sint packFrame_minw = 150, packFrame_minh = 50;

static <A extends Component> A packFrame(final A c) {
  swing {
    Window w = getWindow(c);
    if (w != null) {
      w.pack();
      int maxW = getScreenWidth()-50, maxH = getScreenHeight()-50;
      w.setSize(
        min(maxW, max(w.getWidth(), packFrame_minw)),
        min(maxH, max(w.getHeight(), packFrame_minh)));
    }
  }
  ret c;
}

static JFrame packFrame(ButtonGroup g) {
  ret packFrame(getFrame(g));
}