popupMenu.setLayout(new GridBagLayout());
popupMenu.setLayout(new DefaultMenuLayout(popupMenu, BoxLayout.Y_AXIS));
  public void installUI(JComponent c)  {    super.installUI(c);    popupMenu = (JPopupMenu) c;    popupMenu.setLayout(new GridBagLayout());    popupMenu.setBorderPainted(true);    JPopupMenu.setDefaultLightWeightPopupEnabled(true);    installDefaults();    installListeners();  }