sclass MouseInComponentMonitor extends BoolVarWithNotify is MouseMotionListener {
  JComponent component;
  
  *(JComponent *component) {
    addMouseMotionListener(component, this);
  }
  
  public void mouseEntered(MouseEvent e) { set(true); }
  public void mouseExited(MouseEvent e) { set(false); }
  public void mouseMoved(MouseEvent e) { set(true); }
  public void mouseDragged(MouseEvent e) { set(true); }
}