add paginator in boxes and deliveries

lib/pages/box/model/box_model.dart

@@ -5,13 +5,22 @@ import 'package:fcs/domain/constants.dart';
 import 'package:fcs/domain/entities/box.dart';
 import 'package:fcs/domain/entities/cargo_type.dart';
 import 'package:fcs/domain/entities/package.dart';
+import 'package:fcs/domain/vo/message.dart';
 import 'package:fcs/domain/vo/shipment_status.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
+import 'package:fcs/helpers/paginator.dart';
 import 'package:fcs/pages/main/model/base_model.dart';
 import 'package:logging/logging.dart';
 
 class BoxModel extends BaseModel {
+  List<Box> _boxes = [];
   final log = Logger('BoxModel');
+  List<Box> get boxes =>
+      _selectedIndex == 1 ? _boxes : List<Box>.from(_delivered.values);
+
+  Paginator _delivered;
+  int _selectedIndex = 1;
+  bool isLoading = false;
 
   StreamSubscription<QuerySnapshot> listener;
   static List<ShipmentStatus> statusHistory = [
@@ -26,7 +35,7 @@ class BoxModel extends BaseModel {
     // PackageModel.packages[2]
   ];
 
-  List<Box> boxes = [
+  List<Box> boxeList = [
     Box(
         shipmentNumber: "A202",
         receiverNumber: "3",
@@ -309,6 +318,97 @@ class BoxModel extends BaseModel {
     carton_mix_box
   ];
 
+  set selectedIndex(int index) {
+    _selectedIndex = index;
+    notifyListeners();
+  }
+
+  get selectedIndex => _selectedIndex;
+
+  initData() {
+    _selectedIndex = 1;
+    _loadBoxes();
+
+    if (_delivered != null) _delivered.close();
+    // _delivered = _getDelivered();
+    _delivered = _getDeliveredExample();
+    _delivered.load();
+  }
+
+  int count = 0;
+  Paginator _getDeliveredExample() {
+    count = 1;
+    var pageQuery = Firestore.instance
+        .collection(
+            "/users/8OTfsbVvsUOn1SLxy1OrKk7Y_yNKkVoGalPcIlcHnAY/messages")
+        .orderBy("date", descending: true);
+    var paginator = new Paginator(pageQuery, rowPerLoad: 20, toObj: (data, id) {
+      var m = Message.fromMap(data, id);
+      return Box(
+        id: m.id,
+        shipmentNumber: m.message,
+        boxNumber: "1",
+        receiverNumber: "3",
+        rate: 0,
+        weight: 0,
+        arrivedDate: m.date,
+      );
+    });
+    return paginator;
+  }
+
+  Future<void> _loadBoxes() async {
+    if (user == null || !user.hasCarton()) return;
+    String path = "/$boxes_collection/";
+    if (listener != null) listener.cancel();
+    _boxes = [];
+    try {
+      listener = Firestore.instance
+          .collection("$path")
+          .snapshots()
+          .listen((QuerySnapshot snapshot) {
+        _boxes.clear();
+        _boxes = snapshot.documents.map((documentSnapshot) {
+          var s =
+              Box.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+          return s;
+        }).toList();
+        notifyListeners();
+      });
+    } catch (e) {
+      log.warning("Error!! $e");
+    }
+  }
+
+  Paginator _getDelivered() {
+    if (user == null || !user.hasCarton()) return null;
+
+    var pageQuery = Firestore.instance
+        .collection("/$boxes_collection")
+        .where("is_delivered", isEqualTo: true)
+        .where("is_deleted", isEqualTo: false);
+    var paginator = new Paginator(pageQuery, rowPerLoad: 20, toObj: (data, id) {
+      return Box.fromMap(data, id);
+    });
+    return paginator;
+  }
+
+  Future<void> loadMore() async {
+    if (_delivered.ended) return;
+    isLoading = true;
+    notifyListeners();
+    await _delivered.load(onFinished: () {
+      isLoading = false;
+      notifyListeners();
+    });
+  }
+
+  Future<void> refresh() async {
+    await _delivered.refresh(onFinished: () {
+      notifyListeners();
+    });
+  }
+
   void initUser(user) {
     super.initUser(user);
   }
@@ -316,6 +416,7 @@ class BoxModel extends BaseModel {
   @override
   logout() async {
     if (listener != null) await listener.cancel();
-    boxes = [];
+    if (_delivered != null) _delivered.close();
+    _boxes = [];
   }
 }