Adding editable nodes to JTree

/*
 * This example is from javareference.com
 * for more information visit,
 * http://www.javareference.com
 */

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;

/**
 * This class creates a editable JTree and allows adding
 * new nodes to it, which are immediately made available for
 * editing after adding
 *
 * @author Rahul Sapkal(rahul@javareference.com)
 */
public class EditableTree extends JFrame implements ActionListener {
  private JTree m_tree;
  private DefaultTreeModel m_model;
  private JButton m_addButton;

  /**
   * Constructor
   */
  public EditableTree() {
    setTitle("Editable JTree Demo");

    // constructing tree
    TreeNode rootNode = buildDummyTree();
    m_model = new DefaultTreeModel(rootNode);

    m_tree = new JTree(m_model);
    m_tree.setEditable(true);
    m_tree.setSelectionRow(0);

    JScrollPane scrollPane = new JScrollPane(m_tree);
    getContentPane().add(scrollPane, BorderLayout.CENTER);

    JPanel panel = new JPanel();
    m_addButton = new JButton("Add Node");
    m_addButton.addActionListener(this);
    panel.add(m_addButton);
    getContentPane().add(panel, BorderLayout.SOUTH);

    setSize(300, 400);
    setVisible(true);
  }

  /**
   * This method builds a dummy tree and returns the root node
   *
   * @return root node
   */
  public TreeNode buildDummyTree() {
    DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("JavaReference");
    DefaultMutableTreeNode forums = new DefaultMutableTreeNode("Forum");
    forums.add(new DefaultMutableTreeNode("Thread 1"));
    forums.add(new DefaultMutableTreeNode("Thread 2"));
    forums.add(new DefaultMutableTreeNode("Thread 3"));
    DefaultMutableTreeNode articles = new DefaultMutableTreeNode("Articles");
    articles.add(new DefaultMutableTreeNode("Article 1"));
    articles.add(new DefaultMutableTreeNode("Article 2"));
    DefaultMutableTreeNode examples = new DefaultMutableTreeNode("Examples");
    examples.add(new DefaultMutableTreeNode("Examples 1"));
    examples.add(new DefaultMutableTreeNode("Examples 2"));
    examples.add(new DefaultMutableTreeNode("Examples 3"));

    rootNode.add(forums);
    rootNode.add(articles);
    rootNode.add(examples);

    return rootNode;
  }

  /**
   * Handles the button action
   */
  public void actionPerformed(ActionEvent event) {
    if (event.getSource().equals(m_addButton)) {
      DefaultMutableTreeNode selNode = (DefaultMutableTreeNode) m_tree.getLastSelectedPathComponent();

      if (selNode != null) {
        // add new node as a child of a selected node at the end
        DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("New Node");
        m_model.insertNodeInto(newNode, selNode, selNode.getChildCount());

        //make the node visible by scroll to it
        TreeNode[] nodes = m_model.getPathToRoot(newNode);
        TreePath path = new TreePath(nodes);
        m_tree.scrollPathToVisible(path);

        //select the newly added node
        m_tree.setSelectionPath(path);

        //Make the newly added node editable
        m_tree.startEditingAtPath(path);
      }
    }
  }

  /**
   * Main method to run as an Application
   *
   * @param argv
   */
  public static void main(String[] arg) {
    EditableTree editableTree = new EditableTree();
  }
}

//End EditableTree