DeferredStartListening<T, R> typedef Null safety

DeferredStartListening<T, R> = VoidCallback Function(InheritedContext<R> context, void setState(R value), T controller, R? value)

A callback used to handle the subscription of controller.

It is expected to start the listening process and return a callback that will later be used to stop that listening.

See also:

Implementation

typedef DeferredStartListening<T, R> = VoidCallback Function(
  InheritedContext<R> context,
  void Function(R value) setState,
  T controller,
  R? value,
);