// 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. import 'package:flutter/material.dart'; /// Flutter code sample for [AnimatedSwitcher]. void main() => runApp(const AnimatedSwitcherExampleApp()); class AnimatedSwitcherExampleApp extends StatelessWidget { const AnimatedSwitcherExampleApp({super.key}); @override Widget build(BuildContext context) { return const MaterialApp( home: AnimatedSwitcherExample(), ); } } class AnimatedSwitcherExample extends StatefulWidget { const AnimatedSwitcherExample({super.key}); @override State<AnimatedSwitcherExample> createState() => _AnimatedSwitcherExampleState(); } class _AnimatedSwitcherExampleState extends State<AnimatedSwitcherExample> { int _count = 0; @override Widget build(BuildContext context) { return ColoredBox( color: Colors.white, child: Column( mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[ AnimatedSwitcher( duration: const Duration(milliseconds: 500), transitionBuilder: (Widget child, Animation<double> animation) { return ScaleTransition(scale: animation, child: child); }, child: Text( '$_count', // This key causes the AnimatedSwitcher to interpret this as a "new" // child each time the count changes, so that it will begin its animation // when the count changes. key: ValueKey<int>(_count), style: Theme.of(context).textTheme.headlineMedium, ), ), ElevatedButton( child: const Text('Increment'), onPressed: () { setState(() { _count += 1; }); }, ), ], ), ); } }