Last active
January 31, 2023 19:35
-
-
Save tensor-programming/7bafc564d46740c5f1ac51711a6552b6 to your computer and use it in GitHub Desktop.
Flutter Column Animated expanded widgets
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
| class ExpandableText extends StatefulWidget { | |
| ExpandableText(this.text); | |
| final String text; | |
| @override | |
| _ExpandableTextState createState() => _ExpandableTextState(); | |
| } | |
| class _ExpandableTextState extends State<ExpandableText> | |
| with TickerProviderStateMixin<ExpandableText> { | |
| bool isExpanded = false; | |
| @override | |
| Widget build(BuildContext context) { | |
| return Column(children: <Widget>[ | |
| AnimatedSize( | |
| vsync: this, | |
| duration: const Duration(milliseconds: 500), | |
| child: ConstrainedBox( | |
| constraints: isExpanded | |
| ? BoxConstraints() | |
| : BoxConstraints(maxHeight: 50.0), | |
| child: Text( | |
| widget.text, | |
| softWrap: true, | |
| overflow: TextOverflow.fade, | |
| ))), | |
| isExpanded | |
| ? ConstrainedBox(constraints: BoxConstraints()) | |
| : FlatButton( | |
| child: const Text('...'), | |
| onPressed: () => setState(() => isExpanded = true)) | |
| ]); | |
| } | |
| } | |
| class DemoPage extends StatefulWidget { | |
| final Widget child; | |
| DemoPage({Key key, this.child}) : super(key: key); | |
| _DemoPageState createState() => _DemoPageState(); | |
| } | |
| class _DemoPageState extends State<DemoPage> { | |
| String descText = | |
| "Description Line 1\nDescription Line 2\nDescription Line 3\nDescription Line 4\nDescription Line 5\nDescription Line 6\nDescription Line 7\nDescription Line 8"; | |
| bool descTextShowFlag = false; | |
| @override | |
| Widget build(BuildContext context) { | |
| return Container( | |
| margin: EdgeInsets.all(16.0), | |
| child: Column( | |
| crossAxisAlignment: CrossAxisAlignment.start, | |
| children: <Widget>[ | |
| Text(descText, | |
| maxLines: descTextShowFlag ? 8 : 2, textAlign: TextAlign.start), | |
| InkWell( | |
| onTap: () { | |
| setState(() { | |
| descTextShowFlag = !descTextShowFlag; | |
| }); | |
| }, | |
| child: Row( | |
| mainAxisAlignment: MainAxisAlignment.end, | |
| children: <Widget>[ | |
| descTextShowFlag | |
| ? Text( | |
| "Show Less", | |
| style: TextStyle(color: Colors.blue), | |
| ) | |
| : Text("Show More", style: TextStyle(color: Colors.blue)) | |
| ], | |
| ), | |
| ), | |
| ], | |
| ), | |
| ); | |
| } | |
| } | |
| class CollapseWidget extends StatefulWidget { | |
| @override | |
| _CollapseWidgetState createState() => _CollapseWidgetState(); | |
| } | |
| class _CollapseWidgetState extends State<CollapseWidget> | |
| with TickerProviderStateMixin { | |
| GlobalKey _keyFoldChild; | |
| bool collapsed = false; | |
| double _childWidth; | |
| AnimationController _controller; | |
| Animation<double> _sizeAnimation; | |
| @override | |
| void initState() { | |
| super.initState(); | |
| _controller = | |
| AnimationController(vsync: this, duration: const Duration(seconds: 1)); | |
| _keyFoldChild = GlobalKey(); | |
| WidgetsBinding.instance.addPostFrameCallback(_afterLayout); | |
| } | |
| void _afterLayout(_) { | |
| final RenderBox renderBox = _keyFoldChild.currentContext.findRenderObject(); | |
| _sizeAnimation = | |
| Tween<double>(begin: renderBox.size.height, end: 0.0).animate(_controller); | |
| _childWidth = renderBox.size.width; | |
| } | |
| @override | |
| Widget build(BuildContext context) { | |
| return Column( | |
| children: <Widget>[ | |
| RaisedButton( | |
| onPressed: () { | |
| setState(() { | |
| collapsed = !collapsed; | |
| }); | |
| if (collapsed) { | |
| _controller.forward(); | |
| } else { | |
| _controller.reverse(); | |
| } | |
| }, | |
| child: Text("Click me"), | |
| ), | |
| Row( | |
| crossAxisAlignment: CrossAxisAlignment.start, | |
| children: <Widget>[ | |
| AnimatedContainer( | |
| duration: Duration(seconds: 1), | |
| height: collapsed ? 0 : 100, | |
| color: Colors.orange, | |
| child: Text("Just some text"), | |
| ), | |
| AnimatedBuilder( | |
| animation: _controller, | |
| builder: (context, child) { | |
| if (_sizeAnimation == null) { | |
| return child; | |
| } else { | |
| return ClipRect( | |
| child: SizedOverflowBox( | |
| size: Size(_childWidth, _sizeAnimation.value), | |
| child: child, | |
| ), | |
| ); | |
| } | |
| }, | |
| child: Container( | |
| key: _keyFoldChild, | |
| color: Colors.red, | |
| child: Text("Lorem Ipsum Dolar Sit"), | |
| ), | |
| ), | |
| ], | |
| ) | |
| ], | |
| ); | |
| } | |
| } | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment