feat: added page view support

README.md

@@ -44,8 +44,8 @@ import 'package:firebase_pagination/firebase_pagination.dart';
 ```dart
 FirestorePagination(
   query: FirebaseFirestore.instance.collection('scores').orderBy('score'),
-  itemBuilder: (context, documentSnapshot, index) {
-    final data = documentSnapshot.data() as Map<String, dynamic>;
+  itemBuilder: (context, docs, index) {
+    final data = docs[index].data() as Map<String, dynamic>;
 
     // Do something cool with the data
   },
@@ -58,8 +58,8 @@ FirestorePagination(
 RealtimeDBPagination(
   query: FirebaseDatabase.instance.ref().child('scores').orderByChild('score'),
   orderBy: 'score',
-  itemBuilder: (context, dataSnapshot, index) {
-    final data = dataSnapshot.value as Map<String, dynamic>;
+  itemBuilder: (context, dataNodes, index) {
+    final data = dataNodes[index].value as Map<String, dynamic>;
 
     // Do something cool with the data
   },
@@ -96,6 +96,7 @@ RealtimeDBPagination(
 |      `isLive`      |                 **Whether to fetch newly added items as they are added to Database.**                  |        _bool_        |             `false`             |
 |   `gridDelegate`   |                               **The delegate to use for the GridView.**                                | _SliverGridDelegate_ |       `crossAxisCount: 2`       |
 |   `wrapOptions`    |                                 **The Wrap widget properties to use.**                                 |    _WrapOptions_     |         `WrapOptions()`         |
+|   `pageOptions`    |                               **The PageView widget properties to use.**                               |    _PageOptions_     |         `PageOptions()`         |
 |     `onEmpty`      |                               **The widget to use when data is empty.**                                |       _Widget_       |         `EmptyScreen()`         |
 |   `bottomLoader`   |                            **The widget to use when more data is loading.**                            |       _Widget_       |        `BottomLoader()`         |
 |  `initialLoader`   |                         **The widget to use when data is loading initially.**                          |       _Widget_       |        `InitialLoader()`        |
@@ -104,7 +105,8 @@ RealtimeDBPagination(
 |    `shrinkWrap`    |                              **Should the ScrollView be shrink-wrapped.**                              |        _bool_        |             `false`             |
 |     `physics`      |                           **The scroll behavior to use for the ScrollView.**                           |   _ScrollPhysics_    |                -                |
 |     `padding`      |                               **The padding to use for the ScrollView.**                               | _EdgeInsetsGeometry_ |                -                |
-|    `controller`    |                             **The controller to use for the ScrollView.**                              |  _ScrollController_  |                -                |
+|    `controller`    |                             **The controller to use for the ScrollView.**                              |  _ScrollController_  |       ScrollController()        |
+|  `pageController`  |                              **The controller to use for the PageView.**                               |   _PageController_   |        PageController()         |
 |    `descending`    | **Whether the data should be fetched in descending order or not. Only works for RealtimeDBPagination** |        _bool_        |             `false`             |
 
 ### If you liked the package, then please give it a [Like 👍🏼][package] and [Star ⭐][repository]

lib/src/firestore_pagination.dart

@@ -1,14 +1,15 @@
+// Dart Packages
+import 'dart:async';
+
 // Flutter Packages
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 
-// Dart Packages
-import 'dart:async';
-
 // Firebase Packages
 import 'package:cloud_firestore/cloud_firestore.dart';
 
 // Data Models
+import 'models/page_options.dart';
 import 'models/view_type.dart';
 import 'models/wrap_options.dart';
 
@@ -52,6 +53,7 @@ class FirestorePagination extends StatefulWidget {
       crossAxisCount: 2,
     ),
     this.wrapOptions = const WrapOptions(),
+    this.pageOptions = const PageOptions(),
     this.onEmpty = const EmptyScreen(),
     this.bottomLoader = const BottomLoader(),
     this.initialLoader = const InitialLoader(),
@@ -61,6 +63,7 @@ class FirestorePagination extends StatefulWidget {
     this.physics,
     this.padding,
     this.controller,
+    this.pageController,
   });
 
   /// The query to use to fetch data from Firestore.
@@ -108,6 +111,11 @@ class FirestorePagination extends StatefulWidget {
   /// Defaults to [WrapOptions].
   final WrapOptions wrapOptions;
 
+  /// The [PageView] properties to use.
+  ///
+  /// Defaults to [PageOptions].
+  final PageOptions pageOptions;
+
   /// The widget to use when data is empty.
   ///
   /// Defaults to [EmptyScreen].
@@ -143,6 +151,11 @@ class FirestorePagination extends StatefulWidget {
   /// Defaults to [ScrollController].
   final ScrollController? controller;
 
+  /// The page controller to use for the [PageView].
+  ///
+  /// Defaults to [PageController].
+  final PageController? pageController;
+
   @override
   State<FirestorePagination> createState() => _FirestorePaginationState();
 }
@@ -164,6 +177,10 @@ class _FirestorePaginationState extends State<FirestorePagination> {
   late final ScrollController _controller =
       widget.controller ?? ScrollController();
 
+  /// [PageController] to listen to page changes and load more data.
+  late final PageController _pageController =
+      widget.pageController ?? PageController();
+
   /// Whether initial data is loading.
   bool _isInitialLoading = true;
 
@@ -228,7 +245,8 @@ class _FirestorePaginationState extends State<FirestorePagination> {
       // scroll to the bottom and load more data.
       if (_isInitialLoading || _isFetching || _isEnded) return;
       SchedulerBinding.instance.addPostFrameCallback((_) {
-        if (_controller.position.maxScrollExtent <= 0) {
+        if (_controller.hasClients &&
+            _controller.position.maxScrollExtent <= 0) {
           _loadDocuments();
         }
       });
@@ -268,6 +286,7 @@ class _FirestorePaginationState extends State<FirestorePagination> {
   /// To handle scroll end event and load more data.
   void _scrollListener() {
     if (_isInitialLoading || _isFetching || _isEnded) return;
+    if (!_controller.hasClients) return;
 
     final position = _controller.position;
     if (position.pixels >= (position.maxScrollExtent - 50)) {
@@ -289,6 +308,7 @@ class _FirestorePaginationState extends State<FirestorePagination> {
     _controller
       ..removeListener(_scrollListener)
       ..dispose();
+    _pageController.dispose();
     super.dispose();
   }
 
@@ -307,12 +327,17 @@ class _FirestorePaginationState extends State<FirestorePagination> {
                 bottomLoader: widget.bottomLoader,
                 gridDelegate: widget.gridDelegate,
                 wrapOptions: widget.wrapOptions,
+                pageOptions: widget.pageOptions,
                 scrollDirection: widget.scrollDirection,
                 reverse: widget.reverse,
                 controller: _controller,
+                pageController: _pageController,
                 shrinkWrap: widget.shrinkWrap,
                 physics: widget.physics,
                 padding: widget.padding,
+                onPageChanged: (index) {
+                  if (index >= _docs.length - 1) _loadDocuments();
+                },
               );
   }
 }

lib/src/models/page_options.dart

@@ -0,0 +1,69 @@
+// Flutter Packages
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+
+// Data Models
+import 'view_type.dart';
+
+/// The properties of the [PageView] widget in the [ViewType.page] view.
+class PageOptions {
+  /// Creates a object that contains the properties of the [PageView] widget.
+  const PageOptions({
+    this.clipBehavior = Clip.hardEdge,
+    this.pageSnapping = true,
+    this.padEnds = true,
+    this.scrollBehavior,
+    this.allowImplicitScrolling = false,
+    this.dragStartBehavior = DragStartBehavior.start,
+  });
+
+  /// {@macro flutter.material.Material.clipBehavior}
+  ///
+  /// Defaults to [Clip.hardEdge].
+  final Clip clipBehavior;
+
+  /// Set to false to disable page snapping, useful for custom scroll behavior.
+  ///
+  /// If the [padEnds] is false and [PageController.viewportFraction] < 1.0,
+  /// the page will snap to the beginning of the viewport; otherwise, the page
+  /// will snap to the center of the viewport.
+  final bool pageSnapping;
+
+  /// Whether to add padding to both ends of the list.
+  ///
+  /// If this is set to true and [PageController.viewportFraction] < 1.0, padding will be added
+  /// such that the first and last child slivers will be in the center of
+  /// the viewport when scrolled all the way to the start or end, respectively.
+  ///
+  /// If [PageController.viewportFraction] >= 1.0, this property has no effect.
+  ///
+  /// This property defaults to true.
+  final bool padEnds;
+
+  /// {@macro flutter.widgets.shadow.scrollBehavior}
+  ///
+  /// [ScrollBehavior]s also provide [ScrollPhysics]. If an explicit
+  /// [ScrollPhysics] is provided in [physics], it will take precedence,
+  /// followed by [scrollBehavior], and then the inherited ancestor
+  /// [ScrollBehavior].
+  ///
+  /// The [ScrollBehavior] of the inherited [ScrollConfiguration] will be
+  /// modified by default to not apply a [Scrollbar].
+  final ScrollBehavior? scrollBehavior;
+
+  /// Controls whether the widget's pages will respond to
+  /// [RenderObject.showOnScreen], which will allow for implicit accessibility
+  /// scrolling.
+  ///
+  /// With this flag set to false, when accessibility focus reaches the end of
+  /// the current page and the user attempts to move it to the next element, the
+  /// focus will traverse to the next widget outside of the page view.
+  ///
+  /// With this flag set to true, when accessibility focus reaches the end of
+  /// the current page and user attempts to move it to the next element, focus
+  /// will traverse to the next page in the page view.
+  final bool allowImplicitScrolling;
+
+  /// {@macro flutter.widgets.scrollable.dragStartBehavior}
+  final DragStartBehavior dragStartBehavior;
+}

lib/src/models/view_type.dart

@@ -13,4 +13,7 @@ enum ViewType {
 
   /// Loads the data as a scrollable [Wrap].
   wrap,
+
+  /// Loads the data as a [PageView].
+  page,
 }

lib/src/realtime_db_pagination.dart

@@ -1,14 +1,15 @@
+// Dart Packages
+import 'dart:async';
+
 // Flutter Packages
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 
-// Dart Packages
-import 'dart:async';
-
 // Firebase Packages
 import 'package:firebase_database/firebase_database.dart';
 
 // Data Models
+import 'models/page_options.dart';
 import 'models/view_type.dart';
 import 'models/wrap_options.dart';
 
@@ -54,6 +55,7 @@ class RealtimeDBPagination extends StatefulWidget {
       crossAxisCount: 2,
     ),
     this.wrapOptions = const WrapOptions(),
+    this.pageOptions = const PageOptions(),
     this.onEmpty = const EmptyScreen(),
     this.bottomLoader = const BottomLoader(),
     this.initialLoader = const InitialLoader(),
@@ -63,6 +65,7 @@ class RealtimeDBPagination extends StatefulWidget {
     this.physics,
     this.padding,
     this.controller,
+    this.pageController,
   });
 
   /// The query to use to fetch data from Firebase Realtime Database.
@@ -129,6 +132,11 @@ class RealtimeDBPagination extends StatefulWidget {
   /// Defaults to [WrapOptions].
   final WrapOptions wrapOptions;
 
+  /// The [PageView] properties to use.
+  ///
+  /// Defaults to [PageOptions].
+  final PageOptions pageOptions;
+
   /// The widget to use when data is empty.
   ///
   /// Defaults to [EmptyScreen].
@@ -164,6 +172,11 @@ class RealtimeDBPagination extends StatefulWidget {
   /// Defaults to [ScrollController].
   final ScrollController? controller;
 
+  /// The page controller to use for the [PageView].
+  ///
+  /// Defaults to [PageController].
+  final PageController? pageController;
+
   @override
   State<RealtimeDBPagination> createState() => _RealtimeDBPaginationState();
 }
@@ -185,6 +198,10 @@ class _RealtimeDBPaginationState extends State<RealtimeDBPagination> {
   late final ScrollController _controller =
       widget.controller ?? ScrollController();
 
+  /// [PageController] to listen to page changes and load more data.
+  late final PageController _pageController =
+      widget.pageController ?? PageController();
+
   /// Whether initial data is loading.
   bool _isInitialLoading = true;
 
@@ -275,7 +292,8 @@ class _RealtimeDBPaginationState extends State<RealtimeDBPagination> {
       // scroll to the bottom and load more data.
       if (_isInitialLoading || _isFetching || _isEnded) return;
       SchedulerBinding.instance.addPostFrameCallback((_) {
-        if (_controller.position.maxScrollExtent <= 0) {
+        if (_controller.hasClients &&
+            _controller.position.maxScrollExtent <= 0) {
           _loadData();
         }
       });
@@ -335,6 +353,7 @@ class _RealtimeDBPaginationState extends State<RealtimeDBPagination> {
   /// To handle scroll end event and load more data.
   void _scrollListener() {
     if (_isInitialLoading || _isFetching || _isEnded) return;
+    if (!_controller.hasClients) return;
 
     final position = _controller.position;
     if (position.pixels >= (position.maxScrollExtent - 50)) {
@@ -356,6 +375,7 @@ class _RealtimeDBPaginationState extends State<RealtimeDBPagination> {
     _controller
       ..removeListener(_scrollListener)
       ..dispose();
+    _pageController.dispose();
     super.dispose();
   }
 
@@ -374,12 +394,17 @@ class _RealtimeDBPaginationState extends State<RealtimeDBPagination> {
                 bottomLoader: widget.bottomLoader,
                 gridDelegate: widget.gridDelegate,
                 wrapOptions: widget.wrapOptions,
+                pageOptions: widget.pageOptions,
                 scrollDirection: widget.scrollDirection,
                 reverse: widget.reverse,
                 controller: _controller,
+                pageController: _pageController,
                 shrinkWrap: widget.shrinkWrap,
                 physics: widget.physics,
                 padding: widget.padding,
+                onPageChanged: (index) {
+                  if (index >= _data.length - 1) _loadData();
+                },
               );
   }
 }