listen method

VoidCallback listen(
  1. ValueChanged<T> onValue
)

Listens to ValueListenable and returns a VoidCallback remover.

Example:

final notifier = ValueNotifier(0);

final remover = notifier.listen((value) => print(value));
notifier.value = 1; // prints 1

remover(); // removes the listener
notifier.value = 2; // does not print

Implementation

VoidCallback listen(ValueChanged<T> onValue) {
  void listener() {
    onValue(value);
  }

  addListener(listener);
  return () => removeListener(listener);
}