static <A extends Component> A onResize(A c, Runnable r) {
  if (c != null && r != null) swing {
    c.addComponentListener(new ComponentAdapter {
      public void componentResized(ComponentEvent e) {
        pcallF(r);
      }
    });
  }
  ret c;
}

static <A extends Component> A onResize(Runnable r, A c) {
  ret onResize(c, r);
}