Данный пример взят из книги Swing. Тут нет картинок, но без них все прекрасно работает. | Код |
/**
* Copyright 1999-2002 Matthew Robinson and Pavel Vorobiev.
* All Rights Reserved.
*
* ===================================================
* This program contains code from the book "Swing"
* 2nd Edition by Matthew Robinson and Pavel Vorobiev
* http://www.spindoczine.com/sbe
* ===================================================
*
* The above paragraph must be included in full, unmodified
* and completely intact in the beginning of any source code
* file that references, copies or uses (in any way, shape
* or form) code contained in this file.
*/
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.border.*;
import javax.swing.event.*;
public class DirTree
extends JFrame {
public static final String APP_NAME = "Directories Tree";
public static final ImageIcon ICON_COMPUTER =
new ImageIcon("computer.gif");
public static final ImageIcon ICON_DISK =
new ImageIcon("disk.gif");
public static final ImageIcon ICON_FOLDER =
new ImageIcon("folder.gif");
public static final ImageIcon ICON_EXPANDEDFOLDER =
new ImageIcon("expandedfolder.gif");
protected JTree m_tree;
protected DefaultTreeModel m_model;
protected JTextField m_display;
public DirTree() {
super(APP_NAME);
setSize(400, 300);
DefaultMutableTreeNode top = new DefaultMutableTreeNode(
new IconData(ICON_COMPUTER, null, "Computer"));
DefaultMutableTreeNode node;
File[] roots = File.listRoots();
for (int k=0; k<roots.length; k++) {
node = new DefaultMutableTreeNode(new IconData(ICON_DISK,
null, new FileNode(roots[k])));
top.add(node);
node.add( new DefaultMutableTreeNode(new Boolean(true)));
}
m_model = new DefaultTreeModel(top);
m_tree = new JTree(m_model);
m_tree.putClientProperty("JTree.lineStyle", "Angled");
IconCellRenderer renderer = new
IconCellRenderer();
m_tree.setCellRenderer(renderer);
m_tree.addTreeExpansionListener(new
DirExpansionListener());
m_tree.addTreeSelectionListener(new
DirSelectionListener());
m_tree.getSelectionModel().setSelectionMode(
TreeSelectionModel.SINGLE_TREE_SELECTION);
m_tree.setShowsRootHandles(true);
m_tree.setEditable(false);
JScrollPane s = new JScrollPane();
s.getViewport().add(m_tree);
getContentPane().add(s, BorderLayout.CENTER);
m_display = new JTextField();
m_display.setEditable(false);
m_display.setBorder(new SoftBevelBorder(BevelBorder.LOWERED));
getContentPane().add(m_display, BorderLayout.NORTH);
}
DefaultMutableTreeNode getTreeNode(TreePath path) {
return (DefaultMutableTreeNode)(path.getLastPathComponent());
}
FileNode getFileNode(DefaultMutableTreeNode node) {
if (node == null)
return null;
Object obj = node.getUserObject();
if (obj instanceof IconData)
obj = ((IconData)obj).getObject();
if (obj instanceof FileNode)
return (FileNode)obj;
else
return null;
}
// Make sure expansion is threaded and updating the tree model
// only occurs within the event dispatching thread.
class DirExpansionListener implements TreeExpansionListener {
public void treeExpanded(TreeExpansionEvent event) {
final DefaultMutableTreeNode node = getTreeNode(
event.getPath());
final FileNode fnode = getFileNode(node);
Thread runner = new Thread() {
public void run() {
if (fnode != null && fnode.expand(node)) {
Runnable runnable = new Runnable() {
public void run() {
m_model.reload(node);
}
};
SwingUtilities.invokeLater(runnable);
}
}
};
runner.start();
}
public void treeCollapsed(TreeExpansionEvent event) {}
}
class DirSelectionListener
implements TreeSelectionListener {
public void valueChanged(TreeSelectionEvent event) {
DefaultMutableTreeNode node = getTreeNode(
event.getPath());
FileNode fnode = getFileNode(node);
if (fnode != null)
m_display.setText(fnode.getFile().
getAbsolutePath());
else
m_display.setText("");
}
}
public static void main(String argv[]) {
DirTree frame = new DirTree();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
class IconCellRenderer
extends DefaultTreeCellRenderer {
public IconCellRenderer() {
setLeafIcon(null);
setOpenIcon(null);
}
public Component getTreeCellRendererComponent(JTree tree,
Object value, boolean sel, boolean expanded, boolean leaf,
int row, boolean hasFocus) {
// Invoke default implementation
Component result = super.getTreeCellRendererComponent(tree,
value, sel, expanded, leaf, row, hasFocus);
DefaultMutableTreeNode node =
(DefaultMutableTreeNode)value;
Object obj = node.getUserObject();
setText(obj.toString());
if (obj instanceof Boolean)
setText("Retrieving data...");
if (obj instanceof IconData) {
IconData idata = (IconData)obj;
if (expanded)
setIcon(idata.getExpandedIcon());
else
setIcon(idata.getIcon());
}
else
setIcon(null);
return result;
}
}
class IconData {
protected Icon m_icon;
protected Icon m_expandedIcon;
protected Object m_data;
public IconData(Icon icon, Object data) {
m_icon = icon;
m_expandedIcon = null;
m_data = data;
}
public IconData(Icon icon, Icon expandedIcon, Object data) {
m_icon = icon;
m_expandedIcon = expandedIcon;
m_data = data;
}
public Icon getIcon() {
return m_icon;
}
public Icon getExpandedIcon() {
return m_expandedIcon!=null ? m_expandedIcon : m_icon;
}
public Object getObject() {
return m_data;
}
public String toString() {
return m_data.toString();
}
}
class FileNode {
protected File m_file;
public FileNode(File file) {
m_file = file;
}
public File getFile() {
return m_file;
}
public String toString() {
return m_file.getName().length() > 0 ? m_file.getName() :
m_file.getPath();
}
// Alternatively we copud sub-class TreeNode
public boolean expand(DefaultMutableTreeNode parent) {
DefaultMutableTreeNode flag =
(DefaultMutableTreeNode)parent.getFirstChild();
if (flag==null) // No flag
return false;
Object obj = flag.getUserObject();
if (!(obj instanceof Boolean))
return false; // Already expanded
parent.removeAllChildren(); // Remove Flag
File[] files = listFiles();
if (files == null)
return true;
Vector v = new Vector();
for (int k=0; k<files.length; k++) {
File f = files[k];
if (!(f.isDirectory()))
continue;
FileNode newNode = new FileNode(f);
boolean isAdded = false;
for (int i=0; i<v.size(); i++) {
FileNode nd = (FileNode)v.elementAt(i);
if (newNode.compareTo(nd) < 0) {
v.insertElementAt(newNode, i);
isAdded = true;
break;
}
}
if (!isAdded)
v.addElement(newNode);
}
for (int i=0; i<v.size(); i++) {
FileNode nd = (FileNode)v.elementAt(i);
IconData idata = new IconData(DirTree.ICON_FOLDER,
DirTree.ICON_EXPANDEDFOLDER, nd);
DefaultMutableTreeNode node = new
DefaultMutableTreeNode(idata);
parent.add(node);
if (nd.hasSubDirs())
node.add(new DefaultMutableTreeNode(
new Boolean(true) ));
}
return true;
}
public boolean hasSubDirs() {
File[] files = listFiles();
if (files == null)
return false;
for (int k=0; k<files.length; k++) {
if (files[k].isDirectory())
return true;
}
return false;
}
public int compareTo(FileNode toCompare) {
return m_file.getName().compareToIgnoreCase(
toCompare.m_file.getName() );
}
protected File[] listFiles() {
if (!m_file.isDirectory())
return null;
try {
return m_file.listFiles();
}
catch (Exception ex) {
JOptionPane.showMessageDialog(null,
"Error reading directory "+m_file.getAbsolutePath(),
DirTree.APP_NAME, JOptionPane.WARNING_MESSAGE);
return null;
}
}
}
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