Rounded Corner JButton

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

Code

class RoundedCornerButton extends JButton {
  private static final float ARC_WIDTH = 16f;
  private static final float ARC_HEIGHT = 16f;
  protected static final int FOCUS_STROKE = 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;
  public RoundedCornerButton() {
    super();
  }

  public RoundedCornerButton(Icon icon) {
    super(icon);
  }

  public RoundedCornerButton(String text) {
    super(text);
  }

  public RoundedCornerButton(Action a) {
    super(a);
    // setAction(a);
  }

  public RoundedCornerButton(String text, Icon icon) {
    super(text, icon);
    // setModel(new DefaultButtonModel());
    // init(text, icon);
    // setContentAreaFilled(false);
    // setBackground(new Color(250, 250, 250));
    // initShape();
  }

  @Override public void updateUI() {
    super.updateUI();
    setContentAreaFilled(false);
    setFocusPainted(false);
    setBackground(new Color(250, 250, 250));
    initShape();
  }

  protected void initShape() {
    if (!getBounds().equals(base)) {
      base = getBounds();
      shape = new RoundRectangle2D.Float(
          0, 0, getWidth() - 1, getHeight() - 1, ARC_WIDTH, ARC_HEIGHT);
      border = new RoundRectangle2D.Float(
          FOCUS_STROKE, FOCUS_STROKE, getWidth() - 1 - FOCUS_STROKE * 2,
          getHeight() - 1 - FOCUS_STROKE * 2, ARC_WIDTH, ARC_HEIGHT);
    }
  }

  private void paintFocusAndRollover(Graphics2D g2, Color color) {
    g2.setPaint(new GradientPaint(
        0, 0, color, getWidth() - 1, getHeight() - 1,
        color.brighter(), true));
    g2.fill(shape);
    g2.setColor(getBackground());
    g2.fill(border);
  }

  @Override protected void paintComponent(Graphics g) {
    initShape();
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    if (getModel().isArmed()) {
      g2.setColor(ac);
      g2.fill(shape);
    } else if (isRolloverEnabled() && getModel().isRollover()) {
      paintFocusAndRollover(g2, rc);
    } else if (hasFocus()) {
      paintFocusAndRollover(g2, fc);
    } else {
      g2.setColor(getBackground());
      g2.fill(shape);
    }
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_OFF);
    g2.setColor(getBackground());
    super.paintComponent(g2);
    g2.dispose();
  }

  @Override protected void paintBorder(Graphics g) {
    initShape();
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setColor(getForeground());
    g2.draw(shape);
    g2.dispose();
  }

  @Override public boolean contains(int x, int y) {
    initShape();
    return shape == null ? false : shape.contains(x, y);
  }
}

References

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