JTree not updating

[Rik Sweeney]

Hi,

I'm adding nodes to my JTree, but it is not being updated. If I add a node to the root, then the tree updates OK, but then if I add another, nothing happens. If I then add a node to the child of the node, then the tree updates OK and will show the node number as if all the other nodes have been added.

Anyway, here's the code

public class Tree extends JTree
{
    int i;
    DefaultTreeModel model;
    
    /** Creates a new instance of Tree */
    public Tree()
    {
        super(new DefaultTreeModel(new DefaultMutableTreeNode("root")));
        
        model = (DefaultTreeModel)getDefaultTreeModel();
        
        i = 1;
    }
    
    public void addNode()
    {
        DefaultMutableTreeNode node = (DefaultMutableTreeNode)getLastSelectedPathComponent();
        
        if (node != null)
        {
            DefaultMutableTreeNode child = new DefaultMutableTreeNode("Item " + (i++));
            
            model.insertNodeInto(child, node, node.getChildCount());
            
            expandPath(getSelectionPath());
        }
    }
    
    public void removeNode()
    {
        DefaultMutableTreeNode node = (DefaultMutableTreeNode)getLastSelectedPathComponent();
        
        model.removeNodeFromParent(node);
    }
}

Does anyone know what I'm doing wrong?

Thanks

Richard

[Andr� Latour]

Hello Rik,

only an idea:

After you rebuild your tree, add the "new" rootElement to your DefaultTreeModel

something like this:

dtm=new DefaultTreeModel(rootElement);
tree= new JTree(dtm);    
...
// tree has changed
dtm.setRoot(newRootElement);
 

Regards
Andr�
[ May 23, 2006: Message edited by: Andr� Latour ]

[Rik Sweeney]

Thanks for the suggestion. I had a quick look in the constructor and changed it to

    /** Creates a new instance of Tree */
    public Tree()
    {
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("root");
        
        model = new DefaultTreeModel(root);
        
        setModel(model);
        
        i = 1;
    }

This solved the problem!