private void addMouseListener(Container c, MouseListener listener) {
		c.addMouseListener(listener);
		Component[] children = c.getComponents();
		for (Component element : children) {
			if (element instanceof Container) {
				addMouseListener((Container) element, listener);
			}
			else {
				element.addMouseListener(listener);
			}
		}
	}
Area where user can mouse without hiding the window (in screen coordinates).  A.K.A., the
mouse neutral zone.
Ghidra/Framework/Docking/src/main/java/docking/widgets/PopupWindow.java