static AutoCloseable tempOnFrameIconified(Component c, fO r) {
  ret c == null ? null : swing(() -> {
    JFrame f = getFrame(c);
    if (f == null) null;
    WindowListener l = new WindowAdapter {
      public void windowIconified(WindowEvent e) {
        temp tempRememberListener(f, 'removeWindowListener, this);
        pcallF(r);
      }
    };
    f.addWindowListener(l);
    ret autoCloseable { swing { f.removeWindowListener(l); } };
  });
}