I keep getting "Widget is already disposed" errors from time to time.
I believe it's because threads are updating windows which are already
closed or something.
Two questions:
* Is there a common way get around such Exceptions, or does
(threading) complexity simply add such errors?
* If the way around is about calling "isDisposed()" on the offending
widgets: Can this call be safe? It could return "false" but when I do
the operation on the widgets later in the code, it could be disposed
meanwhile.