onDispose method

VoidCallback onDispose(
  1. VoidCallback callback
)

Registers a callback to be called when the beacon is disposed. Returns a function that can be called to remove the callback.

Implementation

VoidCallback onDispose(VoidCallback callback) {
  assert(!_isDisposed, 'Cannot add a dispose callback to a disposed beacon.');

  _disposeCallbacks.add(callback);

  return () {
    _disposeCallbacks.remove(callback);
  };
}