public void paint(Graphics2D g2d) {
    Dimension dimension = getDimension();

    BufferedImage mainStage = createMainStage();
    g2d.drawImage(mainStage, null, null);
    Color progressbarBackgroundColor = new Color(basicColor);
    Color progressbarShadowStartColor =
        ColorUtils.overwriteAlpha(
            ColorUtils.adjustLightness(progressbarBackgroundColor, 0.7f), 0.6f);
    Color progressbarShadowEndColor =
        ColorUtils.overwriteAlpha(
            ColorUtils.adjustLightness(progressbarBackgroundColor, 0.3f), 0.6f);
    // paint a shadow in the form of semi-transparent gradient
    g2d.setPaint(
        new GradientPaint(0, 0, progressbarShadowStartColor, 0, 7, progressbarShadowEndColor));
    g2d.fillRect(0, 0, dimension.width, 7);
  }
  /**
   * Creates a main stage for progress bar background.
   *
   * @param context resource context
   * @return a <code>BufferedImage</code> object
   */
  private BufferedImage createMainStage() {
    Color progressbarBackgroundColor = new Color(basicColor);
    Color progressbarSpiralColor = ColorUtils.adjustLightness(progressbarBackgroundColor, 0.2f);

    Dimension dimension = getDimension();
    BufferedImage retVal = getImageType().createImage(dimension.width, dimension.height * 2);
    Graphics g = retVal.getGraphics();
    try {
      g.setColor(progressbarBackgroundColor);
      g.fillRect(0, 0, dimension.width, dimension.height * 2);
      g.setColor(progressbarSpiralColor);
      for (int k : new int[] {-24, 0, 24, 48, 72}) {
        g.fillPolygon(new int[] {0, 24, 24, 0}, new int[] {24 + k, k, 12 + k, 36 + k}, 4);
      }
    } finally {
      if (g != null) {
        g.dispose();
      }
    }

    return retVal;
  }