static JSlider jliveSlider(int min, int max, int def, final VF1<Int> f) {
  final JSlider slider = swingNu(JSlider.class, min, max, def);
  onChange(slider, new Runnable {
    int lastValue = slider.getValue();
    public void run {
      int value = slider.getValue();
      if (value != lastValue)
        pcallF(f, lastValue = value);
    }
  });
  ret slider;
}