progressTimeline.addPropertyToInterpolate("position", getStartX(), getEndX());
KeyValues<Float> alphaValues = KeyValues.create(0.0f, 1.0f, 1.0f, 0.0f);
KeyTimes alphaTimes = new KeyTimes(0.0f, 0.3f, 0.7f, 1.0f);
progressTimeline.addPropertyToInterpolate("alpha", new KeyFrames<Float>(alphaValues, alphaTimes));
progressTimeline.setDuration(1500);
swingProgressTimeline = new SwingRepaintTimeline(this);
}