Created
June 19, 2020 20:41
-
-
Save mpfaff/5c6247687d4595dde3f69a7e6008f14e to your computer and use it in GitHub Desktop.
Example of TweenSequence<Color> for a PageView
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import 'package:flutter/material.dart'; | |
void main() { | |
runApp(MyApp()); | |
} | |
class MyApp extends StatelessWidget { | |
@override | |
Widget build(BuildContext context) { | |
return MaterialApp( | |
title: 'stackoverflow question', | |
home: SafeArea( | |
top: false, | |
bottom: true, | |
child: HomepageScreen(), | |
), | |
); | |
} | |
} | |
class HomepageScreen extends StatefulWidget { | |
const HomepageScreen({Key key}) : super(key: key); | |
@override | |
_HomepageScreenState createState() => _HomepageScreenState(); | |
} | |
class _HomepageScreenState extends State<HomepageScreen> | |
with SingleTickerProviderStateMixin { | |
AnimationController _controller; | |
Animation<Color> animation; | |
final colors = <TweenSequenceItem<Color>>[ | |
TweenSequenceItem( | |
weight: 1.0, | |
tween: ColorTween(begin: Colors.red, end: Colors.blue), | |
), | |
TweenSequenceItem( | |
weight: 1.0, | |
tween: ColorTween(begin: Colors.blue, end: Colors.green), | |
), | |
TweenSequenceItem( | |
weight: 1.0, | |
tween: ColorTween(begin: Colors.green, end: Colors.yellow), | |
), | |
TweenSequenceItem( | |
weight: 1.0, | |
tween: ColorTween(begin: Colors.yellow, end: Colors.red), | |
), | |
]; | |
@override | |
void initState() { | |
super.initState(); | |
_controller = AnimationController( | |
duration: const Duration(milliseconds: 600), | |
vsync: this, | |
); | |
animation = TweenSequence<Color>(colors).animate(_controller)..addListener(() { | |
setState(() {}); | |
}); | |
} | |
@override | |
Widget build(BuildContext context) { | |
return Scaffold( | |
backgroundColor: animation.value, | |
body: Container( | |
child: Column( | |
crossAxisAlignment: CrossAxisAlignment.start, | |
children: <Widget>[ | |
Expanded( | |
child: PageView.builder( | |
physics: new PageScrollPhysics(), | |
itemCount: colors.length, | |
controller: PageController(viewportFraction: 0.8), | |
onPageChanged: ((int index) { | |
_controller.animateTo(index / colors.length); | |
}), | |
itemBuilder: (_, i) { | |
return Padding( | |
padding: | |
EdgeInsets.only(left: i % 2 == 0 ? 0 : 15, bottom: 20), | |
child: Container(), | |
); | |
}, | |
), | |
), | |
], | |
), | |
), | |
); | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment