public void paintComponent(Graphics g) {
      super.paintComponent(g);

      Graphics2D g2 = (Graphics2D) g;

      if (!text.equals("")) {
        g2.translate(0, getSize().getHeight());
        g2.rotate(-Math.PI / 2);
        g2.setColor(Color.black);
        g2.drawString(text, 20, 14);

        g2.translate(0, -getSize().getHeight());
        g2.transform(AffineTransform.getQuadrantRotateInstance(1));
      }
    }