JTree help

[Anand Loni]

Hi,

I am using Jtree with DefaultTreeModel and whose nodes are DefaultMutableTreeNode. I have associated JpopupMenu with tree. When I click rename from popup I want to make the selected tree node editable.
Is there any method to do this ? AnyBody can Help....

Regards,
Anand

[Craig Wood]

Since the tree is using a DefaultTreeModel and is editable the default editor is DefaultTreeCellEditor. See the discussion section of this class for the two gestures that trigger editing. Use of the popupMenu button makes three. Press the "enter" key after the edit to save the new value to the model.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
 
public class TreeTest
{
    private JTree getTree()
    {
        String[] birds = {
            "hawks",   "gray",    "red-tailed", "rough-legged",
            "falcons", "harrier", "kestrel",    "kite", 
            "owls",    "barred",  "saw-whet",   "snowy"
        };
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("birds");
        DefaultMutableTreeNode[] nodes = new DefaultMutableTreeNode[birds.length];
        for(int j = 0; j < nodes.length; j++)
            nodes[j] = new DefaultMutableTreeNode(birds[j]);
        for(int j = 0; j < 9; j += 4)
        {
            root.insert(nodes[j], j % 3);
            for(int k = j + 1; k < j + 4; k++)
                nodes[j].insert(nodes[k], k - j - 1);
        }
        DefaultTreeModel model = new DefaultTreeModel(root);
        JTree tree = new JTree(model);
        expandTree(tree);
        tree.getSelectionModel().setSelectionMode(
                                     TreeSelectionModel.SINGLE_TREE_SELECTION);
        tree.setEditable(true);
        return tree;
    }
 
    private void expandTree(JTree tree)
    {
        DefaultMutableTreeNode root = (DefaultMutableTreeNode)tree.getModel().getRoot();
        java.util.Enumeration e = root.breadthFirstEnumeration();
        while(e.hasMoreElements())
        {
            DefaultMutableTreeNode node = (DefaultMutableTreeNode)e.nextElement();
            if(node.isLeaf()) break;
            int row = tree.getRowForPath(new TreePath(node.getPath()));
            tree.expandRow(row);
        }
    }
 
    public static void main(String[] args)
    {
        TreeTest test = new TreeTest();
        JTree tree = test.getTree();
        EditMonitor monitor = new EditMonitor(tree);
        tree.addMouseListener(monitor);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new JScrollPane(tree));
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}
 
class EditMonitor extends MouseAdapter implements ActionListener
{
    JTree tree;
    JPopupMenu popup;
 
    public EditMonitor(JTree tree)
    {
        this.tree = tree;
        popup = new JPopupMenu("edit options");
        JMenuItem menuItem = new JMenuItem("edit node");
        menuItem.addActionListener(this);
        popup.add(menuItem);
        popup.pack();
        tree.add(popup);
    }
 
    public void actionPerformed(ActionEvent e)
    {
        tree.startEditingAtPath(tree.getSelectionPath());
    }
 
    private void checkPopupTrigger(MouseEvent e)
    {
        if(e.isPopupTrigger())
        {
            Point p = e.getPoint();
            TreePath path = tree.getClosestPathForLocation(p.x, p.y);
            if(path != tree.getSelectionPath())
                tree.setSelectionPath(path);
            Rectangle r = tree.getPathBounds(path);
            popup.show(tree, r.x + r.width, p.y);
        }
    }
 
    public void mousePressed(MouseEvent e)  { checkPopupTrigger(e); }
    public void mouseClicked(MouseEvent e)  { checkPopupTrigger(e); }
    public void mouseReleased(MouseEvent e) { checkPopupTrigger(e); }
}

edit words at top for clarity
[ February 24, 2006: Message edited by: Craig Wood ]

[Anand Loni]

Thanx,

This code is Ok , I found the method startEditingAt() but when I start editing popup is not displayed(in my case it should show same popup when we do not edit node). Also I have set CellRenderer for tree to do not show icon and for some other purpose ,then also it is showing icon for editing node.

why this is happening ???

[Craig Wood]

when I start editing popup is not displayed
You can locate it wherever you want and call setVisible to keep it there. Or you can move it around:

    private void checkPopupTrigger(MouseEvent e)
    {
        if(e.isPopupTrigger())
        {
            Point p = e.getPoint();
            TreePath path = tree.getClosestPathForLocation(p.x, p.y);
            if(path != tree.getSelectionPath())
                tree.setSelectionPath(path);
            Rectangle r = tree.getPathBounds(path);
            Point loc = new Point( r.x + r.width, r.y);
            SwingUtilities.convertPointToScreen(loc, tree);
            popup.setLocation(loc.x, loc.y);
            if(!popup.isVisible())
                popup.setVisible(true);
        }
    }

CellRenderer for tree to ... not show icon
You can make up an editor to match your CellRenderer. If you use DefaultTreeCellEditor it has a constructor in which you can specify your renderer as an argument, see api.