I have two ListViews
rendering inside of a TabBarView
using a TabController
.
How do I preserve state (for lack of a better word) between each ListView
so that: 1.) the Widgets don't rebuild and 2.) the ListView
position is remembered between tabs.
class AppState extends State<App> with SingleTickerProviderStateMixin {
TabController _tabController;
@override
void initState() {
super.initState();
_tabController = new TabController(
vsync: this,
length: _allPages.length,
);
}
@override
void dispose() {
_tabController.dispose();
super.dispose();
}
Widget _buildScaffold(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('headlines'),
bottom: new TabBar(
controller: _tabController,
isScrollable: true,
tabs: _allPages
.map((_Page page) => new Tab(text: page.country))
.toList()),
),
body: new TabBarView(
controller: _tabController,
children: _allPages.map((_Page page) {
return new SafeArea(
top: false,
bottom: false,
child: new Container(
key: new ObjectKey(page.country),
child: new Newsfeed(country: page.country),
),
);
}).toList()),
);
}
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'news app',
home: _buildScaffold(context),
);
}
}
In case you want to keep the state of your screen in your TabBarView
, you can use the mixin class called AutomaticKeepAliveClientMixin
in your State class.
After that you have to override the wantKeepAlive
method and return true
.
I wrote a post about that here: https://medium.com/@diegoveloper/flutter-persistent-tab-bars-a26220d322bc