Swing/RatingLabel のバックアップ(No.9)

private final ImageProducer ip = orgIcon.getImage().getSource();
private ImageIcon makeStarImageIcon(float[] filter) {
  SelectedImageFilter sif = new SelectedImageFilter(filter);
  return new ImageIcon(
    createImage(new FilteredImageSource(ip, sif)));
}
private class SelectedImageFilter extends RGBImageFilter {
  private final float[] filter;
  public SelectedImageFilter(float[] filter) {
    this.filter = filter;
    canFilterIndexColorModel = true;
  }
  public int filterRGB(int x, int y, int argb) {
    Color color = new Color(argb, true);
    float[] array = new float[4];
    color.getComponents(array);
    return new Color(array[0]*filter[0],
                     array[1]*filter[1],
                     array[2]*filter[2],
                     array[3]).getRGB();
  }
}