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;
}

Began life as a copy of #1006894