JProgressBarの不確定状態でのアニメーションパターンを変更する

class StripedProgressBarUI extends BasicProgressBarUI {
  private final boolean dir;
  private final boolean slope;
  public StripedProgressBarUI(boolean dir, boolean slope) {
    super();
    this.dir = dir;
    this.slope = slope;
  }

  @Override protected int getBoxLength(
        int availableLength, int otherDimension) {
    return availableLength; // (int) Math.round(availableLength / 6d);
  }

  @Override public void paintIndeterminate(Graphics g, JComponent c) {
    if (!(g instanceof Graphics2D)) {
      return;
    }

    Insets b = progressBar.getInsets(); // area for border
    int barRectWidth  = progressBar.getWidth() - b.right - b.left;
    int barRectHeight = progressBar.getHeight() - b.top - b.bottom;

    if (barRectWidth <= 0 || barRectHeight <= 0) {
      return;
    }

    Graphics2D g2 = (Graphics2D) g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);

    // Paint the striped box.
    boxRect = getBox(boxRect);
    if (boxRect != null) {
      int w = 10;
      int x = getAnimationIndex();
      GeneralPath p = new GeneralPath();
      if (dir) {
        p.moveTo(boxRect.x,           boxRect.y);
        p.lineTo(boxRect.x + w * .5f, boxRect.y + boxRect.height);
        p.lineTo(boxRect.x + w,       boxRect.y + boxRect.height);
        p.lineTo(boxRect.x + w * .5f, boxRect.y);
      } else {
        p.moveTo(boxRect.x,           boxRect.y + boxRect.height);
        p.lineTo(boxRect.x + w * .5f, boxRect.y + boxRect.height);
        p.lineTo(boxRect.x + w,       boxRect.y);
        p.lineTo(boxRect.x + w * .5f, boxRect.y);
      }
      p.closePath();
      g2.setColor(progressBar.getForeground());
      if (slope) {
        for (int i = boxRect.width + x; i > -w; i -= w) {
          g2.fill(AffineTransform.getTranslateInstance(i, 0)
                                 .createTransformedShape(p));
        }
      } else {
        for (int i = -x; i < boxRect.width; i += w) {
          g2.fill(AffineTransform.getTranslateInstance(i, 0)
                                 .createTransformedShape(p));
        }
      }
    }
  }
}