onShowOnScreen property

VoidCallback onShowOnScreen

The handler for SemanticsAction.showOnScreen.

A request to fully show the semantics node on screen. For example, this action might be send to a node in a scrollable list that is partially off screen to bring it on screen.

For elements in a scrollable list the framework provides a default implementation for this action and it is not advised to provide a custom one via this setter.

Implementation 

VoidCallback get onShowOnScreen => _onShowOnScreen;
void onShowOnScreen= (VoidCallback value)

Implementation 

set onShowOnScreen(VoidCallback value) {
  _addArgumentlessAction(SemanticsAction.showOnScreen, value);
  _onShowOnScreen = value;
}