class Glass extends JComponent {
    JLabel label;

    public Glass(JButton butt, JLabel label, RootPaneContainer parent) {
        this.label = label;
        this.addMouseListener(new ButtonMouseListener(this,
                parent.getContentPane(), butt));
    }

    public void paintComponent(Graphics g) {
        Rectangle rect = label.getBounds();
        int x = rect.x + rect.width / 2;
        Graphics2D g2d = (Graphics2D) g;
        g2d.setColor(new Color(0.5f, 0.5f, 0.5f, 0.8f));
        g2d.fillRect(x, rect.y, rect.width / 2, rect.height);
    }
}