---
category: swing
folder: TreeComboBox
title: JComboBoxのItemをTree状に表示する
tags: [JComboBox, TreeModel]
author: aterai
pubdate: 2011-07-11T15:16:42+09:00
description: JComboBoxのドロップダウンリストに表示するItemをTree状に配置します。
image: https://lh6.googleusercontent.com/-5GlQEjeLoH8/ThqUIL9b4UI/AAAAAAAAA_E/9h5dxYzSSm8/s800/TreeComboBox.png
---
* 概要 [#summary]
`JComboBox`のドロップダウンリストに表示する`Item`を`Tree`状に配置します。
#download(https://lh6.googleusercontent.com/-5GlQEjeLoH8/ThqUIL9b4UI/AAAAAAAAA_E/9h5dxYzSSm8/s800/TreeComboBox.png)
* サンプルコード [#sourcecode]
#code(link){{
class TreeComboBox<E extends TreeNode> extends JComboBox<E> {
private boolean isNotSelectableIndex;
private final Action up = new AbstractAction() {
@Override public void actionPerformed(ActionEvent e) {
int si = getSelectedIndex();
for (int i = si - 1; i >= 0; i--) {
if (getItemAt(i).isLeaf()) {
setSelectedIndex(i);
break;
}
}
}
};
private final Action down = new AbstractAction() {
@Override public void actionPerformed(ActionEvent e) {
int si = getSelectedIndex();
for (int i = si + 1; i < getModel().getSize(); i++) {
if (getItemAt(i).isLeaf()) {
setSelectedIndex(i);
break;
}
}
}
};
@Override public void updateUI() {
super.updateUI();
ListCellRenderer<? super E> renderer = getRenderer();
setRenderer(new ListCellRenderer<E>() {
@Override public Component getListCellRendererComponent(
JList<? extends E> list, E value, int index,
boolean isSelected, boolean cellHasFocus) {
JLabel l = (JLabel) renderer.getListCellRendererComponent(
list, value, index, isSelected, cellHasFocus);
l.setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
if (index >= 0 && value instanceof DefaultMutableTreeNode) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
int indent = Math.max(0, node.getLevel() - 1) * 16;
l.setBorder(BorderFactory.createEmptyBorder(1, indent + 1, 1, 1));
if (!value.isLeaf()) {
l.setForeground(Color.WHITE);
l.setBackground(Color.GRAY.darker());
}
}
return l;
}
});
EventQueue.invokeLater(() -> {
ActionMap am = getActionMap();
am.put("selectPrevious3", up);
am.put("selectNext3", down);
InputMap im = getInputMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "selectPrevious3");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_KP_UP, 0), "selectPrevious3");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "selectNext3");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_KP_DOWN, 0), "selectNext3");
});
}
@Override public void setPopupVisible(boolean v) {
if (!v && isNotSelectableIndex) {
isNotSelectableIndex = false;
} else {
super.setPopupVisible(v);
}
}
@Override public void setSelectedIndex(int index) {
TreeNode node = getItemAt(index);
if (Objects.nonNull(node) && node.isLeaf()) {
super.setSelectedIndex(index);
} else {
isNotSelectableIndex = true;
}
}
}
}}
* 解説 [#explanation]
上記のサンプルでは、`TreeModel`から取得した`TreeNode`を`JComboBox`の`Item`として、ドロップダウンリストに表示しています。
- `TreeNode#isLeaf()`の場合のみ選択可能に設定
-- [[JComboBoxのアイテムを選択不可にする>Swing/DisableItemComboBox]]
- 第`0`レベルのルートノードは非表示で第`1`レベルノードのインデントは`0`に設定
- 第`2`レベル以降の子ノードのインデントは`BorderFactory.createEmptyBorder(1, indent + 1, 1, 1)`で設定
----
- `TreeCellRenderer`を使用してノードアイコンなどを表示する場合のサンプル
#code{{
import java.awt.*;
import java.util.Arrays;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Objects;
import java.util.stream.Collectors;
import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeCellRenderer;
public final class TreeComboBoxTest {
private Component makeUI() {
DefaultMutableTreeNode root = (DefaultMutableTreeNode) new JTree().getModel().getRoot();
JPanel p = new JPanel(new BorderLayout());
p.add(new TreeComboBox(root), BorderLayout.NORTH);
p.add(new TreeComboBox(makeRoot()), BorderLayout.NORTH);
p.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
return p;
}
private static DefaultMutableTreeNode makeRoot() {
return (DefaultMutableTreeNode) new JTree().getModel().getRoot();
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch(Exception ex) {
throw new IllegalArgumentException(ex);
}
JFrame f = new JFrame();
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.getContentPane().add(new TreeComboBoxTest().makeUI());
f.setSize(320, 240);
f.setLocationRelativeTo(null);
f.setVisible(true);
});
}
}
class TreeComboBox extends JComboBox<DefaultMutableTreeNode> {
public TreeComboBox(DefaultMutableTreeNode root) {
super();
DefaultComboBoxModel<DefaultMutableTreeNode> m = new DefaultComboBoxModel<>();
Collections.list((Enumeration<?>) root.preorderEnumeration()).stream()
.filter(DefaultMutableTreeNode.class::isInstance)
.map(DefaultMutableTreeNode.class::cast)
.filter(n -> !n.isRoot())
.forEach(m::addElement);
setModel(m);
}
@Override
public void updateUI() {
super.updateUI();
JTree dummyTree = new JTree();
TreeCellRenderer renderer = dummyTree.getCellRenderer();
JTree sampleTree = new JTree();
TreeCellRenderer renderer = sampleTree.getCellRenderer();
ListCellRenderer<? super DefaultMutableTreeNode> r = getRenderer();
setRenderer((list, value, index, isSelected, cellHasFocus) -> {
Component c = r.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
Component c = r.getListCellRendererComponent(
list, value, index, isSelected, cellHasFocus);
if (value == null) {
return c;
}
if (index < 0) {
String txt = Arrays.stream(value.getPath())
.filter(DefaultMutableTreeNode.class::isInstance)
.map(DefaultMutableTreeNode.class::cast)
.filter(n -> !n.isRoot())
.map(Objects::toString)
.collect(Collectors.joining(" / "));
((JLabel) c).setText(txt);
return c;
} else {
boolean leaf = value.isLeaf();
JLabel l = (JLabel) renderer.getTreeCellRendererComponent(
dummyTree, value, isSelected, true, leaf, index, false);
sampleTree, value, isSelected, true, leaf, index, false);
int childIndent = UIManager.getInt("Tree.leftChildIndent") +
UIManager.getInt("Tree.rightChildIndent");
int indent = Math.max(0, value.getLevel() - 1) * childIndent;
l.setBorder(BorderFactory.createEmptyBorder(1, indent + 1, 1, 1));
return l;
}
});
}
}
}}
* 参考リンク [#reference]
- [http://www.jroller.com/santhosh/entry/tree_inside_jcombobox Tree inside JComboBox - Santhosh Kumar's Weblog]
-- `TreeCellRenderer`を使用し、ノードアイコンなども含めて`JTree`をドロップダウンリストに表示するサンプルがある
- [[JComboBoxのアイテムを選択不可にする>Swing/DisableItemComboBox]]
* コメント [#comment]
#comment
- `src.zip`などが正しいディレクトリに配置されてなかったのを修正。 -- &user(aterai); &new{2011-07-13 (水) 19:02:23};
#comment