SliverAppBar() not collapsing with ListView in Flutter - flutter

Question

I'm trying to display tabs for each main tab (Nested Tab Bar) in SliverAppBar(). It's look like this:
See the image
See the GIF
The content of the exam tab it's in Container() widget (That the error in the image came from).
Now, with the Container() widget the SliverAppBar() will collapse when the user scroll the exam tab content (white screen in the image), everything is fine for now.
So, After I replaced the Container() with ListView.builder() to make the tab content scrollable, now I can't collapse SliverAppBar() from the tab content (white screen in the image). but I can from the SliverAppBar().
See this GIF after I added ListView.builder()
So, How I can make the SliverAppBar scrollable (collapsing ) with Listview?
Can anyone help me? please :(
This example (demo):
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(title: 'SliverAppBar App Demo'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
child: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder:
(BuildContext context, bool innerBoxIsScrolled) {
return [
SliverOverlapAbsorber(
handle:
NestedScrollView.sliverOverlapAbsorberHandleFor(context),
child: SliverSafeArea(
top: false,
sliver: SliverAppBar(
pinned: true,
title: Text(widget.title),
expandedHeight: 500,
),
),
),
SliverPersistentHeader(
delegate: _SliverAppBarDelegate(
TabBar(tabs: [Tab(text: 'Tab A'), Tab(text: 'Tab B')]),
Colors.blue,
),
pinned: false,
),
];
},
body: TabBarView(
children: <Widget>[
NestedTabs('A'),
NestedTabs('B'),
],
),
),
),
),
);
}
}
// This class is to handle the main tabs (Tab A & Tab B)
class _SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
_SliverAppBarDelegate(this._tabBar, this._color);
TabBar _tabBar;
final Color _color;
#override
double get minExtent => _tabBar.preferredSize.height;
#override
double get maxExtent => _tabBar.preferredSize.height;
#override
Widget build(
BuildContext context, double shrinkOffset, bool overlapsContent) {
return new Container(
color: _color,
alignment: Alignment.center,
child: _tabBar,
);
}
#override
bool shouldRebuild(_SliverAppBarDelegate oldDelegate) {
return false;
}
}
class NestedTabs extends StatelessWidget {
final String mainTabName;
NestedTabs(this.mainTabName);
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: PreferredSize(
preferredSize: Size.fromHeight(20),
child: Container(
color: Colors.blue,
alignment: Alignment.bottomCenter,
child: TabBar(
tabs: [
Tab(text: 'Tab $mainTabName-1'),
Tab(text: 'Tab $mainTabName-2')
],
),
),
),
body: TabBarView(
children: [
ListView.builder(
padding: const EdgeInsets.all(8),
itemCount: 500,
itemBuilder: (BuildContext context, int index) {
return Container(
height: 50,
width: 200,
color: Colors.black45,
child: Center(child: Text('Index ${index}')));
},
),
ListView.builder(
padding: const EdgeInsets.all(8),
itemCount: 500,
itemBuilder: (BuildContext context, int index) {
return Container(
height: 50,
width: 200,
color: Colors.black45,
child: Center(child: Text('Index ${index}')));
},
)
],
),
);
}
}
Thank you :)

Answer 1

Use SliverList() instead of SliverFillRemaining for ListView