thechiselgroup/biomixer — comment on commit ada26bc557a9aba9d7a1eb6d5b789521e5ddbd04
File: biomixer/src/org/thechiselgroup/biomixer/client/core/ui/widget/listbox/VisibilityChangeEvent.java line 0
By lgrammel:

The event should include the visibility state (boolean). Having explicit event classes is your call if the state is as simple as a boolean value. They make the design explicit and help you to identify the source of the event, but they are also more code than what might be required.