@Override public void paint(Graphics g) { Dimension size = getSize(); Graphics2D g2 = (Graphics2D) g.create(); g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f)); g2.fillRect(0, 0, (int) size.getWidth(), (int) size.getHeight()); super.paint(g2); g2.dispose(); }