GridView inside AnimatedCrossFade throws Exception #51077
Description
I have a GridView inside an AnimatedCrossFade, and I get this error:
The following assertion was thrown during performResize():
Vertical viewport was given unbounded height.Viewports expand in the scrolling direction to fill their container. In this case, a vertical viewport was given an unlimited amount of vertical space in which to expand. This situation typically happens when a scrollable widget is nested inside another scrollable widget.
If this widget is always nested in a scrollable widget there is no need to use a viewport because there will always be enough vertical space for the children. In this case, consider using a Column instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size the height of the viewport to the sum of the heights of its children.
I don't want to use shrinkWrap as this cuts my widget's elevation shadows and BouncingScrollPhysics as per #51078. Things are working fine, but I still get the exception.
Is this something that's missing from the docs or is AnimatedCrossFade not compatible with GridView?
Here's a sample code that triggers the issue:
class MyScreen extends StatefulWidget {
@override
_MyScreenState createState() => _MyScreenState();
}
class _MyScreenState extends State<MyScreen> {
@override
Widget build(BuildContext context) {
return Theme(
data: Theme.of(context).copyWith(primaryColorBrightness: Brightness.dark),
child: Scaffold(
body: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
MediaQuery.removePadding(
context: context,
removeBottom: true,
child: AppBar(
elevation: 10,
backgroundColor: Theme.of(context).canvasColor,
automaticallyImplyLeading: false,
flexibleSpace: Container(height: 300, color: Colors.blue,),
),
),
Expanded(
child: FutureBuilder<void>(
future: Future.delayed(Duration(seconds: 15)),
builder: (context, snapshot) {
return AnimatedCrossFade(
duration: Duration(milliseconds: 300),
crossFadeState:
snapshot.connectionState != ConnectionState.done
? CrossFadeState.showFirst
: CrossFadeState.showSecond,
firstChild: GridView.count(
crossAxisCount: 3,
physics: BouncingScrollPhysics(),
padding: EdgeInsets.all(12),
crossAxisSpacing: 12,
mainAxisSpacing: 12,
children: <Widget>[
for (int i = 0; i < 20; ++i)
Loading(),
],
shrinkWrap: true,
),
secondChild: GridView.count(
crossAxisCount: 3,
physics: BouncingScrollPhysics(),
padding: EdgeInsets.all(12),
crossAxisSpacing: 12,
mainAxisSpacing: 12,
children: <Widget>[
for (int i = 0; i < 5; ++i)
Loading(),
],
shrinkWrap: true,
),
);
},
),
),
],
),
),
);
}
}
class Loading extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Card(
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
elevation: 8,
clipBehavior: Clip.antiAlias,
child: AspectRatio(
aspectRatio: 1,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
width: 70,
height: 70,
color: Colors.white30,
),
SizedBox(height: 4),
Container(
width: 70,
height: 15,
color: Colors.white30,
),
],
),
),
);
}
}Flutter 1.12.13+hotfix.8 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 0b8abb4 (8 days ago) • 2020-02-11 11:44:36 -0800
Engine • revision e1e6ced
Tools • Dart 2.7.0