useValueChanged<T, R> function

R? useValueChanged<T, R>(
  1. T value,
  2. R? valueChange(
    1. T oldValue,
    2. R? oldResult

Watches a value and triggers a callback whenever the value changed.

useValueChanged takes a valueChange callback and calls it whenever value changed. valueChange will not be called on the first useValueChanged call.

useValueChanged can also be used to interpolate Whenever useValueChanged is called with a different value, calls valueChange. The value returned by useValueChanged is the latest returned value of valueChange or null.

The following example calls AnimationController.forward whenever color changes

AnimationController controller;
Color color;

useValueChanged(color, (_, __) {


R? useValueChanged<T, R>(
  T value,
  R? Function(T oldValue, R? oldResult) valueChange,
) {
  return use(_ValueChangedHook(value, valueChange));