Since Frame is a subclass of java.awt.Frame, which is a subclass of java.awt.Window, you can listen for window events with its event mechanism. Import the jinfo class to inspect the event properties of Frame (JFrame's superclass).
>>> import jinfo >>> from java.awt import Frame >>> jinfo.getEventsInfo(Frame) 
As you can see, Frame has no event properties, because its events are defined from its base class, java.awt.Window.
>>> Frame.superclass <jclass java.awt.Window at 228949474>
Therefore, we need to inspect Window's event properties.
>>> jinfo.getEventsInfo(Window) [<beanEventProperty windowIconified for event interface java.awt.event.WindowListener at 861240813>, <beanEventProperty WindowActivated for event ...