Rounded Corner JButton

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

Code

class RoundedCornerButtonUI extends BasicButtonUI{
  private static final float arcwidth  = 16.0f;
  private static final float archeight = 16.0f;
  protected static final int focusstroke = 2;
  protected final Color fc = new Color(100,150,255,200);
  protected final Color ac = new Color(230,230,230);
  protected final Color rc = Color.ORANGE;
  protected Shape shape;
  protected Shape border;
  protected Shape base;

  @Override protected void installDefaults(AbstractButton b) {
    super.installDefaults(b);
    b.setContentAreaFilled(false);
    b.setOpaque(false);
    b.setBackground(new Color(250, 250, 250));
    initShape(b);
  }
  @Override protected void installListeners(AbstractButton b) {
    BasicButtonListener listener = new BasicButtonListener(b) {
      @Override public void mousePressed(MouseEvent e) {
        AbstractButton b = (AbstractButton) e.getSource();
        initShape(b);
        if(shape.contains(e.getX(), e.getY())) {
          super.mousePressed(e);
        }
      }
      @Override public void mouseEntered(MouseEvent e) {
        if(shape.contains(e.getX(), e.getY())) {
          super.mouseEntered(e);
        }
      }
      @Override public void mouseMoved(MouseEvent e) {
        if(shape.contains(e.getX(), e.getY())) {
          super.mouseEntered(e);
        }else{
          super.mouseExited(e);
        }
      }
    };
    if(listener != null) {
      b.addMouseListener(listener);
      b.addMouseMotionListener(listener);
      b.addFocusListener(listener);
      b.addPropertyChangeListener(listener);
      b.addChangeListener(listener);
    }
  }
  @Override public void paint(Graphics g, JComponent c) {
    Graphics2D g2 = (Graphics2D)g;
    AbstractButton b = (AbstractButton) c;
    ButtonModel model = b.getModel();
    initShape(b);
    //ContentArea
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    if(model.isArmed()) {
      g2.setColor(ac);
      g2.fill(shape);
    }else if(b.isRolloverEnabled() && model.isRollover()) {
      paintFocusAndRollover(g2, c, rc);
    }else if(b.hasFocus()) {
      paintFocusAndRollover(g2, c, fc);
    }else{
      g2.setColor(c.getBackground());
      g2.fill(shape);
    }
    //Border
    g2.setPaint(c.getForeground());
    g2.draw(shape);

    g2.setColor(c.getBackground());
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_OFF);
    super.paint(g2, c);
  }
  private void initShape(JComponent c) {
    if(!c.getBounds().equals(base)) {
      base = c.getBounds();
      shape = new RoundRectangle2D.Float(0, 0, c.getWidth()-1, c.getHeight()-1,
                                         arcwidth, archeight);
      border = new RoundRectangle2D.Float(focusstroke, focusstroke,
                        c.getWidth()-1-focusstroke*2,
                        c.getHeight()-1-focusstroke*2,
                        arcwidth, archeight);
    }
  }
  private void paintFocusAndRollover(Graphics2D g2, JComponent c, Color color) {
    g2.setPaint(new GradientPaint(0, 0, color, c.getWidth()-1, c.getHeight()-1,
                                  color.brighter(), true));
    g2.fill(shape);
    g2.setColor(c.getBackground());
    g2.fill(border);
  }
}

References

• CREATING ROUND SWING BUTTONS - JDC Tech Tips: August 26, 1999
• Rounded Corner JButton(Japanese)