public MultipleGradientPaint calculateGradient() {
List<Thumb<Color>> stops = getStops();
int len = stops.size();
// set up the data for the gradient
float[] fractions = new float[len];
Color[] colors = new Color[len];
int i = 0;
for (Thumb<Color> thumb : stops) {
colors[i] = (Color) thumb.getObject();
fractions[i] = thumb.getPosition();
i++;
}
// get the final gradient
this.setGradient(calculateGradient(fractions, colors));
return getGradient();
}