// f: voidfunc(DoubleRange)
static RangeSlider rangeSliderZeroToOne(DoubleRange defRange, O f) {
  ret swing(func -> RangeSlider {
    int max = 9999;
    RangeSlider slider = new RangeSlider(0, max);
    rangeSliderSetZeroToOneDoubleRange(slider, max, defRange);
    slider.addChangeListener(new ChangeListener {
      DoubleRange lastValue = zeroToOneDoubleRangeFromRangeSlider(max, slider);
      public void stateChanged(ChangeEvent e) {
        DoubleRange value = zeroToOneDoubleRangeFromRangeSlider(max, slider);
        if (neq(value, lastValue)) {
          lastValue = value;
          setToolTip(slider, str(value));
          pcallF(f, value);
        }
      }
    });
    ret slider;
  });
}

Began life as a copy of #1005725