// f: voidfunc(float)
static JSlider liveSliderZeroToOne(final float def, fO f) {
  ret swing(func -> JSlider {
    final int max = 9999;
    final JSlider slider = new JSlider(0, max, iround(def*max));
    slider.addChangeListener(new ChangeListener {
      int lastValue = slider.getValue();
      public void stateChanged(ChangeEvent e) {
        int value = slider.getValue();
        if (value != lastValue) {
          lastValue = value;
          float x = value/(float) max;
          setToolTip(slider, str(x));
          pcallF(f, x);
        }
      }
    });
    ret slider;
  });
}