From Javadoc we know that APPLICATION_MODAL modality type "Defines a modal window that blocks events from being delivered to any other application window."

We have possibility to programmly create two children of current window: application modal and window modal. Thus, first children must block second.

Use attached application. In the first window press "init". In the second press "APPWIN" button. There will be two children windows, first is APP and second is WINDOW. First must block the second, but it is not true.