static JPanel jTiledBackground_trackWidth(S imageID) {

  ret jTiledBackground_trackWidth(loadImage2(imageID));

}

static JPanel jTiledBackground_trackWidth(final BufferedImage tileImage) {

  ret swing(func -> JPanel { ret new JPanel {

    protected void paintComponent(Graphics g) {  

      paintTiledBackground(this, g, tileImage);

    }

    public Dimension getPreferredScrollableViewportSize() { ret getPreferredSize(); }

    public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) { return 20; }

    public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) {

      ret (direction == SwingConstants.HORIZONTAL ? visibleRect.width : visibleRect.height)*5/6;

    }

    public bool getScrollableTracksViewportWidth() { true; }

    public bool getScrollableTracksViewportHeight() { false; }

  }; });

}

static JPanel jTiledBackground_trackWidth(S imageID, Component contents) {

  ret jTiledBackground_trackWidth(loadImage2(imageID), contents);

}

static JPanel jTiledBackground_trackWidth(BufferedImage tileImage, Component contents) {

  JPanel panel = jTiledBackground_trackWidth(tileImage);

  panel.setLayout(new BorderLayout);

  panel.add(BorderLayout.CENTER, jtransparent_recursive(contents));

  ret panel;

}