Swing/RoundButton のバックアップ(No.1)

TITLE:JButtonの形を変更

JButtonの形を変更

編集者:Terai Atsuhiro
作成日:2007-07-02
更新日:2021-06-04 (金) 11:33:39

概要

円形や角丸のJButtonを作成します。

#screenshot

サンプルコード

class RoundedCornerButton extends JButton {
  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;
  public RoundedCornerButton(String text) {
    super(text);
    //setRolloverEnabled(true);
    setContentAreaFilled(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,
                        arcwidth, archeight);
      border = new RoundRectangle2D.Float(focusstroke, focusstroke,
                        getWidth()-1-focusstroke*2,
                        getHeight()-1-focusstroke*2,
                        arcwidth, archeight);
    }
  }
  protected void paintComponent(Graphics g) {
    initShape();
    Graphics2D g2 = (Graphics2D)g;
    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);
  }
  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);
  }
  protected void paintBorder(Graphics g) {
    initShape();
    Graphics2D g2 = (Graphics2D)g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setColor(getForeground());
    g2.draw(shape);
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_OFF);
  }
  protected boolean contains(int x, int y) {
    initShape();
    return shape.contains(x, y);
  }
}
  • &jnlp;
  • &jar;
  • &zip;

解説

上記のサンプルでは、JButton#paintComponent()をオーバーライドすることで描画を、Jbutton#contains()をオーバーライドすることでクリック可能な範囲を変更しています。

円ボタンは、以下のように角丸ボタンを継承して作成しています。

  • PreferredSize(高さを幅と同じに)を設定
  • 図形の初期化メソッド*1をオーバーライド
class RoundButton extends RoundedCornerButton {
  public RoundButton(String text) {
    super(text);
    setFocusPainted(false);
    Dimension size = getPreferredSize();
    size.width = size.height = Math.max(size.width, size.height);
    setPreferredSize(size);
    initShape();
  }
  protected void initShape() {
    if(!getBounds().equals(base)) {
      base = getBounds();
      shape = new Ellipse2D.Float(0, 0, getWidth()-1, getHeight()-1);
      border = new Ellipse2D.Float(focusstroke, focusstroke,
                                   getWidth()-1-focusstroke*2,
                                   getHeight()-1-focusstroke*2);
    }
  }
}

参考リンク

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