0a59deb98c
Original PR: https://github.com/flutter/flutter/pull/161514 Cherry-pick issue: https://github.com/flutter/flutter/issues/161664 Original PR description below: Fixes [M3 TabBar indicator animation broken both when swiping or tapping](https://github.com/flutter/flutter/issues/160631) This refactors the elastic `Tab` animation. Added additional tests that follows the elastic animation frame by frame and generates a golden file. <details> <summary>expand to view the code sample</summary> ```dart import 'package:flutter/gestures.dart'; import 'package:flutter/material.dart'; import 'package:flutter/scheduler.dart'; void main() => runApp(const MyApp()); class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { // timeDilation = 10; return MaterialApp( home: ScrollConfiguration( behavior: ScrollConfiguration.of(context).copyWith(dragDevices: <PointerDeviceKind>{ PointerDeviceKind.touch, PointerDeviceKind.mouse, }), child: Directionality( textDirection: TextDirection.ltr, child: DefaultTabController( length: 8, child: Scaffold( appBar: AppBar( bottom: const TabBar( isScrollable: true, tabAlignment: TabAlignment.start, tabs: <Widget>[ Tab(text: 'Home'), Tab(text: 'Search'), Tab(text: 'Add'), Tab(text: 'Favorite'), Tab(text: 'The longest text...'), Tab(text: 'Short'), Tab(text: 'Longer text...'), Tab(text: 'Profile'), ], ), ), body: const TabBarView( children: <Widget>[ Center(child: Text('Page')), Center(child: Text('Page')), Center(child: Text('Page')), Center(child: Text('Page')), Center(child: Text('Page')), Center(child: Text('Page')), Center(child: Text('Page')), Center(child: Text('Page')), ], ), ), ), ), ), ); } } ``` </details> https://github.com/user-attachments/assets/4f69f94b-0bcf-4813-b49f-06ff411435ca https://github.com/user-attachments/assets/65801c1c-d28f-4b42-870a-7140d5d3c4c3 | Before Test Results | After Test Results | | --------------- | --------------- | | <img src="https://github.com/user-attachments/assets/72ae9fbe-fef9-44a0-9b86-5a4c31fd39cf" /> | <img src="https://github.com/user-attachments/assets/2545f35e-ac03-495d-a33b-72b9bc71299b" /> | 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/ 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
Flutter Examples
This directory contains several examples of using Flutter. To run an example,
use flutter run inside that example's directory. See the getting started
guide to install the flutter tool.
For additional samples, see the
flutter/samples repo.
Available examples include:
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Hello, world The hello world app is a minimal Flutter app that shows the text "Hello, world!"
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Flutter gallery The flutter gallery app no longer lives in this repo. Please see the gallery repo.
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Layers The layers vignettes show how to use the various layers in the Flutter framework. For details, see the layers README.
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Platform Channel The platform channel app demonstrates how to connect a Flutter app to platform-specific APIs. For documentation, see https://flutter.dev/to/platform-channels/.
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Platform Channel Swift The platform channel swift app is the same as platform channel but the iOS version is in Swift and there is no Android version.
Notes
Note on Gradle wrapper files in .gitignore:
Gradle wrapper files should normally be checked into source control. The example projects don't do that to avoid having several copies of the wrapper binary in the Flutter repo. Instead, the Gradle wrapper is injected by Flutter tooling, and the wrapper files are .gitignore'd to avoid making the Flutter repository dirty as a side effect of running the examples.