add pagination for pages

lib/pages/delivery/delivery_info.dart

@@ -107,9 +107,9 @@ class _DeliveryInfoState extends State<DeliveryInfo> {
   }
 
   _calShipmentWeight() {
-    double l = double.parse(_lengthController.text);
-    double w = double.parse(_widthController.text);
-    double h = double.parse(_heightController.text);
+    double l = double.tryParse(_lengthController.text) ?? 0;
+    double w = double.tryParse(_widthController.text) ?? 0;
+    double h = double.tryParse(_heightController.text) ?? 0;
     setState(() {
       shipmentWeight = l * w * h / volumetricRatio;
     });

lib/pages/delivery/delivery_list.dart

@@ -7,6 +7,8 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
+import '../../domain/entities/carton.dart';
+import '../../pagination/paginator_listview.dart';
 import 'delivery_list_row.dart';
 import 'model/delivery_model.dart';
 
@@ -17,97 +19,62 @@ class DeliverList extends StatefulWidget {
 
 class _DeliverListState extends State<DeliverList> {
   bool _isLoading = false;
-  var _controller = ScrollController();
+  int _selectedIndex = 1;
 
   @override
   void initState() {
     super.initState();
-    _controller.addListener(() async {
-      if (_controller.position.pixels == _controller.position.maxScrollExtent) {
-        Provider.of<DeliveryModel>(context, listen: false).loadMore();
-      }
-    });
-    Provider.of<DeliveryModel>(context, listen: false).initData();
+    _init();
   }
 
-  @override
-  void dispose() {
-    super.dispose();
+  _init() {
+    var model = context.read<DeliveryModel>();
+    _selectedIndex = model.selectedIndex;
+    model.loadPaginationCartons(_selectedIndex);
+    if (mounted) {
+      setState(() {});
+    }
   }
 
   @override
   Widget build(BuildContext context) {
     var deliveryModel = Provider.of<DeliveryModel>(context);
+
     final popupMenu = LocalPopupMenuButton(
-      popmenus: [
-        LocalPopupMenu(
-            id: 1,
-            textKey: "delivery.popupmenu.active",
-            selected: deliveryModel.selectedIndex == 1),
-        LocalPopupMenu(
-            id: 2,
-            textKey: "delivery.popupmenu.delivered",
-            selected: deliveryModel.selectedIndex == 2)
-      ],
-      popupMenuCallback: (p) => this.setState(() {
-        deliveryModel.selectedIndex = p.id;
-      }),
-    );
+        popmenus: [
+          LocalPopupMenu(
+              id: 1,
+              textKey: "delivery.popupmenu.active",
+              selected: deliveryModel.selectedIndex == 1),
+          LocalPopupMenu(
+              id: 2,
+              textKey: "delivery.popupmenu.delivered",
+              selected: deliveryModel.selectedIndex == 2)
+        ],
+        popupMenuCallback: (p) {
+          setState(() {
+            _selectedIndex = p.id;
+          });
+          context.read<DeliveryModel>().onChanged(_selectedIndex);
+        });
+
     return LocalProgress(
-      inAsyncCall: _isLoading,
-      child: DefaultTabController(
-        length: 2,
+        inAsyncCall: _isLoading,
         child: Scaffold(
-          appBar: AppBar(
-            centerTitle: true,
-            leading: new IconButton(
-              icon: new Icon(CupertinoIcons.back),
-              onPressed: () => Navigator.of(context).pop(),
-            ),
-            backgroundColor: primaryColor,
-            title: LocalText(context, "delivery",
-                color: Colors.white, fontSize: 20),
-            actions: <Widget>[popupMenu],
-          ),
-          body: Column(
-            children: [
-              Expanded(
-                child: RefreshIndicator(
-                  child: new ListView.separated(
-                      physics: AlwaysScrollableScrollPhysics(),
-                      controller: _controller,
-                      separatorBuilder: (context, index) => Divider(
-                            color: Colors.black,
-                            height: 1,
-                          ),
-                      scrollDirection: Axis.vertical,
-                      shrinkWrap: true,
-                      itemCount: deliveryModel.cartons.length,
-                      itemBuilder: (BuildContext context, int index) {
-                        return DeliveryListRow(
-                            key: ValueKey(deliveryModel.cartons[index].id),
-                            box: deliveryModel.cartons[index]);
-                      }),
-                  onRefresh: () => deliveryModel.refresh(),
-                ),
+            appBar: AppBar(
+              centerTitle: true,
+              leading: new IconButton(
+                icon: new Icon(CupertinoIcons.back),
+                onPressed: () => Navigator.of(context).pop(),
               ),
-              deliveryModel.isLoading
-                  ? Container(
-                      padding: EdgeInsets.all(8),
-                      color: primaryColor,
-                      child: Row(
-                        mainAxisAlignment: MainAxisAlignment.center,
-                        children: [
-                          Text("Loading...",
-                              style: TextStyle(color: Colors.white)),
-                        ],
-                      ),
-                    )
-                  : Container(),
-            ],
-          ),
-        ),
-      ),
-    );
+              backgroundColor: primaryColor,
+              title: LocalText(context, "delivery",
+                  color: Colors.white, fontSize: 20),
+              actions: <Widget>[popupMenu],
+            ),
+            body: PaginatorListView<Carton>(
+                paginatorListener: deliveryModel.getCartons!,
+                rowBuilder: (p) => DeliveryListRow(box: p),
+                color: primaryColor)));
   }
 }

lib/pages/delivery/model/delivery_model.dart

@@ -4,100 +4,61 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:fcs/data/services/services.dart';
 import 'package:fcs/domain/constants.dart';
 import 'package:fcs/domain/entities/carton.dart';
-import 'package:fcs/helpers/paginator.dart';
 import 'package:fcs/pages/main/model/base_model.dart';
 import 'package:logging/logging.dart';
 
+import '../../../pagination/paginator_listener.dart';
+
 class DeliveryModel extends BaseModel {
   final log = Logger('DeliveryModel');
-  List<Carton> get cartons => _selectedIndex == 1
-      ? _cartons
-      : List<Carton>.from(_delivered?.values ?? []);
+  PaginatorListener<Carton>? getCartons;
+  int selectedIndex = 1;
 
-  Paginator? _delivered;
-  int _selectedIndex = 1;
-  bool isLoading = false;
-  List<Carton> _cartons = [];
-  StreamSubscription<QuerySnapshot>? listener;
-
-  set selectedIndex(int index) {
-    _selectedIndex = index;
+  onChanged(int index) {
+    selectedIndex = index;
+    loadPaginationCartons(selectedIndex);
     notifyListeners();
   }
 
-  int get selectedIndex => _selectedIndex;
-
-  initData() {
-    _selectedIndex = 1;
-    _loadCartons();
-
-    if (_delivered != null) _delivered!.close();
-    _delivered = _getDelivered();
-    _delivered!.load();
-  }
-
-  Future<void> _loadCartons() async {
+  loadPaginationCartons(int index) {
     if (user == null || !user!.hasDeliveries()) return;
-    String path = "/$cartons_collection/";
-    if (listener != null) listener!.cancel();
-    _cartons = [];
-    try {
-      listener = FirebaseFirestore.instance
-          .collection("$path")
+    String path = "/$cartons_collection";
+
+    Query col = FirebaseFirestore.instance.collection(path);
+    Query pageQuery = FirebaseFirestore.instance.collection(path);
+
+    if (index == 1) {
+      col = col
           .where("status", isEqualTo: carton_shipped_status)
           .where("carton_type", whereIn: [
-            carton_from_packages,
-            carton_from_shipments,
-            carton_small_bag
-          ])
-          .where("is_deleted", isEqualTo: false)
-          .orderBy("carton_number", descending: false)
-          .snapshots()
-          .listen((QuerySnapshot snapshot) {
-            _cartons.clear();
-            _cartons = snapshot.docs.map((documentSnapshot) {
-              var s = Carton.fromMap(
-                  documentSnapshot.data as Map<String, dynamic>,
-                  documentSnapshot.id);
-              return s;
-            }).toList();
-            notifyListeners();
-          });
-    } catch (e) {
-      log.warning("Error!! $e");
+        carton_from_packages,
+        carton_from_shipments,
+        carton_small_bag
+      ]);
+      pageQuery = pageQuery
+          .where("status", isEqualTo: carton_shipped_status)
+          .where("carton_type", whereIn: [
+        carton_from_packages,
+        carton_from_shipments,
+        carton_small_bag
+      ]);
     }
-  }
 
-  Paginator _getDelivered() {
-    if (user == null || !user!.hasDeliveries()) throw "No Privilege";
+    if (index == 2) {
+      col = col
+          .where("is_delivered", isEqualTo: true)
+          .where("status", whereIn: [carton_delivered_status]);
+      pageQuery = pageQuery
+          .where("is_delivered", isEqualTo: true)
+          .where("status", whereIn: [carton_delivered_status]);
+    }
 
-    var pageQuery = FirebaseFirestore.instance
-        .collection("/$cartons_collection")
-        .where("is_delivered", isEqualTo: true)
-        .where("status", whereIn: [carton_delivered_status]).where("is_deleted",
-            isEqualTo: false);
-    var paginator = new Paginator(pageQuery, rowPerLoad: 20, toObj: (data, id) {
-      return Carton.fromMap(data, id);
-    });
-    return paginator;
-  }
+    pageQuery = pageQuery.orderBy("carton_number");
 
-  Future<void> loadMore() async {
-    if (_delivered!.ended || _selectedIndex == 1) return;
-    isLoading = true;
-    notifyListeners();
-    await _delivered!.load(onFinished: () {
-      isLoading = false;
-      notifyListeners();
-    });
-  }
-
-  Future<void> refresh() async {
-    if (_selectedIndex == 1) return;
-
-    await _delivered!.refresh(onFinished: () {
-      notifyListeners();
-    });
+    getCartons?.close();
+    getCartons = PaginatorListener<Carton>(
+        col, pageQuery, (data, id) => Carton.fromMap(data, id),
+        rowPerLoad: 30);
   }
 
   void initUser(user) {
@@ -106,9 +67,7 @@ class DeliveryModel extends BaseModel {
 
   @override
   logout() async {
-    if (listener != null) await listener!.cancel();
-    if (_delivered != null) _delivered!.close();
-    _cartons = [];
+    getCartons?.close();
   }
 
   Future<void> deliver(Carton carton) {