null safety

lib/domain/entities/cargo_type.dart

@@ -1,17 +1,17 @@
 class CargoType {
-  String id;
-  String name;
-  double rate;
-  double weight;
-  bool isChecked;
-  int qty;
-  bool isCutomDuty;
-  double customDutyFee;
+  String? id;
+  String? name;
+  double? rate;
+  double? weight;
+  bool? isChecked;
+  int? qty;
+  bool? isCutomDuty;
+  double? customDutyFee;
 
   double get calAmount => (calRate ?? 0) * (calWeight ?? 0);
 
-  double calRate;
-  double calWeight;
+  double? calRate;
+  double? calWeight;
   CargoType(
       {this.id,
       this.name,
@@ -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) {

lib/pages/buying_instruction/buying_online.dart

@@ -15,7 +15,7 @@ class BuyingOnlinePage extends StatefulWidget {
 
 class _BuyingOnlinePagetate extends State<BuyingOnlinePage>
     with SingleTickerProviderStateMixin {
-  TabController _tabController;
+  late TabController _tabController;
 
   @override
   void initState() {

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) {
-      total += c.weight;
+    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
@@ -81,7 +81,7 @@ class _CargoTableState extends State<CargoTable> {
                   ),
                 )),
           MyDataCell(
-            Text(c.weight == null ? "0" : c.weight.toStringAsFixed(2),
+            Text(c.weight == null ? "0" : c.weight!.toStringAsFixed(2),
                 style: textStyle),
           ),
         ],

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;
@@ -61,7 +61,7 @@ class _CargoTypeAdditionState extends State<CargoTypeAddition> {
             child: InkWell(
               onTap: () {
                 setState(() {
-                  c.isChecked = !c.isChecked;
+                  c.isChecked = !c.isChecked!;
                 });
               },
               child: Row(
@@ -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;
                         });
                       }),
-                  new Text(c.name, style: textStyle),
+                  new Text(c.name ?? '', style: textStyle),
                 ],
               ),
             ),
@@ -88,9 +88,9 @@ class _CargoTypeAdditionState extends State<CargoTypeAddition> {
       getLocalString(context, 'box.cargo.select.btn'),
       callack: () {
         List<CargoType> _cargos =
-            this.cargos.where((c) => c.isChecked).toList();
+            this.cargos.where((c) => c.isChecked!).toList();
         List<CargoType> _scargos =
-            this.specialCargos.where((c) => c.isChecked).toList();
+            this.specialCargos.where((c) => c.isChecked!).toList();
         _cargos.addAll(_scargos);
         Navigator.pop(context, _cargos);
       },

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);
       },
     );

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();
@@ -41,7 +41,7 @@ class _CargoTableState extends State<CargoTable> {
 
   @override
   Widget build(BuildContext context) {
-    print("Cargotypes:${cargoTypes.length}");
+    print("Cargotypes:${cargoTypes!.length}");
     
     return SingleChildScrollView(
       scrollDirection: Axis.horizontal,
@@ -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(
@@ -144,7 +144,7 @@ class _CargoTableState extends State<CargoTable> {
                         context: context,
                         builder: (_) => DialogInput(
                             label: "cargo.weight",
-                            value: c.weight.toStringAsFixed(2)));
+                            value: c.weight!.toStringAsFixed(2)));
 
                     if (_t == null) return;
                     setState(() {
@@ -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),
@@ -162,7 +162,7 @@ class _CargoTableState extends State<CargoTable> {
                       borderRadius: BorderRadius.all(Radius.circular(5.0)),
                     ),
                     child: Text(
-                        c.weight == null ? "0.00" : c.weight.toStringAsFixed(2),
+                        c.weight == null ? "0.00" : c.weight!.toStringAsFixed(2),
                         style: textStyle),
                   ),
                 ),
@@ -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);
                         })
               ],
             ),
@@ -237,21 +237,21 @@ 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) {
+CargoType? autoCalWeight(List<CargoType> cargoTypes, double total) {
   if ((cargoTypes?.length ?? 0) == 0 || total == 0) return null;
   List<CargoType> noWeight = cargoTypes.where((c) => c.weight == 0).toList();
   if (noWeight.length != 1) return null;

lib/pages/carton/carton_cargo_table_old.dart

@@ -13,11 +13,11 @@ 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
@@ -67,15 +67,15 @@ class _CargoTableState extends State<CargoTable> {
     List<String> _types = [];
     double _total = 0;
 
-    var rows = widget.cargoTypes.map((c) {
-      _total += c.weight;
+    var rows = widget.cargoTypes!.map((c) {
+      _total += c.weight!;
       return MyDataRow(
         onSelectChanged: (bool selected) async {},
         cells: [
           MyDataCell(Row(
             children: [
               new Text(
-                c.name == null ? "" : c.name,
+                c.name ?? "",
                 style: textStyle,
               ),
               new Text(
@@ -88,7 +88,7 @@ class _CargoTableState extends State<CargoTable> {
             Row(
               mainAxisAlignment: MainAxisAlignment.end,
               children: [
-                Text(c.weight.toStringAsFixed(2), style: textStyle),
+                Text(c.weight!.toStringAsFixed(2), style: textStyle),
                 widget.onRemove == null
                     ? SizedBox(
                         width: 50,
@@ -99,7 +99,7 @@ class _CargoTableState extends State<CargoTable> {
                           color: primaryColor,
                         ),
                         onPressed: () {
-                          if (widget.onRemove != null) widget.onRemove(c);
+                          if (widget.onRemove != null) widget.onRemove!(c);
                         })
               ],
             ),
@@ -127,7 +127,7 @@ 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 +135,21 @@ 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;
                               }

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
@@ -54,29 +54,29 @@ class _CartonEditorState extends State<CartonEditor> {
   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;
@@ -151,12 +151,12 @@ 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 ?? "");
+        String compare =
+            (p.deliveryAddress.fullName) + (p.deliveryAddress.phoneNumber);
         if (prevCompare != null && compare == prevCompare) {
           p.isChecked = true;
         } else {
@@ -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();
   }
@@ -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,
@@ -757,7 +757,7 @@ class _CartonEditorState extends State<CartonEditor> {
                       .map<DropdownMenuItem<CartonSize>>((CartonSize value) {
                     return DropdownMenuItem<CartonSize>(
                       value: value,
-                      child: Text(value.name ?? "",
+                      child: Text(value.name,
                           overflow: TextOverflow.ellipsis,
                           style: TextStyle(
                               color: value.name == MANAGE_CARTONSIZE
@@ -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(
@@ -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;
@@ -932,11 +931,11 @@ 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;
     }
-    if (_cargoTypes.where((c) => c.weight <= 0).isNotEmpty) {
+    if (_cargoTypes.where((c) => c.weight! <= 0).isNotEmpty) {
       showMsgDialog(context, "Error", "Invalid cargo weight");
       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;

lib/pages/carton/carton_info.dart

@@ -19,7 +19,7 @@ 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 +33,7 @@ import 'widgets.dart';
 final DateFormat dateFormat = DateFormat("d MMM yyyy");
 
 class CartonInfo extends StatefulWidget {
-  final Carton box;
+  final Carton? box;
   CartonInfo({this.box});
 
   @override
@@ -42,7 +42,7 @@ class CartonInfo extends StatefulWidget {
 
 class _CartonInfoState extends State<CartonInfo> {
   bool _isLoading = false;
-  Carton _box;
+  Carton? _box;
   DeliveryAddress _deliveryAddress = new DeliveryAddress();
   TextEditingController _widthController = new TextEditingController();
   TextEditingController _heightController = new TextEditingController();
@@ -50,14 +50,14 @@ class _CartonInfoState extends State<CartonInfo> {
   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() {
@@ -77,29 +77,29 @@ 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;
         });
@@ -110,36 +110,37 @@ 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;
     });
   }
 
@@ -167,32 +168,32 @@ class _CartonInfoState extends State<CartonInfo> {
         readOnly: true,
         values: cartonModel.cartonTypesInfo,
         selectedValue:
-            _box.isShipmentCarton ? carton_from_shipments : _box.cartonType);
+            _box!.isShipmentCarton ? 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());

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);
+  final Carton? box;
+  CartonListRow({Key? key, this.box}) : super(key: key);
 
   final double dotSize = 15.0;
   final DateFormat dateFormat = new DateFormat("dd MMM yyyy");
@@ -47,7 +47,7 @@ class CartonListRow 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),
                             ),
@@ -55,7 +55,7 @@ class CartonListRow 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),
                             ),
@@ -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 == null ? "" : 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),
                       ),

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
                   ? 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),
                   ),
                 ),
@@ -55,16 +55,16 @@ 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(
-                      p.value.cartonNumber ?? "",
+                      p.value.cartonNumber,
                       style: textStyle,
                     )),
                     new Text(
-                      p.value?.actualWeight?.toString() ?? "",
+                      p.value.actualWeight.toString(),
                       style: textStyle,
                     ),
                   ],

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),
                   ),
                 ),
@@ -62,8 +62,8 @@ 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(
@@ -74,11 +74,11 @@ class CartonPackageTable extends StatelessWidget {
                           style: textStyle,
                         ),
                         Text(
-                          p.value.deliveryAddress?.fullName ?? "",
+                          p.value.deliveryAddress.fullName,
                           style: textStyle,
                         ),
                         Text(
-                          p.value.deliveryAddress?.phoneNumber ?? "",
+                          p.value.deliveryAddress.phoneNumber,
                           style: textStyle,
                         ),
                       ],
@@ -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,
                           )
                         ],

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 Carton? box;
+  final OnRemove? onRemove;
+  CartonRow({Key? key, 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(
@@ -45,7 +45,7 @@ class CartonRow 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),
                           ),
@@ -53,7 +53,7 @@ class CartonRow 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),
                           ),
@@ -75,16 +75,16 @@ class CartonRow extends StatelessWidget {
                         color: primaryColor,
                       ),
                       onPressed: () {
-                        if (onRemove != null) onRemove(box);
+                        if (onRemove != null) onRemove!(box!);
                       }),
-              box.actualWeight == 0
+              box!.actualWeight == 0
                   ? Container()
                   : Padding(
                       padding: const EdgeInsets.only(left: 8.0, bottom: 5),
                       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),
                           ),

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(

lib/pages/carton/package_carton_editor.dart

@@ -21,7 +21,7 @@ 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 +29,9 @@ 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 +43,13 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
   TextEditingController _widthCtl = new TextEditingController();
   TextEditingController _heightCtl = new TextEditingController();
 
-  Carton _carton;
+  Carton? _carton;
   bool _isLoading = false;
   DeliveryAddress _deliveryAddress = new DeliveryAddress();
   List<CargoType> _cargoTypes = [];
-  CartonSize selectedCatonSize;
-  bool isFromPackages;
-  bool isFromCartons;
+  CartonSize? selectedCatonSize;
+  bool isFromPackages = false;
+  bool isFromCartons = false;
 
   @override
   void initState() {
@@ -59,19 +59,19 @@ 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 +79,9 @@ 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 +122,7 @@ 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 +134,10 @@ 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 +167,7 @@ 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 +186,14 @@ 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 +245,17 @@ 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,
@@ -263,7 +263,7 @@ class _PackageCartonEditorState extends State<PackageCartonEditor> {
                       .map<DropdownMenuItem<CartonSize>>((CartonSize value) {
                     return DropdownMenuItem<CartonSize>(
                       value: value,
-                      child: Text(value.name ?? "",
+                      child: Text(value.name,
                           overflow: TextOverflow.ellipsis,
                           style: TextStyle(
                               color: value.name == MANAGE_CARTONSIZE
@@ -295,8 +295,7 @@ 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 +304,13 @@ 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 +321,22 @@ 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 +349,12 @@ 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) {

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

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)),
       ),
     ],
   );

lib/pages/carton_search/carton_list_row.dart

@@ -1,17 +1,17 @@
 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;
-  final Carton carton;
+  final CallbackCartonSelect? callbackCartonSelect;
+  final Carton? carton;
 
   // const CartonListRow({this.carton, this.callbackCartonSelect});
   CartonListRow(
-      {Key key, this.carton, this.callbackCartonSelect})
+      {Key? key, this.carton, this.callbackCartonSelect})
       : super(key: key);
 
   @override
@@ -20,7 +20,7 @@ class CartonListRow extends StatefulWidget {
 
 class _CartonListRowState extends State<CartonListRow> {
   final double dotSize = 15.0;
-  Carton _carton;
+  Carton? _carton;
   @override
   void initState() {
     super.initState();
@@ -32,14 +32,14 @@ class _CartonListRowState extends State<CartonListRow> {
     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);
+            widget.callbackCartonSelect!(widget.carton!);
         },
         child: Row(
           children: <Widget>[
@@ -64,7 +64,7 @@ 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 +72,7 @@ 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 +86,7 @@ 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),
                           ),

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,
@@ -158,17 +158,17 @@ 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();

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);
     }
   }
 }

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());

lib/pages/customer/customer_list.dart

@@ -233,11 +233,11 @@ class _CustomerListState extends State<CustomerList> {
   _share(User user) async {
     MainModel mainModel = Provider.of<MainModel>(context, listen: false);
     String appUrl = mainModel.setting.appUrl;
-    final RenderBox box = context.findRenderObject();
+    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);
   }
 }

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!;
     });
   }
 

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());

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() {

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
@@ -48,7 +48,7 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
     super.initState();
     _isNew = widget.shipment == null;
     if (widget.shipment != null) {
-      _shipment = widget.shipment;
+      _shipment = widget.shipment!;
       _shipmentNumberController.text = _shipment.shipmentNumber;
       _cutoffDateController.text = dateFormatter.format(_shipment.cutoffDate);
       _arrivalDateController.text = dateFormatter.format(_shipment.arrivalDate);
@@ -149,7 +149,7 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
               items: mainModel.setting.shipmentTypes
                   .map((e) => DropdownMenuItem(child: Text(e), value: e))
                   .toList(),
-              onChanged: (selected) => {
+              onChanged: (String? selected) => {
                 setState(() {
                   _currentShipmentType = selected;
                 })
@@ -188,7 +188,7 @@ 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 +197,9 @@ 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) {
@@ -288,7 +288,7 @@ class _FcsShipmentEditorState extends State<FcsShipmentEditor> {
           _currentShipmentType != mainModel.setting.shipmentTypes[0];
     } else {
       FcsShipment fcsShipment = _getPayload();
-      return widget.shipment.isChangedForEdit(fcsShipment);
+      return widget.shipment!.isChangedForEdit(fcsShipment);
     }
   }
 }

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 +48,17 @@ class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
   }
 
   _load() {
-    _shipmentNumberController.text = _fcsShipment.shipmentNumber;
-    _cutoffDateController.text = dateFormatter.format(_fcsShipment.cutoffDate);
+    _shipmentNumberController.text = _fcsShipment!.shipmentNumber;
+    _cutoffDateController.text = dateFormatter.format(_fcsShipment!.cutoffDate);
     _arrivalDateController.text =
-        dateFormatter.format(_fcsShipment.arrivalDate);
+        dateFormatter.format(_fcsShipment!.arrivalDate);
     _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 +166,7 @@ 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 +182,14 @@ class _FcsShipmentInfoState extends State<FcsShipmentInfo> {
   }
 
   _edit() async {
-    bool updated = await Navigator.push<bool>(
+    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);
+      var f = await shipmentModel.getFcsShipment(_fcsShipment!.id);
       setState(() {
         _fcsShipment = f;
       });
@@ -238,7 +238,7 @@ 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 +264,11 @@ 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: "",

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 +43,9 @@ class FcsShipmentListRow extends StatelessWidget {
                           Padding(
                             padding: const EdgeInsets.only(left: 8.0),
                             child: new Text(
-                              shipment.shipmentNumber == null
+                              shipment!.shipmentNumber == null
                                   ? ''
-                                  : shipment.shipmentNumber,
+                                  : shipment!.shipmentNumber,
                               style: new TextStyle(
                                   fontSize: 15.0, color: Colors.black),
                             ),
@@ -53,7 +53,7 @@ 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 +67,7 @@ class FcsShipmentListRow extends StatelessWidget {
             ),
             Padding(
               padding: const EdgeInsets.all(0),
-              child: getStatus(shipment.status),
+              child: getStatus(shipment!.status),
             ),
           ],
         ),

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!;
     }
   }
 
@@ -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',

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
@@ -36,20 +36,20 @@ 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
                   ? 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),
                   ),
                 ),
@@ -64,8 +64,8 @@ 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(
@@ -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,
                           ),
                         ],

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),
               ],
             ),
           ),

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
@@ -91,12 +91,12 @@ 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;
     });
   }
 
@@ -104,12 +104,12 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
     ShipmentModel shipmentModel =
         Provider.of<ShipmentModel>(context, listen: false);
     List<Shipment> shipments = await shipmentModel.getShipmentWithHandlingFee(
-        widget.fcsShipment.id, widget.customer.id);
+        widget.fcsShipment!.id, widget.customer!.id);
     shipments.forEach((s) {
       s.isSelected = true;
     });
     setState(() {
-      _invoice.shipments = shipments;
+      _invoice!.shipments = shipments;
     });
   }
 
@@ -117,10 +117,10 @@ class _InvoiceEditorState extends State<InvoiceEditor> {
   _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);

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);
                         })
               ],
             ),

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();
         }
       },

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
@@ -31,15 +31,15 @@ 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) {
+    _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());

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: () {

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 +48,17 @@ 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),
+                            dateFormatter.format(invoice!.invoiceDate),
                             style: new TextStyle(
                                 fontSize: 15.0, color: Colors.grey),
                           )
@@ -70,7 +70,7 @@ class InvoiceListRow extends StatelessWidget {
               ),
             ),
           ),
-          invoice.status == invoice_issued_status
+          invoice!.status == invoice_issued_status
               ? Padding(
                   padding: const EdgeInsets.only(left: 10.0),
                   child: InkWell(

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>[

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,
@@ -61,16 +61,16 @@ 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,
           desc: c.name,
           rate:
-              "${c.calWeight.toStringAsFixed(2)} x ${c.calRate.toStringAsFixed(2)}",
+              "${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 ?? false)).forEach((s) {
       tableRows.add(InvoiceTableRow(
           data: s,
           invoiceDataType: InvoiceDataType.HandlingFeeType,
@@ -79,7 +79,7 @@ class InvoiceTable extends StatelessWidget {
           amount: "${s.handlingFee.toStringAsFixed(2)}"));
     });
     // // add custom fee
-    invoice.customDuties.forEach((c) {
+    invoice!.customDuties.forEach((c) {
       tableRows.add(InvoiceTableRow(
           data: c,
           invoiceDataType: InvoiceDataType.CustomFeeDataType,
@@ -89,18 +89,18 @@ class InvoiceTable extends StatelessWidget {
     });
     // // add delivery fee
     tableRows.add(InvoiceTableRow(
-        data: invoice.deliveryFee == null || invoice.deliveryFee == 0
+        data: invoice!.deliveryFee == null || invoice!.deliveryFee == 0
             ? null
-            : invoice.deliveryFee,
+            : invoice!.deliveryFee,
         invoiceDataType: InvoiceDataType.DeliveryFeeType,
         desc: "Delivery fee",
         rate: "",
         amount: "${invoice?.deliveryFee?.toStringAsFixed(2) ?? '0'}"));
 
     // // 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: "",
@@ -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,
               )

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
@@ -35,15 +35,15 @@ 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();
   }
 
@@ -129,7 +129,7 @@ class _PaymentPageState extends State<PaymentPage> {
   getCustomFeeRows(BuildContext context) {
     List<Widget> dataRow = [];
 
-    dataRow = _invoice?.payments?.map((p) {
+    dataRow = _invoice.payments.map((p) {
           return Container(
             decoration: BoxDecoration(
                 border: Border(bottom: BorderSide(color: Colors.grey))),
@@ -165,7 +165,7 @@ class _PaymentPageState extends State<PaymentPage> {
                         child: Column(
                       children: [Text('\$ ${p.amount}'), Text('${p.status}')],
                     ))),
-                widget.forCustomer
+                widget.forCustomer!
                     ? Container()
                     : Expanded(
                         flex: 1,
@@ -197,8 +197,7 @@ class _PaymentPageState extends State<PaymentPage> {
               ],
             ),
           );
-        })?.toList() ??
-        [];
+        }).toList() ;
 
     dataRow.insert(
         0,
@@ -217,7 +216,7 @@ 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 +249,11 @@ 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 +278,7 @@ class _PaymentPageState extends State<PaymentPage> {
   }
 
   _updatePayment(Payment payment) async {
-    payment.invoiceID = widget.invoice.id;
+    payment.invoiceID = widget.invoice!.id;
     setState(() {
       _isLoading = true;
     });
@@ -314,7 +313,7 @@ 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());

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();
   }
@@ -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')));
       },
     );
   }

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';
@@ -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"]);
@@ -291,7 +291,7 @@ class _HomePageState extends State<HomePage> {
 
     final staffBtn = TaskButton(
       "staff.title",
-      icon: MaterialCommunityIcons.worker,
+      icon: MaterialCommunityIcons.account_tie,
       btnCallback: () => Navigator.of(context).push<void>(CupertinoPageRoute(
         builder: (context) => StaffList(),
       )),
@@ -350,7 +350,7 @@ 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];

lib/pages/main/initial_language_selection.dart

@@ -27,9 +27,9 @@ class _InitialLanguageSelectionPageState
     languagesList[1]: languageCodesList[1],
   };
 
-  String selectedLanguage;
-  int selectedIndex;
-  bool _isLoading;
+  late String selectedLanguage;
+  late int selectedIndex;
+  bool _isLoading = false;
 
   @override
   void initState() {
@@ -102,8 +102,8 @@ class _InitialLanguageSelectionPageState
                                   ? BoxDecoration()
                                   : BoxDecoration(
                                       border: Border(
-                                        bottom:
-                                            BorderSide(color: Colors.grey[300]),
+                                        bottom: BorderSide(
+                                            color: Colors.grey.shade300),
                                       ),
                                     ),
                               child: ListTile(
@@ -134,7 +134,7 @@ class _InitialLanguageSelectionPageState
                                     child: Radio(
                                       value: key,
                                       groupValue: selectedIndex,
-                                      onChanged: (int i) =>
+                                      onChanged: (int? i) =>
                                           _select(key, language),
                                       activeColor: primaryColor,
                                     ),
@@ -178,7 +178,7 @@ class _InitialLanguageSelectionPageState
     setState(() {
       selectedIndex = index;
       selectedLanguage = lang;
-      Translation().onLocaleChanged(Locale(languagesMap[lang]));
+      Translation().onLocaleChanged!(Locale(languagesMap[lang]));
       Provider.of<LanguageModel>(context, listen: false)
           .saveLanguage(selectedLanguage);
     });

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);

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,
             ),
           ),
@@ -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: [
@@ -371,7 +371,7 @@ String getLocalString(BuildContext context, String 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),

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

lib/pages/market/market_editor.dart

@@ -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,
@@ -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();
-              })
-        ],
-      ),
+        );
+      },
     );
   }
 }

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();
     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;
@@ -197,7 +197,7 @@ class _PackageEditorPageState extends State<PackageEditorPage> {
             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
@@ -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);

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});
@@ -38,14 +38,14 @@ 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 {
@@ -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);
       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());

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();
 }

lib/pages/package/package_list_row.dart

@@ -4,20 +4,23 @@ 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
@@ -25,7 +28,7 @@ class PackageListRow extends StatelessWidget {
     return InkWell(
       onTap: () {
         if (callbackPackageSelect != null) {
-          callbackPackageSelect(package);
+          callbackPackageSelect!(package!);
           return;
         }
         Navigator.push(
@@ -57,7 +60,7 @@ 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 +68,7 @@ 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 +84,12 @@ 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),
+                        dateFormat.format(package!.currentStatusDate),
                         style:
                             new TextStyle(fontSize: 15.0, color: Colors.grey),
                       ),

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,
     );
@@ -144,7 +144,7 @@ class _PackageNewState extends State<PackageNew> {
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-                Text(packages[index].market ?? ""),
+                Text(packages[index].market),
                 Text(packages[index].trackingID),
                 // DisplayText(
                 //   labelText: "Tracking ID",
@@ -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());

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();
 }
@@ -85,7 +84,7 @@ 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();
@@ -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;
@@ -152,17 +151,17 @@ class _TrackingIDPageState extends State<TrackingIDPage> {
   }
 
   _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();
@@ -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!));
   }
 }

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 =

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());

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 {
@@ -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'),

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
@@ -38,13 +38,13 @@ 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 {
@@ -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;
     });
   }
 
@@ -77,7 +77,7 @@ 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,
         )),
@@ -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();
     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;
@@ -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);

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();
     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;
@@ -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;
     }

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);

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(
@@ -222,7 +222,7 @@ class _ProcessingInfoState extends State<ProcessingInfo> {
     } else {
       PackageModel packageModel =
           Provider.of<PackageModel>(context, listen: false);
-      Package p = await packageModel.getPackage(_package.id);
+      Package p = await packageModel.getPackage(_package!.id);
       initPackage(p);
     }
   }

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 +81,12 @@ 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),
+                    dateFormat.format(package!.currentStatusDate),
                     style: new TextStyle(fontSize: 15.0, color: Colors.grey),
                   ),
                 ),

lib/pages/profile/profile_currency_edit.dart

@@ -76,9 +76,9 @@ class _ProfileCurrencyEditState extends State<ProfileCurrencyEdit> {
                   activeColor: primaryColor,
                   value: Currency.USD,
                   groupValue: _currency,
-                  onChanged: (Currency value) {
+                  onChanged: (Currency? value) {
                     setState(() {
-                      _currency = value;
+                      _currency = value!;
                     });
                   },
                 ),
@@ -94,9 +94,9 @@ class _ProfileCurrencyEditState extends State<ProfileCurrencyEdit> {
                   activeColor: primaryColor,
                   value: Currency.MMK,
                   groupValue: _currency,
-                  onChanged: (Currency value) {
+                  onChanged: (Currency? value) {
                     setState(() {
-                      _currency = value;
+                      _currency = value!;
                     });
                   },
                 ),

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();
@@ -41,7 +41,7 @@ class _ReceivingEditorState extends State<ReceivingEditor> {
     super.initState();
     _isNew = widget.package == null;
     if (!_isNew) {
-      package = widget.package;
+      package = widget.package!;
       _trackingIDCtl.text = package.trackingID;
       _remarkCtl.text = package.remark;
       _multiImgController.setImageUrls = package.photoUrls;
@@ -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,
     );
@@ -199,17 +199,17 @@ 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();
@@ -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;
     }

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,
                   )
@@ -149,7 +149,7 @@ class _ReceivingInfoState extends State<ReceivingInfo> {
     );
     PackageModel packageModel =
         Provider.of<PackageModel>(context, listen: false);
-    var pkg = await packageModel.getPackage(widget.package.id);
+    var pkg = await packageModel.getPackage(widget.package!.id);
     initPackage(pkg);
   }
 
@@ -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());

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 +79,12 @@ 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),
+                    dateFormat.format(package!.currentStatusDate),
                     style: new TextStyle(fontSize: 15.0, color: Colors.grey),
                   ),
                 ),

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,
                       ),
               ],

pubspec.yaml

@@ -49,10 +49,11 @@ dependencies:
   # 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: