How to add Grids into TabbarView in Flutter? - flutter

Question

So basically I have this widget:
class MyWidget extends StatelessWidget {
const MyWidget({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
body: CustomScrollView(
slivers: [
// ...
SliverToBoxAdapter(
child: TabBar(
controller: this._controller,
indicator: UnderlineTabIndicator(
borderSide: BorderSide(width: 1.0, color: Colors.red),
),
tabs: [
Tab(icon: Icon(CupertinoIcons.camera)),
Tab(icon: Icon(CupertinoIcons.photo)),
Tab(icon: Icon(CupertinoIcons.video_camera)),
],
),
),
SliverFillRemaining(
child: TabBarView(
controller: this._controller,
children: [
// Want Scrollable Grid here
// Want Scrollable Grid here
Center(
child: Text("Hello Reader🙂"),
),
],
),
),
// ...
],
),
);
}
}
I want to add a 2 scrollable grids as children in the TabBarView however when I use GridView.builder(...), there is an annoying gap at the top of the grid and scrolling isn't all too great neither even with shrinkWrap: true and physics: NeverScrollableScrollPhysics().
However when I use a SliverGrid(...), there is this error
RenderObjects expect specific types of children because they coordinate with their children during layout and paint. For example, a RenderSliver cannot be the child of a RenderBox because a RenderSliver does not understand the RenderBox layout protocol.
This obviously makes sense because TabBarView isn't a sliver widget. I have already taken a look at this post but it wasn't really of any help.
How could I implement this? Is there perhaps a way I could create my own widget builder that builds a custom layout?
Thank You!

Answer 1

You need to use SliverOverlapAbsorber/SliverOverlapInjector, the following code works for me (working full code on dart pad):
Here i used SliverFixedExtentList but you can it replace with SliverGrid.
#override
State<StatefulWidget> createState() => _NewsScreenState();
}
class _NewsScreenState extends State<NewsScreen> {
final List<String> listItems = [];
final List<String> _tabs = <String>[
"Featured",
"Popular",
"Latest",
];
#override
Widget build(BuildContext context) {
return Material(
child: Scaffold(
body: DefaultTabController(
length: _tabs.length, // This is the number of tabs.
child: NestedScrollView(
headerSliverBuilder:
(BuildContext context, bool innerBoxIsScrolled) {
// These are the slivers that show up in the "outer" scroll view.
return <Widget>[
SliverOverlapAbsorber(
// This widget takes the overlapping behavior of the SliverAppBar,
// and redirects it to the SliverOverlapInjector below. If it is
// missing, then it is possible for the nested "inner" scroll view
// below to end up under the SliverAppBar even when the inner
// scroll view thinks it has not been scrolled.
// This is not necessary if the "headerSliverBuilder" only builds
// widgets that do not overlap the next sliver.
handle:
NestedScrollView.sliverOverlapAbsorberHandleFor(context),
sliver: SliverSafeArea(
top: false,
sliver: SliverAppBar(
title: const Text('Books'),
floating: true,
pinned: true,
snap: false,
primary: true,
forceElevated: innerBoxIsScrolled,
bottom: TabBar(
// These are the widgets to put in each tab in the tab bar.
tabs: _tabs
.map((String name) => Tab(text: name))
.toList(),
),
),
),
),
];
},
body: TabBarView(
// These are the contents of the tab views, below the tabs.
children: _tabs.map((String name) {
return SafeArea(
top: false,
bottom: false,
child: Builder(
// This Builder is needed to provide a BuildContext that is "inside"
// the NestedScrollView, so that sliverOverlapAbsorberHandleFor() can
// find the NestedScrollView.
builder: (BuildContext context) {
return CustomScrollView(
// The "controller" and "primary" members should be left
// unset, so that the NestedScrollView can control this
// inner scroll view.
// If the "controller" property is set, then this scroll
// view will not be associated with the NestedScrollView.
// The PageStorageKey should be unique to this ScrollView;
// it allows the list to remember its scroll position when
// the tab view is not on the screen.
key: PageStorageKey<String>(name),
slivers: <Widget>[
SliverOverlapInjector(
// This is the flip side of the SliverOverlapAbsorber above.
handle:
NestedScrollView.sliverOverlapAbsorberHandleFor(
context),
),
SliverPadding(
padding: const EdgeInsets.all(8.0),
// In this example, the inner scroll view has
// fixed-height list items, hence the use of
// SliverFixedExtentList. However, one could use any
// sliver widget here, e.g. SliverList or SliverGrid.
sliver: SliverFixedExtentList(
// The items in this example are fixed to 48 pixels
// high. This matches the Material Design spec for
// ListTile widgets.
itemExtent: 60.0,
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
// This builder is called for each child.
// In this example, we just number each list item.
return Container(
color: Color((math.Random().nextDouble() *
0xFFFFFF)
.toInt() <<
0)
.withOpacity(1.0));
},
// The childCount of the SliverChildBuilderDelegate
// specifies how many children this inner list
// has. In this example, each tab has a list of
// exactly 30 items, but this is arbitrary.
childCount: 30,
),
),
),
],
);
},
),
);
}).toList(),
),
),
),
),
);
}
}