Java tutorial
import java.awt.*; import java.awt.event.*; import java.io.*; import java.util.*; import java.text.SimpleDateFormat; import javax.swing.*; import javax.swing.tree.*; import javax.swing.event.*; public class FileTree2 extends JFrame { 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; // NEW protected JPopupMenu m_popup; protected Action m_action; protected TreePath m_clickedPath; public FileTree2() { super("Directories Tree [Popup Menus]"); 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"); TreeCellRenderer 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); getContentPane().add(m_display, BorderLayout.NORTH); // NEW m_popup = new JPopupMenu(); m_action = new AbstractAction() { public void actionPerformed(ActionEvent e) { if (m_clickedPath == null) return; if (m_tree.isExpanded(m_clickedPath)) m_tree.collapsePath(m_clickedPath); else m_tree.expandPath(m_clickedPath); } }; m_popup.add(m_action); m_popup.addSeparator(); Action a1 = new AbstractAction("Delete") { public void actionPerformed(ActionEvent e) { m_tree.repaint(); JOptionPane.showMessageDialog(FileTree2.this, "Delete option is not implemented", "Info", JOptionPane.INFORMATION_MESSAGE); } }; m_popup.add(a1); Action a2 = new AbstractAction("Rename") { public void actionPerformed(ActionEvent e) { m_tree.repaint(); JOptionPane.showMessageDialog(FileTree2.this, "Rename option is not implemented", "Info", JOptionPane.INFORMATION_MESSAGE); } }; m_popup.add(a2); m_tree.add(m_popup); m_tree.addMouseListener(new PopupTrigger()); WindowListener wndCloser = new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }; addWindowListener(wndCloser); setVisible(true); } 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; } // NEW class PopupTrigger extends MouseAdapter { public void mouseReleased(MouseEvent e) { if (e.isPopupTrigger()) { int x = e.getX(); int y = e.getY(); TreePath path = m_tree.getPathForLocation(x, y); if (path != null) { if (m_tree.isExpanded(path)) m_action.putValue(Action.NAME, "Collapse"); else m_action.putValue(Action.NAME, "Expand"); m_popup.show(m_tree, x, y); m_clickedPath = path; } } } } // 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[]) { new FileTree2(); } } class IconCellRenderer extends JLabel implements TreeCellRenderer { protected Color m_textSelectionColor; protected Color m_textNonSelectionColor; protected Color m_bkSelectionColor; protected Color m_bkNonSelectionColor; protected Color m_borderSelectionColor; protected boolean m_selected; public IconCellRenderer() { super(); m_textSelectionColor = UIManager.getColor("Tree.selectionForeground"); m_textNonSelectionColor = UIManager.getColor("Tree.textForeground"); m_bkSelectionColor = UIManager.getColor("Tree.selectionBackground"); m_bkNonSelectionColor = UIManager.getColor("Tree.textBackground"); m_borderSelectionColor = UIManager.getColor("Tree.selectionBorderColor"); setOpaque(false); } public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean 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); setFont(tree.getFont()); setForeground(sel ? m_textSelectionColor : m_textNonSelectionColor); setBackground(sel ? m_bkSelectionColor : m_bkNonSelectionColor); m_selected = sel; return this; } public void paintComponent(Graphics g) { Color bColor = getBackground(); Icon icon = getIcon(); g.setColor(bColor); int offset = 0; if (icon != null && getText() != null) offset = (icon.getIconWidth() + getIconTextGap()); g.fillRect(offset, 0, getWidth() - 1 - offset, getHeight() - 1); if (m_selected) { g.setColor(m_borderSelectionColor); g.drawRect(offset, 0, getWidth() - 1 - offset, getHeight() - 1); } super.paintComponent(g); } } 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(); } 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(FileTree2.ICON_FOLDER, FileTree2.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(), "Warning", JOptionPane.WARNING_MESSAGE); return null; } } }