sint packFrame_minw = 150, packFrame_minh = 50;

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

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