From 61fff253ea2aca90cbcda9bd73372848ca936e7c Mon Sep 17 00:00:00 2001 From: Kazbek Sultanov Date: Wed, 22 Oct 2025 02:37:31 +0400 Subject: [PATCH] Fix(AnimatedScrollView): exclude outgoing items in removeAllItems (#176452) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix: #176362 Issue provided reproducible code related to exception being thrown when removing all items in an `AnimatedList` when some of the item were already being removed but had a long animation duration. In this PR: The `removeAllItems` method now correctly calculates the range of items to remove, excluding those already undergoing a removal animation. This prevents an assert from triggering when `removeAllItems` is called while other items are still being removed.
Video example after fix https://github.com/user-attachments/assets/c7351702-b829-4e35-9978-b95f9f3ae8cd
Updated reproducible code ``` import 'package:flutter/material.dart'; void main() => runApp(const MyApp()); class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { return const MaterialApp(debugShowCheckedModeBanner: false, home: AnimatedListExample()); } } class AnimatedListExample extends StatefulWidget { const AnimatedListExample({super.key}); @override State createState() => _AnimatedListExampleState(); } class _AnimatedListExampleState extends State { final GlobalKey _listKey = GlobalKey(); final List _items = List.generate(10, (int index) => index); void _removeItem(int index) { final int removedItem = _items[index]; _listKey.currentState?.removeItem( index, (BuildContext context, Animation animation) => SizeTransition( sizeFactor: animation, child: _buildItem(removedItem, animation, isRemoved: true), ), // ๐Ÿ‘‡ Long delay so you can press "Remove All" while itโ€™s still animating duration: const Duration(seconds: 10), ); _items.removeAt(index); } void _addItem() { final int addingItem = _items.length; _listKey.currentState?.insertItem(addingItem, duration: const Duration(seconds: 3)); _items.add(addingItem); } void _removeAll() { _listKey.currentState?.removeAllItems((BuildContext context, Animation animation) { return SizeTransition( sizeFactor: animation, child: Container( color: Colors.red[100], child: const ListTile(title: Text('Removing...')), ), ); }, duration: const Duration(seconds: 2)); _items.clear(); } Widget _buildItem(int item, Animation animation, {bool isRemoved = false}) { return SizeTransition( sizeFactor: animation, child: Card( margin: const EdgeInsets.symmetric(vertical: 4, horizontal: 8), child: ListTile( title: Text('Item $item'), trailing: !isRemoved ? IconButton( icon: const Icon(Icons.delete, color: Colors.red), onPressed: () { final int index = _items.indexOf(item); if (index != -1) { _removeItem(index); } }, ) : null, ), ), ); } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: const Text('AnimatedList Example'), actions: [ TextButton(onPressed: _addItem, child: const Text('Add')), TextButton( onPressed: _items.isNotEmpty ? _removeAll : null, child: const Text('Clear list'), ), ], ), body: AnimatedList( key: _listKey, initialItemCount: _items.length, itemBuilder: (BuildContext context, int index, Animation animation) { return _buildItem(_items[index], animation); }, ), ); } } ```
## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [ ] I added new tests to check the change I am making, or this PR is [test-exempt]. - [ ] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). 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[Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md --------- Co-authored-by: chunhtai <47866232+chunhtai@users.noreply.github.com> --- .../lib/src/widgets/animated_scroll_view.dart | 12 +++- .../test/widgets/animated_list_test.dart | 67 +++++++++++++++++++ 2 files changed, 76 insertions(+), 3 deletions(-) diff --git a/packages/flutter/lib/src/widgets/animated_scroll_view.dart b/packages/flutter/lib/src/widgets/animated_scroll_view.dart index 4d03aec22b2..7926fd5bd51 100644 --- a/packages/flutter/lib/src/widgets/animated_scroll_view.dart +++ b/packages/flutter/lib/src/widgets/animated_scroll_view.dart @@ -920,7 +920,9 @@ const Duration _kDuration = Duration(milliseconds: 300); // Incoming and outgoing animated items. class _ActiveItem implements Comparable<_ActiveItem> { _ActiveItem.incoming(this.controller, this.itemIndex) : removedItemBuilder = null; + _ActiveItem.outgoing(this.controller, this.itemIndex, this.removedItemBuilder); + _ActiveItem.index(this.itemIndex) : controller = null, removedItemBuilder = null; final AnimationController? controller; @@ -1436,10 +1438,14 @@ abstract class _SliverAnimatedMultiBoxAdaptorState= 0; i--) { + assert(_itemsCount >= 0); + assert(_itemsCount - _outgoingItems.length >= 0); + final int visibleItemCount = _itemsCount - _outgoingItems.length; + for (int i = visibleItemCount - 1; i >= 0; i--) { removeItem(i, builder, duration: duration); } } diff --git a/packages/flutter/test/widgets/animated_list_test.dart b/packages/flutter/test/widgets/animated_list_test.dart index f02e4704adb..1b7fccecc9d 100644 --- a/packages/flutter/test/widgets/animated_list_test.dart +++ b/packages/flutter/test/widgets/animated_list_test.dart @@ -107,6 +107,73 @@ void main() { expect(find.text('removing item'), findsNothing); }); + testWidgets('AnimatedList should safely execute removeAllItems during long removal of one item', ( + WidgetTester tester, + ) async { + Widget builder(BuildContext context, int index, Animation animation) { + return SizedBox(height: 100.0, child: Center(child: Text('item $index'))); + } + + final GlobalKey listKey = GlobalKey(); + + await tester.pumpWidget( + Directionality( + textDirection: TextDirection.ltr, + child: AnimatedList(key: listKey, initialItemCount: 2, itemBuilder: builder), + ), + ); + + // Check that one AnimatedList with 2 items (item 0, item 1). + expect( + find.byWidgetPredicate((Widget widget) { + return widget is SliverAnimatedList && + widget.initialItemCount == 2 && + widget.itemBuilder == builder; + }), + findsOneWidget, + ); + expect(find.byType(Text), findsExactly(2)); + expect(find.text('item 0'), findsOne); + expect(find.text('item 1'), findsOne); + + // Insert 1 item and check state (item 0, item 1, item 2). + listKey.currentState!.insertItem(0, duration: const Duration(milliseconds: 200)); + await tester.pump(const Duration(milliseconds: 50)); + expect(find.byType(Text), findsExactly(3)); + expect(find.text('item 0'), findsOne); + expect(find.text('item 1'), findsOne); + expect(find.text('item 2'), findsOne); + + // Removing item 2 and check state (item 0, item 1, removing item 2). + listKey.currentState!.removeItem(2, (BuildContext context, Animation animation) { + return const SizedBox(height: 100.0, child: Center(child: Text('removing item 2'))); + }, duration: const Duration(milliseconds: 200)); + await tester.pump(const Duration(milliseconds: 50)); + expect(find.byType(Text), findsExactly(3)); + expect(find.text('item 0'), findsOne); + expect(find.text('item 1'), findsOne); + expect(find.text('removing item 2'), findsOne); + expect(find.text('item 2'), findsNothing); + + // Call removeAllItems and check state (removing all items, removing all items, removing item 2). + listKey.currentState!.removeAllItems((BuildContext context, Animation animation) { + return const SizedBox(height: 100.0, child: Center(child: Text('removing all items'))); + }, duration: const Duration(milliseconds: 100)); + await tester.pump(const Duration(milliseconds: 50)); + expect(find.byType(Text), findsExactly(3)); + expect(find.text('removing all items'), findsExactly(2)); + expect(find.text('removing item 2'), findsWidgets); + expect(find.text('item 0'), findsNothing); + expect(find.text('item 1'), findsNothing); + expect(find.text('item 2'), findsNothing); + + // After animation is done completed, list should be empty. + await tester.pumpAndSettle(); + expect(find.byType(Text), findsNothing); + expect(find.text('removing one item'), findsNothing); + expect(find.text('removing all items'), findsNothing); + }); + group('SliverAnimatedList', () { testWidgets('initialItemCount', (WidgetTester tester) async { final Map> animations = >{};