---
category: swing
folder: TranslucentPopupMenu
title: JPopupMenuを半透明にする
tags: [JPopupMenu, JMenuItem, JWindow, Translucent]
author: aterai
pubdate: 2012-02-27T14:25:17+09:00
description: JPopupMenu自体の背景を透明に設定し、別途そのpaintComponent(...)メソッドをオーバーライドして半透明の背景を描画します。
image: https://lh3.googleusercontent.com/-SKQis3B-SmY/T0dd531MovI/AAAAAAAABJk/fWIZIAeE3oE/s800/TranslucentPopupMenu.png
hreflang:
href: https://java-swing-tips.blogspot.com/2012/07/translucent-jpopupmenu.html
lang: en
---
* 概要 [#summary]
`JPopupMenu`自体の背景を透明に設定し、別途その`paintComponent(...)`メソッドをオーバーライドして半透明の背景を描画します。
#download(https://lh3.googleusercontent.com/-SKQis3B-SmY/T0dd531MovI/AAAAAAAABJk/fWIZIAeE3oE/s800/TranslucentPopupMenu.png)
* サンプルコード [#sourcecode]
#code(link){{
class TranslucentPopupMenu extends JPopupMenu {
private static final Color ALPHA_ZERO = new Color(0x0, true);
private static final Color POPUP_BACK = new Color(250, 250, 250, 200);
private static final Color POPUP_LEFT = new Color(230, 230, 230, 200);
private static final int LEFT_WIDTH = 24;
@Override public boolean isOpaque() {
return false;
}
@Override public void updateUI() {
super.updateUI();
if (UIManager.getBorder("PopupMenu.border") == null) {
setBorder(new BorderUIResource(BorderFactory.createLineBorder(Color.GRAY)));
}
}
@Override public JMenuItem add(JMenuItem menuItem) {
menuItem.setOpaque(false);
// menuItem.setBackground(ALPHA_ZERO);
return super.add(menuItem);
}
@Override public void show(Component c, int x, int y) {
EventQueue.invokeLater(new Runnable() {
@Override public void run() {
Window p = SwingUtilities.getWindowAncestor(TranslucentPopupMenu.this);
if (p instanceof JWindow) {
System.out.println("Heavy weight");
JWindow w = (JWindow) p;
w.setBackground(ALPHA_ZERO);
} else {
System.out.println("Light weight");
}
}
});
super.show(c, x, y);
}
@Override protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setPaint(POPUP_LEFT);
g2.fillRect(0, 0, LEFT_WIDTH, getHeight());
g2.setPaint(POPUP_BACK);
g2.fillRect(LEFT_WIDTH, 0, getWidth(), getHeight());
g2.dispose();
//super.paintComponent(g);
}
}
}}
* 解説 [#explanation]
上記のサンプルでは、`JPopupMenu`は`isOpaque()`メソッドをオーバーライド、`JMenuItem`は`setOpaque(false)`としてそれぞれ透明に設定し、`JPopupMenu#paintComponent(...)`で半透明の背景を描画しています。
`JPopupMenu`が親フレームの外にはみ出す場合は`Heavyweight`の`JWindow`を使って`JPopupMenu`が表示されるので、`JWindow#setBackground(new Color(0x0, true))`で(`JDK 1.6.0_10`では`com.sun.awt.AWTUtilities.setWindowOpaque(w, false)`)、`JPopupMenu#show(...)`が呼ばれるたびに毎回(親フレームの透明度を引き継がないように？)`JWindow`自体を透明にしています。
----
- `JPopupMenu`(ルート)が`Light weight`でその`JMenu`から開く`JPopupMenu`(サブメニュー) が`Heavy weight`のときに半透明にならない
-- [https://bugs.openjdk.org/browse/JDK-7156657 JDK-7156657 Version 7 doesn't support translucent popup menus against a translucent window - Java Bug System]
-- `JDK 1.7.0_06`などで修正された
* 参考リンク [#reference]
- [http://today.java.net/pub/a/today/2008/03/18/translucent-and-shaped-swing-windows.html Translucent and Shaped Swing Windows | Java.net]
- [[JMenuなどから開くPopupMenuを半透明化>Swing/TranslucentSubMenu]]
* コメント [#comment]
#comment
- メモ: [https://bugs.openjdk.org/browse/JDK-7156657 JDK-7156657 Version 7 doesn't support translucent popup menus against a translucent window - Java Bug System]、[http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/4acd0211f48b jdk8/jdk8/jdk: changeset 5453:4acd0211f48b] -- &user(aterai); &new{2012-08-10 (金) 19:22:39};
- メモ: [https://bugs.openjdk.org/browse/JDK-7156657 JDK-7156657 Version 7 doesn't support translucent popup menus against a translucent window - Java Bug System]、[https://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/4acd0211f48b jdk8/jdk8/jdk: changeset 5453:4acd0211f48b] -- &user(aterai); &new{2012-08-10 (金) 19:22:39};
-- `JDK 1.7.0_06`で修正されている？ [https://www.oracle.com/java/technologies/javase/7u6-bugfixes.html Java SE Development Kit 7 Update 6 Bug Fixes] -- &user(aterai); &new{2012-08-15 (水) 13:55:37};
#comment