sclass ScreenOverlay is AutoCloseable {
  JWindow window;
  Color bgColor = colorWithAlpha(Color.blue, .5);
  settable Rect bounds;
  settable bool hideOnMouseOver;
  settable Component component;
  
  void show() swing {
    if (window == null) {
      if (usingJTattoo())
        warn("Screen overlays don't really work with JTattoo");
        
      assertNotNull(+bounds);
      window = new JWindow;
      window.setBackground(bgColor);
      main setBounds(window, bounds);
      window.setAlwaysOnTop(true);
      if (component != null) window.add(component);
      
      disposeWindowOnClick(window);
    
      if (hideOnMouseOver)
        addMouseListener(getContentPane(window), new MouseAdapter {
          @Override
          public void mouseEntered(MouseEvent e) {
            hide();
          }
        });
    }

    window.setVisible(true);
  }
  
  public void hide aka close() swing {
    if (window == null) ret;
    window.setVisible(false);
  }
}