protected void actionPerformed() {
		Swing.runLater(() -> showPopup());
	}
This method is called when the user clicks the button <B>when this action is used as a 
custom button provider and not installed into the default {@link DockingAction} framework.
</B> 

This is the callback to be overridden when the child wishes to respond to user button
presses that are on the button and not the drop-down.  The default behavior is to show the
popup menu when the button is clicked.
Ghidra/Framework/Docking/src/main/java/docking/menu/NonToolbarMultiStateAction.java