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
     super.initState();
     _isNew = widget.processing == null;
     if (!_isNew) {
-      processing = widget.processing;
+      processing = widget.processing!;
       consignee = User(
           fcsID: processing.userID,
           name: processing.userName,
@@ -56,7 +56,7 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: consignee != null ? consignee.fcsID : "",
+          text: consignee != null ? consignee!.fcsID : "",
           labelTextKey: "processing.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -71,14 +71,14 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
     );
 
     final phoneNumberBox = DisplayText(
-      text: consignee != null ? consignee.phoneNumber : "",
+      text: consignee != null ? consignee!.phoneNumber : "",
       labelTextKey: "processing.phone",
       maxLines: 2,
       iconData: Icons.phone,
     );
 
     final namebox = DisplayText(
-      text: consignee != null ? consignee.name : "",
+      text: consignee != null ? consignee!.name : "",
       labelTextKey: "processing.consignee.name",
       maxLines: 2,
       iconData: Icons.person,
@@ -98,7 +98,7 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: sender != null ? sender.fcsID : "",
+          text: sender != null ? sender!.fcsID : "",
           labelTextKey: "processing.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -113,14 +113,14 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
     );
 
     final shipperPhoneNumberBox = DisplayText(
-      text: sender != null ? sender.phoneNumber : "",
+      text: sender != null ? sender!.phoneNumber : "",
       labelTextKey: "processing.phone",
       maxLines: 2,
       iconData: Icons.phone,
     );
 
     final shipperNamebox = DisplayText(
-      text: sender != null ? sender.name : "",
+      text: sender != null ? sender!.name : "",
       labelTextKey: "processing.shipper.name",
       maxLines: 2,
       iconData: Icons.person,
@@ -152,7 +152,7 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
                       context, "Warning", "Please select 'Consignee'");
                   return;
                 }
-                Package _package = await Navigator.push<Package>(
+                Package? _package = await Navigator.push<Package>(
                   context,
                   CupertinoPageRoute(
                       builder: (context) => PackageEditor(
@@ -160,7 +160,7 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
                             consignee: this.consignee,
                           )),
                 );
-                _addPackage(_package);
+                _addPackage(_package!);
                 // _savePackage(_package);
               }),
         ],
@@ -230,10 +230,10 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
     return packages.map((p) {
       return InkWell(
         onTap: () async {
-          Package _package = await Navigator.of(context).push<Package>(
+          Package? _package = await Navigator.of(context).push<Package>(
               CupertinoPageRoute(
                   builder: (context) => PackageInfo(package: p)));
-          _savePackage(_package);
+          _savePackage(_package!);
         },
         child: DisplayText(
           labelTextKey: "processing.tracking.id",
@@ -273,7 +273,7 @@ class _ProcesingEditorState extends State<ProcesingEditor> {
       if (_isNew) {
         await processingModel.createProcessing(processing);
       } else {
-        processing.id = widget.processing.id;
+        processing.id = widget.processing!.id;
         await processingModel.updateProcessing(processing);
       }
       Navigator.pop(context);
diff --git a/lib/pages/processing/processing_info.dart b/lib/pages/processing/processing_info.dart
index 735de59..d15d0c9 100644
--- a/lib/pages/processing/processing_info.dart
+++ b/lib/pages/processing/processing_info.dart
@@ -11,7 +11,7 @@ import 'package:fcs/pages/widgets/progress.dart';
 import 'package:fcs/pages/widgets/status_tree.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
@@ -20,7 +20,7 @@ import 'processing_edit_editor.dart';
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class ProcessingInfo extends StatefulWidget {
-  final Package package;
+  final Package? package;
   ProcessingInfo({this.package});
 
   @override
@@ -29,14 +29,14 @@ class ProcessingInfo extends StatefulWidget {
 
 class _ProcessingInfoState extends State<ProcessingInfo> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
-  Package _package;
+  Package? _package;
   bool _isLoading = false;
   MultiImgController multiImgController = MultiImgController();
 
   @override
   void initState() {
     super.initState();
-    initPackage(widget.package);
+    initPackage(widget.package!);
   }
 
   initPackage(Package package) {
@@ -54,52 +54,52 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
   @override
   Widget build(BuildContext context) {
     final trackingIdBox = DisplayText(
-      text: _package.trackingID,
+      text: _package != null ? _package!.trackingID : '',
       labelTextKey: "processing.tracking.id",
       iconData: MaterialCommunityIcons.barcode_scan,
     );
     var fcsIDBox = DisplayText(
-      text: _package.fcsID,
+      text: _package != null ? _package!.fcsID : "",
       labelTextKey: "processing.fcs.id",
       icon: FcsIDIcon(),
     );
     final phoneNumberBox = DisplayText(
-      text: _package.phoneNumber,
+      text: _package != null ? _package!.phoneNumber : "",
       labelTextKey: "processing.phone",
       iconData: Icons.phone,
     );
     final customerNameBox = DisplayText(
-      text: _package.userName,
+      text:_package!=null? _package!.userName:"",
       labelTextKey: "processing.consignee.name",
       iconData: Icons.perm_identity,
     );
     var senderFcsIDBox = DisplayText(
-      text: _package.senderFCSID,
+      text:_package!=null? _package!.senderFCSID:"",
       labelTextKey: "processing.fcs.id",
       icon: FcsIDIcon(),
     );
     final senderPhoneNumberBox = DisplayText(
-      text: _package.senderPhoneNumber,
+      text: _package!=null?_package!.senderPhoneNumber:"",
       labelTextKey: "processing.phone",
       iconData: Icons.phone,
     );
     final senderNameBox = DisplayText(
-      text: _package.senderName,
+      text:_package!=null? _package!.senderName:"",
       labelTextKey: "processing.shipper.name",
       iconData: Icons.perm_identity,
     );
     final marketBox = DisplayText(
-      text: _package.market ?? "-",
+      text:_package!=null? _package!.market : "-",
       labelTextKey: "processing.market",
       iconData: Icons.store,
     );
     final descBox = DisplayText(
-      text: _package.desc ?? "-",
+      text:_package!=null? _package!.desc : "-",
       labelTextKey: "processing.desc",
       iconData: MaterialCommunityIcons.message_text_outline,
     );
     final remarkBox = DisplayText(
-      text: _package.remark ?? "-",
+      text:_package!=null? _package!.remark : "-",
       labelTextKey: "processing.remark",
       iconData: Entypo.new_message,
     );
@@ -172,10 +172,10 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
                   marketBox,
                   descBox,
                   remarkBox,
-                  _package.photoUrls.length == 0 ? Container() : img,
+                  _package!.photoUrls.length == 0 ? Container() : img,
                   StatusTree(
-                      shipmentHistory: _package.shipmentHistory,
-                      currentStatus: _package.status),
+                      shipmentHistory: _package!.shipmentHistory,
+                      currentStatus: _package!.status??""),
                   SizedBox(
                     height: 20,
                   )
@@ -199,7 +199,7 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     try {
-      await packageModel.deleteProcessing(_package);
+      await packageModel.deleteProcessing(_package!);
       Navigator.pop<bool>(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -211,7 +211,7 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
   }
 
   _gotoEditor() async {
-    bool deleted = await Navigator.push<bool>(
+    bool? deleted = await Navigator.push<bool>(
         context,
         CupertinoPageRoute(
             builder: (context) => ProcessingEditEditor(
@@ -222,8 +222,8 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
     } else {
       PackageModel packageModel =
           Provider.of<PackageModel>(context, listen: false);
-      Package p = await packageModel.getPackage(_package.id);
-      initPackage(p);
+      Package? p = await packageModel.getPackage(_package!.id!);
+      initPackage(p!);
     }
   }
 }
diff --git a/lib/pages/processing/processing_list.dart b/lib/pages/processing/processing_list.dart
index 7f5855a..ec021b0 100644
--- a/lib/pages/processing/processing_list.dart
+++ b/lib/pages/processing/processing_list.dart
@@ -85,7 +85,7 @@ class _ProcessingListState extends State<ProcessingList> {
 
   _searchCallback(Package package) async {
     var packageModel = Provider.of<PackageModel>(context, listen: false);
-    Package _package = await packageModel.getPackage(package.id);
+    Package? _package = await packageModel.getPackage(package.id!);
     if (_package == null) return;
     Navigator.push(
       context,
diff --git a/lib/pages/processing/processing_list_row.dart b/lib/pages/processing/processing_list_row.dart
index cc06c16..d702d4f 100644
--- a/lib/pages/processing/processing_list_row.dart
+++ b/lib/pages/processing/processing_list_row.dart
@@ -3,7 +3,7 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 import 'processing_info.dart';
@@ -11,12 +11,12 @@ import 'processing_info.dart';
 typedef CallbackPackageSelect(Package package);
 
 class ProcessingListRow extends StatelessWidget {
-  final Package package;
-  final CallbackPackageSelect callbackPackageSelect;
+  final Package? package;
+  final CallbackPackageSelect? callbackPackageSelect;
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
 
-  ProcessingListRow({Key key, this.package, this.callbackPackageSelect})
+  ProcessingListRow({Key? key, this.package, this.callbackPackageSelect})
       : super(key: key);
 
   @override
@@ -24,7 +24,7 @@ class ProcessingListRow extends StatelessWidget {
     return InkWell(
       onTap: () {
         if (callbackPackageSelect != null) {
-          callbackPackageSelect(package);
+          callbackPackageSelect!(package!);
           return;
         }
         Navigator.push(
@@ -57,7 +57,7 @@ class ProcessingListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              package.id == null ? '' : package.trackingID,
+                              package!.id == null ? '' : package!.trackingID!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -65,7 +65,7 @@ class ProcessingListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              package.market == null ? '' : package.market,
+                              package!.market == null ? '' : package!.market!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -81,12 +81,14 @@ class ProcessingListRow extends StatelessWidget {
               children: <Widget>[
                 Padding(
                   padding: const EdgeInsets.all(3.0),
-                  child: getStatus(package.status),
+                  child: getStatus(package!.status??""),
                 ),
                 Padding(
                   padding: const EdgeInsets.all(0),
                   child: new Text(
-                    dateFormat.format(package.currentStatusDate),
+                    package!.currentStatusDate != null
+                        ? dateFormat.format(package!.currentStatusDate!)
+                        : '',
                     style: new TextStyle(fontSize: 15.0, color: Colors.grey),
                   ),
                 ),
diff --git a/lib/pages/processing_old/processing_editor.dart b/lib/pages/processing_old/processing_editor.dart
index 634247d..59e0a3c 100644
--- a/lib/pages/processing_old/processing_editor.dart
+++ b/lib/pages/processing_old/processing_editor.dart
@@ -18,12 +18,12 @@ import 'package:fcs/pages/widgets/multi_img_file.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class ProcessingEditor extends StatefulWidget {
-  final Package package;
+  final Package? package;
   ProcessingEditor({this.package});
 
   @override
@@ -34,22 +34,22 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
   TextEditingController _remarkCtl = new TextEditingController();
   TextEditingController _descCtl = new TextEditingController();
 
-  Package _package;
-  User _user;
+  Package? _package;
+  User? _user;
   bool _isLoading = false;
 
   @override
   void initState() {
     super.initState();
     _package = widget.package;
-    selectedMarket = _package.market ?? "";
-    _descCtl.text = _package.desc;
-    _remarkCtl.text = _package.remark;
-    multiImgController.setImageUrls = _package.photoUrls;
+    selectedMarket = _package!.market ?? "";
+    _descCtl.text = _package!.desc!;
+    _remarkCtl.text = _package!.remark!;
+    multiImgController.setImageUrls = _package!.photoUrls;
     _user = User(
-        fcsID: _package.fcsID ?? "",
-        name: _package.userName ?? "",
-        phoneNumber: _package.phoneNumber ?? "");
+        fcsID: _package!.fcsID ?? "",
+        name: _package!.userName ?? "",
+        phoneNumber: _package!.phoneNumber ?? "");
   }
 
   final DateFormat dateFormat = DateFormat("d MMM yyyy");
@@ -63,7 +63,7 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: _user.fcsID,
+          text: _user!.fcsID??"",
           labelTextKey: "processing.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -77,18 +77,18 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
       ],
     );
     final namebox = DisplayText(
-      text: _user.name,
+      text: _user!.name??"",
       labelTextKey: "processing.name",
       iconData: Icons.person,
     );
     final phoneNumberBox = DisplayText(
-      text: _user.phoneNumber,
+      text: _user!.phoneNumber??"",
       labelTextKey: "processing.phone",
       iconData: Icons.phone,
     );
 
     final trackingIdBox = DisplayText(
-      text: _package.trackingID,
+      text: _package!.trackingID??"",
       labelTextKey: "processing.tracking.id",
       iconData: MaterialCommunityIcons.barcode_scan,
     );
@@ -152,13 +152,13 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
     );
   }
 
-  String selectedMarket;
+  String? selectedMarket;
   Widget marketDropdown() {
     List<Market> _markets = Provider.of<MarketModel>(context).markets;
-    List<String> markets = _markets.map((e) => e.name).toList();
+    List<String?> markets = _markets.map((e) => e.name).toList();
     markets.insert(0, MANAGE_MARKET);
     if (!markets.contains(selectedMarket)) {
-      markets.insert(0, selectedMarket);
+      markets.insert(0, selectedMarket!);
     }
 
     return Padding(
@@ -190,7 +190,7 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
                     height: 1,
                     color: Colors.grey,
                   ),
-                  onChanged: (String newValue) {
+                  onChanged: (String? newValue) {
                     setState(() {
                       if (newValue == MANAGE_MARKET) {
                         selectedMarket = null;
@@ -201,7 +201,7 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
                     });
                   },
                   isExpanded: true,
-                  items: markets.map<DropdownMenuItem<String>>((String value) {
+                  items: markets.map<DropdownMenuItem<String>>((String? value) {
                     return DropdownMenuItem<String>(
                       value: value,
                       child: Text(value ?? "",
@@ -229,7 +229,7 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
   }
 
   _completeProcessing() async {
-    if (_user.fcsID == null || _user.fcsID == "") {
+    if (_user!.fcsID == null || _user!.fcsID == "") {
       showMsgDialog(context, "Error", "Expected FCS-ID");
       return;
     }
@@ -239,11 +239,11 @@ class _ProcessingEditorState extends State<ProcessingEditor> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     try {
-      _package.fcsID = _user.fcsID;
-      _package.desc = _descCtl.text;
-      _package.remark = _remarkCtl.text;
-      _package.market = selectedMarket;
-      await packageModel.updateProcessing(_package,
+      _package!.fcsID = _user!.fcsID;
+      _package!.desc = _descCtl.text;
+      _package!.remark = _remarkCtl.text;
+      _package!.market = selectedMarket;
+      await packageModel.updateProcessing(_package!,
           multiImgController.getAddedFile, multiImgController.getDeletedUrl);
       Navigator.pop(context);
     } catch (e) {
diff --git a/lib/pages/processing_old/processing_info.dart b/lib/pages/processing_old/processing_info.dart
index 0b6fe43..d48a433 100644
--- a/lib/pages/processing_old/processing_info.dart
+++ b/lib/pages/processing_old/processing_info.dart
@@ -12,7 +12,8 @@ import 'package:fcs/pages/widgets/progress.dart';
 import 'package:fcs/pages/widgets/status_tree.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
+
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
@@ -21,7 +22,7 @@ import 'processing_editor.dart';
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class ProcessingInfo extends StatefulWidget {
-  final Package package;
+  final Package? package;
   ProcessingInfo({this.package});
 
   @override
@@ -30,14 +31,14 @@ class ProcessingInfo extends StatefulWidget {
 
 class _ProcessingInfoState extends State<ProcessingInfo> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
-  Package _package;
+  Package? _package;
   bool _isLoading = false;
   MultiImgController multiImgController = MultiImgController();
 
   @override
   void initState() {
     super.initState();
-    initPackage(widget.package);
+    initPackage(widget.package!);
   }
 
   initPackage(Package package) {
@@ -55,37 +56,37 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
   @override
   Widget build(BuildContext context) {
     final trackingIdBox = DisplayText(
-      text: _package.trackingID,
+      text: _package!.trackingID ?? "",
       labelTextKey: "processing.tracking.id",
       iconData: MaterialCommunityIcons.barcode_scan,
     );
     var fcsIDBox = DisplayText(
-      text: _package.fcsID,
+      text: _package!.fcsID??"",
       labelTextKey: "processing.fcs.id",
       icon: FcsIDIcon(),
     );
     final phoneNumberBox = DisplayText(
-      text: _package.phoneNumber,
+      text: _package!.phoneNumber??"",
       labelTextKey: "processing.phone",
       iconData: Icons.phone,
     );
     final customerNameBox = DisplayText(
-      text: _package.userName,
+      text: _package!.userName??"",
       labelTextKey: "processing.name",
       iconData: Icons.perm_identity,
     );
     final marketBox = DisplayText(
-      text: _package.market ?? "-",
+      text: _package!.market ?? "-",
       labelTextKey: "processing.market",
       iconData: Icons.store,
     );
     final descBox = DisplayText(
-      text: _package.desc ?? "-",
+      text: _package!.desc ?? "-",
       labelTextKey: "processing.desc",
       iconData: MaterialCommunityIcons.message_text_outline,
     );
     final remarkBox = DisplayText(
-      text: _package.remark ?? "-",
+      text: _package!.remark ?? "-",
       labelTextKey: "processing.remark",
       iconData: Entypo.new_message,
     );
@@ -137,10 +138,10 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
                   marketBox,
                   descBox,
                   remarkBox,
-                  _package.photoUrls.length == 0 ? Container() : img,
+                  _package!.photoUrls.length == 0 ? Container() : img,
                   StatusTree(
-                      shipmentHistory: _package.shipmentHistory,
-                      currentStatus: _package.status),
+                      shipmentHistory: _package!.shipmentHistory,
+                      currentStatus: _package!.status??""),
                   SizedBox(
                     height: 20,
                   )
@@ -164,7 +165,7 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
     try {
-      await packageModel.deleteProcessing(_package);
+      await packageModel.deleteProcessing(_package!);
       Navigator.pop<bool>(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -176,19 +177,19 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
   }
 
   _gotoEditor() async {
-    bool deleted = await Navigator.push<bool>(
+    bool? deleted = await Navigator.push<bool>(
         context,
         CupertinoPageRoute(
             builder: (context) => ProcessingEditor(
-                  package: widget.package,
+                  package: widget.package!,
                 )));
     if (deleted ?? false) {
       Navigator.pop(context);
     } else {
       PackageModel packageModel =
           Provider.of<PackageModel>(context, listen: false);
-      Package p = await packageModel.getPackage(_package.id);
-      initPackage(p);
+      Package? p = await packageModel.getPackage(_package!.id!);
+      initPackage(p!);
     }
   }
 }
diff --git a/lib/pages/processing_old/processing_list.dart b/lib/pages/processing_old/processing_list.dart
index 6ab3497..38e5c0a 100644
--- a/lib/pages/processing_old/processing_list.dart
+++ b/lib/pages/processing_old/processing_list.dart
@@ -77,7 +77,7 @@ class _ProcessingListState extends State<ProcessingList> {
 
   _searchCallback(Package package) async {
     var packageModel = Provider.of<PackageModel>(context, listen: false);
-    Package _package = await packageModel.getPackage(package.id);
+    Package? _package = await packageModel.getPackage(package.id!);
     if (_package == null) return;
     Navigator.push(
       context,
diff --git a/lib/pages/processing_old/processing_list_row.dart b/lib/pages/processing_old/processing_list_row.dart
index cc06c16..a287b2c 100644
--- a/lib/pages/processing_old/processing_list_row.dart
+++ b/lib/pages/processing_old/processing_list_row.dart
@@ -3,7 +3,7 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:intl/intl.dart';
 
 import 'processing_info.dart';
@@ -11,12 +11,12 @@ import 'processing_info.dart';
 typedef CallbackPackageSelect(Package package);
 
 class ProcessingListRow extends StatelessWidget {
-  final Package package;
-  final CallbackPackageSelect callbackPackageSelect;
+  final Package? package;
+  final CallbackPackageSelect? callbackPackageSelect;
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
 
-  ProcessingListRow({Key key, this.package, this.callbackPackageSelect})
+  ProcessingListRow({Key? key, this.package, this.callbackPackageSelect})
       : super(key: key);
 
   @override
@@ -24,7 +24,7 @@ class ProcessingListRow extends StatelessWidget {
     return InkWell(
       onTap: () {
         if (callbackPackageSelect != null) {
-          callbackPackageSelect(package);
+          callbackPackageSelect!(package!);
           return;
         }
         Navigator.push(
@@ -45,7 +45,7 @@ class ProcessingListRow extends StatelessWidget {
                     Container(
                       padding: EdgeInsets.only(left: 5, right: 10),
                       child: Icon(
-                        FontAwesome.dropbox,
+                        FontAwesomeIcons.dropbox,
                         color: primaryColor,
                         size: 30,
                       ),
@@ -57,7 +57,7 @@ class ProcessingListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              package.id == null ? '' : package.trackingID,
+                              package!.id == null ? '' : package!.trackingID!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -65,7 +65,7 @@ class ProcessingListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              package.market == null ? '' : package.market,
+                              package!.market == null ? '' : package!.market!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -81,12 +81,14 @@ class ProcessingListRow extends StatelessWidget {
               children: <Widget>[
                 Padding(
                   padding: const EdgeInsets.all(3.0),
-                  child: getStatus(package.status),
+                  child: getStatus(package!.status ?? ""),
                 ),
                 Padding(
                   padding: const EdgeInsets.all(0),
                   child: new Text(
-                    dateFormat.format(package.currentStatusDate),
+                    package!.currentStatusDate != null
+                        ? dateFormat.format(package!.currentStatusDate!)
+                        : '',
                     style: new TextStyle(fontSize: 15.0, color: Colors.grey),
                   ),
                 ),
diff --git a/lib/pages/profile/profile_currency_edit.dart b/lib/pages/profile/profile_currency_edit.dart
index 92fe1c8..db76f8d 100644
--- a/lib/pages/profile/profile_currency_edit.dart
+++ b/lib/pages/profile/profile_currency_edit.dart
@@ -1,6 +1,4 @@
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/localization/app_translations.dart';
-import 'package:fcs/pages/main/model/language_model.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
@@ -26,7 +24,7 @@ class _ProfileCurrencyEditState extends State<ProfileCurrencyEdit> {
   void initState() {
     super.initState();
     MainModel mainModel = Provider.of<MainModel>(context, listen: false);
-    if (mainModel.user.preferCurrency == "MMK") {
+    if (mainModel.user!.preferCurrency == "MMK") {
       _currency = Currency.MMK;
     } else {
       _currency = Currency.USD;
@@ -76,7 +74,8 @@ class _ProfileCurrencyEditState extends State<ProfileCurrencyEdit> {
                   activeColor: primaryColor,
                   value: Currency.USD,
                   groupValue: _currency,
-                  onChanged: (Currency value) {
+                  onChanged: (Currency? value) {
+                    if(value != null)
                     setState(() {
                       _currency = value;
                     });
@@ -94,7 +93,8 @@ class _ProfileCurrencyEditState extends State<ProfileCurrencyEdit> {
                   activeColor: primaryColor,
                   value: Currency.MMK,
                   groupValue: _currency,
-                  onChanged: (Currency value) {
+                  onChanged: (Currency? value) {
+                    if(value != null)
                     setState(() {
                       _currency = value;
                     });
diff --git a/lib/pages/profile/profile_edit.dart b/lib/pages/profile/profile_edit.dart
index a4ab671..9880a87 100644
--- a/lib/pages/profile/profile_edit.dart
+++ b/lib/pages/profile/profile_edit.dart
@@ -24,7 +24,7 @@ class _ProfileEditState extends State<ProfileEdit> {
   void initState() {
     super.initState();
     MainModel mainModel = Provider.of<MainModel>(context, listen: false);
-    nameController.text = mainModel.user.name;
+    nameController.text = mainModel.user!.name ?? "";
   }
 
   @override
@@ -39,7 +39,7 @@ class _ProfileEditState extends State<ProfileEdit> {
           cursorColor: primaryColor,
           style: textStyle,
           decoration: new InputDecoration(
-            labelText: AppTranslations.of(context).text("profile.name"),
+            labelText: AppTranslations.of(context)!.text("profile.name"),
             labelStyle: languageModel.isEng ? labelStyle : labelStyleMM,
             icon: Icon(
               Icons.person,
diff --git a/lib/pages/profile/profile_page.dart b/lib/pages/profile/profile_page.dart
index 67395f9..3732104 100644
--- a/lib/pages/profile/profile_page.dart
+++ b/lib/pages/profile/profile_page.dart
@@ -1,9 +1,7 @@
 import 'package:fcs/domain/entities/user.dart';
-import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/domain/vo/privilege.dart';
 import 'package:fcs/localization/transalation.dart';
 import 'package:fcs/pages/delivery_address/delivery_address_list.dart';
-import 'package:fcs/pages/delivery_address/delivery_address_row.dart';
 import 'package:fcs/pages/delivery_address/model/delivery_address_model.dart';
 import 'package:fcs/pages/main/model/language_model.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
@@ -11,7 +9,6 @@ import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/profile/profile_currency_edit.dart';
 import 'package:fcs/pages/profile/profile_edit.dart';
 import 'package:fcs/pages/staff/model/staff_model.dart';
-import 'package:fcs/pages/widgets/bottom_up_page_route.dart';
 import 'package:fcs/pages/widgets/defalut_delivery_address.dart';
 import 'package:fcs/pages/widgets/display_text.dart';
 import 'package:fcs/pages/widgets/fcs_id_icon.dart';
@@ -20,8 +17,8 @@ import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
-import 'package:flutter_icons/flutter_icons.dart';
 import 'package:provider/provider.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 
 import '../../helpers/theme.dart';
 
@@ -35,7 +32,7 @@ class Profile extends StatefulWidget {
 class _ProfileState extends State<Profile> {
   GlobalKey key = GlobalKey();
   bool _isLoading = false;
-  String selectedLanguage;
+  String? selectedLanguage;
   TextEditingController bizNameController = new TextEditingController();
 
   static final List<String> languagesList = Translation().supportedLanguages;
@@ -71,18 +68,19 @@ class _ProfileState extends State<Profile> {
         Provider.of<DeliveryAddressModel>(context);
 
     final namebox = DisplayText(
-      text: mainModel.user.name + " (${mainModel.user.status})",
+      text: "${mainModel.user!.name ?? ''}" +
+          " (${mainModel.user!.status ?? ''})",
       labelTextKey: "profile.name",
       iconData: Icons.person,
     );
     final currencyBox = DisplayText(
-      text: mainModel.user.preferCurrency,
+      text: mainModel.user!.preferCurrency ?? "",
       labelTextKey: "profile.currency",
-      iconData: FontAwesome5.money_bill_alt,
+      iconData: FontAwesome5Regular.money_bill_alt,
     );
 
     final phonenumberbox = DisplayText(
-      text: mainModel.user.phone,
+      text: mainModel.user!.phone,
       labelTextKey: "profile.phone",
       iconData: Icons.phone,
     );
@@ -90,15 +88,15 @@ class _ProfileState extends State<Profile> {
       children: [
         Expanded(
           child: DisplayText(
-            text: mainModel.user.fcsID,
+            text: mainModel.user!.fcsID ?? "",
             labelTextKey: "customer.fcs.id",
             icon: FcsIDIcon(),
           ),
         ),
         IconButton(
           icon: Icon(Icons.content_copy, color: Colors.grey),
-          onPressed: () => _copy(
-              getLocalString(context, "customer.fcs.id"), mainModel.user.fcsID),
+          onPressed: () => _copy(getLocalString(context, "customer.fcs.id"),
+              mainModel.user!.fcsID ?? ""),
         )
       ],
     );
@@ -107,7 +105,7 @@ class _ProfileState extends State<Profile> {
       children: [
         Expanded(
           child: DisplayText(
-            text: mainModel.setting.usaAddress,
+            text: mainModel.setting!.usaAddress ?? "",
             labelTextKey: "profile.usa.shipping.address",
             iconData: Icons.location_on,
           ),
@@ -116,7 +114,7 @@ class _ProfileState extends State<Profile> {
           icon: Icon(Icons.content_copy, color: Colors.grey),
           onPressed: () => _copy(
               getLocalString(context, "profile.usa.shipping.address"),
-              mainModel.setting.usaAddress),
+              mainModel.setting!.usaAddress ?? ""),
         )
       ],
     );
@@ -199,14 +197,14 @@ class _ProfileState extends State<Profile> {
   }
 
   Widget getPrivilegeBox(BuildContext context) {
-    User user = Provider.of<MainModel>(context, listen: false).user;
+    User? user = Provider.of<MainModel>(context, listen: false).user;
     List<Privilege> _privileges =
         Provider.of<StaffModel>(context, listen: false).privileges;
 
     if (user == null || user.isCustomer()) return Container();
     List<Privilege> privileges = [];
     user.privileges.forEach((e) {
-      var p = _privileges.firstWhere((p) => p.id == e, orElse: () => null);
+      var p = _privileges.firstWhere((p) => p.id == e);
       if (p != null) {
         privileges.add(p);
       }
@@ -274,7 +272,7 @@ class _ProfileState extends State<Profile> {
   }
 
   _showToast(String title) {
-    final ScaffoldState scaffold = key.currentState;
+    final ScaffoldState scaffold = key.currentState as ScaffoldState;
     scaffold.showSnackBar(
       SnackBar(
         content: Text('copied "$title" data to clipboard'),
diff --git a/lib/pages/rates/cargo_editor.dart b/lib/pages/rates/cargo_editor.dart
index d084754..2c25d86 100644
--- a/lib/pages/rates/cargo_editor.dart
+++ b/lib/pages/rates/cargo_editor.dart
@@ -11,7 +11,7 @@ import 'package:provider/provider.dart';
 import 'model/shipment_rate_model.dart';
 
 class CargoEditor extends StatefulWidget {
-  final CargoType cargo;
+  final CargoType? cargo;
   CargoEditor({this.cargo});
 
   @override
@@ -23,15 +23,15 @@ class _CargoEditorState extends State<CargoEditor> {
   TextEditingController _rateController = new TextEditingController();
 
   bool _isLoading = false;
-  CargoType _cargo;
+  late CargoType _cargo;
   bool _isNew = false;
 
   @override
   void initState() {
     super.initState();
     if (widget.cargo != null) {
-      _cargo = widget.cargo;
-      _descController.text = _cargo.name;
+      _cargo = widget.cargo!;
+      _descController.text = _cargo.name ?? "";
       _rateController.text = _cargo.rate.toStringAsFixed(2);
     } else {
       _isNew = true;
@@ -71,7 +71,7 @@ class _CargoEditorState extends State<CargoEditor> {
             },
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("cargo.form.title")),
+          title: Text(AppTranslations.of(context)!.text("cargo.form.title")),
           actions: [
             IconButton(
               icon: Icon(Icons.delete),
@@ -114,7 +114,7 @@ class _CargoEditorState extends State<CargoEditor> {
       if (_isNew) {
         await shipmentRateModel.addCargoType(_cargo);
       } else {
-        _cargo.id = widget.cargo.id;
+        _cargo.id = this._cargo.id;
         await shipmentRateModel.updateCargoType(_cargo);
       }
       Navigator.pop(context);
@@ -138,7 +138,7 @@ class _CargoEditorState extends State<CargoEditor> {
     try {
       var shipmentRateModel =
           Provider.of<ShipmentRateModel>(context, listen: false);
-      await shipmentRateModel.deleteCargoType(widget.cargo.id);
+      await shipmentRateModel.deleteCargoType(this._cargo.id!);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -155,7 +155,7 @@ class _CargoEditorState extends State<CargoEditor> {
     } else {
       CargoType _cargo = CargoType(
           name: _descController.text, rate: double.parse(_rateController.text));
-      return widget.cargo.isChangedForEdit(_cargo);
+      return this._cargo.isChangedForEdit(_cargo);
     }
   }
 }
diff --git a/lib/pages/rates/cargo_type_list.dart b/lib/pages/rates/cargo_type_list.dart
index 1e766c3..0fab20a 100644
--- a/lib/pages/rates/cargo_type_list.dart
+++ b/lib/pages/rates/cargo_type_list.dart
@@ -10,7 +10,7 @@ import 'cargo_editor.dart';
 import 'model/shipment_rate_model.dart';
 
 class CargoTypeList extends StatefulWidget {
-  const CargoTypeList({Key key}) : super(key: key);
+  const CargoTypeList({Key? key}) : super(key: key);
   @override
   _CargoTypeListState createState() => _CargoTypeListState();
 }
@@ -75,7 +75,7 @@ class _CargoTypeListState extends State<CargoTypeList> {
                               )));
                     },
                     child: Container(
-                      child: _row(cargo.name,
+                      child: _row(cargo.name ?? "",
                           "\$ " + cargo.rate.toStringAsFixed(2), 'per pound'),
                     ),
                   );
diff --git a/lib/pages/rates/custom_editor.dart b/lib/pages/rates/custom_editor.dart
index 018804d..bec5ddb 100644
--- a/lib/pages/rates/custom_editor.dart
+++ b/lib/pages/rates/custom_editor.dart
@@ -12,7 +12,7 @@ import 'package:provider/provider.dart';
 import 'model/shipment_rate_model.dart';
 
 class CustomEditor extends StatefulWidget {
-  final CargoType custom;
+  final CargoType? custom;
   CustomEditor({this.custom});
 
   @override
@@ -32,8 +32,8 @@ class _CustomEditorState extends State<CustomEditor> {
   void initState() {
     super.initState();
     if (widget.custom != null) {
-      _custom = widget.custom;
-      _productController.text = _custom.name;
+      _custom = widget.custom!;
+      _productController.text = _custom.name??"";
       _feeController.text = _custom.customDutyFee.toStringAsFixed(2);
       _shipmentRateController.text =
           _custom.rate == null ? "" : _custom.rate.toStringAsFixed(2);
@@ -83,7 +83,7 @@ class _CustomEditorState extends State<CustomEditor> {
           ),
           backgroundColor: primaryColor,
           title:
-              Text(AppTranslations.of(context).text("rate.custom.form.title")),
+              Text(AppTranslations.of(context)!.text("rate.custom.form.title")),
           actions: [
             IconButton(
               icon: Icon(Icons.delete),
@@ -129,7 +129,7 @@ class _CustomEditorState extends State<CustomEditor> {
       if (_isNew) {
         await shipmentRateModel.addCustomDuty(_customduty);
       } else {
-        _customduty.id = widget.custom.id;
+        _customduty.id = this._custom.id;
         await shipmentRateModel.updateCustomDuty(_customduty);
       }
       Navigator.pop(context);
@@ -154,7 +154,7 @@ class _CustomEditorState extends State<CustomEditor> {
     try {
       var shipmentRateModel =
           Provider.of<ShipmentRateModel>(context, listen: false);
-      await shipmentRateModel.deleteCustomDuty(widget.custom.id);
+      await shipmentRateModel.deleteCustomDuty(this._custom.id!);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -175,7 +175,7 @@ class _CustomEditorState extends State<CustomEditor> {
           name: _productController.text,
           customDutyFee: double.parse(_feeController.text),
           rate: double.parse(_shipmentRateController.text));
-      return widget.custom.isChangedForEditCustomDuty(_customduty);
+      return this._custom.isChangedForEditCustomDuty(_customduty);
     }
   }
 }
diff --git a/lib/pages/rates/custom_list.dart b/lib/pages/rates/custom_list.dart
index bbff27c..f5a1dc9 100644
--- a/lib/pages/rates/custom_list.dart
+++ b/lib/pages/rates/custom_list.dart
@@ -1,11 +1,6 @@
 import 'package:fcs/domain/entities/cargo_type.dart';
-import 'package:fcs/domain/entities/custom_duty.dart';
-import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/pages/delivery_address/delivery_address_editor.dart';
-import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/rates/custom_editor.dart';
-import 'package:fcs/pages/widgets/bottom_up_page_route.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
@@ -14,8 +9,8 @@ import 'package:provider/provider.dart';
 import 'model/shipment_rate_model.dart';
 
 class CustomList extends StatefulWidget {
-  final bool selected;
-  const CustomList({Key key, this.selected}) : super(key: key);
+  final bool? selected;
+  const CustomList({Key? key, this.selected}) : super(key: key);
   @override
   _CustomListState createState() => _CustomListState();
 }
@@ -28,7 +23,7 @@ class _CustomListState extends State<CustomList> {
   void initState() {
     super.initState();
     if (widget.selected != null) {
-      _selected = widget.selected;
+      _selected = widget.selected!;
     }
   }
 
@@ -86,11 +81,12 @@ class _CustomListState extends State<CustomList> {
                     },
                     child: Container(
                       child: _row(
-                          custom.name,
+                          custom.name??"",
                           "Custom Fee \$ " + custom.customDutyFee.toStringAsFixed(2),
                           custom.rate == null
                               ? ""
-                              : "Shipment rate \$ " + custom.rate.toStringAsFixed(2)),
+                              : "Shipment rate \$ " +
+                                  custom.rate.toStringAsFixed(2)),
                     ),
                   );
                 }),
diff --git a/lib/pages/rates/custom_row.dart b/lib/pages/rates/custom_row.dart
index 87a1a89..359c1b8 100644
--- a/lib/pages/rates/custom_row.dart
+++ b/lib/pages/rates/custom_row.dart
@@ -1,17 +1,16 @@
 import 'package:fcs/domain/entities/custom_duty.dart';
-import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 
 typedef SelectionCallback(CustomDuty custom);
 
 class CustomRow extends StatelessWidget {
   final CustomDuty custom;
-  final SelectionCallback selectionCallback;
-  const CustomRow({Key key, this.custom, this.selectionCallback})
+  final SelectionCallback? selectionCallback;
+  const CustomRow({Key? key, required this.custom, this.selectionCallback})
       : super(key: key);
 
   @override
@@ -19,7 +18,7 @@ class CustomRow extends StatelessWidget {
     return InkWell(
       onTap: selectionCallback == null
           ? null
-          : () => this.selectionCallback(custom),
+          : () => this.selectionCallback!(custom),
       child: Row(
         children: <Widget>[
           Expanded(
@@ -40,8 +39,8 @@ class CustomRow extends StatelessWidget {
     );
   }
 
-  Widget line(BuildContext context, String text,
-      {IconData iconData, Color color, double fontSize}) {
+  Widget line(BuildContext context, String? text,
+      {IconData? iconData, Color? color, double? fontSize}) {
     return Row(
       children: [
         iconData == null
@@ -55,7 +54,7 @@ class CustomRow extends StatelessWidget {
             context,
             text ?? "",
             fontSize: fontSize ?? 14,
-            color: color,
+            color: color ?? Colors.grey,
           ),
         ),
       ],
diff --git a/lib/pages/rates/discount_by weight_list.dart b/lib/pages/rates/discount_by weight_list.dart
index 73b7467..ad54af2 100644
--- a/lib/pages/rates/discount_by weight_list.dart	
+++ b/lib/pages/rates/discount_by weight_list.dart	
@@ -1,24 +1,16 @@
-import 'package:fcs/domain/entities/custom_duty.dart';
-import 'package:fcs/domain/entities/discount.dart';
 import 'package:fcs/domain/entities/discount_by_weight.dart';
-import 'package:fcs/domain/vo/delivery_address.dart';
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/pages/delivery_address/delivery_address_editor.dart';
-import 'package:fcs/pages/main/util.dart';
-import 'package:fcs/pages/rates/custom_editor.dart';
 import 'package:fcs/pages/rates/discount_by_weight_editor.dart';
-import 'package:fcs/pages/widgets/bottom_up_page_route.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
-import 'custom_row.dart';
 import 'model/shipment_rate_model.dart';
 
 class DiscountByWeightList extends StatefulWidget {
-  const DiscountByWeightList({Key key}) : super(key: key);
+  const DiscountByWeightList({Key? key}) : super(key: key);
   @override
   _DiscountByWeightListState createState() => _DiscountByWeightListState();
 }
diff --git a/lib/pages/rates/discount_by_weight_editor.dart b/lib/pages/rates/discount_by_weight_editor.dart
index 973d156..11096fd 100644
--- a/lib/pages/rates/discount_by_weight_editor.dart
+++ b/lib/pages/rates/discount_by_weight_editor.dart
@@ -11,7 +11,7 @@ import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:provider/provider.dart';
 
 class DiscountByWeightEditor extends StatefulWidget {
-  final DiscountByWeight discountByWeight;
+  final DiscountByWeight? discountByWeight;
   DiscountByWeightEditor({this.discountByWeight});
 
   @override
@@ -23,14 +23,14 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
   TextEditingController _discountController = new TextEditingController();
 
   bool _isLoading = false;
-  bool _isNew;
+  bool _isNew = false;
   DiscountByWeight _discountByWeight = new DiscountByWeight();
 
   @override
   void initState() {
     super.initState();
     if (widget.discountByWeight != null) {
-      _discountByWeight = widget.discountByWeight;
+      _discountByWeight = widget.discountByWeight!;
       _weightController.text = _discountByWeight.weight.toStringAsFixed(2);
       _discountController.text = _discountByWeight.discount.toString();
       _isNew = false;
@@ -73,7 +73,7 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
             },
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("discount.new")),
+          title: Text(AppTranslations.of(context)!.text("discount.new")),
           actions: [
             IconButton(
               icon: Icon(Icons.delete),
@@ -117,7 +117,7 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
       if (_isNew) {
         await shipmentRateModel.addDiscountByWeight(_discount);
       } else {
-        _discount.id = widget.discountByWeight.id;
+        _discount.id = this._discountByWeight.id;
         await shipmentRateModel.updateDiscountByWeight(_discount);
       }
       Navigator.pop(context);
@@ -143,7 +143,7 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
       var shipmentRateModel =
           Provider.of<ShipmentRateModel>(context, listen: false);
       await shipmentRateModel
-          .deleteDiscountByWeight(widget.discountByWeight.id);
+          .deleteDiscountByWeight(this._discountByWeight.id!);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -161,7 +161,7 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
       DiscountByWeight _discount = DiscountByWeight(
           weight: double.parse(_weightController.text),
           discount: double.parse(_discountController.text));
-      return widget.discountByWeight.isChangedForEdit(_discount);
+      return this._discountByWeight.isChangedForEdit(_discount);
     }
   }
 }
diff --git a/lib/pages/rates/model/shipment_rate_model.dart b/lib/pages/rates/model/shipment_rate_model.dart
index 4304dc1..83ba871 100644
--- a/lib/pages/rates/model/shipment_rate_model.dart
+++ b/lib/pages/rates/model/shipment_rate_model.dart
@@ -2,7 +2,6 @@ import 'dart:async';
 
 import 'package:fcs/data/services/services.dart';
 import 'package:fcs/domain/entities/cargo_type.dart';
-import 'package:fcs/domain/entities/custom_duty.dart';
 import 'package:fcs/domain/entities/discount_by_weight.dart';
 import 'package:fcs/domain/entities/rate.dart';
 import 'package:fcs/pages/main/model/base_model.dart';
@@ -11,12 +10,12 @@ import 'package:logging/logging.dart';
 class ShipmentRateModel extends BaseModel {
   final log = Logger('ShipmentRateModel');
 
-  StreamSubscription<Rate> listener;
-  Rate rate;
+  StreamSubscription<Rate>? listener;
+  late Rate rate;
 
   void initUser(user) {
     super.initUser(user);
-    if (listener != null) listener.cancel();
+    if (listener != null) listener!.cancel();
     listener = Services.instance.rateService.getRateStream().listen((rate) {
       this.rate = rate;
       notifyListeners();
@@ -25,7 +24,7 @@ class ShipmentRateModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
   }
 
   // Rate
@@ -51,12 +50,12 @@ class ShipmentRateModel extends BaseModel {
   //CustomDuty
 
   Future<void> addCustomDuty(CargoType customDuty) {
-    customDuty.isCutomDuty=true;
+    customDuty.isCutomDuty = true;
     return Services.instance.rateService.createCargoType(customDuty);
   }
 
   Future<void> updateCustomDuty(CargoType customDuty) {
-    customDuty.isCutomDuty=true;
+    customDuty.isCutomDuty = true;
     return Services.instance.rateService.updateCargoType(customDuty);
   }
 
diff --git a/lib/pages/rates/shipment_rates.dart b/lib/pages/rates/shipment_rates.dart
index ff4d865..1613d70 100644
--- a/lib/pages/rates/shipment_rates.dart
+++ b/lib/pages/rates/shipment_rates.dart
@@ -1,5 +1,4 @@
 import 'package:fcs/domain/entities/cargo_type.dart';
-import 'package:fcs/domain/entities/custom_duty.dart';
 import 'package:fcs/domain/entities/discount_by_weight.dart';
 import 'package:fcs/domain/entities/rate.dart';
 import 'package:fcs/helpers/theme.dart';
@@ -185,8 +184,8 @@ class _ShipmentRatesState extends State<ShipmentRates> {
   List<Widget> getCargoWidget(List<CargoType> cargos) {
     return cargos.map((cargo) {
       return Container(
-        child: _row(
-            cargo.name, "\$ " + cargo.rate.toStringAsFixed(2), 'per pound'),
+        child: _row(cargo.name ?? "", "\$ " + cargo.rate.toStringAsFixed(2),
+            'per pound'),
       );
     }).toList();
   }
@@ -194,7 +193,8 @@ class _ShipmentRatesState extends State<ShipmentRates> {
   List<Widget> getCustonWidget(List<CargoType> customs) {
     return customs.map((c) {
       return Container(
-        child: _row(c.name, "\$ " + c.customDutyFee.toStringAsFixed(2), ''),
+        child:
+            _row(c.name ?? "", "\$ " + c.customDutyFee.toStringAsFixed(2), ''),
       );
     }).toList();
   }
diff --git a/lib/pages/rates/shipment_rates_calculate.dart b/lib/pages/rates/shipment_rates_calculate.dart
index 8d21d54..c722c86 100644
--- a/lib/pages/rates/shipment_rates_calculate.dart
+++ b/lib/pages/rates/shipment_rates_calculate.dart
@@ -2,7 +2,6 @@ import 'package:fcs/domain/entities/carton.dart';
 import 'package:fcs/domain/entities/cargo_type.dart';
 import 'package:fcs/domain/entities/rate.dart';
 import 'package:fcs/helpers/theme.dart';
-import 'package:fcs/pages/main/util.dart';
 import 'package:fcs/pages/rates/model/shipment_rate_model.dart';
 import 'package:fcs/pages/widgets/display_text.dart';
 import 'package:fcs/pages/widgets/input_text.dart';
@@ -12,7 +11,7 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:provider/provider.dart';
 
 class ShipmentRatesCal extends StatefulWidget {
@@ -24,7 +23,7 @@ class ShipmentRatesCal extends StatefulWidget {
 
 class _ShipmentRatesCalState extends State<ShipmentRatesCal> {
   bool _isLoading = false;
-  CargoType _cargoType;
+  late CargoType _cargoType;
   TextEditingController _widthController = new TextEditingController();
   TextEditingController _heightController = new TextEditingController();
   TextEditingController _lengthController = new TextEditingController();
diff --git a/lib/pages/rates/shipment_rates_edit.dart b/lib/pages/rates/shipment_rates_edit.dart
index b85f5aa..c5590c3 100644
--- a/lib/pages/rates/shipment_rates_edit.dart
+++ b/lib/pages/rates/shipment_rates_edit.dart
@@ -1,12 +1,8 @@
-import 'package:fcs/domain/entities/cargo_type.dart';
-import 'package:fcs/domain/entities/custom_duty.dart';
-import 'package:fcs/domain/entities/discount_by_weight.dart';
 import 'package:fcs/domain/entities/rate.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/localization/app_translations.dart';
 import 'package:fcs/pages/rates/model/shipment_rate_model.dart';
 import 'package:fcs/pages/widgets/input_text.dart';
-import 'package:fcs/pages/widgets/my_data_table.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
@@ -14,8 +10,6 @@ import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:provider/provider.dart';
 
 import '../main/util.dart';
-import 'cargo_editor.dart';
-import 'custom_editor.dart';
 
 class ShipmentRatesEdit extends StatefulWidget {
   ShipmentRatesEdit();
@@ -32,7 +26,7 @@ class _ShipmentRatesEditState extends State<ShipmentRatesEdit> {
   TextEditingController _diffDiscountWeight = new TextEditingController();
   TextEditingController _diffWeightRate = new TextEditingController();
 
-  Rate rate;
+  late Rate rate;
 
   @override
   void initState() {
@@ -41,12 +35,11 @@ class _ShipmentRatesEditState extends State<ShipmentRatesEdit> {
         Provider.of<ShipmentRateModel>(context, listen: false);
     rate = shipmentRateModel.rate;
 
-    _minWeight.text = rate.freeDeliveryWeight?.toStringAsFixed(2) ?? "";
-    _deliveryFee.text = rate.deliveryFee?.toStringAsFixed(2) ?? "";
-    _volumetricRatio.text = rate.volumetricRatio?.toStringAsFixed(2) ?? "";
-    _diffDiscountWeight.text =
-        rate.diffDiscountWeight?.toStringAsFixed(2) ?? "";
-    _diffWeightRate.text = rate.diffWeightRate?.toStringAsFixed(2) ?? "";
+    _minWeight.text = rate.freeDeliveryWeight.toStringAsFixed(2);
+    _deliveryFee.text = rate.deliveryFee.toStringAsFixed(2);
+    _volumetricRatio.text = rate.volumetricRatio.toStringAsFixed(2);
+    _diffDiscountWeight.text = rate.diffDiscountWeight.toStringAsFixed(2);
+    _diffWeightRate.text = rate.diffWeightRate.toStringAsFixed(2);
   }
 
   @override
@@ -99,7 +92,7 @@ class _ShipmentRatesEditState extends State<ShipmentRatesEdit> {
             },
           ),
           backgroundColor: primaryColor,
-          title: Text(AppTranslations.of(context).text("rate.edit.title")),
+          title: Text(AppTranslations.of(context)!.text("rate.edit.title")),
         ),
         body: Container(
           padding: EdgeInsets.all(18),
diff --git a/lib/pages/receiving/receiving_editor.dart b/lib/pages/receiving/receiving_editor.dart
index b8ccc7a..a120ee0 100644
--- a/lib/pages/receiving/receiving_editor.dart
+++ b/lib/pages/receiving/receiving_editor.dart
@@ -14,14 +14,14 @@ import 'package:fcs/pages/widgets/multi_img_file.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:permission_handler/permission_handler.dart';
 import 'package:provider/provider.dart';
 
 typedef void FindCallBack();
 
 class ReceivingEditor extends StatefulWidget {
-  final Package package;
+  final Package? package;
   const ReceivingEditor({this.package});
   @override
   _ReceivingEditorState createState() => _ReceivingEditorState();
@@ -30,8 +30,8 @@ class ReceivingEditor extends StatefulWidget {
 class _ReceivingEditorState extends State<ReceivingEditor> {
   Package package = Package();
   bool _isLoading = false;
-  bool _isNew;
-  User user;
+  late bool _isNew;
+  User? user;
   TextEditingController _trackingIDCtl = new TextEditingController();
   TextEditingController _remarkCtl = new TextEditingController();
   MultiImgController _multiImgController = MultiImgController();
@@ -41,9 +41,9 @@ class _ReceivingEditorState extends State<ReceivingEditor> {
     super.initState();
     _isNew = widget.package == null;
     if (!_isNew) {
-      package = widget.package;
-      _trackingIDCtl.text = package.trackingID;
-      _remarkCtl.text = package.remark;
+      package = widget.package!;
+      _trackingIDCtl.text = package.trackingID!;
+      _remarkCtl.text = package.remark!;
       _multiImgController.setImageUrls = package.photoUrls;
       user = User(
           fcsID: package.fcsID,
@@ -71,7 +71,7 @@ class _ReceivingEditorState extends State<ReceivingEditor> {
       children: <Widget>[
         Expanded(
             child: DisplayText(
-          text: user != null ? user.fcsID : "",
+          text: user != null ? user!.fcsID : "",
           labelTextKey: "receiving.fcs.id",
           icon: FcsIDIcon(),
         )),
@@ -124,7 +124,7 @@ class _ReceivingEditorState extends State<ReceivingEditor> {
       title: "Receiving",
     );
     final namebox = DisplayText(
-      text: user != null ? user.name : "",
+      text: user != null ? user!.name : "",
       labelTextKey: "receiving.consignee.name",
       iconData: Icons.person,
     );
@@ -199,20 +199,20 @@ class _ReceivingEditorState extends State<ReceivingEditor> {
   }
 
   _scan() async {
-    PermissionStatus permission =
-        await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
-    if (permission != PermissionStatus.granted) {
-      Map<PermissionGroup, PermissionStatus> permissions =
-          await PermissionHandler()
-              .requestPermissions([PermissionGroup.camera]);
-      if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
-        showMsgDialog(context, "Error", "Camera permission is not granted");
-        return null;
-      }
-    }
+    // PermissionStatus permission =
+    //     await PermissionHandler().checkPermissionStatus(PermissionGroup.camera);
+    // if (permission != PermissionStatus.granted) {
+    //   Map<PermissionGroup, PermissionStatus> permissions =
+    //       await PermissionHandler()
+    //           .requestPermissions([PermissionGroup.camera]);
+    //   if (permissions[PermissionGroup.camera] != PermissionStatus.granted) {
+    //     showMsgDialog(context, "Error", "Camera permission is not granted");
+    //     return null;
+    //   }
+    // }
 
     try {
-      String barcode = await scanBarcode();
+      String? barcode = await scanBarcode();
       if (barcode != null) {
         setState(() {
           _trackingIDCtl.text = barcode;
@@ -239,12 +239,12 @@ class _ReceivingEditorState extends State<ReceivingEditor> {
     try {
       if (_isNew) {
         await packageModel.createReceiving(
-            user, _p, _multiImgController.getAddedFile);
+            user!, _p, _multiImgController.getAddedFile);
       } else {
-        _p.id = widget.package.id;
+        _p.id = widget.package!.id;
         _p.photoUrls = package.photoUrls;
         await packageModel.updateReceiving(
-            user,
+            user!,
             _p,
             _multiImgController.getAddedFile,
             _multiImgController.getDeletedUrl);
@@ -269,9 +269,9 @@ class _ReceivingEditorState extends State<ReceivingEditor> {
       var _package = Package(
           trackingID: _trackingIDCtl.text,
           remark: _remarkCtl.text,
-          fcsID: user.fcsID,
-          photoUrls: widget.package.photoUrls);
-      return widget.package.isChangedForEdit(_package) ||
+          fcsID: user!.fcsID,
+          photoUrls: widget.package!.photoUrls);
+      return widget.package!.isChangedForEdit(_package) ||
           _multiImgController.getAddedFile.isNotEmpty ||
           _multiImgController.getDeletedUrl.isNotEmpty;
     }
diff --git a/lib/pages/receiving/receiving_info.dart b/lib/pages/receiving/receiving_info.dart
index ff5c12a..d029bf8 100644
--- a/lib/pages/receiving/receiving_info.dart
+++ b/lib/pages/receiving/receiving_info.dart
@@ -13,7 +13,7 @@ import 'package:fcs/pages/widgets/progress.dart';
 import 'package:fcs/pages/widgets/status_tree.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
@@ -22,7 +22,7 @@ import 'receiving_editor.dart';
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class ReceivingInfo extends StatefulWidget {
-  final Package package;
+  final Package? package;
   ReceivingInfo({this.package});
 
   @override
@@ -30,14 +30,14 @@ class ReceivingInfo extends StatefulWidget {
 }
 
 class _ReceivingInfoState extends State<ReceivingInfo> {
-  Package _package;
+  Package? _package;
   bool _isLoading = false;
   MultiImgController multiImgController = MultiImgController();
 
   @override
   void initState() {
     super.initState();
-    initPackage(widget.package);
+    initPackage(widget.package!);
   }
 
   initPackage(Package package) {
@@ -57,22 +57,22 @@ class _ReceivingInfoState extends State<ReceivingInfo> {
     bool isCustomer = Provider.of<MainModel>(context).isCustomer();
 
     final trackingIdBox = DisplayText(
-      text: _package.trackingID,
+      text: _package!.trackingID,
       labelTextKey: "package.tracking.id",
       iconData: MaterialCommunityIcons.barcode_scan,
     );
     var fcsIDBox = DisplayText(
-      text: _package.fcsID,
+      text: _package!.fcsID,
       labelTextKey: "processing.fcs.id",
       icon: FcsIDIcon(),
     );
     final customerNameBox = DisplayText(
-      text: _package.userName,
+      text: _package!.userName,
       labelTextKey: "package.create.name",
       iconData: Icons.perm_identity,
     );
     final remarkBox = DisplayText(
-      text: _package.remark ?? "-",
+      text: _package!.remark ?? "-",
       labelTextKey: "package.edit.remark",
       iconData: Entypo.new_message,
     );
@@ -123,10 +123,10 @@ class _ReceivingInfoState extends State<ReceivingInfo> {
                   fcsIDBox,
                   customerNameBox,
                   remarkBox,
-                  _package.photoUrls.length == 0 ? Container() : img,
+                  _package!.photoUrls.length == 0 ? Container() : img,
                   StatusTree(
-                      shipmentHistory: _package.shipmentHistory,
-                      currentStatus: _package.status),
+                      shipmentHistory: _package!.shipmentHistory,
+                      currentStatus: _package!.status),
                   SizedBox(
                     height: 20,
                   )
@@ -149,8 +149,8 @@ class _ReceivingInfoState extends State<ReceivingInfo> {
     );
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
-    var pkg = await packageModel.getPackage(widget.package.id);
-    initPackage(pkg);
+    var pkg = await packageModel.getPackage(widget.package!.id!);
+    initPackage(pkg!);
   }
 
   _delete() {
@@ -164,7 +164,7 @@ class _ReceivingInfoState extends State<ReceivingInfo> {
     try {
       PackageModel packageModel =
           Provider.of<PackageModel>(context, listen: false);
-      await packageModel.deleteReceiving(_package);
+      await packageModel.deleteReceiving(_package!);
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/receiving/receiving_list.dart b/lib/pages/receiving/receiving_list.dart
index d8e9777..8f23bbb 100644
--- a/lib/pages/receiving/receiving_list.dart
+++ b/lib/pages/receiving/receiving_list.dart
@@ -94,7 +94,7 @@ class _ReceivingListState extends State<ReceivingList> {
 
   _searchCallback(Package package) async {
     var packageModel = Provider.of<PackageModel>(context, listen: false);
-    Package _package = await packageModel.getPackage(package.id);
+    Package? _package = await packageModel.getPackage(package.id!);
     if (_package == null) return;
     Navigator.push(
       context,
diff --git a/lib/pages/receiving/receiving_list_row.dart b/lib/pages/receiving/receiving_list_row.dart
index d7a4393..95430de 100644
--- a/lib/pages/receiving/receiving_list_row.dart
+++ b/lib/pages/receiving/receiving_list_row.dart
@@ -3,7 +3,7 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/main/util.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 
 import 'receiving_info.dart';
@@ -11,12 +11,12 @@ import 'receiving_info.dart';
 typedef CallbackPackageSelect(Package package);
 
 class ReceivingListRow extends StatelessWidget {
-  final Package package;
-  final CallbackPackageSelect callbackPackageSelect;
+  final Package? package;
+  final CallbackPackageSelect? callbackPackageSelect;
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
 
-  ReceivingListRow({Key key, this.package, this.callbackPackageSelect})
+  ReceivingListRow({Key? key, this.package, this.callbackPackageSelect})
       : super(key: key);
 
   @override
@@ -24,7 +24,7 @@ class ReceivingListRow extends StatelessWidget {
     return InkWell(
       onTap: () {
         if (callbackPackageSelect != null) {
-          callbackPackageSelect(package);
+          callbackPackageSelect!(package!);
           return;
         }
         Navigator.push(
@@ -55,7 +55,7 @@ class ReceivingListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              package.id == null ? '' : package.trackingID,
+                              package!.id == null ? '' : package!.trackingID!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -63,7 +63,7 @@ class ReceivingListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              package.market == null ? '' : package.market,
+                              package!.market == null ? '' : package!.market!,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -79,12 +79,14 @@ class ReceivingListRow extends StatelessWidget {
               children: <Widget>[
                 Padding(
                   padding: const EdgeInsets.all(3.0),
-                  child: getStatus(package.status),
+                  child: getStatus(package!.status??""),
                 ),
                 Padding(
                   padding: const EdgeInsets.all(0),
                   child: new Text(
-                    dateFormat.format(package.currentStatusDate),
+                    package!.currentStatusDate != null
+                        ? dateFormat.format(package!.currentStatusDate!)
+                        : '',
                     style: new TextStyle(fontSize: 15.0, color: Colors.grey),
                   ),
                 ),
diff --git a/lib/pages/shipment/box_row.dart b/lib/pages/shipment/box_row.dart
index 5b41300..7e9d589 100644
--- a/lib/pages/shipment/box_row.dart
+++ b/lib/pages/shipment/box_row.dart
@@ -5,7 +5,7 @@ import 'package:flutter/material.dart';
 class BoxRow extends StatelessWidget {
   final Carton box;
 
-  const BoxRow({Key key, this.box}) : super(key: key);
+  const BoxRow({Key? key, required this.box}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/lib/pages/shipment/model/shipment_model.dart b/lib/pages/shipment/model/shipment_model.dart
index b78c4bb..0dd8c56 100644
--- a/lib/pages/shipment/model/shipment_model.dart
+++ b/lib/pages/shipment/model/shipment_model.dart
@@ -11,7 +11,7 @@ import 'package:logging/logging.dart';
 class ShipmentModel extends BaseModel {
   final log = Logger('ShipmentModel');
 
-  StreamSubscription<QuerySnapshot> listener;
+  StreamSubscription<QuerySnapshot>? listener;
 
   List<Shipment> get shipments => _menuSelectedIndex == 1
       ? _shipments
@@ -19,7 +19,7 @@ class ShipmentModel extends BaseModel {
 
   List<Shipment> _shipments = [];
 
-  Paginator _delivered;
+  late Paginator _delivered;
   bool isLoading = false;
   int _menuSelectedIndex = 1;
 
@@ -28,7 +28,7 @@ class ShipmentModel extends BaseModel {
     notifyListeners();
   }
 
-  get menuSelectedIndex => _menuSelectedIndex;
+  int get menuSelectedIndex => _menuSelectedIndex;
 
   initData(bool forCustomer, {bool myPickup = false}) {
     logout();
@@ -43,11 +43,11 @@ class ShipmentModel extends BaseModel {
   @override
   logout() async {
     if (_delivered != null) _delivered.close();
-    if (listener != null) await listener.cancel();
+    if (listener != null) await listener!.cancel();
     _shipments = [];
   }
 
-  Future<void> loadMore({bool isCustomer}) async {
+  Future<void> loadMore({bool? isCustomer}) async {
     if (menuSelectedIndex == 1)
       return; // when delivered menu is not selected return
     if (_delivered.ended) return;
@@ -59,7 +59,7 @@ class ShipmentModel extends BaseModel {
     });
   }
 
-  Future<void> refresh({bool isCustomer}) async {
+  Future<void> refresh({bool? isCustomer}) async {
     if (menuSelectedIndex == 1)
       return; // when delivered menu is not selected return
     await _delivered.refresh(onFinished: () {
@@ -70,16 +70,16 @@ class ShipmentModel extends BaseModel {
   Paginator _getDelivered(bool isCustomer) {
     if (!isCustomer) {
       if (user == null ||
-          !((user.hasPackages() ||
-              user.hasReceiving() ||
-              user.hasProcessing()))) throw "No privilege";
+          !((user!.hasPackages() ||
+              user!.hasReceiving() ||
+              user!.hasProcessing()))) throw "No privilege";
     }
-    var pageQuery = Firestore.instance
+    var pageQuery = FirebaseFirestore.instance
         .collection("/$shipments_collection")
         .where("is_delivered", isEqualTo: true)
         .where("is_deleted", isEqualTo: false);
     if (isCustomer) {
-      pageQuery = pageQuery.where("user_id", isEqualTo: user.id);
+      pageQuery = pageQuery.where("user_id", isEqualTo: user!.id);
     }
     pageQuery = pageQuery.orderBy("status_date", descending: true);
     var paginator = new Paginator(pageQuery, rowPerLoad: 20, toObj: (data, id) {
@@ -90,30 +90,31 @@ class ShipmentModel extends BaseModel {
 
   Future<void> _loadShipments(bool forCustomer, bool myPickup) async {
     if (user == null) return;
-    if (!forCustomer && !user.hasShipment()) return;
-    if (listener != null) listener.cancel();
+    if (!forCustomer && !user!.hasShipment()) return;
+    if (listener != null) listener!.cancel();
     _shipments = [];
 
     try {
-      var q = Firestore.instance
+      var q = FirebaseFirestore.instance
           .collection("$shipments_collection")
           .where("is_delivered", isEqualTo: false)
           .where("is_canceled", isEqualTo: false)
           .where("is_deleted", isEqualTo: false);
 
       if (forCustomer) {
-        q = q.where("user_id", isEqualTo: user.id);
+        q = q.where("user_id", isEqualTo: user!.id);
       }
       if (myPickup) {
-        q = q.where("pickup_user_id", isEqualTo: user.id);
+        q = q.where("pickup_user_id", isEqualTo: user!.id);
       }
       q = q.orderBy("created_at", descending: true);
 
       listener = q.snapshots().listen((QuerySnapshot snapshot) {
         _shipments.clear();
-        _shipments = snapshot.documents.map((documentSnapshot) {
+        _shipments = snapshot.docs.map((documentSnapshot) {
           var s = Shipment.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+              documentSnapshot.data as Map<String, dynamic>,
+              documentSnapshot.id);
           return s;
         }).toList();
         notifyListeners();
@@ -130,18 +131,17 @@ class ShipmentModel extends BaseModel {
     shipment_courier_dropoff
   ];
 
-  Shipment getActiveShipment(String shipmentID) {
-    return _shipments?.firstWhere((e) => e.id == shipmentID,
-        orElse: () => null);
+  Shipment? getActiveShipment(String shipmentID) {
+    return _shipments.firstWhere((e) => e.id == shipmentID);
   }
 
-  Future<Shipment> getShipment(String shipmentID) async {
+  Future<Shipment?> getShipment(String shipmentID) async {
     String path = "/$shipments_collection";
     try {
-      var ref = Firestore.instance.collection("$path").document(shipmentID);
-      var snap = await ref.get(source: Source.server);
+      var ref = FirebaseFirestore.instance.collection("$path").doc(shipmentID);
+      var snap = await ref.get(const GetOptions(source: Source.server));
       if (snap.exists) {
-        var s = Shipment.fromMap(snap.data, snap.documentID);
+        var s = Shipment.fromMap(snap.data as Map<String, dynamic>, snap.id);
         return s;
       }
     } catch (e) {
@@ -150,20 +150,20 @@ class ShipmentModel extends BaseModel {
     return null;
   }
 
-  Future<List<Shipment>> getShipmentWithHandlingFee(
+  Future<List<Shipment?>?> getShipmentWithHandlingFee(
       String fcsShipmentID, String userID) async {
     String path = "/$shipments_collection";
     try {
-      var q = Firestore.instance
+      var q = FirebaseFirestore.instance
           .collection("$path")
           .where("user_id", isEqualTo: userID)
           .where("is_deleted", isEqualTo: false)
           .where("handling_fee", isGreaterThan: 0)
           .where("fcs_shipment_id", isEqualTo: fcsShipmentID);
-      var snaps = await q.getDocuments(source: Source.server);
-      List<Shipment> shipments = snaps.documents.map((snap) {
+      var snaps = await q.get(const GetOptions(source: Source.server));
+      List<Shipment?> shipments = snaps.docs.map((snap) {
         if (snap.exists) {
-          var s = Shipment.fromMap(snap.data, snap.documentID);
+          var s = Shipment.fromMap(snap.data as Map<String, dynamic>, snap.id);
           return s;
         }
       }).toList();
diff --git a/lib/pages/shipment/shipment_assign.dart b/lib/pages/shipment/shipment_assign.dart
index 5d160b2..ad2e808 100644
--- a/lib/pages/shipment/shipment_assign.dart
+++ b/lib/pages/shipment/shipment_assign.dart
@@ -14,14 +14,14 @@ import 'package:fcs/pages/widgets/local_title.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 import 'widgets.dart';
 
 class ShipmentAssign extends StatefulWidget {
-  final Shipment shipment;
+  final Shipment? shipment;
   ShipmentAssign({this.shipment});
 
   @override
@@ -38,13 +38,13 @@ class _ShipmentAssignState extends State<ShipmentAssign> {
   TextEditingController _pickupDate = new TextEditingController();
   TextEditingController _handlingFee = new TextEditingController();
 
-  Shipment _shipment;
+  Shipment? _shipment;
   bool _isLoading = false;
   var now = new DateTime.now();
 
-  String _selectedShipmentType;
-  User _user;
-  List<User> _users;
+  String? _selectedShipmentType;
+  User? _user;
+  List<User>? _users;
 
   @override
   void initState() {
@@ -53,18 +53,19 @@ class _ShipmentAssignState extends State<ShipmentAssign> {
     _shipment = widget.shipment;
     _loadUsers();
 
-    _selectedShipmentType = _shipment.shipmentType;
-    _fromTimeEditingController.text = _shipment.pickupTimeStart;
-    _toTimeEditingController.text = _shipment.pickupTimeEnd;
-    _pickupDate.text = dateFormatter.format(_shipment.pickupDate ?? now);
-    _handlingFee.text = _shipment.handlingFee?.toString() ?? "0";
+    _selectedShipmentType = _shipment!.shipmentType;
+    _fromTimeEditingController.text = _shipment!.pickupTimeStart!;
+    _toTimeEditingController.text = _shipment!.pickupTimeEnd!;
+    _pickupDate.text = dateFormatter.format(_shipment!.pickupDate ?? now);
+    _handlingFee.text = _shipment!.handlingFee != null
+        ? _shipment!.handlingFee.toString()
+        : "0";
   }
 
   _loadUsers() async {
     StaffModel staffModel = Provider.of<StaffModel>(context, listen: false);
     var users = await staffModel.getPickupEmployees();
-    var selectUser = users.firstWhere((e) => e.id == _shipment.pickupUserID,
-        orElse: () => null);
+    var selectUser = users.firstWhere((e) => e.id == _shipment!.pickupUserID);
     setState(() {
       _users = users;
       _user = selectUser;
@@ -74,7 +75,7 @@ class _ShipmentAssignState extends State<ShipmentAssign> {
   @override
   Widget build(BuildContext context) {
     ShipmentModel pickupModel = Provider.of<ShipmentModel>(context);
-    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment);
+    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment!);
     bool isLocalPickup = _selectedShipmentType == shipment_local_pickup;
     bool isCourierPickup = _selectedShipmentType == shipment_courier_pickup;
     bool isLocalDropoff = _selectedShipmentType == shipment_local_dropoff;
@@ -146,15 +147,15 @@ class _ShipmentAssignState extends State<ShipmentAssign> {
   }
 
   _save() async {
-    _shipment.pickupUserID = this._user.id;
-    _shipment.handlingFee = double.tryParse(_handlingFee.text) ?? 0;
+    _shipment!.pickupUserID = this._user!.id;
+    _shipment!.handlingFee = double.tryParse(_handlingFee.text) ?? 0;
     setState(() {
       _isLoading = true;
     });
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.assignShipment(_shipment);
+      await shipmentModel.assignShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/shipment/shipment_box_editor.dart b/lib/pages/shipment/shipment_box_editor.dart
index c04338d..1fd3778 100644
--- a/lib/pages/shipment/shipment_box_editor.dart
+++ b/lib/pages/shipment/shipment_box_editor.dart
@@ -17,11 +17,12 @@ import 'package:fcs/pages/widgets/my_data_table.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
+
 import 'package:provider/provider.dart';
 
 class ShipmentBoxEditor extends StatefulWidget {
-  final Carton box;
+  final Carton? box;
   ShipmentBoxEditor({this.box});
 
   @override
@@ -33,9 +34,9 @@ class _ShipmentBoxEditorState extends State<ShipmentBoxEditor> {
   TextEditingController _widthCtl = new TextEditingController();
   TextEditingController _heightCtl = new TextEditingController();
 
-  Carton _box;
+  Carton? _box;
   bool _isLoading = false;
-  bool _isNew;
+  late bool _isNew;
   double volumetricRatio = 0;
   double shipmentWeight = 0;
 
@@ -50,16 +51,16 @@ class _ShipmentBoxEditorState extends State<ShipmentBoxEditor> {
     if (widget.box != null) {
       _box = widget.box;
       _isNew = false;
-      _lengthCtl.text = _box.length.toString();
-      _widthCtl.text = _box.width.toString();
-      _heightCtl.text = _box.height.toString();
+      _lengthCtl.text = _box!.length != null ? _box!.length.toString() : '';
+      _widthCtl.text = _box!.width != null ? _box!.width.toString() : '';
+      _heightCtl.text = _box!.height != null ? _box!.height.toString() : '';
     } else {
       var shipmentModel =
           Provider.of<DeliveryAddressModel>(context, listen: false);
 
       _isNew = true;
       _box = Carton(cargoTypes: []);
-      _box.deliveryAddress = shipmentModel.defalutAddress;
+      _box!.deliveryAddress = shipmentModel.defalutAddress;
 
       _lengthCtl.text = "12";
       _widthCtl.text = "12";
@@ -151,10 +152,11 @@ class _ShipmentBoxEditorState extends State<ShipmentBoxEditor> {
                       color: primaryColor,
                     ),
                     onPressed: () async {
-                      CargoType cargo = await Navigator.push<CargoType>(
+                      CargoType? cargo = await Navigator.push<CargoType>(
                           context,
                           CupertinoPageRoute(
                               builder: (context) => CargoTypeEditor()));
+                      if (cargo == null) return;
                       _addCargo(cargo);
                     }),
               ),
@@ -186,19 +188,19 @@ class _ShipmentBoxEditorState extends State<ShipmentBoxEditor> {
               shipmentWeightBox,
               LocalTitle(textKey: "shipment.box.delivery"),
               DefaultDeliveryAddress(
-                  deliveryAddress: _box.deliveryAddress,
+                  deliveryAddress: _box!.deliveryAddress,
                   labelKey: "shipment.box.delivery",
                   onTap: () async {
-                    DeliveryAddress d = await Navigator.push<DeliveryAddress>(
+                    DeliveryAddress? d = await Navigator.push<DeliveryAddress>(
                       context,
                       CupertinoPageRoute(
                           builder: (context) => DeliveryAddressSelection(
-                              deliveryAddress: _box.deliveryAddress,
+                              deliveryAddress: _box!.deliveryAddress,
                               user: mainModel.user)),
                     );
                     if (d == null) return;
                     setState(() {
-                      _box.deliveryAddress = d;
+                      _box!.deliveryAddress = d;
                     });
                   }),
               createBtn
@@ -210,25 +212,26 @@ class _ShipmentBoxEditorState extends State<ShipmentBoxEditor> {
   }
 
   List<MyDataRow> getCargoRows(BuildContext context) {
-    if (_box.cargoTypes == null) {
+    if (_box!.cargoTypes == null) {
       return [];
     }
     double total = 0;
-    var rows = _box.cargoTypes.map((c) {
+    var rows = _box!.cargoTypes.map((c) {
       total += c.weight;
       return MyDataRow(
         onSelectChanged: (bool selected) async {
-          CargoType cargo = await Navigator.push<CargoType>(
+          CargoType? cargo = await Navigator.push<CargoType>(
               context,
               CupertinoPageRoute(
                   builder: (context) => CargoTypeEditor(
                         cargo: c,
                       )));
+          if (cargo == null) return;
           _addCargo(cargo);
         },
         cells: [
           MyDataCell(new Text(
-            c.name == null ? "" : c.name,
+            c.name == null ? "" : c.name!,
             style: textStyle,
           )),
           MyDataCell(
@@ -281,14 +284,14 @@ class _ShipmentBoxEditorState extends State<ShipmentBoxEditor> {
   _addCargo(CargoType cargo) {
     if (cargo == null) return;
     setState(() {
-      _box.cargoTypes.remove(cargo);
-      _box.cargoTypes.add(cargo);
+      _box!.cargoTypes.remove(cargo);
+      _box!.cargoTypes.add(cargo);
     });
   }
 
   _removeCargo(CargoType cargo) {
     setState(() {
-      _box.cargoTypes.remove(cargo);
+      _box!.cargoTypes.remove(cargo);
     });
   }
 
@@ -296,9 +299,9 @@ class _ShipmentBoxEditorState extends State<ShipmentBoxEditor> {
     double l = double.parse(_lengthCtl.text, (s) => 0);
     double w = double.parse(_widthCtl.text, (s) => 0);
     double h = double.parse(_heightCtl.text, (s) => 0);
-    _box.length = l;
-    _box.width = w;
-    _box.height = h;
+    _box!.length = l;
+    _box!.width = w;
+    _box!.height = h;
     Navigator.pop(context, _box);
   }
 }
diff --git a/lib/pages/shipment/shipment_confirm.dart b/lib/pages/shipment/shipment_confirm.dart
index 5017eed..05ed394 100644
--- a/lib/pages/shipment/shipment_confirm.dart
+++ b/lib/pages/shipment/shipment_confirm.dart
@@ -8,14 +8,15 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
+import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 import 'widgets.dart';
 
 class ShipmentConfirm extends StatefulWidget {
-  final Shipment shipment;
+  final Shipment? shipment;
   ShipmentConfirm({this.shipment});
 
   @override
@@ -27,7 +28,7 @@ class _ShipmentConfirmState extends State<ShipmentConfirm> {
   var timeFormatter = new DateFormat('jm');
   TextEditingController _handlingFee = new TextEditingController();
 
-  Shipment _shipment;
+  Shipment? _shipment;
   bool _isLoading = false;
   var now = new DateTime.now();
 
@@ -36,17 +37,17 @@ class _ShipmentConfirmState extends State<ShipmentConfirm> {
     super.initState();
 
     _shipment = widget.shipment;
-    _handlingFee.text = _shipment.handlingFee?.toString() ?? "0";
+    _handlingFee.text = _shipment!.handlingFee.toString();
   }
 
   @override
   Widget build(BuildContext context) {
-    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment);
+    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment!);
 
     final handlingFeeBox = InputText(
       labelTextKey: "shipment.handling.fee",
       controller: _handlingFee,
-      iconData: FontAwesome.truck,
+      iconData: FontAwesomeIcons.truck,
     );
     final confirmbtn = LocalButton(
       textKey: "shipment.confirm.btn",
@@ -94,14 +95,14 @@ class _ShipmentConfirmState extends State<ShipmentConfirm> {
   }
 
   _save() async {
-    _shipment.handlingFee = double.tryParse(_handlingFee.text) ?? 0;
+    _shipment!.handlingFee = double.tryParse(_handlingFee.text) ?? 0;
     setState(() {
       _isLoading = true;
     });
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.confirmShipment(_shipment);
+      await shipmentModel.confirmShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/shipment/shipment_editor.dart b/lib/pages/shipment/shipment_editor.dart
index 6ea4f81..8dda866 100644
--- a/lib/pages/shipment/shipment_editor.dart
+++ b/lib/pages/shipment/shipment_editor.dart
@@ -29,7 +29,7 @@ import 'shipment_box_editor.dart';
 import 'widgets.dart';
 
 class ShipmentEditor extends StatefulWidget {
-  final Shipment shipment;
+  final Shipment? shipment;
   ShipmentEditor({this.shipment});
 
   @override
@@ -45,12 +45,12 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
   TextEditingController _toTimeEditingController = new TextEditingController();
   TextEditingController _pickupDate = new TextEditingController();
 
-  Shipment _shipment;
+  Shipment? _shipment;
   bool _isLoading = false;
   var now = new DateTime.now();
-  bool _isNew;
+  late bool _isNew;
 
-  String _selectedShipmentType;
+  String? _selectedShipmentType;
 
   @override
   void initState() {
@@ -59,20 +59,21 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
     if (widget.shipment != null) {
       _isNew = false;
       _shipment = widget.shipment;
-      _selectedShipmentType = _shipment.shipmentType;
-      _fromTimeEditingController.text = _shipment.pickupTimeStart;
-      _toTimeEditingController.text = _shipment.pickupTimeEnd;
-      _pickupDate.text = dateFormatter.format(_shipment.pickupDate ?? now);
+      _selectedShipmentType = _shipment!.shipmentType;
+      _fromTimeEditingController.text = _shipment!.pickupTimeStart ?? "";
+      _toTimeEditingController.text = _shipment!.pickupTimeEnd ?? "";
+      _pickupDate.text = dateFormatter.format(_shipment!.pickupDate ?? now);
     } else {
       _isNew = true;
       _selectedShipmentType = shipment_local_pickup;
       _pickupDate.text = dateFormatter.format(now);
       _fromTimeEditingController.text = "${timeFormatter.format(now)}";
       _toTimeEditingController.text = "${timeFormatter.format(now)}";
-      _shipment = Shipment(boxes: []);
+      // _shipment = Shipment(boxes: []);
       var shipmentModel =
           Provider.of<DeliveryAddressModel>(context, listen: false);
-      _shipment.pickupAddress = shipmentModel.defalutAddress;
+      _shipment!.pickupAddress = shipmentModel.defalutAddress;
+      _shipment!.boxes = [];
       _pickupDate.text = dateFormatter.format(now);
     }
   }
@@ -86,7 +87,7 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
   Widget build(BuildContext context) {
     MainModel mainModel = Provider.of<MainModel>(context);
     ShipmentModel pickupModel = Provider.of<ShipmentModel>(context);
-    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment);
+    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment!);
     bool isLocalPickup = _selectedShipmentType == shipment_local_pickup;
     bool isCourierPickup = _selectedShipmentType == shipment_courier_pickup;
     bool isLocalDropoff = _selectedShipmentType == shipment_local_dropoff;
@@ -121,20 +122,20 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
           backgroundColor: Colors.white,
         ));
     final pickupAddressBox = DefaultDeliveryAddress(
-      deliveryAddress: _shipment.pickupAddress,
+      deliveryAddress: _shipment!.pickupAddress,
       iconData: Icons.location_on,
       labelKey: "shipment.location",
       onTap: () async {
-        DeliveryAddress address = await Navigator.push<DeliveryAddress>(
+        DeliveryAddress? address = await Navigator.push<DeliveryAddress>(
           context,
           CupertinoPageRoute(
               builder: (context) => DeliveryAddressSelection(
-                  deliveryAddress: _shipment.pickupAddress,
+                  deliveryAddress: _shipment!.pickupAddress,
                   user: mainModel.user)),
         );
         if (address == null) return;
         setState(() {
-          _shipment.pickupAddress = address;
+          _shipment!.pickupAddress = address;
         });
       },
     );
@@ -142,7 +143,7 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
       FcsIDIcon(),
       Expanded(
         child: DisplayText(
-          text: mainModel.setting.usaAddress,
+          text: mainModel.setting!.usaAddress,
         ),
       )
     ]);
@@ -194,7 +195,7 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
               LocalRadioButtons(
                   values: pickupModel.shipmentTypes,
                   selectedValue: _selectedShipmentType,
-                  callback: (v) {
+                  callback: (String? v) {
                     setState(() {
                       _selectedShipmentType = v;
                     });
@@ -239,7 +240,7 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
                 ),
               ),
               Column(
-                children: getBoxList(context, _shipment.boxes),
+                children: getBoxList(context, _shipment!.boxes),
               ),
               _isNew ? createBtn : updateBtn,
             ],
@@ -276,7 +277,7 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
   _addBox(Carton box) {
     if (box == null) return;
     box.cartonType = carton_from_shipments;
-    _shipment.boxes.add(box);
+    _shipment!.boxes.add(box);
     setState(() {});
   }
 
@@ -287,15 +288,15 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
 
   _removeBox(Carton box) {
     if (box == null) return;
-    _shipment.boxes.remove(box);
+    _shipment!.boxes.remove(box);
     setState(() {});
   }
 
   _save() async {
-    _shipment.shipmentType = this._selectedShipmentType;
-    _shipment.pickupDate = dateFormatter.parse(_pickupDate.text);
-    _shipment.pickupTimeStart = _fromTimeEditingController.text;
-    _shipment.pickupTimeEnd = _toTimeEditingController.text;
+    _shipment!.shipmentType = this._selectedShipmentType;
+    _shipment!.pickupDate = dateFormatter.parse(_pickupDate.text);
+    _shipment!.pickupTimeStart = _fromTimeEditingController.text;
+    _shipment!.pickupTimeEnd = _toTimeEditingController.text;
     setState(() {
       _isLoading = true;
     });
@@ -303,9 +304,9 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
       if (_isNew) {
-        await shipmentModel.createShipment(_shipment);
+        await shipmentModel.createShipment(_shipment!);
       } else {
-        await shipmentModel.updateShipment(_shipment);
+        await shipmentModel.updateShipment(_shipment!);
       }
       Navigator.pop(context, true);
     } catch (e) {
@@ -319,10 +320,10 @@ class _ShipmentEditorState extends State<ShipmentEditor> {
 
   _openCourierWebsite() {
     MainModel mainModel = Provider.of<MainModel>(context, listen: false);
-    launch("${mainModel.setting.courierWebsite}");
+    launch("${mainModel.setting!.courierWebsite}");
   }
 
   isDataChanged() {
-    return _shipment.boxes.isNotEmpty;
+    return _shipment!.boxes.isNotEmpty;
   }
 }
diff --git a/lib/pages/shipment/shipment_info.dart b/lib/pages/shipment/shipment_info.dart
index 0b011bc..ee29ad5 100644
--- a/lib/pages/shipment/shipment_info.dart
+++ b/lib/pages/shipment/shipment_info.dart
@@ -20,7 +20,7 @@ import 'package:fcs/pages/widgets/multi_img_controller.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 import 'package:url_launcher/url_launcher.dart';
@@ -32,8 +32,8 @@ import 'shipment_editor.dart';
 import 'widgets.dart';
 
 class ShipmentInfo extends StatefulWidget {
-  final bool isCustomer;
-  final Shipment shipment;
+  final bool? isCustomer;
+  final Shipment? shipment;
   ShipmentInfo({this.shipment, this.isCustomer});
 
   @override
@@ -62,39 +62,42 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
   TextEditingController _pickupDate = new TextEditingController();
   TextEditingController _handlingFeeController = new TextEditingController();
 
-  Shipment _shipment;
+  Shipment? _shipment;
   bool _isLoading = false;
-  bool _isCustomer;
+  late bool _isCustomer;
   var now = new DateTime.now();
 
   @override
   void initState() {
     super.initState();
     _shipment = widget.shipment;
-    _isCustomer = widget.isCustomer;
-    _loadCartons(_shipment.id);
+    _isCustomer = widget.isCustomer!;
+    _loadCartons(_shipment!.id!);
 
-    _addressEditingController.text = _shipment.address;
-    _fromTimeEditingController.text = _shipment.pickupTimeStart;
-    _toTimeEditingController.text = _shipment.pickupTimeEnd;
-    _noOfPackageEditingController.text = _shipment.numberOfPackage.toString();
-    _weightEditingController.text = _shipment.weight.toString();
-    _pickupDate.text = dateFormatter.format(_shipment.pickupDate ?? now);
+    _addressEditingController.text = _shipment!.address ?? "";
+    _fromTimeEditingController.text = _shipment!.pickupTimeStart ?? "";
+    _toTimeEditingController.text = _shipment!.pickupTimeEnd ?? "";
+    _noOfPackageEditingController.text = _shipment!.numberOfPackage != null
+        ? _shipment!.numberOfPackage.toString()
+        : "";
+    _weightEditingController.text =
+        _shipment!.weight != null ? _shipment!.weight.toString() : "";
+    _pickupDate.text = dateFormatter.format(_shipment!.pickupDate ?? now);
   }
 
   _loadCartons(String shipmentID) async {
     CartonModel cartonModel = Provider.of<CartonModel>(context, listen: false);
     var cartons = await cartonModel.getCartons(shipmentID);
     setState(() {
-      _shipment.boxes = cartons;
+      _shipment!.boxes = cartons;
     });
   }
 
   _loadShipment(String id) async {
     ShipmentModel shipmentModel =
         Provider.of<ShipmentModel>(context, listen: false);
-    Shipment s = await shipmentModel.getShipment(id);
-    s.boxes = _shipment.boxes;
+    Shipment? s = await shipmentModel.getShipment(id);
+    s!.boxes = _shipment!.boxes;
     setState(() {
       _shipment = s;
     });
@@ -109,31 +112,34 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
   Widget build(BuildContext context) {
     MainModel mainModel = Provider.of<MainModel>(context);
     ShipmentModel pickupModel = Provider.of<ShipmentModel>(context);
-    bool isLocalPickup = _shipment.shipmentType == shipment_local_pickup;
-    bool isCourierPickup = _shipment.shipmentType == shipment_courier_pickup;
-    bool isLocalDropoff = _shipment.shipmentType == shipment_local_dropoff;
-    bool isCourierDropoff = _shipment.shipmentType == shipment_courier_dropoff;
-    bool isEditable = widget.isCustomer
-        ? (_shipment.isPending || _shipment.isAssigned)
-        : (_shipment.isPending || _shipment.isAssigned || _shipment.isPickuped);
+    bool isLocalPickup = _shipment!.shipmentType == shipment_local_pickup;
+    bool isCourierPickup = _shipment!.shipmentType == shipment_courier_pickup;
+    bool isLocalDropoff = _shipment!.shipmentType == shipment_local_dropoff;
+    bool isCourierDropoff = _shipment!.shipmentType == shipment_courier_dropoff;
+    bool isEditable = widget.isCustomer!
+        ? (_shipment!.isPending || _shipment!.isAssigned)
+        : (_shipment!.isPending ||
+            _shipment!.isAssigned ||
+            _shipment!.isPickuped);
     bool canCancel =
-        _shipment.isPending || _shipment.isConfirmed || _shipment.isAssigned;
+        _shipment!.isPending || _shipment!.isConfirmed || _shipment!.isAssigned;
 
     final popupMenu = LocalPopupMenuButton(
       popmenus: [
         LocalPopupMenu(
-          enabled: _shipment.isPending && isLocalPickup,
+          enabled: _shipment!.isPending && isLocalPickup,
           id: 1,
           textKey: "shipment.assign.for.pickup",
         ),
         LocalPopupMenu(
           enabled:
-              (_shipment.isPickuped && isLocalPickup) || _shipment.isReceived,
+              (_shipment!.isPickuped && isLocalPickup) || _shipment!.isReceived,
           id: 3,
           textKey: "shipment.pack.menuitem",
         ),
         LocalPopupMenu(
-          enabled: _shipment.isPending && (isCourierPickup || isCourierDropoff),
+          enabled:
+              _shipment!.isPending && (isCourierPickup || isCourierDropoff),
           id: 4,
           textKey: "shipment.confirm.menuitem",
         ),
@@ -149,7 +155,11 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
           ? _gotoAssign()
           : p.id == 2
               ? _cancel()
-              : p.id == 3 ? _gotoPack() : p.id == 4 ? _gotoConfirm() : null,
+              : p.id == 3
+                  ? _gotoPack()
+                  : p.id == 4
+                      ? _gotoConfirm()
+                      : null,
     );
     final popupMenuCustomer = LocalPopupMenuButton(
       popmenus: [
@@ -163,29 +173,31 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
       buttonIcon: Icons.more_vert,
       popupMenuCallback: (p) => p.id == 2 ? _cancel() : null,
     );
-    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment);
+    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment!);
 
     final fromTimeBox = DisplayText(
       labelTextKey: 'shipment.from',
       iconData: Icons.timer,
-      text: _shipment.pickupTimeStart,
+      text: _shipment!.pickupTimeStart ?? "",
     );
     final toTimeBox = DisplayText(
       labelTextKey: 'shipment.to',
       iconData: Icons.timer_off,
-      text: _shipment.pickupTimeEnd,
+      text: _shipment!.pickupTimeEnd ?? "",
     );
 
     final pickupDateBox = DisplayText(
       labelTextKey: "shipment.date",
       iconData: Icons.date_range,
-      text: dateFormatter.format(_shipment.pickupDate),
+      text: _shipment!.pickupDate != null
+          ? dateFormatter.format(_shipment!.pickupDate!)
+          : '',
     );
     var localDropoffAddressBox = Row(children: [
       FcsIDIcon(),
       Expanded(
         child: DisplayText(
-          text: mainModel.setting.usaAddress,
+          text: mainModel.setting!.usaAddress ?? "",
         ),
       )
     ]);
@@ -201,17 +213,17 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
           backgroundColor: Colors.white,
         ));
     final pickupAddressBox = DefaultDeliveryAddress(
-      deliveryAddress: _shipment.pickupAddress,
+      deliveryAddress: _shipment!.pickupAddress,
       iconData: Icons.location_on,
       labelKey: "shipment.location",
     );
     var usersBox = DisplayText(
         labelTextKey: "shipment.staff",
-        text: _shipment.pickupUserName,
+        text: _shipment!.pickupUserName ?? "",
         iconData: MaterialCommunityIcons.worker);
     var handlingFeeBox = DisplayText(
         labelTextKey: "shipment.handling.fee",
-        text: (_shipment.handlingFee ?? 0).toString(),
+        text: (_shipment!.handlingFee).toString(),
         iconData: FontAwesome.truck);
 
     final assignCompleteBtn = LocalButton(
@@ -232,7 +244,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
     );
 
     final fcsShipmentNumberBox = DisplayText(
-      text: _shipment.fcsShipmentNumber,
+      text: _shipment!.fcsShipmentNumber ?? "",
       labelTextKey: "FCSshipment.number",
       iconData: Ionicons.ios_airplane,
     );
@@ -267,7 +279,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
                     color: isEditable ? primaryColor : Colors.grey),
                 onPressed: isEditable ? _edit : null,
               ),
-              widget.isCustomer ? popupMenuCustomer : popupMenu,
+              widget.isCustomer! ? popupMenuCustomer : popupMenu,
             ]),
         body: Padding(
           padding: const EdgeInsets.all(10.0),
@@ -278,7 +290,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
               LocalRadioButtons(
                 readOnly: true,
                 values: pickupModel.shipmentTypes,
-                selectedValue: _shipment.shipmentType,
+                selectedValue: _shipment!.shipmentType,
               ),
               ...(isLocalDropoff
                   ? [
@@ -305,13 +317,13 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
               LocalTitle(
                 textKey: "boxes.name",
                 trailing: Text(
-                    "${_shipment.totalCount} Cartons - ${_shipment.totalWeight} lb"),
+                    "${_shipment!.totalCount} Cartons - ${_shipment!.totalWeight} lb"),
               ),
               Column(
-                children: getBoxList(context, _shipment.boxes),
+                children: getBoxList(context, _shipment!.boxes),
               ),
               !_isCustomer ? fcsShipmentNumberBox : Container(),
-              ...(!_shipment.isPending
+              ...(!_shipment!.isPending
                   ? [
                       handlingFeeBox,
                     ]
@@ -324,22 +336,22 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
                   : []),
               ...(isLocalPickup && !_isCustomer
                   ? [
-                      _shipment.isPending ? assignCompleteBtn : Container(),
-                      _shipment.isAssigned ? completePickupBtn : Container(),
-                      _shipment.isPickuped ? completePackBtn : Container(),
+                      _shipment!.isPending ? assignCompleteBtn : Container(),
+                      _shipment!.isAssigned ? completePickupBtn : Container(),
+                      _shipment!.isPickuped ? completePackBtn : Container(),
                     ]
                   : []),
               ...((isCourierPickup || isCourierDropoff) && !_isCustomer
                   ? [
-                      _shipment.isPending ? confirmCompleteBtn : Container(),
-                      _shipment.isConfirmed ? completeReceiveBtn : Container(),
-                      _shipment.isReceived ? completePackBtn : Container(),
+                      _shipment!.isPending ? confirmCompleteBtn : Container(),
+                      _shipment!.isConfirmed ? completeReceiveBtn : Container(),
+                      _shipment!.isReceived ? completePackBtn : Container(),
                     ]
                   : []),
               ...((isLocalDropoff) && !_isCustomer
                   ? [
-                      _shipment.isPending ? completeReceiveBtn : Container(),
-                      _shipment.isReceived ? completePackBtn : Container(),
+                      _shipment!.isPending ? completeReceiveBtn : Container(),
+                      _shipment!.isReceived ? completePackBtn : Container(),
                     ]
                   : []),
             ],
@@ -361,7 +373,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
   }
 
   _edit() async {
-    bool updated = await Navigator.push<bool>(
+    bool? updated = await Navigator.push<bool>(
       context,
       CupertinoPageRoute(
           builder: (context) => ShipmentEditor(
@@ -369,8 +381,8 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
               )),
     );
     if (updated ?? false) {
-      await _loadShipment(_shipment.id);
-      await _loadCartons(_shipment.id);
+      await _loadShipment(_shipment!.id!);
+      await _loadCartons(_shipment!.id!);
     }
   }
 
@@ -387,7 +399,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.cancelShipment(_shipment);
+      await shipmentModel.cancelShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -400,11 +412,11 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
 
   _openCourierWebsite() {
     MainModel mainModel = Provider.of<MainModel>(context, listen: false);
-    launch("${mainModel.setting.courierWebsite}");
+    launch("${mainModel.setting!.courierWebsite}");
   }
 
   _gotoAssign() async {
-    bool assigned = await Navigator.push<bool>(
+    bool? assigned = await Navigator.push<bool>(
       context,
       CupertinoPageRoute(
           builder: (context) => ShipmentAssign(
@@ -412,7 +424,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
               )),
     );
     if (assigned ?? false) {
-      await _loadShipment(_shipment.id);
+      await _loadShipment(_shipment!.id!);
     }
   }
 
@@ -429,7 +441,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.completeAssignShipment(_shipment);
+      await shipmentModel.completeAssignShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -453,7 +465,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.completePickupShipment(_shipment);
+      await shipmentModel.completePickupShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -465,16 +477,16 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
   }
 
   _gotoPack() async {
-    bool assigned = await Navigator.push<bool>(
+    bool? assigned = await Navigator.push<bool>(
       context,
       CupertinoPageRoute(
           builder: (context) => ShipmentPack(
-                shipment: _shipment,
+                shipment: _shipment!,
               )),
     );
     if (assigned ?? false) {
-      await _loadShipment(_shipment.id);
-      await _loadCartons(_shipment.id);
+      await _loadShipment(_shipment!.id!);
+      await _loadCartons(_shipment!.id!);
     }
   }
 
@@ -491,7 +503,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.completePackShipment(_shipment);
+      await shipmentModel.completePackShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -503,7 +515,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
   }
 
   _gotoConfirm() async {
-    bool assigned = await Navigator.push<bool>(
+    bool? assigned = await Navigator.push<bool>(
       context,
       CupertinoPageRoute(
           builder: (context) => ShipmentConfirm(
@@ -511,7 +523,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
               )),
     );
     if (assigned ?? false) {
-      await _loadShipment(_shipment.id);
+      await _loadShipment(_shipment!.id!);
     }
   }
 
@@ -528,7 +540,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.completeConfirmShipment(_shipment);
+      await shipmentModel.completeConfirmShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -552,7 +564,7 @@ class _ShipmentInfoState extends State<ShipmentInfo> {
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.completeReceiveShipment(_shipment);
+      await shipmentModel.completeReceiveShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/shipment/shipment_list.dart b/lib/pages/shipment/shipment_list.dart
index 1424639..af047ab 100644
--- a/lib/pages/shipment/shipment_list.dart
+++ b/lib/pages/shipment/shipment_list.dart
@@ -17,7 +17,7 @@ import 'shipment_list_row.dart';
 class ShipmentList extends StatefulWidget {
   final bool forCustomer;
 
-  const ShipmentList({Key key, this.forCustomer = true}) : super(key: key);
+  const ShipmentList({Key? key, this.forCustomer = true}) : super(key: key);
   @override
   _ShipmentListState createState() => _ShipmentListState();
 }
diff --git a/lib/pages/shipment/shipment_list_row.dart b/lib/pages/shipment/shipment_list_row.dart
index d09d086..329e29b 100644
--- a/lib/pages/shipment/shipment_list_row.dart
+++ b/lib/pages/shipment/shipment_list_row.dart
@@ -2,15 +2,15 @@ import 'package:fcs/domain/entities/shipment.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 
 import '../main/util.dart';
 import 'shipment_info.dart';
 
 class ShipmentListRow extends StatelessWidget {
-  final Shipment shipment;
-  final bool isCustomer;
-  const ShipmentListRow({Key key, this.shipment, this.isCustomer})
+  final Shipment? shipment;
+  final bool? isCustomer;
+  const ShipmentListRow({Key? key, this.shipment, this.isCustomer})
       : super(key: key);
 
   @override
@@ -45,7 +45,7 @@ class ShipmentListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              shipment.shipmentNumber ?? "",
+                              shipment!.shipmentNumber ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -69,7 +69,7 @@ class ShipmentListRow extends StatelessWidget {
               children: <Widget>[
                 Padding(
                   padding: const EdgeInsets.all(0),
-                  child: getStatus(shipment.status ?? ""),
+                  child: getStatus(shipment!.status ?? ""),
                 ),
                 // Padding(
                 //   padding: const EdgeInsets.only(left: 8.0, top: 5, bottom: 5),
diff --git a/lib/pages/shipment/shipment_pack.dart b/lib/pages/shipment/shipment_pack.dart
index 245c1ff..affdfad 100644
--- a/lib/pages/shipment/shipment_pack.dart
+++ b/lib/pages/shipment/shipment_pack.dart
@@ -11,14 +11,14 @@ import 'package:fcs/pages/widgets/local_title.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_icons_null_safety/flutter_icons_null_safety.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 import 'widgets.dart';
 
 class ShipmentPack extends StatefulWidget {
-  final Shipment shipment;
+  final Shipment? shipment;
   ShipmentPack({this.shipment});
 
   @override
@@ -29,12 +29,12 @@ class _ShipmentPackState extends State<ShipmentPack> {
   var dateFormatter = new DateFormat('dd MMM yyyy');
   var timeFormatter = new DateFormat('jm');
 
-  Shipment _shipment;
+  Shipment? _shipment;
   bool _isLoading = false;
   var now = new DateTime.now();
 
-  FcsShipment _fcsShipment;
-  List<FcsShipment> _fcsShipments;
+  FcsShipment? _fcsShipment;
+  List<FcsShipment>? _fcsShipments;
 
   @override
   void initState() {
@@ -48,8 +48,8 @@ class _ShipmentPackState extends State<ShipmentPack> {
     FcsShipmentModel fcsShipmentModel =
         Provider.of<FcsShipmentModel>(context, listen: false);
     var fcsShipments = await fcsShipmentModel.getActiveFcsShipments();
-    var fcsShipment = fcsShipments
-        .firstWhere((e) => e.id == _shipment.fcsShipmentID, orElse: () => null);
+    var fcsShipment =
+        fcsShipments.firstWhere((e) => e.id == _shipment?.fcsShipmentID);
     setState(() {
       _fcsShipments = fcsShipments;
       _fcsShipment = fcsShipment;
@@ -58,7 +58,7 @@ class _ShipmentPackState extends State<ShipmentPack> {
 
   @override
   Widget build(BuildContext context) {
-    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment);
+    final shipmentNumberBox = getShipmentNumberStatus(context, _shipment!);
 
     var fcsShipmentsBox = LocalDropdown<FcsShipment>(
       callback: (v) {
@@ -120,14 +120,14 @@ class _ShipmentPackState extends State<ShipmentPack> {
   }
 
   _save() async {
-    _shipment.fcsShipmentID = this._fcsShipment.id;
+    _shipment!.fcsShipmentID = this._fcsShipment!.id;
     setState(() {
       _isLoading = true;
     });
     try {
       ShipmentModel shipmentModel =
           Provider.of<ShipmentModel>(context, listen: false);
-      await shipmentModel.packShipment(_shipment);
+      await shipmentModel.packShipment(_shipment!);
       Navigator.pop(context, true);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/signin/invitation_request_page.dart b/lib/pages/signin/invitation_request_page.dart
index 5e94f6d..8099283 100644
--- a/lib/pages/signin/invitation_request_page.dart
+++ b/lib/pages/signin/invitation_request_page.dart
@@ -16,7 +16,7 @@ class RequestInvitationPage extends StatefulWidget {
 
 class _RequestInvitationPageState extends State<RequestInvitationPage> {
   bool _isLoading = false;
-  TextEditingController nameCtl;
+  TextEditingController nameCtl = new TextEditingController();
 
   @override
   void initState() {
diff --git a/lib/pages/signin/signin_logic.dart b/lib/pages/signin/signin_logic.dart
index bdde97a..b0d788e 100644
--- a/lib/pages/signin/signin_logic.dart
+++ b/lib/pages/signin/signin_logic.dart
@@ -3,21 +3,20 @@ import 'package:fcs/domain/entities/user.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
 import 'package:fcs/pages/signin/invitation_request_page.dart';
 import 'package:fcs/pages/signin/signup_page.dart';
-import 'package:fcs/pages/widgets/bottom_up_page_route.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/widgets.dart';
 import 'package:provider/provider.dart';
 
 navigateAfterAuthVerified(BuildContext context) async {
-  User user = Provider.of<MainModel>(context, listen: false).user;
-  Setting setting = Provider.of<MainModel>(context, listen: false).setting;
+  User? user = Provider.of<MainModel>(context, listen: false).user;
+  Setting? setting = Provider.of<MainModel>(context, listen: false).setting;
 
   if (setting == null) return;
 
   if (user != null && (user.joined || user.requested)) {
     Navigator.pushNamedAndRemoveUntil(context, "/home", (r) => false);
   } else {
-    if (setting.inviteRequired) {
+    if (setting.inviteRequired ?? false) {
       bool invited =
           await Provider.of<MainModel>(context, listen: false).hasInvite();
       if (!invited) {
diff --git a/lib/pages/signin/signin_page.dart b/lib/pages/signin/signin_page.dart
index 3e3470d..6eaeca8 100644
--- a/lib/pages/signin/signin_page.dart
+++ b/lib/pages/signin/signin_page.dart
@@ -3,7 +3,6 @@ import 'package:fcs/domain/entities/auth_result.dart';
 import 'package:fcs/domain/entities/auth_status.dart';
 import 'package:fcs/pages/main/model/main_model.dart';
 import 'package:fcs/pages/signin/signin_logic.dart';
-import 'package:fcs/pages/widgets/bottom_up_page_route.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
@@ -23,9 +22,9 @@ class SigninPage extends StatefulWidget {
 
 class _SigninPageState extends State<SigninPage> {
   bool _isLoading = false;
-  String dialCode;
+  late String dialCode;
 
-  TextEditingController phonenumberCtl;
+  TextEditingController phonenumberCtl = new TextEditingController();
 
   @override
   void initState() {
@@ -82,7 +81,7 @@ class _SigninPageState extends State<SigninPage> {
           children: <Widget>[
             Container(
               decoration: BoxDecoration(
-                  border: Border.all(color: Colors.grey[400], width: 1),
+                  border: Border.all(color: Colors.grey.shade400, width: 1),
                   borderRadius: BorderRadius.all(Radius.circular(12.0))),
               child: CountryCodePicker(
                 onChanged: _countryChange,
@@ -152,7 +151,7 @@ class _SigninPageState extends State<SigninPage> {
 
   _countryChange(CountryCode countryCode) {
     setState(() {
-      dialCode = countryCode.dialCode;
+      dialCode = countryCode.dialCode ?? '+95';
     });
   }
 
@@ -182,7 +181,7 @@ class _SigninPageState extends State<SigninPage> {
         await navigateAfterAuthVerified(context);
       }
       if (auth.authStatus == AuthStatus.ERROR) {
-        showMsgDialog(context, "Error", auth.authErrorMsg);
+        showMsgDialog(context, "Error", auth.authErrorMsg ?? "");
       }
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
diff --git a/lib/pages/signin/signup_page.dart b/lib/pages/signin/signup_page.dart
index 4f96e6e..04a08c8 100644
--- a/lib/pages/signin/signup_page.dart
+++ b/lib/pages/signin/signup_page.dart
@@ -17,7 +17,7 @@ class SignupPage extends StatefulWidget {
 
 class _SignupPageState extends State<SignupPage> {
   bool _isLoading = false;
-  TextEditingController nameCtl;
+  TextEditingController nameCtl = new TextEditingController();
 
   @override
   void initState() {
diff --git a/lib/pages/signin/sms_code_page.dart b/lib/pages/signin/sms_code_page.dart
index dfe677c..73ef48e 100644
--- a/lib/pages/signin/sms_code_page.dart
+++ b/lib/pages/signin/sms_code_page.dart
@@ -18,18 +18,19 @@ const resend_count_sec = 30;
 
 class SmsCodePage extends StatefulWidget {
   final String phoneNumber;
-  const SmsCodePage({Key key, this.phoneNumber}) : super(key: key);
+  const SmsCodePage({Key? key, required this.phoneNumber}) : super(key: key);
   @override
   _SmsCodePageState createState() => _SmsCodePageState();
 }
 
 class _SmsCodePageState extends State<SmsCodePage> {
   bool _isLoading = false;
-  String pin;
-  bool allNumberEntered;
-  Timer _timer;
-  int _start = resend_count_sec;
   bool canResend = false;
+  int _start = resend_count_sec;
+
+  late String pin;
+  late bool allNumberEntered;
+  late Timer _timer;
 
   @override
   void initState() {
@@ -116,7 +117,7 @@ class _SmsCodePageState extends State<SmsCodePage> {
                       pinLength: 6,
                       decoration: BoxLooseDecoration(
                           strokeColorBuilder: PinListenColorBuilder(
-                              primaryColor, Colors.grey[400])),
+                              primaryColor, Colors.grey.shade400)),
                       textInputAction: TextInputAction.done,
                       autoFocus: true,
                       onChanged: _pinChange,
@@ -133,13 +134,13 @@ class _SmsCodePageState extends State<SmsCodePage> {
                           child: LocalText(context, 'sms.resend',
                               fontSize: 16,
                               color:
-                                  canResend ? primaryColor : Colors.grey[400]),
+                                  canResend ? primaryColor : Colors.grey.shade400),
                           shape: RoundedRectangleBorder(
                               borderRadius: BorderRadius.circular(10.0),
                               side: BorderSide(
                                   color: canResend
                                       ? primaryColor
-                                      : Colors.grey[400])),
+                                      : Colors.grey.shade400)),
                         ),
                         InkWell(
                           onTap: allNumberEntered ? _verify : null,
diff --git a/lib/pages/staff/model/staff_model.dart b/lib/pages/staff/model/staff_model.dart
index cadb5a4..b2c2ebb 100644
--- a/lib/pages/staff/model/staff_model.dart
+++ b/lib/pages/staff/model/staff_model.dart
@@ -11,8 +11,8 @@ import 'package:logging/logging.dart';
 
 class StaffModel extends BaseModel {
   final log = Logger('StaffModel');
-  StreamSubscription<QuerySnapshot> listener;
-  StreamSubscription<QuerySnapshot> privilegeListener;
+  StreamSubscription<QuerySnapshot>? listener;
+  StreamSubscription<QuerySnapshot>? privilegeListener;
 
   List<User> employees = [];
   List<Privilege> privileges = [];
@@ -26,28 +26,28 @@ class StaffModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) listener.cancel();
-    if (privilegeListener != null) privilegeListener.cancel();
+    if (listener != null) listener!.cancel();
+    if (privilegeListener != null) privilegeListener!.cancel();
     employees = [];
     privileges = [];
   }
 
   Future<void> _loadEmployees() async {
-    if (user == null || !user.hasStaffs()) return;
+    if (user == null || !user!.hasStaffs()) throw "No Privilege";
 
     try {
-      if (listener != null) listener.cancel();
+      if (listener != null) listener!.cancel();
 
-      listener = Firestore.instance
+      listener = FirebaseFirestore.instance
           .collection("/$user_collection")
           .where("is_employee", isEqualTo: true)
           .where("is_sys_admin", isEqualTo: false)
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         employees.clear();
-        employees = snapshot.documents.map((documentSnapshot) {
+        employees = snapshot.docs.map((documentSnapshot) {
           var user =
-              User.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+              User.fromMap(documentSnapshot.data as Map<String,dynamic>, documentSnapshot.id);
           return user;
         }).toList();
         notifyListeners();
@@ -59,14 +59,14 @@ class StaffModel extends BaseModel {
 
   Future<void> _loadPrivileges() async {
     try {
-      privilegeListener = Firestore.instance
+      privilegeListener = FirebaseFirestore.instance
           .collection("/$privilege_collection")
           .snapshots()
           .listen((QuerySnapshot snapshot) {
         privileges.clear();
-        privileges = snapshot.documents.map((documentSnapshot) {
+        privileges = snapshot.docs.map((documentSnapshot) {
           var privilege = Privilege.fromMap(
-              documentSnapshot.data, documentSnapshot.documentID);
+              documentSnapshot.data as Map<String,dynamic>, documentSnapshot.id);
           return privilege;
         }).toList();
         notifyListeners();
@@ -82,27 +82,27 @@ class StaffModel extends BaseModel {
         token: await getToken());
   }
 
-  Future<User> findUser(String phoneNumber) {
+  Future<User?> findUser(String phoneNumber) {
     return Services.instance.userService.findUser(phoneNumber);
   }
 
   Future<List<User>> getPickupEmployees() async {
-    if (user == null || !user.hasShipment()) return [];
+    if (user == null || !user!.hasShipment()) return [];
     return _getUsers(privilege_shipment);
   }
 
   Future<List<User>> _getUsers(String privilege) async {
     List<User> users = [];
     try {
-      var snaps = await Firestore.instance
+      var snaps = await FirebaseFirestore.instance
           .collection("/$user_collection")
           .where("is_employee", isEqualTo: true)
           .where("is_sys_admin", isEqualTo: false)
           .where("privileges", arrayContains: privilege)
-          .getDocuments(source: Source.server);
-      users = snaps.documents.map((documentSnapshot) {
+          .get(const GetOptions(source: Source.server));
+      users = snaps.docs.map((documentSnapshot) {
         var user =
-            User.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+            User.fromMap(documentSnapshot.data as Map<String,dynamic>, documentSnapshot.id);
         return user;
       }).toList();
     } catch (e) {
diff --git a/lib/pages/staff/staff_editor.dart b/lib/pages/staff/staff_editor.dart
index 4812c32..67197e0 100644
--- a/lib/pages/staff/staff_editor.dart
+++ b/lib/pages/staff/staff_editor.dart
@@ -15,7 +15,7 @@ import 'package:provider/provider.dart';
 typedef void FindCallBack();
 
 class StaffEditor extends StatefulWidget {
-  final User staff;
+  final User? staff;
   const StaffEditor({this.staff});
   @override
   _StaffEditorState createState() => _StaffEditorState();
@@ -25,8 +25,8 @@ class _StaffEditorState extends State<StaffEditor> {
   TextEditingController _phoneInput = new TextEditingController();
 
   bool _isLoading = false;
-  User user;
-  User selectedUser;
+  late User user;
+  User? selectedUser;
   List<Privilege> privileges = [];
   bool isNew = true;
 
@@ -38,8 +38,8 @@ class _StaffEditorState extends State<StaffEditor> {
     user = User();
     if (!isNew) {
       user =
-          User(name: widget.staff.name, phoneNumber: widget.staff.phoneNumber);
-      user.privileges = widget.staff.privileges;
+          User(name: widget.staff!.name, phoneNumber: widget.staff!.phoneNumber);
+      user.privileges = widget.staff!.privileges;
       privileges.forEach((p) => user.privileges.contains(p.id)
           ? p.isChecked = true
           : p.isChecked = false);
@@ -56,7 +56,7 @@ class _StaffEditorState extends State<StaffEditor> {
           title: InkWell(
         onTap: () {
           setState(() {
-            p.isChecked = p.isChecked == null ? true : !p.isChecked;
+            p.isChecked = p.isChecked == null ? true : !p.isChecked!;
           });
         },
         child: new Row(
@@ -64,7 +64,8 @@ class _StaffEditorState extends State<StaffEditor> {
             new Checkbox(
                 value: p.isChecked == null ? false : p.isChecked,
                 activeColor: primaryColor,
-                onChanged: (bool value) {
+                onChanged: (bool? value) {
+                  if(value != null)
                   setState(() {
                     p.isChecked = value;
                   });
@@ -78,10 +79,10 @@ class _StaffEditorState extends State<StaffEditor> {
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: <Widget>[
                   new Text(
-                    p.name,
+                    p.name ??"",
                     style: TextStyle(fontSize: 15.0, color: primaryColor),
                   ),
-                  Text(p.desc,
+                  Text(p.desc ?? "",
                       style: TextStyle(fontSize: 13, color: Colors.grey[600]))
                 ],
               ),
@@ -110,7 +111,7 @@ class _StaffEditorState extends State<StaffEditor> {
               style: textStyle,
               decoration: new InputDecoration(
                 labelText:
-                    AppTranslations.of(context).text('staff.phone.search'),
+                    AppTranslations.of(context)!.text('staff.phone.search'),
                 labelStyle: languageModel.isEng ? labelStyle : labelStyleMM,
                 // icon: Icon(
                 //   Icons.search,
@@ -150,7 +151,7 @@ class _StaffEditorState extends State<StaffEditor> {
             ? Container()
             : IconButton(
                 icon: Icon(Icons.open_in_new, color: primaryColor),
-                onPressed: () => call(context, user.phoneNumber)),
+                onPressed: () => call(context, user.phoneNumber!)),
       ],
     );
 
@@ -226,7 +227,7 @@ class _StaffEditorState extends State<StaffEditor> {
     });
     StaffModel staffModel = Provider.of<StaffModel>(context, listen: false);
     try {
-      await staffModel.updatePrivileges(this.selectedUser.id, privilegesIDs());
+      await staffModel.updatePrivileges(this.selectedUser!.id!, privilegesIDs());
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -238,7 +239,7 @@ class _StaffEditorState extends State<StaffEditor> {
   }
 
   List<String> privilegesIDs() {
-    return this.privileges.where((p) => p.isChecked).map((p) => p.id).toList();
+    return this.privileges.where((p) => p.isChecked!).map((p) => p.id).toList();
   }
 
   _save() async {
@@ -248,7 +249,7 @@ class _StaffEditorState extends State<StaffEditor> {
     if (widget.staff == null) return;
     StaffModel staffModel = Provider.of<StaffModel>(context, listen: false);
     try {
-      await staffModel.updatePrivileges(widget.staff.id, privilegesIDs());
+      await staffModel.updatePrivileges(widget.staff!.id!, privilegesIDs());
       Navigator.pop(context);
     } catch (e) {
       showMsgDialog(context, "Error", e.toString());
@@ -267,7 +268,7 @@ class _StaffEditorState extends State<StaffEditor> {
       _isLoading = true;
     });
     try {
-      User _user = await staffModel.findUser(_phoneInput.text);
+      User? _user = await staffModel.findUser(_phoneInput.text);
       if (_user == null) {
         showMsgDialog(context, "Error", _phoneInput.text + " not found!");
         return;
diff --git a/lib/pages/staff/staff_list.dart b/lib/pages/staff/staff_list.dart
index fabcc6c..11fd119 100644
--- a/lib/pages/staff/staff_list.dart
+++ b/lib/pages/staff/staff_list.dart
@@ -5,7 +5,6 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
@@ -84,7 +83,7 @@ class _StaffListState extends State<StaffList> {
                     padding: new EdgeInsets.symmetric(
                         horizontal: 32.0 - dotSize / 2),
                     child: Icon(
-                      MaterialCommunityIcons.worker,
+                      Icons.person,
                       color: primaryColor,
                       size: 40,
                     ),
@@ -94,13 +93,13 @@ class _StaffListState extends State<StaffList> {
                       crossAxisAlignment: CrossAxisAlignment.start,
                       children: <Widget>[
                         new Text(
-                          user.name,
+                          user.name ?? "",
                           style: new TextStyle(fontSize: 15.0),
                         ),
                         Padding(
                           padding: const EdgeInsets.only(top: 8.0),
                           child: new Text(
-                            user.phoneNumber,
+                            user.phoneNumber ?? "",
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           ),
diff --git a/lib/pages/user_search/user_list_row.dart b/lib/pages/user_search/user_list_row.dart
index da8822f..d7758c7 100644
--- a/lib/pages/user_search/user_list_row.dart
+++ b/lib/pages/user_search/user_list_row.dart
@@ -3,23 +3,12 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/user_search/user_serach.dart';
 import 'package:flutter/material.dart';
 
-class UserListRow extends StatefulWidget {
-  final OnUserRowSelect onUserRowSelect;
+class UserListRow extends StatelessWidget {
+  final OnUserRowSelect? onUserRowSelect;
   final User user;
-  const UserListRow({this.user, this.onUserRowSelect});
+  const UserListRow({required this.user, this.onUserRowSelect});
 
-  @override
-  _UserListRowState createState() => _UserListRowState();
-}
-
-class _UserListRowState extends State<UserListRow> {
   final double dotSize = 15.0;
-  User user;
-  @override
-  void initState() {
-    super.initState();
-    this.user = widget.user;
-  }
 
   @override
   Widget build(BuildContext context) {
@@ -30,8 +19,7 @@ class _UserListRowState extends State<UserListRow> {
         color: Colors.white,
         child: InkWell(
           onTap: () {
-            if (widget.onUserRowSelect != null)
-              widget.onUserRowSelect(widget.user);
+            if (onUserRowSelect != null) onUserRowSelect!(user);
           },
           child: Row(
             children: <Widget>[
@@ -53,17 +41,17 @@ class _UserListRowState extends State<UserListRow> {
                           crossAxisAlignment: CrossAxisAlignment.start,
                           children: <Widget>[
                             new Text(
-                              user.name == null ? '' : user.name,
+                              user.name ?? "",
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
                             new Text(
-                              user.fcsID == null ? "" : user.fcsID,
+                              user.fcsID ?? "",
                               style: new TextStyle(
                                   fontSize: 13.0, color: Colors.grey),
                             ),
                             new Text(
-                              user.phoneNumber == null ? "" : user.phoneNumber,
+                              user.phoneNumber ?? "",
                               style: new TextStyle(
                                   fontSize: 13.0, color: Colors.grey),
                             ),
diff --git a/lib/pages/user_search/user_serach.dart b/lib/pages/user_search/user_serach.dart
index 0225b62..c61731c 100644
--- a/lib/pages/user_search/user_serach.dart
+++ b/lib/pages/user_search/user_serach.dart
@@ -8,8 +8,8 @@ import 'package:provider/provider.dart';
 typedef OnUserSelect(User suer);
 typedef OnUserRowSelect(User suer);
 
-Future<User> searchUser(BuildContext context,
-        {OnUserSelect onUserSelect, bool popPage = false}) async =>
+Future<User?> searchUser(BuildContext context,
+        {required OnUserSelect onUserSelect, bool popPage = false}) async =>
     await showSearch<User>(
       context: context,
       delegate:
@@ -17,10 +17,10 @@ Future<User> searchUser(BuildContext context,
     );
 
 class UserSearchDelegate extends SearchDelegate<User> {
-  final OnUserSelect onUserSelect;
+  final OnUserSelect? onUserSelect;
   final bool popPage;
 
-  UserSearchDelegate({this.onUserSelect, this.popPage});
+  UserSearchDelegate({required this.onUserSelect, required this.popPage});
 
   @override
   String get searchFieldLabel => 'Search by FCS ID or Name';
@@ -31,10 +31,10 @@ class UserSearchDelegate extends SearchDelegate<User> {
     return theme.copyWith(
       inputDecorationTheme: InputDecorationTheme(
           hintStyle: TextStyle(
-              color: theme.primaryTextTheme.caption.color, fontSize: 14)),
+              color: theme.primaryTextTheme.caption?.color, fontSize: 14)),
       textTheme: theme.textTheme.copyWith(
-          title: theme.textTheme.title.copyWith(
-              color: theme.primaryTextTheme.title.color, fontSize: 16)),
+          title: theme.textTheme.title?.copyWith(
+              color: theme.primaryTextTheme.title?.color, fontSize: 16)),
       primaryColor: primaryColor,
     );
   }
@@ -53,7 +53,7 @@ class UserSearchDelegate extends SearchDelegate<User> {
   Widget buildLeading(BuildContext context) {
     return IconButton(
       icon: Icon(Icons.arrow_back),
-      onPressed: () => close(context, null),
+      onPressed: () => close(context, new User()),
     );
   }
 
@@ -64,7 +64,7 @@ class UserSearchDelegate extends SearchDelegate<User> {
         future: packageModel.searchUser(query),
         builder: (context, AsyncSnapshot<List<User>> snapshot) {
           if (snapshot.hasData) {
-            if (snapshot.data.length == 0) {
+            if (snapshot.data == null || snapshot.data!.length == 0) {
               return Container(
                 child: Center(
                   child: Text(
@@ -77,7 +77,7 @@ class UserSearchDelegate extends SearchDelegate<User> {
             return Container(
               padding: EdgeInsets.only(top: 15),
               child: ListView(
-                children: snapshot.data
+                children: snapshot.data!
                     .map((u) => UserListRow(
                           user: u,
                           onUserRowSelect: (u) => _onUserRowSelect(context, u),
@@ -119,7 +119,7 @@ class UserSearchDelegate extends SearchDelegate<User> {
 
   _onUserRowSelect(BuildContext context, User user) {
     if (onUserSelect != null) {
-      onUserSelect(user);
+      onUserSelect!(user);
     }
     if (popPage) {
       Navigator.pop(context);
diff --git a/lib/pages/widgets/banner.dart b/lib/pages/widgets/banner.dart
index 0b36a16..ef37127 100644
--- a/lib/pages/widgets/banner.dart
+++ b/lib/pages/widgets/banner.dart
@@ -3,7 +3,7 @@ import 'package:flutter/material.dart';
 
 class FlavorBanner extends StatelessWidget {
   final Widget child;
-  FlavorBanner({@required this.child});
+  FlavorBanner({required this.child});
 
   @override
   Widget build(BuildContext context) {
diff --git a/lib/pages/widgets/barcode_scanner.dart b/lib/pages/widgets/barcode_scanner.dart
index 2706a21..a8124b8 100644
--- a/lib/pages/widgets/barcode_scanner.dart
+++ b/lib/pages/widgets/barcode_scanner.dart
@@ -1,9 +1,9 @@
-import 'package:barcode_scan/barcode_scan.dart';
+import 'package:barcode_scan2/platform_wrapper.dart';
 
-Future<String> scanBarcode() async {
+Future<String?> scanBarcode() async {
   try {
-    String barcode = await BarcodeScanner.scan();
-    if (barcode == null) return null;
+    var scanResult = await BarcodeScanner.scan();
+    String barcode = scanResult.rawContent;
 
     String gs = String.fromCharCode(29);
     if (barcode.contains(gs)) {
diff --git a/lib/pages/widgets/bottom_widgets.dart b/lib/pages/widgets/bottom_widgets.dart
index c64ff11..067a134 100644
--- a/lib/pages/widgets/bottom_widgets.dart
+++ b/lib/pages/widgets/bottom_widgets.dart
@@ -5,7 +5,7 @@ import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:provider/provider.dart';
 
 class BottomWidgets extends StatelessWidget {
@@ -13,7 +13,7 @@ class BottomWidgets extends StatelessWidget {
   Widget build(BuildContext context) {
     var pkgInfo = Provider.of<MainModel>(context).packageInfo;
     final versionBox = Text(
-      "v${pkgInfo.version}+${pkgInfo.buildNumber}",
+      "v${pkgInfo?.version}+${pkgInfo?.buildNumber}",
       style: TextStyle(color: Colors.white30),
     );
     return Column(
diff --git a/lib/pages/widgets/defalut_delivery_address.dart b/lib/pages/widgets/defalut_delivery_address.dart
index 649abcf..3610701 100644
--- a/lib/pages/widgets/defalut_delivery_address.dart
+++ b/lib/pages/widgets/defalut_delivery_address.dart
@@ -3,20 +3,20 @@ import 'package:fcs/helpers/theme.dart';
 import 'package:fcs/pages/delivery_address/delivery_address_row.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 
 import 'callbacks.dart';
 import 'display_text.dart';
 import 'local_text.dart';
 
 class DefaultDeliveryAddress extends StatelessWidget {
-  final DeliveryAddress deliveryAddress;
-  final String labelKey;
-  final OnTap onTap;
-  final IconData iconData;
+  final DeliveryAddress? deliveryAddress;
+  final String? labelKey;
+  final OnTap? onTap;
+  final IconData? iconData;
 
   const DefaultDeliveryAddress(
-      {Key key, this.deliveryAddress, this.onTap, this.labelKey, this.iconData})
+      {Key? key, this.deliveryAddress, this.onTap, this.labelKey, this.iconData})
       : super(key: key);
 
   @override
@@ -37,7 +37,7 @@ class DefaultDeliveryAddress extends StatelessWidget {
             onTap == null
                 ? Container()
                 : GestureDetector(
-                    onTap: () => onTap(),
+                    onTap: () => onTap!(),
                     child: Chip(
                         label: LocalText(
                             context, "delivery_address.change_address",
@@ -50,8 +50,8 @@ class DefaultDeliveryAddress extends StatelessWidget {
           child: deliveryAddress == null
               ? Container()
               : DeliveryAddressRow(
-                  key: ValueKey(deliveryAddress.id),
-                  deliveryAddress: deliveryAddress),
+                  key: ValueKey(deliveryAddress!.id),
+                  deliveryAddress: deliveryAddress!),
         ),
       ],
     );
diff --git a/lib/pages/widgets/delivery_address_selection.dart b/lib/pages/widgets/delivery_address_selection.dart
index 08ee77f..1f1b0a6 100644
--- a/lib/pages/widgets/delivery_address_selection.dart
+++ b/lib/pages/widgets/delivery_address_selection.dart
@@ -10,11 +10,11 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 class DeliveryAddressSelection extends StatefulWidget {
-  final DeliveryAddress deliveryAddress;
-  final User user;
+  final DeliveryAddress? deliveryAddress;
+  final User? user;
 
   const DeliveryAddressSelection({
-    Key key,
+    Key? key,
     this.deliveryAddress,
     this.user,
   }) : super(key: key);
@@ -38,7 +38,7 @@ class _DeliveryAddressSelectionState extends State<DeliveryAddressSelection> {
         Provider.of<DeliveryAddressModel>(context, listen: false);
 
     var deliveryAddresses =
-        await addressModel.getDeliveryAddresses(widget.user.id);
+        await addressModel.getDeliveryAddresses(widget.user!.id!);
     setState(() {
       this._deliveryAddresses = deliveryAddresses;
     });
@@ -64,7 +64,7 @@ class _DeliveryAddressSelectionState extends State<DeliveryAddressSelection> {
             bool updated = await Navigator.of(context).push(CupertinoPageRoute(
                 builder: (context) =>
                     DeliveryAddressEditor(user: widget.user)));
-            if (updated ?? false) {
+            if (updated) {
               _getDeliverAddresses();
             }
           },
@@ -95,7 +95,7 @@ class _DeliveryAddressSelectionState extends State<DeliveryAddressSelection> {
             padding: const EdgeInsets.all(10.0),
             child: Icon(Icons.check,
                 color: widget.deliveryAddress != null &&
-                        _deliveryAddress.id == widget.deliveryAddress.id
+                        _deliveryAddress.id == widget.deliveryAddress!.id
                     ? primaryColor
                     : Colors.black26),
           ),
@@ -117,7 +117,7 @@ class _DeliveryAddressSelectionState extends State<DeliveryAddressSelection> {
     bool updated = await Navigator.of(context).push(CupertinoPageRoute(
         builder: (context) => DeliveryAddressEditor(
             user: widget.user, deliveryAddress: deliveryAddress)));
-    if (updated ?? false) {
+    if (updated) {
       _getDeliverAddresses();
     }
   }
diff --git a/lib/pages/widgets/dialog_input.dart b/lib/pages/widgets/dialog_input.dart
index 249e3a1..c1c0a4a 100644
--- a/lib/pages/widgets/dialog_input.dart
+++ b/lib/pages/widgets/dialog_input.dart
@@ -5,10 +5,10 @@ import 'package:flutter/material.dart';
 import 'local_text.dart';
 
 class DialogInput extends StatefulWidget {
-  final String value;
-  final String label;
+  final String? value;
+  final String? label;
 
-  const DialogInput({Key key, this.label, this.value}) : super(key: key);
+  const DialogInput({Key? key, this.label, this.value}) : super(key: key);
   @override
   _DialogInputState createState() => _DialogInputState();
 }
@@ -24,7 +24,7 @@ class _DialogInputState extends State<DialogInput> {
   void initState() {
     super.initState();
     if (widget.value != null) {
-      _controller.text = widget.value;
+      _controller.text = widget.value!;
       _focusNode.addListener(() {
         if (_focusNode.hasFocus) {
           _controller.selection = TextSelection(
@@ -41,7 +41,7 @@ class _DialogInputState extends State<DialogInput> {
       child: AlertDialog(
         title: LocalText(
           context,
-          widget.label,
+          widget.label!,
           fontSize: 20,
           color: primaryColor,
         ),
@@ -77,7 +77,7 @@ class _DialogInputState extends State<DialogInput> {
                 fontWeight: FontWeight.bold,
               ),
               onPressed: () async {
-                if (!_formKey.currentState.validate()) return;
+                if (!_formKey.currentState!.validate()) return;
                 _save();
               })
         ],
diff --git a/lib/pages/widgets/discount_dropdown.dart b/lib/pages/widgets/discount_dropdown.dart
index 63bf769..8f00fa7 100644
--- a/lib/pages/widgets/discount_dropdown.dart
+++ b/lib/pages/widgets/discount_dropdown.dart
@@ -6,13 +6,13 @@ import 'package:flutter/material.dart';
 import 'local_text.dart';
 
 class DiscountDropdown<T> extends StatelessWidget {
-  final Function(T) callback;
-  final IconData iconData;
-  final T selectedValue;
-  final List<T> values;
+  final Function(T)? callback;
+  final IconData? iconData;
+  final T? selectedValue;
+  final List<T>? values;
 
   const DiscountDropdown(
-      {Key key, this.callback, this.iconData, this.selectedValue, this.values})
+      {Key? key, this.callback, this.iconData, this.selectedValue, this.values})
       : super(key: key);
 
   @override
@@ -46,14 +46,15 @@ class DiscountDropdown<T> extends StatelessWidget {
                     height: 1,
                     color: primaryColor,
                   ),
-                  onChanged: (T newValue) {
-                    callback(newValue);
+                  onChanged: (T? newValue) {
+                    callback!(newValue!);
                   },
                   isExpanded: true,
-                  items: values.map<DropdownMenuItem<T>>((T value) {
+                  items: values!.map<DropdownMenuItem<T>>((T value) {
                     return DropdownMenuItem<T>(
                       value: value,
-                      child: Text(value == null ? "" : (value as Discount).code,
+                      child: Text(
+                          value == null ? "" : (value as Discount).code!,
                           overflow: TextOverflow.ellipsis,
                           style: TextStyle(color: primaryColor)),
                     );
diff --git a/lib/pages/widgets/display_image_source.dart b/lib/pages/widgets/display_image_source.dart
index 444586d..b60ad53 100644
--- a/lib/pages/widgets/display_image_source.dart
+++ b/lib/pages/widgets/display_image_source.dart
@@ -4,21 +4,30 @@ import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/widgets.dart';
 
 class DisplayImageSource {
-  String url;
-  File file;
+  String? url;
+  File? file;
   DisplayImageSource({this.url, this.file});
 
-  ImageProvider get imageProvider =>
-      file == null ? CachedNetworkImageProvider(url) : FileImage(file);
+  ImageProvider get imageProvider {
+    if (file == null) {
+      return CachedNetworkImageProvider(url!);
+    } else {
+      return FileImage(file!);
+    }
+  }
 
   @override
   bool operator ==(other) {
-    if (identical(this, other)) {
+    if (identical(this, other) && other is DisplayImageSource) {
       return true;
     }
-    return (other.file == this.file &&
+
+    return (other is DisplayImageSource &&
+            other.file == this.file &&
             (other.file != null || this.file != null)) ||
-        (other.url == this.url && (other.url != null || this.url != null));
+        (other is DisplayImageSource &&
+            other.url == this.url &&
+            (other.url != null || this.url != null));
   }
 
   @override
diff --git a/lib/pages/widgets/display_text.dart b/lib/pages/widgets/display_text.dart
index 8d36a9f..c8f8801 100644
--- a/lib/pages/widgets/display_text.dart
+++ b/lib/pages/widgets/display_text.dart
@@ -6,16 +6,16 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 class DisplayText extends StatelessWidget {
-  final String text;
-  final String labelTextKey;
-  final IconData iconData;
-  final int maxLines;
-  final bool withBorder;
-  final Color borderColor;
-  final Widget icon;
+  final String? text;
+  final String? labelTextKey;
+  final IconData? iconData;
+  final int? maxLines;
+  final bool? withBorder;
+  final Color? borderColor;
+  final Widget? icon;
 
   const DisplayText({
-    Key key,
+    Key? key,
     this.text,
     this.labelTextKey,
     this.iconData,
@@ -44,7 +44,9 @@ class DisplayText extends StatelessWidget {
       child: Row(
         children: [
           iconData == null
-              ? icon == null ? Container() : icon
+              ? icon == null
+                  ? Container()
+                  : icon!
               : Padding(
                   padding: const EdgeInsets.only(
                       left: .0, right: 15.0, top: 8.0, bottom: 8.0),
@@ -60,13 +62,13 @@ class DisplayText extends StatelessWidget {
                 labelTextKey == null
                     ? Container()
                     : Text(
-                        AppTranslations.of(context).text(labelTextKey),
+                        AppTranslations.of(context)!.text(labelTextKey!),
                         style: labelStyle,
                       ),
                 text == null
                     ? Container()
                     : Text(
-                        text,
+                        text!,
                         style: textStyle,
                       ),
               ],
diff --git a/lib/pages/widgets/fcs_expansion_tile.dart b/lib/pages/widgets/fcs_expansion_tile.dart
index f74365e..e1d31eb 100644
--- a/lib/pages/widgets/fcs_expansion_tile.dart
+++ b/lib/pages/widgets/fcs_expansion_tile.dart
@@ -5,10 +5,10 @@ import 'package:flutter/material.dart';
 import 'callbacks.dart';
 
 class FcsExpansionTile extends StatefulWidget {
-  final ValueChanged<bool> onExpansionChanged;
-  final CallBack onEditPress;
-  final List<Widget> children;
-  final Widget title;
+  final ValueChanged<bool>? onExpansionChanged;
+  final CallBack? onEditPress;
+  final List<Widget>? children;
+  final Widget? title;
   final bool isEdit;
   const FcsExpansionTile(
       {this.onExpansionChanged,
@@ -21,7 +21,7 @@ class FcsExpansionTile extends StatefulWidget {
 }
 
 class _FcsExpansionTileState extends State<FcsExpansionTile> {
-  bool expanded;
+  bool? expanded;
   @override
   void initState() {
     this.expanded = false;
@@ -39,22 +39,22 @@ class _FcsExpansionTileState extends State<FcsExpansionTile> {
             expanded = value;
           });
           if (widget.onExpansionChanged != null)
-            widget.onExpansionChanged(value);
+            widget.onExpansionChanged!(value);
         },
-        title: widget.title,
-        children: widget.children,
+        title: widget.title != null ? widget.title! : Container(),
+        children: widget.children != null ? widget.children! : [Container()],
         trailing: widget.isEdit
             ? IconButton(
                 padding: EdgeInsets.all(0),
                 iconSize: 20,
                 onPressed: () =>
-                    widget.onEditPress != null ? widget.onEditPress() : {},
+                    widget.onEditPress != null ? widget.onEditPress!() : {},
                 icon: Icon(
                   Icons.edit,
                   color: primaryColor,
                 ))
             : AnimatedSwitcher(
-                child: expanded
+                child: expanded!
                     ? Icon(
                         Icons.remove,
                         color: primaryColor,
diff --git a/lib/pages/widgets/fcs_icons.dart b/lib/pages/widgets/fcs_icons.dart
index 19c844e..8f7e95b 100644
--- a/lib/pages/widgets/fcs_icons.dart
+++ b/lib/pages/widgets/fcs_icons.dart
@@ -1,4 +1,4 @@
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 
 const cartonIconData = MaterialCommunityIcons.package;
 const customFeeIconData = MaterialCommunityIcons.security;
diff --git a/lib/pages/widgets/image_file_picker.dart b/lib/pages/widgets/image_file_picker.dart
index 8efc2f6..a495e97 100644
--- a/lib/pages/widgets/image_file_picker.dart
+++ b/lib/pages/widgets/image_file_picker.dart
@@ -1,13 +1,13 @@
 import 'dart:io';
 
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:image_picker/image_picker.dart';
 import 'local_text.dart';
 
 typedef OnFile = void Function(File);
 
-modelBottomSheet(BuildContext context, {final OnFile onFile}) {
+modelBottomSheet(BuildContext context, {final OnFile? onFile}) {
   showModalBottomSheet(
       elevation: 10,
       backgroundColor: Colors.white,
@@ -18,15 +18,15 @@ modelBottomSheet(BuildContext context, {final OnFile onFile}) {
 }
 
 class ImageFile extends StatefulWidget {
-  final OnFile onFile;
+  final OnFile? onFile;
 
-  const ImageFile({Key key, this.onFile}) : super(key: key);
+  const ImageFile({Key? key, this.onFile}) : super(key: key);
   @override
   _ImageFileState createState() => _ImageFileState();
 }
 
 class _ImageFileState extends State<ImageFile> {
-  File selectedFile;
+  File? selectedFile;
   @override
   Widget build(BuildContext context) {
     return Container(
@@ -44,7 +44,7 @@ class _ImageFileState extends State<ImageFile> {
               onTap: () async {
                 Navigator.pop(context);
                 selectedFile = await pickImage(ImageSource.gallery);
-                if (widget.onFile != null) widget.onFile(selectedFile);
+                if (widget.onFile != null) widget.onFile!(selectedFile!);
               }),
           new ListTile(
             leading: CircleAvatar(
@@ -58,7 +58,7 @@ class _ImageFileState extends State<ImageFile> {
               Navigator.pop(context);
               selectedFile = await pickImage(ImageSource.camera);
 
-              if (widget.onFile != null) widget.onFile(selectedFile);
+              if (widget.onFile != null) widget.onFile!(selectedFile!);
             },
           ),
           new ListTile(
@@ -75,7 +75,7 @@ class _ImageFileState extends State<ImageFile> {
                 selectedFile = null;
               });
 
-              if (widget.onFile != null) widget.onFile(selectedFile);
+              if (widget.onFile != null) widget.onFile!(selectedFile!);
             },
           ),
         ],
@@ -84,7 +84,7 @@ class _ImageFileState extends State<ImageFile> {
   }
 
   pickImage(ImageSource source) async {
-    var tempImage = await ImagePicker.pickImage(source: source);
+    var tempImage = await ImagePicker().pickImage(source: source);
     return tempImage;
   }
 }
diff --git a/lib/pages/widgets/img_picker.dart b/lib/pages/widgets/img_picker.dart
index 71fc9c2..43e2fb1 100644
--- a/lib/pages/widgets/img_picker.dart
+++ b/lib/pages/widgets/img_picker.dart
@@ -1,5 +1,6 @@
 import 'dart:io';
 
+import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
@@ -7,19 +8,19 @@ import 'package:image_picker/image_picker.dart';
 
 import 'show_img.dart';
 
-typedef OnFile = void Function(File);
+typedef OnFile = void Function(File?);
 
 class LocalImagePicker extends StatefulWidget {
-  final Color color;
+  final Color? color;
   final String title;
-  final OnFile onFile;
+  final OnFile? onFile;
   final bool enabled;
-  final String initialImgUrl;
+  final String? initialImgUrl;
   final ImageSource imageSource;
 
   const LocalImagePicker(
-      {Key key,
-      this.title,
+      {Key? key,
+      required this.title,
       this.onFile,
       this.enabled = true,
       this.initialImgUrl,
@@ -31,8 +32,8 @@ class LocalImagePicker extends StatefulWidget {
 }
 
 class _LocalImagePickerState extends State<LocalImagePicker> {
-  String url;
-  File file;
+  String? url;
+  File? file;
 
   @override
   void initState() {
@@ -56,16 +57,16 @@ class _LocalImagePickerState extends State<LocalImagePicker> {
                 await _dialog(
                     context, () => camera = true, () => gallery = true);
                 if (camera || gallery) {
-                  var selectedFile = await ImagePicker.pickImage(
+                  var selectedFile = await ImagePicker().pickImage(
                       source: camera ? ImageSource.camera : ImageSource.gallery,
                       imageQuality: 80,
                       maxWidth: 1000);
                   if (selectedFile != null) {
                     setState(() {
-                      this.file = selectedFile;
+                      this.file = File(selectedFile.path);
                     });
                     if (widget.onFile != null) {
-                      widget.onFile(selectedFile);
+                      widget.onFile!(File(selectedFile.path));
                     }
                   }
                 }
@@ -93,7 +94,7 @@ class _LocalImagePickerState extends State<LocalImagePicker> {
                             this.file = null;
                             this.url = null;
                             if (widget.onFile != null) {
-                              widget.onFile(null);
+                              widget.onFile!(null);
                             }
                           });
                         },
diff --git a/lib/pages/widgets/img_url.dart b/lib/pages/widgets/img_url.dart
index 5747a5e..6cdb69e 100644
--- a/lib/pages/widgets/img_url.dart
+++ b/lib/pages/widgets/img_url.dart
@@ -8,10 +8,10 @@ import 'show_img.dart';
 typedef OnFile = void Function(File);
 
 class ImageUrl extends StatefulWidget {
-  final String title;
-  final String url;
+  final String? title;
+  final String? url;
 
-  const ImageUrl({Key key, this.title, this.url}) : super(key: key);
+  const ImageUrl({Key? key, this.title, this.url}) : super(key: key);
   @override
   _ImageUrlState createState() => _ImageUrlState();
 }
@@ -25,12 +25,12 @@ class _ImageUrlState extends State<ImageUrl> {
           context,
           MaterialPageRoute(
               builder: (context) =>
-                  ShowImage(url: widget.url, fileName: widget.title)),
+                  ShowImage(url: widget.url!, fileName: widget.title!)),
         )
       },
       child: Chip(
         avatar: Icon(Icons.image),
-        label: Text(widget.title),
+        label: Text(widget.title!),
       ),
     );
   }
diff --git a/lib/pages/widgets/input_date.dart b/lib/pages/widgets/input_date.dart
index c490584..4ee726a 100644
--- a/lib/pages/widgets/input_date.dart
+++ b/lib/pages/widgets/input_date.dart
@@ -10,19 +10,19 @@ class InputDate extends StatelessWidget {
   final String labelTextKey;
   final IconData iconData;
   final TextEditingController controller;
-  final FormFieldValidator<String> validator;
+  final FormFieldValidator<String>? validator;
   final int maxLines;
   final bool withBorder;
-  final Color borderColor;
-  final TextInputType textInputType;
+  final Color? borderColor;
+  final TextInputType? textInputType;
   final bool autoFocus;
   final String dateFormatString;
 
   const InputDate(
-      {Key key,
-      this.labelTextKey,
-      this.iconData,
-      this.controller,
+      {Key? key,
+      required this.labelTextKey,
+      required this.iconData,
+      required this.controller,
       this.validator,
       this.maxLines = 1,
       this.withBorder = false,
@@ -72,7 +72,7 @@ class InputDate extends StatelessWidget {
             ),
             labelText: labelTextKey == null
                 ? null
-                : AppTranslations.of(context).text(labelTextKey),
+                : AppTranslations.of(context)!.text(labelTextKey),
             labelStyle: languageModel.isEng
                 ? newLabelStyle(color: Colors.black54, fontSize: 20)
                 : newLabelStyleMM(color: Colors.black54, fontSize: 20),
diff --git a/lib/pages/widgets/input_text.dart b/lib/pages/widgets/input_text.dart
index c94d3ab..639d4b0 100644
--- a/lib/pages/widgets/input_text.dart
+++ b/lib/pages/widgets/input_text.dart
@@ -6,20 +6,20 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 class InputText extends StatelessWidget {
-  final String labelTextKey;
-  final IconData iconData;
-  final TextEditingController controller;
-  final FormFieldValidator<String> validator;
+  final String? labelTextKey;
+  final IconData? iconData;
+  final TextEditingController? controller;
+  final FormFieldValidator<String>? validator;
   final int maxLines;
   final bool withBorder;
-  final Color borderColor;
-  final TextInputType textInputType;
+  final Color? borderColor;
+  final TextInputType? textInputType;
   final bool autoFocus;
   final TextAlign textAlign;
   final bool enabled;
 
   const InputText(
-      {Key key,
+      {Key? key,
       this.labelTextKey,
       this.iconData,
       this.controller,
@@ -30,7 +30,7 @@ class InputText extends StatelessWidget {
       this.autoFocus = false,
       this.textInputType,
       this.enabled = true,
-      this.textAlign})
+      this.textAlign = TextAlign.start})
       : super(key: key);
   @override
   Widget build(BuildContext context) {
@@ -46,7 +46,7 @@ class InputText extends StatelessWidget {
           style: textStyle,
           maxLines: maxLines,
           keyboardType: textInputType,
-          textAlign: textAlign ?? TextAlign.start,
+          textAlign: textAlign,
           decoration: new InputDecoration(
             // hintText: '',
             hintStyle: TextStyle(
@@ -54,7 +54,7 @@ class InputText extends StatelessWidget {
             ),
             labelText: labelTextKey == null
                 ? null
-                : AppTranslations.of(context).text(labelTextKey),
+                : AppTranslations.of(context)!.text(labelTextKey!),
             labelStyle: languageModel.isEng
                 ? newLabelStyle(color: Colors.black54, fontSize: 20)
                 : newLabelStyleMM(color: Colors.black54, fontSize: 20),
diff --git a/lib/pages/widgets/input_time.dart b/lib/pages/widgets/input_time.dart
index 1311bf6..8c283a1 100644
--- a/lib/pages/widgets/input_time.dart
+++ b/lib/pages/widgets/input_time.dart
@@ -7,18 +7,18 @@ import 'package:intl/intl.dart';
 import 'package:provider/provider.dart';
 
 class InputTime extends StatelessWidget {
-  final String labelTextKey;
-  final IconData iconData;
-  final TextEditingController controller;
-  final FormFieldValidator<String> validator;
+  final String? labelTextKey;
+  final IconData? iconData;
+  final TextEditingController? controller;
+  final FormFieldValidator<String>? validator;
   final int maxLines;
   final bool withBorder;
-  final Color borderColor;
-  final TextInputType textInputType;
+  final Color? borderColor;
+  final TextInputType? textInputType;
   final bool autoFocus;
 
   const InputTime(
-      {Key key,
+      {Key? key,
       this.labelTextKey,
       this.iconData,
       this.controller,
@@ -45,14 +45,14 @@ class InputTime extends StatelessWidget {
               try {
                 final format = DateFormat.jm(); //"6:00 AM"
                 initialDate =
-                    TimeOfDay.fromDateTime(format.parse(controller.text));
+                    TimeOfDay.fromDateTime(format.parse(controller!.text));
                 // var values = controller.text.split(":");
                 // initialDate = TimeOfDay(
                 //     hour: int.parse(values[0]), minute: int.parse(values[1]));
               } catch (e) {} // ignore error
             }
 
-            TimeOfDay t = await showTimePicker(
+            TimeOfDay? t = await showTimePicker(
               initialTime: initialDate,
               context: context,
             );
@@ -61,7 +61,7 @@ class InputTime extends StatelessWidget {
               final now = new DateTime.now();
               final dt =
                   DateTime(now.year, now.month, now.day, t.hour, t.minute);
-              controller.text = "${format.format(dt)}";
+              controller!.text = "${format.format(dt)}";
             }
           },
           controller: controller,
@@ -77,7 +77,7 @@ class InputTime extends StatelessWidget {
             ),
             labelText: labelTextKey == null
                 ? null
-                : AppTranslations.of(context).text(labelTextKey),
+                : AppTranslations.of(context)!.text(labelTextKey!),
             labelStyle: languageModel.isEng
                 ? newLabelStyle(color: Colors.black54, fontSize: 20)
                 : newLabelStyleMM(color: Colors.black54, fontSize: 20),
diff --git a/lib/pages/widgets/length_picker.dart b/lib/pages/widgets/length_picker.dart
index fe298c8..79bbd81 100644
--- a/lib/pages/widgets/length_picker.dart
+++ b/lib/pages/widgets/length_picker.dart
@@ -10,13 +10,13 @@ const MAX_INC = 50.0;
 const MAX_FEET = 25.0;
 
 class LengthPicker extends StatefulWidget {
-  final TextEditingController controller;
-  final String lableKey;
+  final TextEditingController? controller;
+  final String? lableKey;
   final bool isReadOnly;
   final bool displayFeet;
 
   const LengthPicker(
-      {Key key,
+      {Key? key,
       this.controller,
       this.lableKey,
       this.isReadOnly = false,
@@ -35,14 +35,14 @@ class _LengthPickerState extends State<LengthPicker> {
     super.initState();
     if (widget.controller != null) {
       _setText();
-      widget.controller.addListener(() {
+      widget.controller!.addListener(() {
         _setText();
       });
     }
   }
 
   _setText() {
-    double v = double.parse(widget.controller.text, (s) => 0);
+    double v = double.parse(widget.controller!.text, (s) => 0);
     int _v = v.toInt();
 
     int f = (v / 12).floor();
@@ -72,8 +72,8 @@ class _LengthPickerState extends State<LengthPicker> {
       context: context,
       builder: (BuildContext context) {
         return LengthPickerDialog(
-          controller: widget.controller,
-          labelKey: widget.lableKey,
+          controller: widget.controller!,
+          labelKey: widget.lableKey!,
           displayFeet: widget.displayFeet,
         );
       },
@@ -82,12 +82,12 @@ class _LengthPickerState extends State<LengthPicker> {
 }
 
 class LengthPickerDialog extends StatefulWidget {
-  final TextEditingController controller;
-  final String labelKey;
-  final bool displayFeet;
+  final TextEditingController? controller;
+  final String? labelKey;
+  final bool? displayFeet;
 
   const LengthPickerDialog(
-      {Key key, this.controller, this.labelKey, this.displayFeet})
+      {Key? key, this.controller, this.labelKey, this.displayFeet})
       : super(key: key);
 
   @override
@@ -95,8 +95,8 @@ class LengthPickerDialog extends StatefulWidget {
 }
 
 class _LengthPickerDialogState extends State<LengthPickerDialog> {
-  int _valueFeet;
-  int _valueInc;
+  late int _valueFeet;
+  late int _valueInc;
   TextEditingController inchInputController = TextEditingController();
   TextEditingController feetInputController = TextEditingController();
   final _focusNode = FocusNode();
@@ -107,9 +107,9 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
     _valueFeet = 0;
     _valueInc = 0;
     if (widget.controller != null) {
-      double v = double.parse(widget.controller.text, (s) => 0);
+      double v = double.parse(widget.controller!.text, (s) => 0);
       _valueFeet = (v / 12).floor();
-      _valueInc = widget.displayFeet ? (v % 12).toInt() : v.toInt();
+      _valueInc = widget.displayFeet! ? (v % 12).toInt() : v.toInt();
       inchInputController.text = _valueInc.toString();
       feetInputController.text = _valueFeet.toString();
     }
@@ -144,7 +144,8 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
                     borderSide: BorderSide(color: primaryColor, width: 1.0),
                   ),
                   enabledBorder: OutlineInputBorder(
-                    borderSide: BorderSide(color: Colors.grey[400], width: 1.0),
+                    borderSide:
+                        BorderSide(color: Colors.grey.shade400, width: 1.0),
                   ),
                 ),
               ),
@@ -196,7 +197,8 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
                     borderSide: BorderSide(color: primaryColor, width: 1.0),
                   ),
                   enabledBorder: OutlineInputBorder(
-                    borderSide: BorderSide(color: Colors.grey[400], width: 1.0),
+                    borderSide:
+                        BorderSide(color: Colors.grey.shade400, width: 1.0),
                   ),
                 ),
               ),
@@ -233,14 +235,14 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
       title: Center(
           child: LocalText(
         context,
-        widget.labelKey,
+        widget.labelKey!,
         color: primaryColor,
         fontSize: 16,
       )),
       children: [
         Row(
           mainAxisAlignment: MainAxisAlignment.spaceAround,
-          children: widget.displayFeet
+          children: widget.displayFeet!
               ? [
                   Container(width: 100, child: feetBox),
                   Container(width: 100, child: inchBox),
@@ -252,7 +254,7 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
         SizedBox(
           height: 10,
         ),
-        widget.displayFeet
+        widget.displayFeet!
             ? Column(
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [
@@ -273,7 +275,7 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
                     min: 0,
                     max: MAX_FEET,
                     divisions: 100,
-                    label: (_valueFeet ?? 0).round().toString(),
+                    label: _valueFeet.round().toString(),
                     onChanged: (double v) {
                       _updateFeet(v);
                     },
@@ -295,13 +297,13 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
             ),
             Slider(
               activeColor: primaryColor,
-              value: _valueInc.toDouble() > (widget.displayFeet ? 11 : MAX_INC)
+              value: _valueInc.toDouble() > (widget.displayFeet! ? 11 : MAX_INC)
                   ? 0
                   : _valueInc.toDouble(),
               min: 0,
-              max: widget.displayFeet ? 11 : MAX_INC,
+              max: widget.displayFeet! ? 11 : MAX_INC,
               divisions: 100,
-              label: (_valueInc ?? 0).round().toString(),
+              label: _valueInc.round().toString(),
               onChanged: (double v) {
                 _updateInc(v);
               },
@@ -318,10 +320,10 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
     });
     int _v = _valueInc.round() + _valueFeet.round() * 12;
     if (widget.controller != null) {
-      widget.controller.text = _v.toString();
+      widget.controller!.text = _v.toString();
     }
     feetInputController.text =
-        widget.displayFeet ? _valueFeet.round().toString() : _v.toString();
+        widget.displayFeet! ? _valueFeet.round().toString() : _v.toString();
   }
 
   _updateInc(double v) {
@@ -330,8 +332,8 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
     });
     int _v = _valueInc.round() + _valueFeet.round() * 12;
     if (widget.controller != null) {
-      widget.controller.text =
-          widget.displayFeet ? _v.toString() : _valueInc.toString();
+      widget.controller!.text =
+          widget.displayFeet! ? _v.toString() : _valueInc.toString();
     }
     inchInputController.text = _valueInc.toString();
   }
@@ -343,8 +345,8 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
     });
     int _v = _valueInc.round() + _valueFeet.round() * 12;
     if (widget.controller != null) {
-      widget.controller.text =
-          widget.displayFeet ? _v.toString() : _valueInc.toString();
+      widget.controller!.text =
+          widget.displayFeet! ? _v.toString() : _valueInc.toString();
     }
   }
 
@@ -355,7 +357,7 @@ class _LengthPickerDialogState extends State<LengthPickerDialog> {
     });
     int _v = _valueInc.round() + _valueFeet.round() * 12;
     if (widget.controller != null) {
-      widget.controller.text = _v.toString();
+      widget.controller!.text = _v.toString();
     }
   }
 
diff --git a/lib/pages/widgets/local_button.dart b/lib/pages/widgets/local_button.dart
index e7d4edf..8c52eb2 100644
--- a/lib/pages/widgets/local_button.dart
+++ b/lib/pages/widgets/local_button.dart
@@ -6,13 +6,13 @@ import 'package:flutter/material.dart';
 import 'callbacks.dart';
 
 class LocalButton extends StatelessWidget {
-  final CallBack callBack;
-  final IconData iconData;
-  final String textKey;
-  final Color color;
+  final CallBack? callBack;
+  final IconData? iconData;
+  final String? textKey;
+  final Color? color;
 
   const LocalButton(
-      {Key key,
+      {Key? key,
       this.callBack,
       this.iconData,
       this.textKey,
@@ -33,7 +33,7 @@ class LocalButton extends StatelessWidget {
           minWidth: 900.0,
           height: 100.0,
           child: FlatButton(
-            onPressed: callBack == null ? null : () => callBack(),
+            onPressed: callBack == null ? null : () => callBack!(),
             child: Row(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
@@ -48,7 +48,7 @@ class LocalButton extends StatelessWidget {
                 ),
                 LocalText(
                   context,
-                  textKey,
+                  textKey!,
                   color: Colors.white,
                   fontSize: 16,
                 ),
diff --git a/lib/pages/widgets/local_dropdown.dart b/lib/pages/widgets/local_dropdown.dart
index b61c3b8..aa6eb8e 100644
--- a/lib/pages/widgets/local_dropdown.dart
+++ b/lib/pages/widgets/local_dropdown.dart
@@ -5,15 +5,15 @@ import 'package:flutter/material.dart';
 import 'local_text.dart';
 
 class LocalDropdown<T> extends StatelessWidget {
-  final Function(T) callback;
-  final IconData iconData;
-  final T selectedValue;
-  final List<T> values;
-  final Function(T) display;
-  final String labelKey;
+  final Function(T)? callback;
+  final IconData? iconData;
+  final T? selectedValue;
+  final List<T>? values;
+  final Function(T)? display;
+  final String? labelKey;
 
   const LocalDropdown(
-      {Key key,
+      {Key? key,
       this.callback,
       this.iconData,
       this.selectedValue,
@@ -40,7 +40,7 @@ class LocalDropdown<T> extends StatelessWidget {
                   padding: const EdgeInsets.only(right: 18.0),
                   child: LocalText(
                     context,
-                    labelKey,
+                    labelKey!,
                     color: Colors.black54,
                     fontSize: 16,
                   ),
@@ -53,20 +53,20 @@ class LocalDropdown<T> extends StatelessWidget {
                     height: 1,
                     color: Colors.grey,
                   ),
-                  onChanged: (T newValue) {
-                    callback(newValue);
+                  onChanged: (T? newValue) {
+                    callback!(newValue!);
                   },
                   isExpanded: true,
                   items: values == null
                       ? []
-                      : values.map<DropdownMenuItem<T>>((T value) {
+                      : values!.map<DropdownMenuItem<T>>((T value) {
                           return DropdownMenuItem<T>(
                             value: value,
                             child: Text(
                                 value == null
                                     ? ""
                                     : display != null
-                                        ? display(value)
+                                        ? display!(value)
                                         : value.toString(),
                                 overflow: TextOverflow.ellipsis,
                                 style: TextStyle(color: primaryColor)),
diff --git a/lib/pages/widgets/local_popup_menu_button.dart b/lib/pages/widgets/local_popup_menu_button.dart
index 53701e7..8fa1e62 100644
--- a/lib/pages/widgets/local_popup_menu_button.dart
+++ b/lib/pages/widgets/local_popup_menu_button.dart
@@ -7,15 +7,15 @@ import 'local_popupmenu.dart';
 typedef PopupMenuCallback = Function(LocalPopupMenu popupMenu);
 
 class LocalPopupMenuButton extends StatefulWidget {
-  final PopupMenuCallback popupMenuCallback;
-  final List<LocalPopupMenu> popmenus;
+  final PopupMenuCallback? popupMenuCallback;
+  final List<LocalPopupMenu>? popmenus;
   final bool multiSelect;
   final bool selectable;
-  final IconData buttonIcon;
+  final IconData? buttonIcon;
   final Color buttonColor;
 
   const LocalPopupMenuButton(
-      {Key key,
+      {Key? key,
       this.popupMenuCallback,
       this.popmenus,
       this.buttonIcon,
@@ -29,11 +29,11 @@ class LocalPopupMenuButton extends StatefulWidget {
 }
 
 class _LocalPopupMenuButtonState extends State<LocalPopupMenuButton> {
-  List<LocalPopupMenu> popmenus;
+  late List<LocalPopupMenu> popmenus;
 
   @override
   void initState() {
-    popmenus = widget.popmenus;
+    popmenus = widget.popmenus!;
     super.initState();
   }
 
@@ -64,7 +64,7 @@ class _LocalPopupMenuButtonState extends State<LocalPopupMenuButton> {
             }
           }
           if (selected.enabled && widget.popupMenuCallback != null)
-            widget.popupMenuCallback(selected);
+            widget.popupMenuCallback!(selected);
         },
         icon: Container(
             width: 30,
@@ -78,7 +78,7 @@ class _LocalPopupMenuButtonState extends State<LocalPopupMenuButton> {
               children: <Widget>[
                 Icon(
                   widget.buttonIcon ?? Icons.filter_list,
-                  color: widget.buttonColor ?? primaryColor,
+                  color: widget.buttonColor,
                 ),
                 hightlight
                     ? Positioned(
@@ -98,14 +98,12 @@ class _LocalPopupMenuButtonState extends State<LocalPopupMenuButton> {
             )),
         itemBuilder: (BuildContext context) {
           return popmenus.map((LocalPopupMenu choice) {
-            if (choice == null) return null;
             return PopupMenuItem<LocalPopupMenu>(
               value: choice,
               child: Row(
                 children: <Widget>[
-                  LocalText(context, choice.textKey,
-                      color:
-                          choice?.enabled ?? true ? primaryColor : Colors.grey),
+                  LocalText(context, choice.textKey ?? "",
+                      color: choice.enabled ? primaryColor : Colors.grey),
                   SizedBox(
                     width: 10,
                   ),
@@ -124,8 +122,8 @@ class _LocalPopupMenuButtonState extends State<LocalPopupMenuButton> {
 
   bool _needHighlight() {
     popmenus.forEach((e) {
-      if (e == null) return false;
-      if (e.selected && e.highlight) return true;
+      if (e == null) return;
+      if (e.selected && e.highlight) return;
     });
     return false;
   }
diff --git a/lib/pages/widgets/local_popupmenu.dart b/lib/pages/widgets/local_popupmenu.dart
index d3778ee..d5931b1 100644
--- a/lib/pages/widgets/local_popupmenu.dart
+++ b/lib/pages/widgets/local_popupmenu.dart
@@ -1,11 +1,11 @@
 class LocalPopupMenu {
   int id;
-  String textKey;
+  String? textKey;
   bool selected;
   bool highlight;
   bool enabled;
   LocalPopupMenu(
-      {this.id,
+      {required this.id,
       this.textKey,
       this.selected = false,
       this.highlight = false,
diff --git a/lib/pages/widgets/local_radio_buttons.dart b/lib/pages/widgets/local_radio_buttons.dart
index e2b2f96..11c72ad 100644
--- a/lib/pages/widgets/local_radio_buttons.dart
+++ b/lib/pages/widgets/local_radio_buttons.dart
@@ -3,15 +3,15 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
 class LocalRadioButtons<T> extends StatelessWidget {
-  final Function(T) callback;
-  final IconData iconData;
-  final T selectedValue;
-  final List<T> values;
+  final Function(T)? callback;
+  final IconData? iconData;
+  final T? selectedValue;
+  final List<T>? values;
   final bool readOnly;
   final bool hideUnselected;
 
   const LocalRadioButtons(
-      {Key key,
+      {Key? key,
       this.callback,
       this.iconData,
       this.selectedValue,
@@ -26,19 +26,19 @@ class LocalRadioButtons<T> extends StatelessWidget {
   }
 
   List<Widget> getChildren() {
-    return values
+    return values!
         .toList()
         .map((e) => SizedBox(
             height: 30,
             child: InkWell(
-              onTap: () => callback(e),
+              onTap: () => callback!(e),
               child: Row(children: <Widget>[
                 Radio<T>(
                   activeColor: primaryColor,
                   groupValue: selectedValue,
                   value: e,
-                  onChanged: (T value) {
-                    callback(value);
+                  onChanged: (T? value) {
+                    callback!(value!);
                   },
                 ),
                 Text(e.toString()),
@@ -48,7 +48,7 @@ class LocalRadioButtons<T> extends StatelessWidget {
   }
 
   List<Widget> getReadonlyChildren() {
-    return values
+    return values!
         .toList()
         .map((e) => hideUnselected && e == selectedValue
             ? SizedBox(
diff --git a/lib/pages/widgets/local_text.dart b/lib/pages/widgets/local_text.dart
index c302796..92fbff8 100644
--- a/lib/pages/widgets/local_text.dart
+++ b/lib/pages/widgets/local_text.dart
@@ -7,26 +7,26 @@ import 'package:fcs/helpers/theme.dart';
 class LocalText extends Text {
   final BuildContext context;
   LocalText(this.context, String translationKey,
-      {Color color,
-      double fontSize,
-      FontWeight fontWeight,
-      List<String> translationVariables,
-      String text,
+      {Color? color,
+      double? fontSize,
+      FontWeight? fontWeight,
+      List<String>? translationVariables,
+      String? text,
       bool underline = false})
       : super(
             text ??
-                AppTranslations.of(context).text(translationKey,
+                AppTranslations.of(context)!.text(translationKey,
                     translationVariables: translationVariables),
             style: Provider.of<LanguageModel>(context, listen: false).isEng
                 ? newLabelStyle(
-                    color: color,
-                    fontSize: fontSize,
-                    fontWeight: fontWeight,
+                    color: color!,
+                    fontSize: fontSize!,
+                    fontWeight: fontWeight!,
                     underline: underline)
                 : newLabelStyleMM(
-                    color: color,
-                    fontSize: fontSize,
-                    fontWeight: fontWeight,
+                    color: color!,
+                    fontSize: fontSize!,
+                    fontWeight: fontWeight!,
                     underline: underline));
 }
 
@@ -35,10 +35,10 @@ class LocalLargeTitle extends Text {
   LocalLargeTitle(
     this.context,
     String translationKey, {
-    Color color,
-    List<String> translationVariables,
+    Color? color,
+    List<String>? translationVariables,
   }) : super(
-            AppTranslations.of(context).text(translationKey,
+            AppTranslations.of(context)!.text(translationKey,
                 translationVariables: translationVariables),
             style: Provider.of<LanguageModel>(context).isEng
                 ? TextStyle(color: color)
@@ -48,7 +48,7 @@ class LocalLargeTitle extends Text {
 class TextLocalStyle extends Text {
   final BuildContext context;
   TextLocalStyle(this.context, String text,
-      {Color color, double fontSize, FontWeight fontWeight})
+      {Color? color, double? fontSize, FontWeight? fontWeight})
       : super(text,
             style: Provider.of<LanguageModel>(context).isEng
                 ? TextStyle(
diff --git a/lib/pages/widgets/local_title.dart b/lib/pages/widgets/local_title.dart
index 8fc8c72..80397d3 100644
--- a/lib/pages/widgets/local_title.dart
+++ b/lib/pages/widgets/local_title.dart
@@ -4,10 +4,10 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
 class LocalTitle extends StatelessWidget {
-  final String textKey;
-  final Widget trailing;
+  final String? textKey;
+  final Widget? trailing;
 
-  const LocalTitle({Key key, this.textKey, this.trailing}) : super(key: key);
+  const LocalTitle({Key? key, this.textKey, this.trailing}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -20,13 +20,13 @@ class LocalTitle extends StatelessWidget {
             children: [
               LocalText(
                 context,
-                textKey,
+                textKey!,
                 fontSize: 20,
                 fontWeight: FontWeight.bold,
                 color: primaryColor,
               ),
               trailing != null ? Spacer() : Container(),
-              trailing != null ? trailing : Container()
+              trailing != null ? trailing! : Container()
             ],
           ),
         ),
diff --git a/lib/pages/widgets/multi_img_controller.dart b/lib/pages/widgets/multi_img_controller.dart
index 84654da..ad0be39 100644
--- a/lib/pages/widgets/multi_img_controller.dart
+++ b/lib/pages/widgets/multi_img_controller.dart
@@ -5,12 +5,12 @@ import 'display_image_source.dart';
 
 class MultiImgController {
   List<String> imageUrls = [];
-  List<File> imageFiles = [];
+  List<File?> imageFiles = [];
   List<DisplayImageSource> addedFiles = [];
   List<DisplayImageSource> removedFiles = [];
 
   List<DisplayImageSource> fileContainers = [];
-  CallBack callback;
+  CallBack? callback;
   MultiImgController() {
     fileContainers = [];
   }
@@ -26,7 +26,7 @@ class MultiImgController {
       fileContainers.add(DisplayImageSource(url: e));
     });
     if (callback != null) {
-      callback();
+      callback!();
     }
   }
 
@@ -42,7 +42,7 @@ class MultiImgController {
       fileContainers.add(DisplayImageSource(file: e));
     });
     if (callback != null) {
-      callback();
+      callback!();
     }
   }
 
@@ -54,7 +54,7 @@ class MultiImgController {
     // if (fileContainers.contains(fileContainer)) return;
     addedFiles.add(fileContainer);
     if (callback != null) {
-      callback();
+      callback!();
     }
   }
 
@@ -74,21 +74,21 @@ class MultiImgController {
     }
 
     if (callback != null) {
-      callback();
+      callback!();
     }
   }
 
-  List<File> get getUpdatedFile {
-    List<File> _addfiles = getAddedFile;
+  List<File?> get getUpdatedFile {
+    List<File?> _addfiles = getAddedFile;
     this.imageFiles.addAll(_addfiles);
     return this.imageFiles;
   }
 
-  List<File> get getAddedFile {
+  List<File?> get getAddedFile {
     return addedFiles.map((e) => e.file).toList();
   }
 
-  List<String> get getDeletedUrl {
+  List<String?> get getDeletedUrl {
     return removedFiles.map((e) => e.url).toList();
   }
 }
diff --git a/lib/pages/widgets/multi_img_file.dart b/lib/pages/widgets/multi_img_file.dart
index 70d7cb4..057869b 100644
--- a/lib/pages/widgets/multi_img_file.dart
+++ b/lib/pages/widgets/multi_img_file.dart
@@ -8,7 +8,7 @@ import 'package:fcs/pages/widgets/show_img.dart';
 import 'package:fcs/pages/widgets/show_multiple_img.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:image_picker/image_picker.dart';
 
@@ -18,13 +18,13 @@ import 'multi_img_controller.dart';
 typedef OnFile = void Function(File);
 
 class MultiImageFile extends StatefulWidget {
-  final String title;
+  final String? title;
   final bool enabled;
   final ImageSource imageSource;
-  final MultiImgController controller;
+  final MultiImgController? controller;
 
   const MultiImageFile(
-      {Key key,
+      {Key? key,
       this.title,
       this.enabled = true,
       this.controller,
@@ -39,10 +39,10 @@ class _MultiImageFileState extends State<MultiImageFile> {
   @override
   void initState() {
     super.initState();
-    fileContainers = widget.controller.fileContainers;
-    widget.controller.onChange(() {
+    fileContainers = widget.controller!.fileContainers;
+    widget.controller!.onChange(() {
       setState(() {
-        this.fileContainers = widget.controller.fileContainers;
+        this.fileContainers = widget.controller!.fileContainers;
       });
     });
   }
@@ -133,7 +133,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
                               fit: BoxFit.cover,
                               width: 50,
                               height: 50,
-                              imageUrl: fileContainers[index].url,
+                              imageUrl: fileContainers[index].url!,
                               placeholder: (context, url) => Column(
                                 mainAxisAlignment: MainAxisAlignment.center,
                                 mainAxisSize: MainAxisSize.min,
@@ -150,7 +150,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
                           : FittedBox(
                               fit: BoxFit.cover,
                               child: Image.file(
-                                fileContainers[index].file,
+                                fileContainers[index].file!,
                               ),
                             ),
                     ),
@@ -189,13 +189,13 @@ class _MultiImageFileState extends State<MultiImageFile> {
     fileContainer.file = selectedFile;
     setState(() {
       fileContainers.add(fileContainer);
-      widget.controller.addFile = fileContainer;
+      widget.controller!.addFile = fileContainer;
     });
   }
 
   _fileRemove(DisplayImageSource fileContainer) {
     setState(() {
-      widget.controller.removeFile = fileContainer;
+      widget.controller!.removeFile = fileContainer;
     });
   }
 
@@ -232,11 +232,11 @@ class _MultiImageFileState extends State<MultiImageFile> {
                     context,
                     MaterialPageRoute(
                         builder: (context) => ShowImage(
-                            imageFile: fileContainer.file,
+                            imageFile: fileContainer.file!,
                             url: fileContainer.file == null
-                                ? fileContainer.url
-                                : null,
-                            fileName: widget.title)),
+                                ? fileContainer.url!
+                                : '',
+                            fileName: widget.title!)),
                   )
                 },
                 child: Chip(
@@ -249,7 +249,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
                   deleteIcon: Icon(
                     Icons.close,
                   ),
-                  label: Text(widget.title + " - ${index + 1}"),
+                  label: Text("${widget.title}" + " - ${index + 1}"),
                 ),
               ),
             ),
@@ -308,7 +308,7 @@ class _MultiImageFileState extends State<MultiImageFile> {
     );
   }
 
-  Widget actionIcon({OnTap onTap, Color color, IconData iconData}) {
+  Widget actionIcon({OnTap? onTap, Color? color, IconData? iconData}) {
     return InkWell(
       onTap: onTap,
       child: ClipOval(
diff --git a/lib/pages/widgets/my_data_table.dart b/lib/pages/widgets/my_data_table.dart
index 52932b0..f86925f 100644
--- a/lib/pages/widgets/my_data_table.dart
+++ b/lib/pages/widgets/my_data_table.dart
@@ -20,7 +20,7 @@ class MyDataColumn {
   ///
   /// The [label] argument must not be null.
   const MyDataColumn({
-    @required this.label,
+    required this.label,
     this.tooltip,
     this.numeric = false,
     this.onSort,
@@ -40,7 +40,7 @@ class MyDataColumn {
   /// This is a longer description of the column heading, for cases
   /// where the heading might have been abbreviated to keep the column
   /// width to a reasonable size.
-  final String tooltip;
+  final String? tooltip;
 
   /// Whether this column represents numeric data or not.
   ///
@@ -53,7 +53,7 @@ class MyDataColumn {
   /// If null, the column will not be considered sortable.
   ///
   /// See [MyDataTable.sortColumnIndex] and [MyDataTable.sortAscending].
-  final MyDataColumnSortCallback onSort;
+  final MyDataColumnSortCallback? onSort;
 
   bool get _debugInteractive => onSort != null;
 }
@@ -75,7 +75,7 @@ class MyDataRow {
     this.key,
     this.selected = false,
     this.onSelectChanged,
-    @required this.cells,
+    required this.cells,
   }) : assert(cells != null);
 
   /// Creates the configuration for a row of a [MyDataTable], deriving
@@ -83,12 +83,12 @@ class MyDataRow {
   ///
   /// The [cells] argument must not be null.
   MyDataRow.byIndex({
-    int index,
+    int? index,
     this.selected = false,
     this.onSelectChanged,
-    @required this.cells,
+    required this.cells,
   })  : assert(cells != null),
-        key = ValueKey<int>(index);
+        key = ValueKey<int>(index!);
 
   /// A [Key] that uniquely identifies this row. This is used to
   /// ensure that if a row is added or removed, any stateful widgets
@@ -96,7 +96,7 @@ class MyDataRow {
   /// remain on the right row visually.
   ///
   /// If the table never changes once created, no key is necessary.
-  final LocalKey key;
+  final LocalKey? key;
 
   /// Called when the user selects or unselects a selectable row.
   ///
@@ -111,7 +111,7 @@ class MyDataRow {
   /// A row whose [onSelectChanged] callback is null is ignored for
   /// the purposes of determining the state of the "all" checkbox,
   /// and its checkbox is disabled.
-  final ValueChanged<bool> onSelectChanged;
+  final ValueChanged<bool>? onSelectChanged;
 
   /// Whether the row is selected.
   ///
@@ -193,7 +193,7 @@ class MyDataCell {
   /// If non-null, tapping the cell will call this callback. If
   /// null, tapping the cell will attempt to select the row (if
   /// [MyDataRow.onSelectChanged] is provided).
-  final VoidCallback onTap;
+  final VoidCallback? onTap;
 
   bool get _debugInteractive => onTap != null;
 }
@@ -309,8 +309,8 @@ class MyDataTable extends StatelessWidget {
   /// the sort order is ascending, this should be true (the default),
   /// otherwise it should be false.
   MyDataTable({
-    Key key,
-    @required this.columns,
+    Key? key,
+    required this.columns,
     this.sortColumnIndex,
     this.sortAscending = true,
     this.onSelectAll,
@@ -320,7 +320,7 @@ class MyDataTable extends StatelessWidget {
     this.columnSpacing = 56.0,
     this.oddLine,
     this.evenLine,
-    @required this.rows,
+    required this.rows,
   })  : assert(columns != null),
         assert(columns.isNotEmpty),
         assert(sortColumnIndex == null ||
@@ -339,8 +339,8 @@ class MyDataTable extends StatelessWidget {
   /// The configuration and labels for the columns in the table.
   final List<MyDataColumn> columns;
 
-  final Decoration oddLine;
-  final Decoration evenLine;
+  final Decoration? oddLine;
+  final Decoration? evenLine;
 
   /// The current primary sort key's column.
   ///
@@ -353,7 +353,7 @@ class MyDataTable extends StatelessWidget {
   ///
   /// When this is null, it implies that the table's sort order does
   /// not correspond to any of the columns.
-  final int sortColumnIndex;
+  final int? sortColumnIndex;
 
   /// Whether the column mentioned in [sortColumnIndex], if any, is sorted
   /// in ascending order.
@@ -376,7 +376,7 @@ class MyDataTable extends StatelessWidget {
   /// To control whether a particular row is selectable or not, see
   /// [MyDataRow.onSelectChanged]. This callback is only relevant if any
   /// row is selectable.
-  final ValueSetter<bool> onSelectAll;
+  final ValueSetter<bool>? onSelectAll;
 
   /// The height of each row (excluding the row that contains column headings).
   ///
@@ -413,11 +413,10 @@ class MyDataTable extends StatelessWidget {
   // non-numeric, if there is exactly one, otherwise null.
   final int _onlyTextColumn;
   static int _initOnlyTextColumn(List<MyDataColumn> columns) {
-    int result;
+    int result = 0;
     for (int index = 0; index < columns.length; index += 1) {
       final MyDataColumn column = columns[index];
       if (!column.numeric) {
-        if (result != null) return null;
         result = index;
       }
     }
@@ -433,11 +432,11 @@ class MyDataTable extends StatelessWidget {
 
   void _handleSelectAll(bool checked) {
     if (onSelectAll != null) {
-      onSelectAll(checked);
+      onSelectAll!(checked);
     } else {
       for (MyDataRow row in rows) {
         if ((row.onSelectChanged != null) && (row.selected != checked))
-          row.onSelectChanged(checked);
+          row.onSelectChanged!(checked);
       }
     }
   }
@@ -452,10 +451,10 @@ class MyDataTable extends StatelessWidget {
       Color(0x1E000000); // Dark theme variant is just a guess.
 
   Widget _buildCheckbox({
-    Color color,
-    bool checked,
-    VoidCallback onRowTap,
-    ValueChanged<bool> onCheckboxChanged,
+    Color? color,
+    bool? checked,
+    VoidCallback? onRowTap,
+    ValueChanged<bool>? onCheckboxChanged,
   }) {
     Widget contents = Semantics(
       container: true,
@@ -466,7 +465,9 @@ class MyDataTable extends StatelessWidget {
           child: Checkbox(
             activeColor: color,
             value: checked,
-            onChanged: onCheckboxChanged,
+            onChanged: (bool? value) {
+              onCheckboxChanged!(value ?? false);
+            },
           ),
         ),
       ),
@@ -484,32 +485,33 @@ class MyDataTable extends StatelessWidget {
   }
 
   Widget _buildHeadingCell({
-    BuildContext context,
-    EdgeInsetsGeometry padding,
-    Widget label,
-    String tooltip,
-    bool numeric,
-    VoidCallback onSort,
-    bool sorted,
-    bool ascending,
+    required BuildContext context,
+    EdgeInsetsGeometry? padding,
+    Widget? label,
+    String? tooltip,
+    bool? numeric,
+    VoidCallback? onSort,
+    bool? sorted,
+    bool? ascending,
   }) {
     if (onSort != null) {
       final Widget arrow = _SortArrow(
-        visible: sorted,
+        visible: sorted!,
         down: sorted ? ascending : null,
         duration: _sortArrowAnimationDuration,
       );
       const Widget arrowPadding = SizedBox(width: _sortArrowPadding);
       label = Row(
-        textDirection: numeric ? TextDirection.rtl : null,
-        children: <Widget>[label, arrowPadding, arrow],
+        textDirection: (numeric ?? false) ? TextDirection.rtl : null,
+        children: <Widget>[label ?? Container(), arrowPadding, arrow],
       );
     }
     label = Container(
       padding: padding,
       height: headingRowHeight,
-      alignment:
-          numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
+      alignment: (numeric ?? false)
+          ? Alignment.centerRight
+          : AlignmentDirectional.centerStart,
       child: AnimatedDefaultTextStyle(
         style: TextStyle(
           // TODO(ianh): font family should match Theme; see https://github.com/flutter/flutter/issues/3116
@@ -517,12 +519,16 @@ class MyDataTable extends StatelessWidget {
           fontSize: _headingFontSize,
           height: math.min(1.0, headingRowHeight / _headingFontSize),
           color: (Theme.of(context).brightness == Brightness.light)
-              ? ((onSort != null && sorted) ? Colors.black87 : Colors.black54)
-              : ((onSort != null && sorted) ? Colors.white : Colors.white70),
+              ? ((onSort != null && (sorted ?? false))
+                  ? Colors.black87
+                  : Colors.black54)
+              : ((onSort != null && (sorted ?? false))
+                  ? Colors.white
+                  : Colors.white70),
         ),
         softWrap: false,
         duration: _sortArrowAnimationDuration,
-        child: label,
+        child: label ?? Container(),
       ),
     );
     if (tooltip != null) {
@@ -541,42 +547,43 @@ class MyDataTable extends StatelessWidget {
   }
 
   Widget _buildMyDataCell({
-    BuildContext context,
-    EdgeInsetsGeometry padding,
-    Widget label,
-    bool numeric,
-    bool placeholder,
-    bool showEditIcon,
-    VoidCallback onTap,
-    VoidCallback onSelectChanged,
+    required BuildContext context,
+    EdgeInsetsGeometry? padding,
+    Widget? label,
+    bool? numeric,
+    bool? placeholder,
+    bool? showEditIcon,
+    VoidCallback? onTap,
+    VoidCallback? onSelectChanged,
   }) {
     final bool isLightTheme = Theme.of(context).brightness == Brightness.light;
-    if (showEditIcon) {
+    if (showEditIcon ?? false) {
       const Widget icon = Icon(Icons.edit, size: 18.0);
-      label = Expanded(child: label);
+      label = Expanded(child: label ?? Container());
       label = Row(
-        textDirection: numeric ? TextDirection.rtl : null,
+        textDirection: (numeric ?? false) ? TextDirection.rtl : null,
         children: <Widget>[label, icon],
       );
     }
     label = Container(
       padding: padding,
       height: MyDataRowHeight,
-      alignment:
-          numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
+      alignment: (numeric ?? false)
+          ? Alignment.centerRight
+          : AlignmentDirectional.centerStart,
       child: DefaultTextStyle(
         style: TextStyle(
           // TODO(ianh): font family should be Roboto; see https://github.com/flutter/flutter/issues/3116
           fontSize: 13.0,
           color: isLightTheme
-              ? (placeholder ? Colors.black38 : Colors.black87)
-              : (placeholder ? Colors.white38 : Colors.white70),
+              ? ((placeholder ?? false) ? Colors.black38 : Colors.black87)
+              : ((placeholder ?? false) ? Colors.white38 : Colors.white70),
         ),
         child: IconTheme.merge(
           data: IconThemeData(
             color: isLightTheme ? Colors.black54 : Colors.white70,
           ),
-          child: DropdownButtonHideUnderline(child: label),
+          child: DropdownButtonHideUnderline(child: label ?? Container()),
         ),
       ),
     );
@@ -613,8 +620,9 @@ class MyDataTable extends StatelessWidget {
     final bool showCheckboxColumn = false;
     final bool allChecked = false;
 
-    final List<TableColumnWidth> tableColumns =
-        List<TableColumnWidth>(columns.length + (showCheckboxColumn ? 1 : 0));
+    final List<TableColumnWidth> tableColumns = (columns.length +
+        (showCheckboxColumn ? 1 : 0)) as List<TableColumnWidth>;
+
     final List<TableRow> tableRows = List<TableRow>.generate(
       rows.length + 1, // the +1 is for the header row
       (int index) {
@@ -627,36 +635,36 @@ class MyDataTable extends StatelessWidget {
                   : index.isEven && evenLine != null
                       ? evenLine
                       : _kUnselectedDecoration,
-          children: List<Widget>(tableColumns.length),
+          children: tableColumns.map((e) => Container()).toList(),
         );
       },
     );
 
     int rowIndex;
 
-    int displayColumnIndex = 0;
-    if (showCheckboxColumn) {
-      tableColumns[0] = FixedColumnWidth(
-          horizontalMargin + Checkbox.width + horizontalMargin / 2.0);
-      tableRows[0].children[0] = _buildCheckbox(
-        color: theme.accentColor,
-        checked: allChecked,
-        onCheckboxChanged: _handleSelectAll,
-      );
-      rowIndex = 1;
-      for (MyDataRow row in rows) {
-        tableRows[rowIndex].children[0] = _buildCheckbox(
-          color: theme.accentColor,
-          checked: row.selected,
-          onRowTap: () => row.onSelectChanged != null
-              ? row.onSelectChanged(!row.selected)
-              : null,
-          onCheckboxChanged: row.onSelectChanged,
-        );
-        rowIndex += 1;
-      }
-      displayColumnIndex += 1;
-    }
+    int displayColumnIndex = 0;   
+    // if (showCheckboxColumn) {
+    //   tableColumns[0] = FixedColumnWidth(
+    //       horizontalMargin + Checkbox.width + horizontalMargin / 2.0);
+    //   tableRows[0].children![0] = _buildCheckbox(
+    //     color: theme.accentColor,
+    //     checked: allChecked,
+    //     onCheckboxChanged: _handleSelectAll,
+    //   );
+    //   rowIndex = 1;
+    //   for (MyDataRow row in rows) {
+    //     tableRows[rowIndex].children[0] = _buildCheckbox(
+    //       color: theme.accentColor,
+    //       checked: row.selected,
+    //       onRowTap: () => row.onSelectChanged != null
+    //           ? row.onSelectChanged(!row.selected)
+    //           : null,
+    //       onCheckboxChanged: row.onSelectChanged,
+    //     );
+    //     rowIndex += 1;
+    //   }
+    //   displayColumnIndex += 1;
+    // }
 
     for (int MyDataColumnIndex = 0;
         MyDataColumnIndex < columns.length;
@@ -689,14 +697,14 @@ class MyDataTable extends StatelessWidget {
       } else {
         tableColumns[displayColumnIndex] = const IntrinsicColumnWidth();
       }
-      tableRows[0].children[displayColumnIndex] = _buildHeadingCell(
+      tableRows[0].children![displayColumnIndex] = _buildHeadingCell(
         context: context,
         padding: padding,
         label: column.label,
         tooltip: column.tooltip,
         numeric: column.numeric,
         onSort: () => column.onSort != null
-            ? column.onSort(MyDataColumnIndex,
+            ? column.onSort!(MyDataColumnIndex,
                 sortColumnIndex != MyDataColumnIndex || !sortAscending)
             : null,
         sorted: MyDataColumnIndex == sortColumnIndex,
@@ -705,7 +713,7 @@ class MyDataTable extends StatelessWidget {
       rowIndex = 1;
       for (MyDataRow row in rows) {
         final MyDataCell cell = row.cells[MyDataColumnIndex];
-        tableRows[rowIndex].children[displayColumnIndex] = _buildMyDataCell(
+        tableRows[rowIndex].children?[displayColumnIndex] = _buildMyDataCell(
           context: context,
           padding: padding,
           label: cell.child,
@@ -714,7 +722,7 @@ class MyDataTable extends StatelessWidget {
           showEditIcon: cell.showEditIcon,
           onTap: cell.onTap,
           onSelectChanged: () => row.onSelectChanged != null
-              ? row.onSelectChanged(!row.selected)
+              ? row.onSelectChanged!(!row.selected)
               : null,
         );
         rowIndex += 1;
@@ -745,12 +753,12 @@ class MyDataTable extends StatelessWidget {
 class TableRowInkWell extends InkResponse {
   /// Creates an ink well for a table row.
   const TableRowInkWell({
-    Key key,
-    Widget child,
-    GestureTapCallback onTap,
-    GestureTapCallback onDoubleTap,
-    GestureLongPressCallback onLongPress,
-    ValueChanged<bool> onHighlightChanged,
+    Key? key,
+    Widget? child,
+    GestureTapCallback? onTap,
+    GestureTapCallback? onDoubleTap,
+    GestureLongPressCallback? onLongPress,
+    ValueChanged<bool>? onHighlightChanged,
   }) : super(
           key: key,
           child: child,
@@ -766,7 +774,7 @@ class TableRowInkWell extends InkResponse {
   RectCallback getRectCallback(RenderBox referenceBox) {
     return () {
       RenderObject cell = referenceBox;
-      AbstractNode table = cell.parent;
+      AbstractNode? table = cell.parent;
       final Matrix4 transform = Matrix4.identity();
       while (table is RenderObject && table is! RenderTable) {
         final RenderObject parentBox = table as RenderObject;
@@ -779,11 +787,11 @@ class TableRowInkWell extends InkResponse {
         final TableCellParentData cellParentData =
             cell.parentData as TableCellParentData;
         assert(cellParentData.y != null);
-        final Rect rect = table.getRowBox(cellParentData.y);
+        final Rect rect = table.getRowBox(cellParentData.y!);
         // The rect is in the table's coordinate space. We need to change it to the
         // TableRowInkWell's coordinate space.
         table.applyPaintTransform(cell, transform);
-        final Offset offset = MatrixUtils.getAsTranslation(transform);
+        final Offset? offset = MatrixUtils.getAsTranslation(transform);
         if (offset != null) return rect.shift(-offset);
       }
       return Rect.zero;
@@ -799,31 +807,31 @@ class TableRowInkWell extends InkResponse {
 
 class _SortArrow extends StatefulWidget {
   const _SortArrow({
-    Key key,
+    Key? key,
     this.visible,
     this.down,
     this.duration,
   }) : super(key: key);
 
-  final bool visible;
+  final bool? visible;
 
-  final bool down;
+  final bool? down;
 
-  final Duration duration;
+  final Duration? duration;
 
   @override
   _SortArrowState createState() => _SortArrowState();
 }
 
 class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
-  AnimationController _opacityController;
-  Animation<double> _opacityAnimation;
+  AnimationController? _opacityController;
+  Animation<double>? _opacityAnimation;
 
-  AnimationController _orientationController;
-  Animation<double> _orientationAnimation;
+  AnimationController? _orientationController;
+  Animation<double>? _orientationAnimation;
   double _orientationOffset = 0.0;
 
-  bool _down;
+  bool? _down;
 
   static final Animatable<double> _turnTween =
       Tween<double>(begin: 0.0, end: math.pi)
@@ -839,15 +847,16 @@ class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
       ),
       curve: Curves.fastOutSlowIn,
     )..addListener(_rebuild);
-    _opacityController.value = widget.visible ? 1.0 : 0.0;
+    _opacityController!.value = (widget.visible ?? false) ? 1.0 : 0.0;
     _orientationController = AnimationController(
       duration: widget.duration,
       vsync: this,
     );
-    _orientationAnimation = _orientationController.drive(_turnTween)
+    _orientationAnimation = _orientationController!.drive(_turnTween)
       ..addListener(_rebuild)
       ..addStatusListener(_resetOrientationAnimation);
-    if (widget.visible) _orientationOffset = widget.down ? 0.0 : math.pi;
+    if (widget.visible ?? false)
+      _orientationOffset = (widget.down ?? false) ? 0.0 : math.pi;
   }
 
   void _rebuild() {
@@ -858,9 +867,9 @@ class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
 
   void _resetOrientationAnimation(AnimationStatus status) {
     if (status == AnimationStatus.completed) {
-      assert(_orientationAnimation.value == math.pi);
+      assert(_orientationAnimation!.value == math.pi);
       _orientationOffset += math.pi;
-      _orientationController.value =
+      _orientationController!.value =
           0.0; // TODO(ianh): This triggers a pointless rebuild.
     }
   }
@@ -869,26 +878,26 @@ class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
   void didUpdateWidget(_SortArrow oldWidget) {
     super.didUpdateWidget(oldWidget);
     bool skipArrow = false;
-    final bool newDown = widget.down ?? _down;
+    final bool newDown = widget.down ?? _down!;
     if (oldWidget.visible != widget.visible) {
-      if (widget.visible &&
-          (_opacityController.status == AnimationStatus.dismissed)) {
-        _orientationController.stop();
-        _orientationController.value = 0.0;
+      if (widget.visible! &&
+          (_opacityController!.status == AnimationStatus.dismissed)) {
+        _orientationController!.stop();
+        _orientationController!.value = 0.0;
         _orientationOffset = newDown ? 0.0 : math.pi;
         skipArrow = true;
       }
-      if (widget.visible) {
-        _opacityController.forward();
+      if ((widget.visible ?? false)) {
+        _opacityController!.forward();
       } else {
-        _opacityController.reverse();
+        _opacityController!.reverse();
       }
     }
     if ((_down != newDown) && !skipArrow) {
-      if (_orientationController.status == AnimationStatus.dismissed) {
-        _orientationController.forward();
+      if (_orientationController!.status == AnimationStatus.dismissed) {
+        _orientationController?.forward();
       } else {
-        _orientationController.reverse();
+        _orientationController?.reverse();
       }
     }
     _down = newDown;
@@ -896,8 +905,8 @@ class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
 
   @override
   void dispose() {
-    _opacityController.dispose();
-    _orientationController.dispose();
+    _opacityController?.dispose();
+    _orientationController?.dispose();
     super.dispose();
   }
 
@@ -907,10 +916,10 @@ class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
   @override
   Widget build(BuildContext context) {
     return Opacity(
-      opacity: _opacityAnimation.value,
+      opacity: _opacityAnimation!.value,
       child: Transform(
         transform:
-            Matrix4.rotationZ(_orientationOffset + _orientationAnimation.value)
+            Matrix4.rotationZ(_orientationOffset + _orientationAnimation!.value)
               ..setTranslationRaw(0.0, _arrowIconBaselineOffset, 0.0),
         alignment: Alignment.center,
         child: Icon(
diff --git a/lib/pages/widgets/number_cell.dart b/lib/pages/widgets/number_cell.dart
index ec3efeb..9ec16c2 100644
--- a/lib/pages/widgets/number_cell.dart
+++ b/lib/pages/widgets/number_cell.dart
@@ -5,9 +5,9 @@ import 'package:fcs/helpers/theme.dart' as theme;
 class NumberCell extends StatelessWidget {
   final int number;
   final numberFormatter;
-  final TextStyle textStyle;
+  final TextStyle? textStyle;
 
-  NumberCell(this.number, {Key key, this.textStyle})
+  NumberCell(this.number, {Key? key, this.textStyle})
       : numberFormatter = new NumberFormat("#,###"),
         super(key: key);
 
diff --git a/lib/pages/widgets/offline_redirect.dart b/lib/pages/widgets/offline_redirect.dart
index 9e4609d..df7ec32 100644
--- a/lib/pages/widgets/offline_redirect.dart
+++ b/lib/pages/widgets/offline_redirect.dart
@@ -6,14 +6,14 @@ import 'package:provider/provider.dart';
 
 class OfflineRedirect extends StatefulWidget {
   final Widget child;
-  OfflineRedirect({@required this.child});
+  OfflineRedirect({required this.child});
 
   @override
   _OfflineRedirectState createState() => _OfflineRedirectState();
 }
 
 class _OfflineRedirectState extends State<OfflineRedirect> {
-  Timer offlineTimer;
+  Timer? offlineTimer;
 
   @override
   void initState() {
@@ -27,7 +27,7 @@ class _OfflineRedirectState extends State<OfflineRedirect> {
   }
 
   _startOfflineTimer() async {
-    if (offlineTimer != null && offlineTimer.isActive) return;
+    if (offlineTimer != null && offlineTimer!.isActive) return;
     var _duration = new Duration(milliseconds: 500);
     this.offlineTimer = new Timer.periodic(_duration, offlineNav);
   }
@@ -41,7 +41,7 @@ class _OfflineRedirectState extends State<OfflineRedirect> {
   }
 
   void dispose() {
-    offlineTimer.cancel();
+    offlineTimer!.cancel();
     super.dispose();
   }
 
diff --git a/lib/pages/widgets/pdf_screen.dart b/lib/pages/widgets/pdf_screen.dart
index e9a1397..d0490c3 100644
--- a/lib/pages/widgets/pdf_screen.dart
+++ b/lib/pages/widgets/pdf_screen.dart
@@ -11,10 +11,10 @@ import 'package:flutter_pdfview/flutter_pdfview.dart';
 import 'package:share/share.dart';
 
 class PDFScreen extends StatefulWidget {
-  final String title;
-  final String url;
+  final String? title;
+  final String? url;
 
-  PDFScreen({Key key, this.url, this.title}) : super(key: key);
+  PDFScreen({Key? key, this.url, this.title}) : super(key: key);
 
   _PDFScreenState createState() => _PDFScreenState();
 }
@@ -33,10 +33,10 @@ class _PDFScreenState extends State<PDFScreen> with WidgetsBindingObserver {
     download();
   }
 
-  File file;
+  File? file;
   Future<void> download() async {
     try {
-      File f = await PdfCacheMgr.pdfs.getSingleFile(widget.url);
+      File f = await PdfCacheMgr.pdfs.getSingleFile(widget.url!);
       setState(() {
         file = f;
       });
@@ -89,23 +89,23 @@ class _PDFScreenState extends State<PDFScreen> with WidgetsBindingObserver {
                     fitPolicy: FitPolicy.BOTH,
                     preventLinkNavigation:
                         false, // if set to true the link is handled in flutter
-                    onRender: (_pages) {
+                    onRender: (int?_pages) {
                       print(('pages => $pages'));
                       setState(() {
-                        pages = _pages;
+                        pages = _pages!;
                         isReady = true;
                       });
                     },
                     onViewCreated: (PDFViewController pdfViewController) {
                       _controller.complete(pdfViewController);
                     },
-                    onLinkHandler: (String uri) {
+                    onLinkHandler: (String? uri) {
                       print('goto uri: $uri');
                     },
-                    onPageChanged: (int page, int total) {
+                    onPageChanged: (int? page, int? total) {
                       print('page change: $page/$total');
                       setState(() {
-                        currentPage = page;
+                        currentPage = page!;
                       });
                     },
                   ),
@@ -116,8 +116,8 @@ class _PDFScreenState extends State<PDFScreen> with WidgetsBindingObserver {
   }
 
   _share() async {
-    final RenderBox box = context.findRenderObject();
-    await Share.shareFiles([file.path],
+    final RenderBox box = context.findRenderObject() as RenderBox;
+    await Share.shareFiles([file!.path],
         mimeTypes: ["application/pdf"],
         subject: "File",
         sharePositionOrigin: box.localToGlobal(Offset.zero) & box.size);
diff --git a/lib/pages/widgets/popupmenu.dart b/lib/pages/widgets/popupmenu.dart
index 3587571..d4092f9 100644
--- a/lib/pages/widgets/popupmenu.dart
+++ b/lib/pages/widgets/popupmenu.dart
@@ -1,7 +1,7 @@
 class PopupMenu {
   int id;
   String status;
-  PopupMenu({this.id, this.status});
+  PopupMenu({required this.id, required this.status});
 }
 
 List<PopupMenu> menuPopup = <PopupMenu>[
diff --git a/lib/pages/widgets/progress.dart b/lib/pages/widgets/progress.dart
index 9608049..df0c18d 100644
--- a/lib/pages/widgets/progress.dart
+++ b/lib/pages/widgets/progress.dart
@@ -4,7 +4,7 @@ import 'package:provider/provider.dart';
 import 'package:fcs/helpers/theme.dart';
 
 class LocalProgress extends Progress {
-  LocalProgress({bool inAsyncCall, Widget child})
+  LocalProgress({required bool inAsyncCall, required Widget child})
       : super(
             inAsyncCall: inAsyncCall,
             child: child,
diff --git a/lib/pages/widgets/show_img.dart b/lib/pages/widgets/show_img.dart
index 130cdad..191096a 100644
--- a/lib/pages/widgets/show_img.dart
+++ b/lib/pages/widgets/show_img.dart
@@ -6,12 +6,12 @@ import 'package:flutter/material.dart';
 import 'package:photo_view/photo_view.dart';
 
 class ShowImage extends StatefulWidget {
-  final String url;
-  final File imageFile;
-  final String fileName;
-  final String localImage;
+  final String? url;
+  final File? imageFile;
+  final String? fileName;
+  final String? localImage;
   const ShowImage(
-      {Key key, this.imageFile, this.fileName, this.url, this.localImage})
+      {Key? key, this.imageFile, this.fileName, this.url, this.localImage})
       : super(key: key);
   @override
   _ShowImageState createState() => _ShowImageState();
@@ -20,6 +20,13 @@ class ShowImage extends StatefulWidget {
 class _ShowImageState extends State<ShowImage> {
   @override
   Widget build(BuildContext context) {
+    final ImageProvider<Object>? p;
+    if (widget.imageFile != null) {
+      p = FileImage(widget.imageFile!);
+    } else {
+      p = AssetImage(widget.localImage!);
+    }
+
     return Scaffold(
       appBar: AppBar(
         leading: new IconButton(
@@ -35,11 +42,7 @@ class _ShowImageState extends State<ShowImage> {
               backgroundDecoration: const BoxDecoration(
                 color: primaryColor,
               ),
-              imageProvider: widget.url != null
-                  ? NetworkImage(widget.url)
-                  : widget.imageFile != null
-                      ? FileImage(widget.imageFile)
-                      : AssetImage(widget.localImage),
+              imageProvider: widget.url != null ? NetworkImage(widget.url!) : p,
               minScale: PhotoViewComputedScale.contained * 1)),
     );
   }
diff --git a/lib/pages/widgets/show_multiple_img.dart b/lib/pages/widgets/show_multiple_img.dart
index f94e81d..17e0821 100644
--- a/lib/pages/widgets/show_multiple_img.dart
+++ b/lib/pages/widgets/show_multiple_img.dart
@@ -8,14 +8,14 @@ class ShowMultiImage extends StatefulWidget {
   final List<DisplayImageSource> displayImageSources;
   final int initialPage;
   const ShowMultiImage(
-      {Key key, this.displayImageSources, this.initialPage = 0})
+      {Key? key, required this.displayImageSources, this.initialPage = 0})
       : super(key: key);
   @override
   _ShowMultiImageState createState() => _ShowMultiImageState();
 }
 
 class _ShowMultiImageState extends State<ShowMultiImage> {
-  PageController pageController;
+  late PageController pageController;
   @override
   void initState() {
     pageController = PageController(initialPage: widget.initialPage);
@@ -58,7 +58,7 @@ class _ShowMultiImageState extends State<ShowMultiImage> {
                       value: event == null
                           ? 0
                           : event.cumulativeBytesLoaded /
-                              event.expectedTotalBytes,
+                              event.expectedTotalBytes!,
                     ),
                   ),
                 ),
diff --git a/lib/pages/widgets/status_tree.dart b/lib/pages/widgets/status_tree.dart
index 27e2e49..a01cb7e 100644
--- a/lib/pages/widgets/status_tree.dart
+++ b/lib/pages/widgets/status_tree.dart
@@ -4,7 +4,7 @@ import 'package:fcs/domain/vo/shipment_status.dart';
 import 'package:fcs/helpers/theme.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_icons/flutter_icons.dart';
+import 'package:flutter_vector_icons/flutter_vector_icons.dart';
 import 'package:intl/intl.dart';
 import 'package:timeline_list/timeline.dart';
 import 'package:timeline_list/timeline_model.dart';
@@ -12,10 +12,10 @@ import 'package:timeline_list/timeline_model.dart';
 var dateFormatter = new DateFormat('dd MMM yyyy');
 
 class StatusTree extends StatelessWidget {
-  final List<ShipmentStatus> shipmentHistory;
-  final String currentStatus;
+  final List<ShipmentStatus>? shipmentHistory;
+  final String? currentStatus;
 
-  const StatusTree({Key key, this.shipmentHistory, this.currentStatus})
+  const StatusTree({Key? key, this.shipmentHistory, this.currentStatus})
       : super(key: key);
   @override
   Widget build(BuildContext context) {
@@ -39,7 +39,7 @@ class StatusTree extends StatelessWidget {
     if (shipmentHistory == null || currentStatus == null) return [];
     bool isPacked = currentStatus != package_received_status &&
         currentStatus != package_processed_status;
-    return shipmentHistory
+    return shipmentHistory!
         .map((e) => TimelineModel(
             Padding(
               padding: const EdgeInsets.all(18.0),
@@ -48,17 +48,17 @@ class StatusTree extends StatelessWidget {
                 children: <Widget>[
                   Text(e.status,
                       style: TextStyle(
-                          color: e.done ? primaryColor : Colors.grey,
+                          color: e.done! ? primaryColor : Colors.grey,
                           fontSize: 16,
                           fontWeight: FontWeight.bold)),
-                  e.done || isPacked
+                  e.done! || isPacked
                       ? Text(dateFormatter.format(e.date))
                       : Container(),
-                  e.staffName == null ? Container() : Text(e.staffName)
+                  e.staffName == null ? Container() : Text(e.staffName!)
                 ],
               ),
             ),
-            iconBackground: e.done ? primaryColor : Colors.grey,
+            iconBackground: e.done! ? primaryColor : Colors.grey,
             icon: Icon(
               e.status == "shipped"
                   ? Ionicons.ios_airplane
diff --git a/lib/pages/widgets/task_button.dart b/lib/pages/widgets/task_button.dart
index 5ad828c..638cc91 100644
--- a/lib/pages/widgets/task_button.dart
+++ b/lib/pages/widgets/task_button.dart
@@ -9,11 +9,11 @@ typedef BtnCallback();
 
 /// TaskButton is used to navigate to eash task
 class TaskButton extends StatelessWidget {
-  final String titleKey;
-  final IconData icon;
-  final BtnCallback btnCallback;
+  final String? titleKey;
+  final IconData? icon;
+  final BtnCallback? btnCallback;
 
-  const TaskButton(this.titleKey, {Key key, this.icon, this.btnCallback})
+  const TaskButton(this.titleKey, {Key? key, this.icon, this.btnCallback})
       : super(key: key);
 
   @override
@@ -45,7 +45,7 @@ class TaskButton extends StatelessWidget {
             Container(
               height: 45,
               alignment: Alignment.topCenter,
-              child: Text(AppTranslations.of(context).text(titleKey),
+              child: Text(AppTranslations.of(context)!.text(titleKey!),
                   textAlign: TextAlign.center,
                   style: languageModel.isEng
                       ? TextStyle(
diff --git a/lib/pages/widgets/title_with_add_button.dart b/lib/pages/widgets/title_with_add_button.dart
index c006f35..e988f4e 100644
--- a/lib/pages/widgets/title_with_add_button.dart
+++ b/lib/pages/widgets/title_with_add_button.dart
@@ -6,11 +6,11 @@ import 'package:flutter/material.dart';
 import 'callbacks.dart';
 
 class TitleWithAddButton extends StatelessWidget {
-  final IconData iconData;
-  final String titleKey;
-  final OnTap onTap;
+  final IconData? iconData;
+  final String? titleKey;
+  final OnTap? onTap;
 
-  const TitleWithAddButton({Key key, this.iconData, this.titleKey, this.onTap})
+  const TitleWithAddButton({Key? key, this.iconData, this.titleKey, this.onTap})
       : super(key: key);
 
   @override
@@ -28,7 +28,7 @@ class TitleWithAddButton extends StatelessWidget {
             ),
             LocalText(
               context,
-              titleKey,
+              titleKey!,
               color: Colors.black54,
               fontSize: 20,
             )
@@ -40,7 +40,7 @@ class TitleWithAddButton extends StatelessWidget {
             : Padding(
                 padding: const EdgeInsets.only(right: 0),
                 child: IconButton(
-                    onPressed: () => onTap(),
+                    onPressed: () => onTap!(),
                     icon: Icon(
                       Icons.add_circle,
                       color: primaryColor,
diff --git a/pubspec.lock b/pubspec.lock
index a551a79..2901b05 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -112,21 +112,21 @@ packages:
       name: cloud_firestore
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0"
+    version: "2.5.2"
   cloud_firestore_platform_interface:
     dependency: transitive
     description:
       name: cloud_firestore_platform_interface
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.4.0"
+    version: "5.4.1"
   cloud_firestore_web:
     dependency: transitive
     description:
       name: cloud_firestore_web
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.4.0"
+    version: "2.4.2"
   collection:
     dependency: transitive
     description:
@@ -280,7 +280,7 @@ packages:
       name: firebase_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.0"
+    version: "1.6.0"
   firebase_core_platform_interface:
     dependency: transitive
     description:
@@ -349,6 +349,27 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.5.1"
+  flutter_icons_null_safety:
+    dependency: "direct main"
+    description:
+      name: flutter_icons_null_safety
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
+  flutter_local_notifications:
+    dependency: "direct main"
+    description:
+      name: flutter_local_notifications
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "8.2.0"
+  flutter_local_notifications_platform_interface:
+    dependency: transitive
+    description:
+      name: flutter_local_notifications_platform_interface
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "4.0.1"
   flutter_localizations:
     dependency: "direct main"
     description: flutter
@@ -373,6 +394,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_vector_icons:
+    dependency: "direct main"
+    description:
+      name: flutter_vector_icons
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.0"
   flutter_web_plugins:
     dependency: transitive
     description: flutter
@@ -866,6 +894,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.0.5"
+  timezone:
+    dependency: transitive
+    description:
+      name: timezone
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.8.0"
   typed_data:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index 6d589fb..e60aa6c 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,7 +14,7 @@ dependencies:
 
   cupertino_icons: ^1.0.3
   firebase_core: ^1.5.0
-  cloud_firestore: ^2.5.0
+  cloud_firestore: ^2.5.2
   firebase_storage: ^10.0.2
   firebase_auth: "^3.0.2"
   # firebase_messaging: ^6.0.15
@@ -43,16 +43,16 @@ dependencies:
   permission_handler: ^8.1.4+2
   country_code_picker: ^2.0.2
   pin_input_text_field: ^4.1.0
-  # flutter_icons: ^1.1.0
+  flutter_icons_null_safety: ^1.1.0
   country_icons: ^2.0.2
   timeline_list: ^0.0.5
-  # barcode_scan: ^2.0.2
   barcode_scan2: ^4.1.4
   flutter_pdfview: ^1.2.1
-  # flutter_local_notifications: ^8.1.1+1 
+  flutter_local_notifications: ^8.2.0
   share: ^2.0.4
   cached_network_image: ^3.1.0
   flutter_cache_manager: ^3.1.2
+  flutter_vector_icons: ^1.0.0
 
 dev_dependencies:
   flutter_test: