---
category: swing
folder: NineSliceScalingButton
title: JButtonに9分割した画像を使用する
tags: [JButton, Icon, BufferedImage, RGBImageFilter]
author: aterai
pubdate: 2013-08-12T00:58:18+09:00
description: JButtonを拡大縮小しても四隅などのサイズが変更しないようにように9分割した画像を使用します。
image: https://lh5.googleusercontent.com/-yYRfTw-3_BU/UgaFQAAiUcI/AAAAAAAABx4/koHqjZ3o36Q/s800/NineSliceScalingButton.png
hreflang:
href: https://java-swing-tips.blogspot.com/2013/08/create-9-slice-scaling-image-jbutton.html
lang: en
---
* Summary [#summary]
`JButton`を拡大縮小しても四隅などのサイズが変更しないようにように`9`分割した画像を使用します。
#download(https://lh5.googleusercontent.com/-yYRfTw-3_BU/UgaFQAAiUcI/AAAAAAAABx4/koHqjZ3o36Q/s800/NineSliceScalingButton.png)
* Source Code Examples [#sourcecode]
#code(link){{
class NineSliceScalingIcon implements Icon {
private final BufferedImage image;
private final int leftw;
private final int rightw;
private final int toph;
private final int bottomh;
private int width;
private int height;
protected NineSliceScalingIcon(
BufferedImage image, int leftw, int rightw, int toph, int bottomh) {
this.image = image;
this.leftw = leftw;
this.rightw = rightw;
this.toph = toph;
this.bottomh = bottomh;
}
@Override public int getIconWidth() {
return width; // Math.max(image.getWidth(null), width);
}
@Override public int getIconHeight() {
return Math.max(image.getHeight(null), height);
}
@Override public void paintIcon(Component cmp, Graphics g, int x, int y) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
Insets i = cmp instanceof Container ? ((Container) cmp).getInsets()
: new Insets(0, 0, 0, 0);
// g2.translate(x, y); // 1.8.0: work fine?
int iw = image.getWidth(cmp);
int ih = image.getHeight(cmp);
width = cmp.getWidth() - i.left - i.right;
height = cmp.getHeight() - i.top - i.bottom;
g2.drawImage(
image.getSubimage(leftw, toph, iw - leftw - rightw, ih - toph - bottomh),
leftw, toph, width - leftw - rightw, height - toph - bottomh, cmp);
if (leftw > 0 && rightw > 0 && toph > 0 && bottomh > 0) {
g2.drawImage(image.getSubimage(leftw, 0, iw - leftw - rightw, toph),
leftw, 0, width - leftw - rightw, toph, cmp);
g2.drawImage(image.getSubimage(leftw, ih - bottomh, iw - leftw - rightw, bottomh),
leftw, height - bottomh, width - leftw - rightw, bottomh, cmp);
g2.drawImage(image.getSubimage(0, toph, leftw, ih - toph - bottomh),
0, toph, leftw, height - toph - bottomh, cmp);
g2.drawImage(image.getSubimage(iw - rightw, toph, rightw, ih - toph - bottomh),
width - rightw, toph, rightw, height - toph - bottomh, cmp);
g2.drawImage(image.getSubimage(0, 0, leftw, toph),
0, 0, cmp);
g2.drawImage(image.getSubimage(iw - rightw, 0, rightw, toph),
width - rightw, 0, cmp);
g2.drawImage(image.getSubimage(0, ih - bottomh, leftw, bottomh),
0, height - bottomh, cmp);
g2.drawImage(image.getSubimage(iw - rightw, ih - bottomh, rightw, bottomh),
width - rightw, height - bottomh, cmp);
}
g2.dispose();
}
}
}}
* Description [#explanation]
* Description [#description]
上記のサンプルでは、`BufferedImage#getSubimage(...)`メソッドで元画像を`9`分割し、`4`隅はサイズ変更なし、上下辺は幅のみ拡大縮小、左右辺は高さのみ拡大縮小、中央は幅高さが拡大縮小可能になるように`Graphics#drawImage(...)`メソッドのスケーリングを利用して描画しています。
- `4`隅などの固定サイズ
-- `leftw`: 左側、上下隅の幅
-- `rightw`: 右側、上下隅の幅
-- `toph`: 上側、左右隅の高さ
-- `bottomh`: 下側、左右隅の高さ
* Reference [#reference]
- [https://docs.oracle.com/javase/jp/8/docs/api/java/awt/image/BufferedImage.html#getSubimage-int-int-int-int- BufferedImage#getSubimage(int, int, int, int) (Java Platform SE 8)]
- [https://rwillustrator.blogspot.jp/2007/04/understanding-9-slice-scaling.html Real World Illustrator: Understanding 9-Slice Scaling]
-- テスト用の画像(`symbol_scale_2.jpg`)を拝借
* Comment [#comment]
#comment
#comment