Inverse the display position of JSlider's ticks and knobs

• download example.jar
• download src.zip
• repository

Code

class VerticalFlipLayerUI extends LayerUI<JComponent> {
  @Override public void paint(Graphics g, JComponent c) {
    if (c instanceof JLayer) {
      Graphics2D g2 = (Graphics2D) g.create();
      g2.setTransform(getAffineTransform(c.getSize()));
      super.paint(g2, c);
      g2.dispose();
    } else {
      super.paint(g, c);
    }
  }

  @Override public void installUI(JComponent c) {
    super.installUI(c);
    if (c instanceof JLayer) {
      JLayer<?> l = (JLayer<?>) c;
      l.setLayerEventMask(
          AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK);
    }
  }

  @Override public void uninstallUI(JComponent c) {
    if (c instanceof JLayer) {
      ((JLayer<?>) c).setLayerEventMask(0);
    }
    super.uninstallUI(c);
  }

  @Override public void eventDispatched(
        AWTEvent e, JLayer<? extends JComponent> l) {
    if (e instanceof MouseEvent) {
      MouseEvent me = (MouseEvent) e;
      Point2D pt = me.getPoint();
      try {
        pt = getAffineTransform(l.getSize()).inverseTransform(pt, null);
      } catch (NoninvertibleTransformException ex) {
        ex.printStackTrace();
        UIManager.getLookAndFeel().provideErrorFeedback(me.getComponent());
      }
      // Horizontal: me.translatePoint((int) pt.getX() - me.getX(), 0);
      me.translatePoint(0, (int) pt.getY() - me.getY());
      me.getComponent().repaint();
    }
    super.eventDispatched(e, l);
  }

  private AffineTransform getAffineTransform(Dimension d) {
    AffineTransform at = AffineTransform.getTranslateInstance(0d, d.height);
    at.scale(1d, -1d);
    return at;
  }
}

References

• Inverse the display position of JSlider's ticks and knobs(Japanese)