I have a SliverAppBar.large and Tab inside NestedScrollView. However the app bar not displaying properly. Title in app bar hides behind Tabs and a padding above appbar title is present while scrolling. Is this a bug ?
class MyStatelessWidget extends StatelessWidget {
const MyStatelessWidget({super.key});
#override
Widget build(BuildContext context) {
final List<String> tabs = <String>['Tab 1', 'Tab 2'];
return DefaultTabController(
length: tabs.length,
child: Scaffold(
body: NestedScrollView(
headerSliverBuilder: (context, innerBoxIsScrolled) {
return <Widget>[
SliverOverlapAbsorber(
handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
sliver: SliverAppBar.large(
leading: const Icon(Icons.arrow_back),
title: const Text('Books'),
forceElevated: innerBoxIsScrolled,
bottom: TabBar(
tabs: tabs.map((name) => Tab(text: name)).toList(),
),
),
),
];
},
body: TabBarView(
children: tabs.map((name) {
return SafeArea(
top: false,
bottom: false,
child: Builder(
builder: (context) {
return CustomScrollView(
key: PageStorageKey<String>(name),
slivers: <Widget>[
SliverOverlapInjector(
handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
),
SliverPadding(
padding: const EdgeInsets.all(8.0),
sliver: SliverFixedExtentList(
itemExtent: 48.0,
delegate: SliverChildBuilderDelegate(
(context, index) {
return ListTile(
title: Text('Item $index'),
);
},
childCount: 30,
),
),
),
],
);
},
),
);
}).toList(),
),
),
),
);
}
}
Related
The glow acts like the entire screen is a list. There some way that I can put the glow below the appbar? (edit: without losing the floating effect of the appbar)
CustomScrollView(
slivers: <Widget>[
SliverAppBar(
title: Text('Home Scree'),
floating: true,
leading: Icon(Icons.alarm),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(ctx, i) {
return Column(
children: <Widget>[
ProductCard(),
Divider(
height: 0,
thickness: 1,
),
],
);
},
childCount: 10,
),
),
],
),
Maybe you can try to use NestedScrollView,like this:
#override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return [SliverAppBar(
leading: Icon(Icons.alarm),
title: Text('Home Scree'),
expandedHeight: kToolbarHeight,
floating: true,
)];
},
body: ListView.builder(
padding: EdgeInsets.zero,
itemCount: 10,
itemBuilder: (context, index) {
return Column(
children: <Widget>[
ProductCard(),
Divider(
height: 0,
thickness: 1,
),
],
);
}),
),
);
}
I've been investigating SliverAppBar, CustomScrollView, NestedScrollView, SliverPersistentHeader, and more. I cannot find a way to build something like the Instagram user profile screen's header where only the tab bar is pinned. The main body of the screen is a TabBarView and each pane has a scrollable list.
With SliverAppBar, it is easy to add the TabBar in the bottom parameter. But I want to have an extra widget of unknown/variable height above that TabBar. The extra widget should scroll out of the way when the page is scrolled and and then the TabBar is what is pinned at the top of the screen.
All I could manage was a fixed content before the tab bar and a fixed tab bar. I cannot get the header to scroll up and stick the TabBar at the top just just below the AppBar.
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: MyApp()));
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return DefaultTabController(
length: 2,
child: Scaffold(
appBar: AppBar(
title: Text("pabloaleko"),
),
body: CustomScrollView(
physics: const BouncingScrollPhysics(),
slivers: <Widget>[
SliverToBoxAdapter(
child: SafeArea(
child: Text("an unknown\namount of content\n goes here in the header"),
),
),
SliverToBoxAdapter(
child: TabBar(
tabs: [
Tab(child: Text('Days', style: TextStyle(color: Colors.black))),
Tab(child: Text('Months', style: TextStyle(color: Colors.black))),
],
),
),
SliverFillRemaining(
child: TabBarView(
children: [
ListView(
children: <Widget>[
ListTile(title: Text('Sunday 1')),
ListTile(title: Text('Monday 2')),
ListTile(title: Text('Tuesday 3')),
ListTile(title: Text('Wednesday 4')),
ListTile(title: Text('Thursday 5')),
ListTile(title: Text('Friday 6')),
ListTile(title: Text('Saturday 7')),
ListTile(title: Text('Sunday 8')),
ListTile(title: Text('Monday 9')),
ListTile(title: Text('Tuesday 10')),
ListTile(title: Text('Wednesday 11')),
ListTile(title: Text('Thursday 12')),
ListTile(title: Text('Friday 13')),
ListTile(title: Text('Saturday 14')),
],
),
ListView(
children: <Widget>[
ListTile(title: Text('January')),
ListTile(title: Text('February')),
ListTile(title: Text('March')),
ListTile(title: Text('April')),
ListTile(title: Text('May')),
ListTile(title: Text('June')),
ListTile(title: Text('July')),
ListTile(title: Text('August')),
ListTile(title: Text('September')),
ListTile(title: Text('October')),
ListTile(title: Text('November')),
ListTile(title: Text('December')),
],
),
],
),
),
],
),
),
);
}
}
You can achieve this behaviour using NestedScrollView with Scaffold.
As we need the widgets between the AppBar and TabBar to be dynamically built and scrolled until TabBar reaches AppBar, use the appBar property of the Scaffold to build your AppBar and use headerSliverBuilder to build other widgets of unknown heights. Use the body property of NestedScrollView to build your tab views.
This way the elements of the headerSliverBuilder would scroll away till the body reaches the bottom of the AppBar.
Might be a little confusing to understand with mere words, here is an example for you.
Code:
// InstaProfilePage
class InstaProfilePage extends StatefulWidget {
#override
_InstaProfilePageState createState() => _InstaProfilePageState();
}
class _InstaProfilePageState extends State<InstaProfilePage> {
double get randHeight => Random().nextInt(100).toDouble();
List<Widget> _randomChildren;
// Children with random heights - You can build your widgets of unknown heights here
// I'm just passing the context in case if any widgets built here needs access to context based data like Theme or MediaQuery
List<Widget> _randomHeightWidgets(BuildContext context) {
_randomChildren ??= List.generate(3, (index) {
final height = randHeight.clamp(
50.0,
MediaQuery.of(context).size.width, // simply using MediaQuery to demonstrate usage of context
);
return Container(
color: Colors.primaries[index],
height: height,
child: Text('Random Height Child ${index + 1}'),
);
});
return _randomChildren;
}
#override
Widget build(BuildContext context) {
return Scaffold(
// Persistent AppBar that never scrolls
appBar: AppBar(
title: Text('AppBar'),
elevation: 0.0,
),
body: DefaultTabController(
length: 2,
child: NestedScrollView(
// allows you to build a list of elements that would be scrolled away till the body reached the top
headerSliverBuilder: (context, _) {
return [
SliverList(
delegate: SliverChildListDelegate(
_randomHeightWidgets(context),
),
),
];
},
// You tab view goes here
body: Column(
children: <Widget>[
TabBar(
tabs: [
Tab(text: 'A'),
Tab(text: 'B'),
],
),
Expanded(
child: TabBarView(
children: [
GridView.count(
padding: EdgeInsets.zero,
crossAxisCount: 3,
children: Colors.primaries.map((color) {
return Container(color: color, height: 150.0);
}).toList(),
),
ListView(
padding: EdgeInsets.zero,
children: Colors.primaries.map((color) {
return Container(color: color, height: 150.0);
}).toList(),
)
],
),
),
],
),
),
),
);
}
}
Output:
Hope this helps!
Another solution is that you could use a pinned SliverAppBar with FlexibleSpaceBar within DefaultTabController. Sample codes:
Scaffold(
body: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder: (context, value) {
return [
SliverAppBar(
floating: true,
pinned: true,
bottom: TabBar(
tabs: [
Tab(text: "Posts"),
Tab(text: "Likes"),
],
),
expandedHeight: 450,
flexibleSpace: FlexibleSpaceBar(
collapseMode: CollapseMode.pin,
background: Profile(), // This is where you build the profile part
),
),
];
},
body: TabBarView(
children: [
Container(
child: ListView.builder(
itemCount: 100,
itemBuilder: (context, index) {
return Container(
height: 40,
alignment: Alignment.center,
color: Colors.lightBlue[100 * (index % 9)],
child: Text('List Item $index'),
);
},
),
),
Container(
child: ListView.builder(
itemCount: 100,
itemBuilder: (context, index) {
return Container(
height: 40,
alignment: Alignment.center,
color: Colors.lightBlue[100 * (index % 9)],
child: Text('List Item $index'),
);
},
),
),
],
),
),
),
),
Before scrolling:
After scrolling:
I'm trying to implement a custom tab bar widget inside a SliverAppBar. So far I've tried wrapping my CustomTabBar within a PreferredSize widget.
Here's my code:
Widget _buildBody(){
return NestedScrollView(
headerSliverBuilder: (BuildContext context, bool boxIsScrolled) {
return <Widget>[
SliverAppBar(
leading: Container(),
backgroundColor: Colors.transparent,
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
collapseMode: CollapseMode.pin,
background: Column(
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Text(
"Item 1"
),
Text(
"Item 2"
),
Text(
"Item 3"
)
],
)
]),
),
bottom: PreferredSize(
preferredSize: Size.fromHeight(kToolbarHeight),
child: CustomTabWidget(
items: ['Challenge', 'My friends'],
activeColor: secondaryColor,
currentIndex: currentIndex,
backgroundColor: tabColor,
activeTextColor: Colors.white,
backgroundTextColor: Colors.white,
onTabSelect: (int index) {
onLeaderboardTabSelect(index);
},
),
),];
},
body: ListView.separated(
itemCount: 50,
itemBuilder: (context, index) {
return ListTile(
title: Text('row $index'),
);
},
separatorBuilder: (context, index) {
return Divider();
},
) // should return listview depending on the tab
);
}
CustomTabWidget
Widget build(BuildContext context) {
return Container(
height: height,
decoration: BoxDecoration(
color: backgroundColor,
borderRadius: BorderRadius.circular(
30.0,
),
),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: _buildItems(context),
),
);
}
The code successfully shows the my custom tab bar widget but whenever I scroll down or tap another tab, it disappears.
I might have overlooked something within the code.
Can anyone help me?
this work on my project
class TabBarInSliverAppbar extends StatelessWidget {
#override
Widget build(BuildContext context) {
return DefaultTabController(
length: 2,
child: Scaffold(
body: CustomScrollView(
slivers: [
SliverAppBar(
title: Text("Tabbar in SliverAppbar Example"),
pinned: true,
floating: true,
bottom: TabBar(
tabs: <Widget>[
Tab(
text: "First Tab",
),
Tab(
text: "Second Tab",
),
],
),
),
SliverToBoxAdapter(
child: TabBarView(
children: <Widget>[
Center(
child: Text("First Tab"),
),
Center(
child: Text("Second Tab"),
),
],
),
),
],
),
),
);
}
}
you can also checki this link :Flutter TabBar and SliverAppBar that hides when you scroll down
How add build collapsing app bar with pinned tabBar in Flutter like in this GIF
I managed to build it like so
class Test extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: DefaultTabController(
length: 2,
child: NestedScrollView(
headerSliverBuilder: (context, value) {
return [
SliverAppBar(
floating: true,
pinned: true,
title: Text('Test'),
bottom: TabBar(
tabs: [
Tab( text: "Call"),
Tab( text: "Message"),
],
),
),
];
},
body: TabBarView(
children: [
Container(child: ListView.builder(
itemCount: 100,
itemBuilder: (context,index){
return Text("Item $index");
})),
Container(child: ListView.builder(
itemCount: 100,
itemBuilder: (context,index){
return Text("Item $index");
})),
],
),
),
),
);
}
}
You can use the SilverAppBar
SliverAppBar(
expandedHeight: 150.0,
floating:true,
pinned: true,
flexibleSpace: const FlexibleSpaceBar(
title: Text('Available seats'),
),
actions: <Widget>[
IconButton(
icon: const Icon(Icons.add_circle),
tooltip: 'Add new entry',
onPressed: () { /* ... */ },
),
]
)
References
SliverAppBar Class
SliverAppBar Widget of the week
Keep the TabBarView seperate from the SliverAppBar.
Make it look continuous by setting SliverAppBar's elevation to 0 and use shadow or elevation for the TabBarView, whatever you prefer.
Wrapping TabBarView with SliverFillRemaining (fill remaining empty space like Expanded) gives the following error output.
flutter: A RenderPositionedBox expected a child of type RenderBox but received a child of type
flutter: RenderSliverList.
TabController tabContoller;
#override
void initState() {
tabContoller = new TabController(
vsync: this,
length: 3,
);
#override
Widget build(BuildContext context) {
return new Scaffold(
floatingActionButton:floatActionBtn(...),
bottomNavigationBar: bottomNavigationBar(...),
appBar: apBar(),
body: Stack(
children: <Widget>[
CustomScrollView(
slivers: <Widget>[
SliverAppBar(
backgroundColor: Colors.transparent,
automaticallyImplyLeading: false,
expandedHeight: 195.0,
flexibleSpace: FlexibleSpaceBar(
background: new Stack(
children: <Widget>[
...
]),
),
),
new SliverFillRemaining(
child: TabBarView(
controller: tabContoller,
children: <Widget>[
Tab(...),
Tab(...),
Tab(...)
],
),
),
],
),
],
)
Don't forget the DefaultTabController, this code is working fine:
#override
Widget build(BuildContext context) {
return DefaultTabController(
length: 3,
child: Container(
child: CustomScrollView(slivers: <Widget>[
SliverAppBar(),
new SliverFillRemaining(
child: TabBarView(
children: <Widget>[
Text("Tab 1"),
Text("Tab 2"),
Text("Tab 3"),
],
),
),
])),
);
}
You can use NestedScrollView like this
#override
Widget build(BuildContext context) {
return DefaultTabController(
length: 3,
child: Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
forceElevated: innerBoxIsScrolled,
automaticallyImplyLeading: false,
expandedHeight: 195.0,
flexibleSpace: FlexibleSpaceBar(
),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(_, int index) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
TabBar(
labelColor: AppColors.black,
unselectedLabelColor: AppColors.gray,
indicatorColor: AppColors.primaryColor,
indicatorWeight: 4,
indicatorPadding: EdgeInsets.symmetric(horizontal: 16),
labelPadding: EdgeInsets.zero,
tabs: [
Text("FIRST"),
Text("SECOND"),
Text("THIRD"),
],
)
],
);
},
childCount: 1,
),
),
];
},
body: TabBarView(
children: <Widget>[
Text("FIRST TAB"),
Text("SECOND TAB"),
Text("THIRD TAB"),
],
),
),
),
);
}