I imagine that this would be related to separating your GUI code from your “business logic”/“effects”. You can make a rule that code should only ever invoke wi

I imagine that this would be related to separating your GUI code from your “business logic”/“effects”. You can make a rule that code should only ever invoke widget code if it “owns” that widget. Then, have the code “owning” your widget be responsible for both showing and hiding the widget. That code then always knows when to invoke cleanup for related resources.