static JMenu addFullyDynamicMenu(Component c, S menuName, final VF1<JMenu> populate) {
  final JMenu m = addMenu(c, menuName);
  addMenuListener(m, new MenuListener {
    public void menuSelected(MenuEvent e) {
      clearMenu(m);
      callF(populate, m);
    }
    
    public void menuDeselected(MenuEvent e) {
      clearMenu(m);
    }
    
    public void menuCanceled(MenuEvent e) {
      clearMenu(m);
    }
  });
  ret m;
}