---
category: swing
folder: RoundedComboBox
title: JComboBoxの角を丸める
tags: [JComboBox, Border, Path2D, ArrowButton]
author: aterai
pubdate: 2012-04-23T11:59:28+09:00
description: JComboBoxの左上、右上の角を丸めるBorderを設定します。
image: https://lh6.googleusercontent.com/-0VloXBzelwQ/T5TD3KZRIzI/AAAAAAAABLs/siwBGiic6Tw/s800/RoundedComboBox.png
hreflang:
href: https://java-swing-tips.blogspot.com/2012/07/rounded-corner-jcombobox-border.html
lang: en
---
* Summary [#summary]
`JComboBox`の左上、右上の角を丸める`Border`を設定します。
#download(https://lh6.googleusercontent.com/-0VloXBzelwQ/T5TD3KZRIzI/AAAAAAAABLs/siwBGiic6Tw/s800/RoundedComboBox.png)
* Source Code Examples [#sourcecode]
#code(link){{
class RoundedCornerBorder extends AbstractBorder {
@Override public void paintBorder(
Component c, Graphics g, int x, int y, int width, int height) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int r = 12;
int w = width - 1;
int h = height - 1;
Area round = new Area(new RoundRectangle2D.Float(x, y, w, h, r, r));
Container parent = c.getParent();
if (parent != null) {
g2.setColor(parent.getBackground());
Area corner = new Area(new Rectangle2D.Float(x, y, width, height));
corner.subtract(round);
g2.fill(corner);
}
g2.setPaint(c.getForeground());
g2.draw(round);
g2.dispose();
}
@Override public Insets getBorderInsets(Component c) {
return new Insets(4, 8, 4, 8);
}
@Override public Insets getBorderInsets(Component c, Insets insets) {
insets.left = insets.right = 8;
insets.top = insets.bottom = 4;
return insets;
}
}
class KamabokoBorder extends RoundedCornerBorder {
@Override public void paintBorder(
Component c, Graphics g, int x, int y, int width, int height) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int r = 12;
int w = width - 1;
int h = height - 1;
Path2D p = new Path2D.Float();
p.moveTo(x, y + h);
p.lineTo(x, y + r);
p.quadTo(x, y, x + r, y);
p.lineTo(x + w - r, y);
p.quadTo(x + w, y, x + w, y + r);
p.lineTo(x + w, y + h);
p.closePath();
Area round = new Area(p);
Container parent = c.getParent();
if (parent != null) {
g2.setColor(parent.getBackground());
Area corner = new Area(new Rectangle2D.Float(x, y, width, height));
corner.subtract(round);
g2.fill(corner);
}
g2.setPaint(c.getForeground());
g2.draw(round);
g2.dispose();
}
}
}}
* Description [#explanation]
* Description [#description]
上記のサンプルでは、`Path2D#lineTo(...)`、`Path2D#quadTo(...)`メソッドを使用してかまぼこ型の図形を作成し、`JComboBox`の`Border`として設定しています。
- 上: `MetalComboBoxUI`
-- `BasicComboBoxUI`を設定
- 中: `BasicComboBoxUI`
-- `RoundRectangle2D`に下の角を上書きするような矩形を追加して作成
-- `UIManager.put("ComboBox.foreground", color)`などで`JComboBox`の色を変更しているが、これだけでは`ArrowButton`の色が変更できない
-- [[JComboBoxのBorderを変更する>Swing/ComboBoxBorder]]
- 下: `BasicComboBoxUI#createArrowButton()`
-- `BasicComboBoxUI#createArrowButton()`をオーバーライドして`ArrowButton`の背景色などを変更
----
- 上記の方法で角丸の`JComboBox`が作成可能なのは`BasicLookAndFeel`と`WindowsLookAndFeel`のみ？
- 以下のような方法でもかまぼこ型の図形を作成可能
#code{{
Area round = new Area(
new RoundRectangle2D.Float(x, y, width - 1, height - 1, r, r));
Rectangle b = round.getBounds();
b.setBounds(b.x, b.y + r, b.width, b.height - r);
round.add(new Area(b));
}}
* Reference [#reference]
- [[JComboBoxのBorderを変更する>Swing/ComboBoxBorder]]
- [[JTextFieldの角を丸める>Swing/RoundedTextField]]
* Comment [#comment]
#comment
- 編集可不可の切り替えと、`WindowsLookAndFeel`に適用したサンプルを追加 -- &user(aterai); &new{2012-06-30 (土) 04:07:30};
#comment