stateOf<T> method

ValueState<T> stateOf<T>(
  1. T create(), {
  2. Key? key,
  3. StateMode mode = .watch,
  4. dynamic onDispose(
    1. T
    )?,
})

Retrieves or lazily creates a state of type T, and binds its ValueState lifecycle to this BuildContext's widget lifecycle.

onDispose is called with the current value when the state is removed from its scope and disposed.

Implementation

ValueState<T> stateOf<T>(
  T Function() create, {
  Key? key,
  StateMode mode = .watch,
  Function(T)? onDispose,
}) {
  final element = getElementForInheritedWidgetOfExactType<StateScope>();

  if (element is! StateScopeElement) {
    throw FlutterError(
      'StateScope was not found above this BuildContext.\n'
      'Place StateScope above this context or use ServiceScope.withState.',
    );
  }

  final dependent = this as Element;
  final id = StateId(element: dependent, key: key, type: T);
  return element.ensureState<T>(dependent, id, mode, create, onDispose);
}