---
category: swing
folder: MenuBarBackground
title: JMenuBarの背景に画像を表示する
tags: [JMenuBar, JMenu, JMenuItem, TexturePaint]
author: aterai
pubdate: 2009-08-10T15:27:32+09:00
description: JMenuが未選択状態の場合はその背景を透明にし、JMenuBarの背景に設定した画像を表示可能にします。
image: https://lh3.googleusercontent.com/_9Z4BYR88imo/TQTPxQA13fI/AAAAAAAAAeg/SAN79wHPkQc/s800/MenuBarBackground.png
hreflang:
href: https://java-swing-tips.blogspot.com/2009/08/jmenubar-background-image.html
lang: en
---
* 概要 [#summary]
`JMenu`が未選択状態の場合はその背景を透明にし、`JMenuBar`の背景に設定した画像を表示可能にします。
#download(https://lh3.googleusercontent.com/_9Z4BYR88imo/TQTPxQA13fI/AAAAAAAAAeg/SAN79wHPkQc/s800/MenuBarBackground.png)
* サンプルコード [#sourcecode]
#code(link){{
public JMenuBar createMenubar() {
final TexturePaint texture = makeTexturePaint();
JMenuBar mb = new JMenuBar() {
@Override protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
g2.setPaint(texture);
g2.fillRect(0, 0, getWidth(), getHeight());
g2.dispose();
}
};
mb.setOpaque(false);
String[] menuKeys = {"File", "Edit", "Help"};
for (String key: menuKeys) {
JMenu m = createMenu(key);
if (m != null) {
mb.add(m);
}
}
return mb;
}
private JMenu createMenu(String key) {
JMenu menu = new JMenu(key) {
@Override protected void fireStateChanged() {
ButtonModel m = getModel();
if (m.isPressed() && m.isArmed()) {
setOpaque(true);
} else if (m.isSelected()) {
setOpaque(true);
} else if (isRolloverEnabled() && m.isRollover()) {
setOpaque(true);
} else {
setOpaque(false);
}
super.fireStateChanged();
};
};
if ("Windows XP".equals(System.getProperty("os.name"))) {
menu.setBackground(new Color(0x0, true)); // XXX: Windows XP lnf?
}
menu.add("dummy1"); menu.add("dummy2"); menu.add("dummy3");
menu.add("JMenuItem1");
menu.add("JMenuItem2");
menu.add("JMenuItem3");
return menu;
}
}}
* 解説 [#explanation]
上記のサンプルでは、`JMenuBar`に画像を描画し、これに追加する`JMenu`を通常は透明、選択されたときなどは不透明となるように`setOpaque`メソッドで切り替えています。
- `WindowsLookAndFeel`の場合、`JMenu#setBackground(new Color(0x0, true))`を設定する必要がある
- `WindowsLookAndFeel`に切り替えた直後のメニュー文字色などがおかしい？
----
- 以下は`JFrame#setJMenuBar()`で追加した`JMenuBar`を透明にする場合のテスト
#code{{
import java.awt.*;
import java.awt.image.*;
import java.util.Objects;
import javax.swing.*;
import javax.swing.plaf.*;
public class MenuBarRootPaneTest {
private static final Color ALPHA_ZERO = new Color(0x0, true);
private static final Color POPUP_BACK = new Color(0, 0, 0, 100);
private static JMenuBar createMenuBar() {
JMenuBar mb = new JMenuBar() {
@Override public Dimension getPreferredSize() {
Dimension d = super.getPreferredSize();
d.height = 30;
return d;
}
};
mb.setBackground(POPUP_BACK);
String[] menuKeys = {"File", "Edit", "Help"};
for (String key : menuKeys) {
mb.add(createMenu(key));
}
return mb;
}
private static JMenu createMenu(String key) {
JMenu menu = new TransparentMenu(key);
menu.add(new JMenuItem("dummy1"));
menu.add(new JMenuItem("dummy2"));
menu.add(new JMenuItem("dummy3"));
menu.add(new JMenuItem("JMenuItem1"));
menu.add(new JMenuItem("JMenuItem2"));
menu.add(new JMenuItem("JMenuItem3"));
return menu;
}
public static void main(String... args) {
EventQueue.invokeLater(() -> {
UIManager.put("MenuBar.background", POPUP_BACK);
UIManager.put("MenuBar.border", BorderFactory.createEmptyBorder());
UIManager.put("PopupMenu.border", BorderFactory.createEmptyBorder());
UIManager.put("MenuBar.border", BorderFactory.createEmptyBorder());
UIManager.put("PopupMenu.border", BorderFactory.createEmptyBorder());
UIManager.put("Menu.foreground", Color.WHITE);
UIManager.put("Menu.background", ALPHA_ZERO);
UIManager.put("Menu.selectionBackground", POPUP_BACK);
UIManager.put("Menu.selectionForeground", Color.WHITE);
UIManager.put("Menu.borderPainted", Boolean.FALSE);
UIManager.put("Menu.foreground", Color.WHITE);
UIManager.put("Menu.background", ALPHA_ZERO);
UIManager.put("Menu.selectionBackground", POPUP_BACK);
UIManager.put("Menu.selectionForeground", Color.WHITE);
UIManager.put("Menu.borderPainted", Boolean.FALSE);
UIManager.put("MenuItem.foreground", Color.WHITE);
UIManager.put("MenuItem.background", ALPHA_ZERO);
UIManager.put("MenuItem.foreground", Color.WHITE);
UIManager.put("MenuItem.background", ALPHA_ZERO);
UIManager.put("MenuItem.selectionBackground", POPUP_BACK);
UIManager.put("MenuItem.selectionForeground", Color.WHITE);
UIManager.put("MenuItem.borderPainted", Boolean.FALSE);
UIManager.put("MenuItem.borderPainted", Boolean.FALSE);
JFrame frame = new JFrame() {
@Override protected JRootPane createRootPane() {
return new JRootPane() {
private final TexturePaint texture = makeTexturePaint();
@Override protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
g2.setPaint(texture);
g2.fillRect(0, 0, getWidth(), getHeight());
g2.dispose();
}
@Override public boolean isOpaque() {
return true;
}
};
}
};
frame.getRootPane().setBackground(Color.BLUE);
frame.getLayeredPane().setBackground(Color.GREEN);
frame.getContentPane().setBackground(Color.RED);
((JComponent) frame.getContentPane()).setOpaque(false);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setJMenuBar(createMenuBar());
frame.setSize(320, 240);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
});
}
// TranslucentPopupMenu
// https://ateraimemo.com/Swing/TranslucentPopupMenu.html
static class TranslucentPopupMenu extends JPopupMenu {
@Override public boolean isOpaque() {
return false;
}
@Override public void show(Component c, int x, int y) {
EventQueue.invokeLater(() -> {
Container p = getTopLevelAncestor();
if (p instanceof JWindow) {
System.out.println("Heavy weight");
((JWindow) p).setBackground(ALPHA_ZERO);
}
});
super.show(c, x, y);
}
@Override protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setPaint(POPUP_BACK);
g2.fillRect(0, 0, getWidth(), getHeight());
g2.dispose();
}
}
static class TransparentMenu extends JMenu {
private JPopupMenu popupMenu;
protected TransparentMenu(String title) {
super(title);
}
@Override public boolean isOpaque() {
return false;
}
// Bug ID: JDK-4688783 JPopupMenu hardcoded i JMenu
// https://bugs.openjdk.org/browse/JDK-4688783
private void ensurePopupMenuCreated() {
if (Objects.isNull(popupMenu)) {
this.popupMenu = new TranslucentPopupMenu();
popupMenu.setInvoker(this);
popupListener = createWinListener(popupMenu);
}
}
@Override public JPopupMenu getPopupMenu() {
ensurePopupMenuCreated();
return popupMenu;
}
@Override public JMenuItem add(JMenuItem menuItem) {
ensurePopupMenuCreated();
menuItem.setOpaque(false);
return popupMenu.add(menuItem);
}
@Override public Component add(Component c) {
ensurePopupMenuCreated();
if (c instanceof JComponent) {
((JComponent) c).setOpaque(false);
}
popupMenu.add(c);
return c;
}
@Override public void addSeparator() {
ensurePopupMenuCreated();
popupMenu.addSeparator();
}
@Override public void insert(String s, int pos) {
if (pos < 0) {
throw new IllegalArgumentException("index less than zero.");
}
ensurePopupMenuCreated();
popupMenu.insert(new JMenuItem(s), pos);
}
@Override public JMenuItem insert(JMenuItem mi, int pos) {
if (pos < 0) {
throw new IllegalArgumentException("index less than zero.");
}
ensurePopupMenuCreated();
popupMenu.insert(mi, pos);
return mi;
}
@Override public void insertSeparator(int index) {
if (index < 0) {
throw new IllegalArgumentException("index less than zero.");
}
ensurePopupMenuCreated();
popupMenu.insert(new JPopupMenu.Separator(), index);
}
@Override public boolean isPopupMenuVisible() {
ensurePopupMenuCreated();
return popupMenu.isVisible();
}
}
private static TexturePaint makeTexturePaint() {
int cs = 6;
int sz = cs * cs;
BufferedImage img = new BufferedImage(sz, sz, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setPaint(new Color(222, 222, 222, 50));
g2.fillRect(0, 0, sz, sz);
for (int i = 0; i * cs < sz; i++) {
for (int j = 0; j * cs < sz; j++) {
if ((i + j) % 2 == 0) {
g2.fillRect(i * cs, j * cs, cs, cs);
}
}
}
g2.dispose();
return new TexturePaint(img, new Rectangle(sz, sz));
}
}
// //https://ateraimemo.com/Swing/TranslucentPopupMenu.html
// class TranslucentPopupMenu extends JPopupMenu {
}}
* 参考リンク [#reference]
- [https://docs.oracle.com/javase/jp/8/docs/api/javax/swing/AbstractButton.html#fireStateChanged-- AbstractButton#fireStateChanged() (Java Platform SE 8)]
- [[JRootPaneの背景として画像を表示>Swing/RootPaneBackground]]
* コメント [#comment]
#comment
- 選択状態を半透明にするテスト -- &user(aterai); &new{2010-01-09 (土) 23:08:42};
-- `Windows7`での`WindowsLookAndFeel`でうまくいかない場合があるようなので、すこし修正。 -- &user(aterai); &new{2011-09-26 (月) 21:13:47};
-- [[JRootPaneの背景として画像を表示>Swing/RootPaneBackground]]に移動
#comment