TabController class - material library

Coordinates tab selection between a TabBar and a TabBarView.

The index property is the index of the selected tab and the animation represents the current scroll positions of the tab bar and the tab bar view. The selected tab's index can be changed with animateTo.

A stateful widget that builds a TabBar or a TabBarView can create a TabController and share it directly.

When the TabBar and TabBarView don't have a convenient stateful ancestor, a TabController can be shared by providing a DefaultTabController inherited widget.

link

class MyTabbedPage extends StatefulWidget {
  const MyTabbedPage({ super.key });
  @override
  State<MyTabbedPage> createState() => _MyTabbedPageState();
}

class _MyTabbedPageState extends State<MyTabbedPage> with SingleTickerProviderStateMixin {
  static const List<Tab> myTabs = <Tab>[
    Tab(text: 'LEFT'),
    Tab(text: 'RIGHT'),
  ];

  late TabController _tabController;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(vsync: this, length: myTabs.length);
  }

 @override
 void dispose() {
   _tabController.dispose();
   super.dispose();
 }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        bottom: TabBar(
          controller: _tabController,
          tabs: myTabs,
        ),
      ),
      body: TabBarView(
        controller: _tabController,
        children: myTabs.map((Tab tab) {
          final String label = tab.text!.toLowerCase();
          return Center(
            child: Text(
              'This is the $label tab',
              style: const TextStyle(fontSize: 36),
            ),
          );
        }).toList(),
      ),
    );
  }
}

link

To create a local project with this code sample, run:
flutter create --sample=material.TabController.2 mysample

Inheritance

Object
ChangeNotifier
TabController

Constructors

TabController({int initialIndex = 0, Duration? animationDuration, required int length, required TickerProvider vsync}): Creates an object that manages the state required by TabBar and a TabBarView.

Properties

animation → Animation<double>?: An animation whose value represents the current position of the TabBar's selected tab indicator as well as the scrollOffsets of the TabBar and TabBarView.
no setter
animationDuration → Duration: Controls the duration of TabController and TabBarView animations.
no setter
hashCode → int: The hash code for this object.
no setterinherited
hasListeners → bool: Whether any listeners are currently registered.
no setterinherited
index ↔ int: The index of the currently selected tab.
getter/setter pair
indexIsChanging → bool: True while we're animating from previousIndex to index as a consequence of calling animateTo.
no setter
length → int: The total number of tabs.
final
offset ↔ double: The difference between the animation's value and index.
getter/setter pair
previousIndex → int: The index of the previously selected tab.
no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

addListener(VoidCallback listener) → void: Register a closure to be called when the object changes.
inherited
animateTo(int value, {Duration? duration, Curve curve = Curves.ease}) → void: Immediately sets index and previousIndex and then plays the animation from its current value to index.
dispose() → void: Discards any resources used by the object. After this is called, the object is not in a usable state and should be discarded (calls to addListener will throw after the object is disposed).
override
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
notifyListeners() → void: Call all the registered listeners.
inherited
removeListener(VoidCallback listener) → void: Remove a previously registered closure from the list of closures that are notified when the object changes.
inherited
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited