Description Steffen Kriese 2010-10-18 10:43:26 EDT

A call to notifyListeners(SWT.Dispose, event) on any widget, results in a ClassCastException. To reproduce it, just add the following lines to a widget like Text:

final Event newEvent = new Event();
newEvent.widget = this;
newEvent.type = SWT.Dispose;
newEvent.display = getDisplay();
notifyListeners(SWT.Dispose, newEvent);

This bug can also be reproduced by using the Riena ExampleClient and then go to Playground => Playground => Combos => CompletionCombo. 

Widget.notfyListener() calls UntypedEventAdapter.notifyListeners( final int eventType, final Event event ) which checks if it is a DisposeEventType and then tries to create a new DisposeEvent(event). DisposeEvent has a single argument constructor of type object, but the super constructor in TypedEvent expects the first parameter to be a widget. This of course results in a ClassCastException, because we passed in a Event instead of a Widget.

In my opinion UntypedEventAdapter should pass the widget from the source event to the new created DisposeEvent like: 


...
case SWT.Dispose:
        typedEvent = new DisposeEvent( event.widget);
  ...