| // Copyright 2014 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| /// Flutter code sample for [DefaultTextStyleTransition]. |
| |
| import 'package:flutter/material.dart'; |
| |
| void main() => runApp(const MyApp()); |
| |
| class MyApp extends StatelessWidget { |
| const MyApp({super.key}); |
| |
| static const String _title = 'Flutter Code Sample'; |
| |
| @override |
| Widget build(BuildContext context) { |
| return const MaterialApp( |
| title: _title, |
| home: MyStatefulWidget(), |
| ); |
| } |
| } |
| |
| class MyStatefulWidget extends StatefulWidget { |
| const MyStatefulWidget({super.key}); |
| |
| @override |
| State<MyStatefulWidget> createState() => _MyStatefulWidgetState(); |
| } |
| |
| /// [AnimationController]s can be created with `vsync: this` because of |
| /// [TickerProviderStateMixin]. |
| class _MyStatefulWidgetState extends State<MyStatefulWidget> |
| with TickerProviderStateMixin { |
| late AnimationController _controller; |
| late TextStyleTween _styleTween; |
| late CurvedAnimation _curvedAnimation; |
| |
| @override |
| void initState() { |
| super.initState(); |
| _controller = AnimationController( |
| duration: const Duration(seconds: 2), |
| vsync: this, |
| )..repeat(reverse: true); |
| _styleTween = TextStyleTween( |
| begin: const TextStyle( |
| fontSize: 50, color: Colors.blue, fontWeight: FontWeight.w900), |
| end: const TextStyle( |
| fontSize: 50, color: Colors.red, fontWeight: FontWeight.w100), |
| ); |
| _curvedAnimation = CurvedAnimation( |
| parent: _controller, |
| curve: Curves.elasticInOut, |
| ); |
| } |
| |
| @override |
| void dispose() { |
| _controller.dispose(); |
| super.dispose(); |
| } |
| |
| @override |
| Widget build(BuildContext context) { |
| return Center( |
| child: DefaultTextStyleTransition( |
| style: _styleTween.animate(_curvedAnimation), |
| child: const Text('Flutter'), |
| ), |
| ); |
| } |
| } |