dispose method

@override void dispose()

Disposes this disposable and any resources it has open.

Implementation

@override
void dispose() {
  overlayElement.remove();
  if (_onVisibleController != null) {
    _onVisibleController!.close();
  }
  if (_delegatePortalHost.hasAttached == true) {
    _delegatePortalHost.dispose();
  }
  _stateUpdateListener.cancel();
}