How to use

lengthProperty

method

in

javafx.scene.shape.Arc

private KeyFrame[] getKeyFrames(double angle, double duration, Paint color) {
  KeyFrame[] frames = new KeyFrame[4];
  frames[0] = new KeyFrame(Duration.seconds(duration),
    new KeyValue(arc.lengthProperty(), 5, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 45 + control.getStartingAngle(),
      Interpolator.LINEAR));
  frames[1] = new KeyFrame(Duration.seconds(duration + 0.4),
    new KeyValue(arc.lengthProperty(), 250, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 90 + control.getStartingAngle(),
      Interpolator.LINEAR));
  frames[2] = new KeyFrame(Duration.seconds(duration + 0.7),
    new KeyValue(arc.lengthProperty(), 250, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 135 + control.getStartingAngle(),
      Interpolator.LINEAR));
  frames[3] = new KeyFrame(Duration.seconds(duration + 1.1),
    new KeyValue(arc.lengthProperty(), 5, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 435 + control.getStartingAngle(),
      Interpolator.LINEAR),
    new KeyValue(arc.strokeProperty(), color, Interpolator.EASE_BOTH));
  return frames;
}

new KeyValue(arc.lengthProperty(), 5, Interpolator.LINEAR),
new KeyValue(arc.startAngleProperty(),
  1845 + control.getStartingAngle(),

private KeyFrame[] getKeyFrames(double angle, double duration, Paint color) {
  KeyFrame[] frames = new KeyFrame[4];
  frames[0] = new KeyFrame(Duration.seconds(duration),
    new KeyValue(arc.lengthProperty(), 5, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 45 + control.getStartingAngle(),
      Interpolator.LINEAR));
  frames[1] = new KeyFrame(Duration.seconds(duration + 0.4),
    new KeyValue(arc.lengthProperty(), 250, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 90 + control.getStartingAngle(),
      Interpolator.LINEAR));
  frames[2] = new KeyFrame(Duration.seconds(duration + 0.7),
    new KeyValue(arc.lengthProperty(), 250, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 135 + control.getStartingAngle(),
      Interpolator.LINEAR));
  frames[3] = new KeyFrame(Duration.seconds(duration + 1.1),
    new KeyValue(arc.lengthProperty(), 5, Interpolator.LINEAR),
    new KeyValue(arc.startAngleProperty(),
      angle + 435 + control.getStartingAngle(),
      Interpolator.LINEAR),
    new KeyValue(arc.strokeProperty(), color, Interpolator.EASE_BOTH));
  return frames;
}

new KeyValue(arc.lengthProperty(), 5, Interpolator.LINEAR),
new KeyValue(arc.startAngleProperty(),
  1845 + control.getStartingAngle(),