@Override
		public void mouseEntered(MouseEvent e) {
			if (popupIsShowing()) {
				return;
			}

			for (MouseListener listener : parentListeners) {
				listener.mouseEntered(e);
			}
		}
Show a popup containing all the actions below the button

@return the popup menu that was shown
Ghidra/Framework/Docking/src/main/java/docking/menu/MultiStateButton.java