Revert "Sliver animated list (#28834)" (#32135)

This reverts commit d2de911d.

packages/flutter/lib/src/widgets/animated_list.dart

@@ -10,7 +10,6 @@ import 'framework.dart';
 import 'scroll_controller.dart';
 import 'scroll_physics.dart';
 import 'scroll_view.dart';
-import 'sliver.dart';
 import 'ticker_provider.dart';
 
 /// Signature for the builder callback used by [AnimatedList].
@@ -76,13 +75,11 @@ class AnimatedList extends StatefulWidget {
   /// [AnimatedListState.removeItem] removes an item immediately.
   final AnimatedListItemBuilder itemBuilder;
 
-  /// {@template flutter.widgets.animatedList.initialItemCount}
   /// The number of items the list will start with.
   ///
   /// The appearance of the initial items is not animated. They
   /// are created, as needed, by [itemBuilder] with an animation parameter
   /// of [kAlwaysCompleteAnimation].
-  /// {@endtemplate}
   final int initialItemCount;
 
   /// The axis along which the scroll view scrolls.
@@ -210,150 +207,6 @@ class AnimatedList extends StatefulWidget {
 /// [AnimatedList] item input handlers can also refer to their [AnimatedListState]
 /// with the static [AnimatedList.of] method.
 class AnimatedListState extends State<AnimatedList> with TickerProviderStateMixin<AnimatedList> {
-  final GlobalKey<SliverAnimatedListState> _sliverAnimatedListKey = GlobalKey();
-
-  /// Insert an item at [index] and start an animation that will be passed
-  /// to [AnimatedList.itemBuilder] when the item is visible.
-  ///
-  /// This method's semantics are the same as Dart's [List.insert] method:
-  /// it increases the length of the list by one and shifts all items at or
-  /// after [index] towards the end of the list.
-  void insertItem(int index, { Duration duration = _kDuration }) {
-    _sliverAnimatedListKey.currentState.insertItem(index, duration: duration);
-  }
-
-  /// Remove the item at [index] and start an animation that will be passed
-  /// to [builder] when the item is visible.
-  ///
-  /// Items are removed immediately. After an item has been removed, its index
-  /// will no longer be passed to the [AnimatedList.itemBuilder]. However the
-  /// item will still appear in the list for [duration] and during that time
-  /// [builder] must construct its widget as needed.
-  ///
-  /// This method's semantics are the same as Dart's [List.remove] method:
-  /// it decreases the length of the list by one and shifts all items at or
-  /// before [index] towards the beginning of the list.
-  void removeItem(int index, AnimatedListRemovedItemBuilder builder, { Duration duration = _kDuration }) {
-    _sliverAnimatedListKey.currentState.removeItem(index, builder, duration: duration);
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return CustomScrollView(
-      scrollDirection: widget.scrollDirection,
-      reverse: widget.reverse,
-      controller: widget.controller,
-      primary: widget.primary,
-      physics: widget.physics,
-      shrinkWrap: widget.shrinkWrap,
-      slivers: <Widget>[
-        SliverPadding(
-          padding: widget.padding ?? const EdgeInsets.all(0),
-          sliver: SliverAnimatedList(
-            key: _sliverAnimatedListKey,
-            itemBuilder: widget.itemBuilder,
-            initialItemCount: widget.initialItemCount,
-          ),
-        ),
-      ],
-    );
-  }
-}
-
-/// A sliver that animates items when they are inserted or removed.
-///
-/// This widget's [SliverAnimatedListState] can be used to dynamically insert or
-/// remove items. To refer to the [SliverAnimatedListState] either provide a
-/// [GlobalKey] or use the static [SliverAnimatedList.of] method from an item's
-/// input callback.
-///
-/// See also:
-///
-/// * [SliverList], which does not animate items when they are inserted or removed.
-class SliverAnimatedList extends StatefulWidget {
-  /// Creates a sliver that animates items when they are inserted or removed.
-  const SliverAnimatedList({
-    Key key,
-    @required this.itemBuilder,
-    this.initialItemCount = 0,
-  }) : assert(itemBuilder != null),
-       assert(initialItemCount != null && initialItemCount >= 0),
-       super(key: key);
-
-  /// Called, as needed, to build list item widgets.
-  ///
-  /// List items are only built when they're scrolled into view.
-  ///
-  /// The [AnimatedListItemBuilder] index parameter indicates the item's
-  /// position in the list. The value of the index parameter will be between 0
-  /// and [initialItemCount] plus the total number of items that have been
-  /// inserted with [SliverAnimatedListState.insertItem] and less the total
-  /// number of items that have been removed with
-  /// [SliverAnimatedListState.removeItem].
-  ///
-  /// Implementations of this callback should assume that
-  /// [SliverAnimatedListState.removeItem] removes an item immediately.
-  final AnimatedListItemBuilder itemBuilder;
-
-  /// {@macro flutter.widgets.animatedList.initialItemCount}
-  final int initialItemCount;
-
-  @override
-  SliverAnimatedListState createState() => SliverAnimatedListState();
-
-  /// The state from the closest instance of this class that encloses the given context.
-  ///
-  /// This method is typically used by [SliverAnimatedList] item widgets that
-  /// insert or remove items in response to user input.
-  ///
-  /// ```dart
-  /// SliverAnimatedListState animatedList = SliverAnimatedList.of(context);
-  /// ```
-  static SliverAnimatedListState of(BuildContext context, {bool nullOk = false}) {
-    assert(context != null);
-    assert(nullOk != null);
-    final SliverAnimatedListState result = context.ancestorStateOfType(const TypeMatcher<SliverAnimatedListState>());
-    if (nullOk || result != null)
-      return result;
-    throw FlutterError(
-        'SliverAnimatedList.of() called with a context that does not contain a SliverAnimatedList.\n'
-        'No SliverAnimatedListState ancestor could be found starting from the '
-        'context that was passed to SliverAnimatedListState.of(). '
-        'This can happen when the context provided is from the same StatefulWidget that '
-        'built the AnimatedList. Please see the SliverAnimatedList documentation '
-        'for examples of how to refer to an AnimatedListState object: '
-        '  https://docs.flutter.io/flutter/widgets/SliverAnimatedListState-class.html \n'
-        'The context used was:\n'
-        '  $context');
-  }
-}
-
-/// The state for a sliver that animates items when they are
-/// inserted or removed.
-///
-/// When an item is inserted with [insertItem] an animation begins running. The
-/// animation is passed to [SliverAnimatedList.itemBuilder] whenever the item's
-/// widget is needed.
-///
-/// When an item is removed with [removeItem] its animation is reversed.
-/// The removed item's animation is passed to the [removeItem] builder
-/// parameter.
-///
-/// An app that needs to insert or remove items in response to an event
-/// can refer to the [SliverAnimatedList]'s state with a global key:
-///
-/// ```dart
-/// GlobalKey<SliverAnimatedListState> listKey = GlobalKey<SliverAnimatedListState>();
-/// ...
-/// SliverAnimatedList(key: listKey, ...);
-/// ...
-/// listKey.currentState.insert(123);
-/// ```
-///
-/// [SliverAnimatedList] item input handlers can also refer to their
-/// [SliverAnimatedListState] with the static [SliverAnimatedList.of] method.
-class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProviderStateMixin {
-
   final List<_ActiveItem> _incomingItems = <_ActiveItem>[];
   final List<_ActiveItem> _outgoingItems = <_ActiveItem>[];
   int _itemsCount = 0;
@@ -366,9 +219,10 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
 
   @override
   void dispose() {
-    for (_ActiveItem item in _incomingItems.followedBy(_outgoingItems)) {
+    for (_ActiveItem item in _incomingItems)
+      item.controller.dispose();
+    for (_ActiveItem item in _outgoingItems)
       item.controller.dispose();
-    }
     super.dispose();
   }
 
@@ -411,12 +265,8 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
     return index;
   }
 
-  SliverChildDelegate _createDelegate() {
-    return SliverChildBuilderDelegate(_itemBuilder, childCount: _itemsCount);
-  }
-
-  /// Insert an item at [index] and start an animation that will be passed to
-  /// [SliverAnimatedList.itemBuilder] when the item is visible.
+  /// Insert an item at [index] and start an animation that will be passed
+  /// to [AnimatedList.itemBuilder] when the item is visible.
   ///
   /// This method's semantics are the same as Dart's [List.insert] method:
   /// it increases the length of the list by one and shifts all items at or
@@ -457,8 +307,8 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
   /// to [builder] when the item is visible.
   ///
   /// Items are removed immediately. After an item has been removed, its index
-  /// will no longer be passed to the [SliverAnimatedList.itemBuilder]. However
-  /// the item will still appear in the list for [duration] and during that time
+  /// will no longer be passed to the [AnimatedList.itemBuilder]. However the
+  /// item will still appear in the list for [duration] and during that time
   /// [builder] must construct its widget as needed.
   ///
   /// This method's semantics are the same as Dart's [List.remove] method:
@@ -515,8 +365,16 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
 
   @override
   Widget build(BuildContext context) {
-    return SliverList(
-      delegate: _createDelegate(),
+    return ListView.builder(
+      itemBuilder: _itemBuilder,
+      itemCount: _itemsCount,
+      scrollDirection: widget.scrollDirection,
+      reverse: widget.reverse,
+      controller: widget.controller,
+      primary: widget.primary,
+      physics: widget.physics,
+      shrinkWrap: widget.shrinkWrap,
+      padding: widget.padding,
     );
   }
 }

packages/flutter/test/widgets/animated_list_test.dart

@@ -6,64 +6,13 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/widgets.dart';
 
 void main() {
-  testWidgets('AnimatedList', (WidgetTester tester) async {
-    final AnimatedListItemBuilder builder = (BuildContext context, int index, Animation<double> animation) {
-      return SizedBox(
-        height: 100.0,
-        child: Center(
-          child: Text('item $index'),
-        ),
-      );
-    };
-    final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();
-
-    await tester.pumpWidget(
-      Directionality(
-        textDirection: TextDirection.ltr,
-        child: AnimatedList(
-          key: listKey,
-          initialItemCount: 2,
-          itemBuilder: builder,
-        ),
-      ),
-    );
-
-    expect(find.byWidgetPredicate((Widget widget) {
-      return widget is SliverAnimatedList
-         && widget.initialItemCount == 2
-         && widget.itemBuilder == builder;
-    }), findsOneWidget);
-
-    listKey.currentState.insertItem(0);
-    await tester.pump();
-    expect(find.text('item 2'), findsOneWidget);
-
-    listKey.currentState.removeItem(2, (BuildContext context, Animation<double> animation) {
-      return const SizedBox(
-        height: 100.0,
-        child: Center(
-          child: Text('removing item'),
-        ),
-      );
-    }, duration: const Duration(milliseconds: 100));
-    await tester.pump();
-    expect(find.text('removing item'), findsOneWidget);
-    expect(find.text('item 2'), findsNothing);
-
-    await tester.pumpAndSettle(const Duration(milliseconds: 100));
-    expect(find.text('removing item'), findsNothing);
-  });
-
-  group('SliverAnimatedList', () {
-    testWidgets('initialItemCount', (WidgetTester tester) async {
+  testWidgets('AnimatedList initialItemCount', (WidgetTester tester) async {
     final Map<int, Animation<double>> animations = <int, Animation<double>>{};
 
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
-          child: CustomScrollView(
-            slivers: <Widget>[
-              SliverAnimatedList(
+        child: AnimatedList(
           initialItemCount: 2,
           itemBuilder: (BuildContext context, int index, Animation<double> animation) {
             animations[index] = animation;
@@ -74,8 +23,6 @@ void main() {
               ),
             );
           },
-              )
-            ],
         ),
       ),
     );
@@ -88,15 +35,13 @@ void main() {
     expect(animations[1].value, 1.0);
   });
 
-    testWidgets('insert', (WidgetTester tester) async {
-      final GlobalKey<SliverAnimatedListState> listKey = GlobalKey<SliverAnimatedListState>();
+  testWidgets('AnimatedList insert', (WidgetTester tester) async {
+    final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();
 
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
-          child: CustomScrollView(
-            slivers: <Widget>[
-              SliverAnimatedList(
+        child: AnimatedList(
           key: listKey,
           itemBuilder: (BuildContext context, int index, Animation<double> animation) {
             return SizeTransition(
@@ -111,8 +56,6 @@ void main() {
               ),
             );
           },
-              )
-            ],
         ),
       ),
     );
@@ -166,8 +109,8 @@ void main() {
     expect(itemBottom(2), 300.0);
   });
 
-    testWidgets('remove', (WidgetTester tester) async {
-      final GlobalKey<SliverAnimatedListState> listKey = GlobalKey<SliverAnimatedListState>();
+  testWidgets('AnimatedList remove', (WidgetTester tester) async {
+    final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();
     final List<int> items = <int>[0, 1, 2];
 
     Widget buildItem(BuildContext context, int item, Animation<double> animation) {
@@ -187,16 +130,12 @@ void main() {
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
-          child: CustomScrollView(
-            slivers: <Widget>[
-              SliverAnimatedList(
+        child: AnimatedList(
           key: listKey,
           initialItemCount: 3,
           itemBuilder: (BuildContext context, int index, Animation<double> animation) {
             return buildItem(context, items[index], animation);
           },
-              )
-            ],
         ),
       ),
     );
@@ -241,67 +180,4 @@ void main() {
     expect(itemTop(2), 100.0);
     expect(itemBottom(2), 200.0);
   });
-
-    testWidgets('works in combination with other slivers', (WidgetTester tester) async {
-      final GlobalKey<SliverAnimatedListState> listKey = GlobalKey<SliverAnimatedListState>();
-
-      await tester.pumpWidget(
-        Directionality(
-          textDirection: TextDirection.ltr,
-          child: CustomScrollView(
-            slivers: <Widget>[
-              const SliverList(
-                delegate: SliverChildListDelegate(<Widget>[
-                  SizedBox(height: 100),
-                  SizedBox(height: 100),
-                ]),
-              ),
-              SliverAnimatedList(
-                key: listKey,
-                initialItemCount: 3,
-                itemBuilder: (BuildContext context, int index, Animation<double> animation) {
-                  return SizedBox(
-                    height: 100,
-                    child: Text('item $index'),
-                  );
-                },
-              ),
-            ],
-          ),
-        ),
-      );
-
-      expect(tester.getTopLeft(find.text('item 0')).dy, 200);
-      expect(tester.getTopLeft(find.text('item 1')).dy, 300);
-
-      listKey.currentState.insertItem(3);
-      await tester.pumpAndSettle();
-      expect(tester.getTopLeft(find.text('item 3')).dy, 500);
-
-      listKey.currentState.removeItem(0,
-        (BuildContext context, Animation<double> animation) {
-          return SizeTransition(
-            sizeFactor: animation,
-            key: const ObjectKey('removing'),
-            child: const SizedBox(
-              height: 100,
-              child: Text('removing'),
-            ),
-          );
-        },
-        duration: const Duration(seconds: 1),
-      );
-
-      await tester.pump();
-      expect(find.text('item 3'), findsNothing);
-
-      await tester.pump(const Duration(milliseconds: 500));
-      expect(tester.getSize(find.byKey(const ObjectKey('removing'))).height, 50);
-      expect(tester.getTopLeft(find.text('item 0')).dy, 250);
-
-      await tester.pumpAndSettle();
-      expect(find.text('removing'), findsNothing);
-      expect(tester.getTopLeft(find.text('item 0')).dy, 200);
-    });
-  });
 }