Flutter - Effect of flip card - dart

Question

I'm trying to make a flip card, what would be the best way to get the effect

Answer 1

I would use an AnimatedBuilder or AnimatedWidget to animate the values of a Transform widget. ScaleTransition almost does this for you, but it scales both directions, and you only want one.
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,
);
},
),
],
),
),
);
}
}

Answer 2

I used simple approach, rotated it on X axis. Here is the full code.
void main() => runApp(MaterialApp(home: HomePage()));
class HomePage extends StatefulWidget {
#override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> with SingleTickerProviderStateMixin {
AnimationController _controller;
bool _flag = true;
Color _color = Colors.blue;
#override
void initState() {
super.initState();
_controller = AnimationController(vsync: this, duration: Duration(seconds: 1), value: 1);
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.crop_rotate),
onPressed: () async {
if (_flag) {
await _controller.reverse();
setState(() {
_color = Colors.orange;
});
await _controller.forward();
} else {
await _controller.reverse();
setState(() {
_color = Colors.blue;
});
await _controller.forward();
}
_flag = !_flag;
},
),
body: Center(
child: AnimatedBuilder(
animation: _controller,
builder: (context, child) {
return Transform(
transform: Matrix4.rotationX((1 - _controller.value) * math.pi / 2),
alignment: Alignment.center,
child: Container(
height: 100,
margin: EdgeInsets.symmetric(horizontal: 20),
padding: EdgeInsets.symmetric(vertical: 12),
alignment: Alignment.center,
decoration: BoxDecoration(color: _color.withOpacity(0.2), border: Border.all(color: Colors.grey)),
child: FlutterLogo(colors: _color, size: double.maxFinite),
),
);
},
),
),
);
}
}

Answer 3

You can use the flip_card Flutter package. It lets you define a front and back widget and can be flipped horizontally or vertically.