Quick JTree Question...

[claude jones]

Hello:
Is there a way to set a treeNode that does not currently contain any childern with the closedFolderIcon instead of the leafIcon?
Example:
If I created a node that allows childern, but is currently empty, I would like to display this node with the closedFolderIcon. This would be similar to an empty directory within a file system.
I plan on having a "Add Folder" and "Add Node" button to manipulate the tree.
When I add a rootNode to the JTree I get a leafIcon instead of the closedFolderIcon. I only get the closedFolderIcon once I have added a childNode to the rootNode.
Any ideas?
Thanks,
claude jones

[Manfred Leonhardt]

Hi Claude,
Just one. Look at the following code. I have bolded the important items to do what you want.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
public class JTreeExample extends JFrame
{
  JTree tree;
  String[] nodeNames = { "Root Node", 
                         "Folder1 Node", 
                         "Leaf1 Node",
                         "Folder2 Node",
                         "Leaf2 Node" };
  public JTreeExample()
  {
    DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode( nodeNames[0] );
    DefaultTreeModel treeModel = new DefaultTreeModel( rootNode );
    [B]treeModel.setAsksAllowsChildren( true )[/B];
    tree = new JTree();
    tree.setModel( treeModel );
    //
    // Add some folder nodes (leaf without children)
    //
    for( int i = 1; i < nodeNames.length; ++i )
    {
      DefaultMutableTreeNode childNode = new DefaultMutableTreeNode( nodeNames[i] );
      [B]childNode.setAllowsChildren( ((i % 2) != 0) )[/B];
      treeModel.insertNodeInto( childNode, rootNode, rootNode.getChildCount() );
    }
    setSize( 500, 500 );
    getContentPane().add( tree );
    addWindowListener( 
      new WindowAdapter()
      {
        public void windowClosing( WindowEvent we )
        {
          System.exit( 0 );
        }
      });
  }
  public static void main(String[] args) 
  {
    new JTreeExample().setVisible( true );
  }
}

Regards,
Manfred.

[claude jones]

Manfred,
Thanks for the reply. That did the trick!
claude