import 'package:flutter/material.dart';
void main() { runApp(new MyApp());
}
class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return new MaterialApp( home: new MyHomePage(), ); }
}
class MyHomePage extends StatefulWidget { MyHomePageState createState() => new MyHomePageState();
}
class MyCustomCard extends StatelessWidget { MyCustomCard({ this.colors }); final MaterialColor colors; Widget build(BuildContext context) { return new Container( alignment: FractionalOffset.center, height: 144.0, width: 360.0, decoration: new BoxDecoration( color: colors.shade50, border: new Border.all(color: new Color(0xFF9E9E9E)), ), child: new FlutterLogo(size: 100.0, colors: colors), ); }
}
class MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin { AnimationController _controller; Animation<double> _frontScale; Animation<double> _backScale; @override void initState() { super.initState(); _controller = new AnimationController( vsync: this, duration: const Duration(seconds: 1), ); _frontScale = new Tween( begin: 1.0, end: 0.0, ).animate(new CurvedAnimation( parent: _controller, curve: new Interval(0.0, 0.5, curve: Curves.easeIn), )); _backScale = new CurvedAnimation( parent: _controller, curve: new Interval(0.5, 1.0, curve: Curves.easeOut), ); } @override void dispose() { _controller.dispose(); super.dispose(); } @override Widget build(BuildContext context) { ThemeData theme = Theme.of(context); return new Scaffold( appBar: new AppBar(), floatingActionButton: new FloatingActionButton( child: new Icon(Icons.flip_to_back), onPressed: () { setState(() { if (_controller.isCompleted || _controller.velocity > 0) _controller.reverse(); else _controller.forward(); }); }, ), body: new Center( child: new Stack( children: <Widget>[ new AnimatedBuilder( child: new MyCustomCard(colors: Colors.orange), animation: _backScale, builder: (BuildContext context, Widget child) { final Matrix4 transform = new Matrix4.identity() ..scale(1.0, _backScale.value, 1.0); return new Transform( transform: transform, alignment: FractionalOffset.center, child: child, ); }, ), new AnimatedBuilder( child: new MyCustomCard(colors: Colors.blue), animation: _frontScale, builder: (BuildContext context, Widget child) { final Matrix4 transform = new Matrix4.identity() ..scale(1.0, _frontScale.value, 1.0); return new Transform( transform: transform, alignment: FractionalOffset.center, child: child, ); }, ), ], ), ), ); }
}