DefaultTreeModel.nodeChanged() has no effect when applied to the root of a JTree

Name: dbT83986 Date: 12/22/98


1. Compile and execute the example below. Clicking
on the top button changes the value of the root
node and calls nodeChanged(). However, the root
node is not repainted.

The bottom button shows that the same code applied
to the child node works correctly and repaints the
child node with the new value.

2.

import com.sun.java.swing.*;
import com.sun.java.swing.tree.*;
import java.awt.BorderLayout;

public class TreeNodeBug extends Object {

  public static void main(String[] argv) {
    JFrame frame = new JFrame();
    frame.addWindowListener(new java.awt.event.WindowAdapter() {
      public void windowClosing(java.awt.event.WindowEvent event) {
        event.getWindow().dispose();
        System.exit(0);
      }
    });
    frame.setSize(450, 300);
    frame.getContentPane().setLayout(new BorderLayout());
    frame.show();

    // Create 3 nodes
    final DefaultMutableTreeNode root = new DefaultMutableTreeNode("root", true);
    final DefaultMutableTreeNode child = new DefaultMutableTreeNode("child", true);
    final DefaultMutableTreeNode leaf = new DefaultMutableTreeNode("leaf", false);
    root.add(child);
    child.add(leaf);

    // Create the tree and add it to the frame
    final JTree tree = new JTree(root);
    frame.getContentPane().add(tree, BorderLayout.CENTER);

    // Create a button that changes the root node
    JButton button1 = new JButton("Change the \"root\" node");
    button1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(java.awt.event.ActionEvent event) {
        root.setUserObject("New root");
        ((DefaultTreeModel)tree.getModel()).nodeChanged(root);
      }
    });
    frame.getContentPane().add(button1, BorderLayout.NORTH);

    // Create a button that changes the child node
    JButton button2 = new JButton("Change the \"child\" node");
    button2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(java.awt.event.ActionEvent event) {
        child.setUserObject("New child");
        ((DefaultTreeModel)tree.getModel()).nodeChanged(child);
      }
    });
    frame.getContentPane().add(button2, BorderLayout.SOUTH);

    frame.validate();
  }
}

3. N/A

4. N/A

5. N/A
(Review ID: 38796)
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