How to dynamically add Nodes to JTree?

[Jon Campbell]

I can add nodes to my JTree, but after expanding a node, I can not add any child nodes to that node, or at least they dont show on the screen? Actually I can use the .add(new DefaultMutableTreeNode("Label")); to add a node to a parent node, but the new child node doesn't show on the display of the JTree?

Any help appreciated,
Jon

[Paul Clapham]

After you add a child to a node, you have to tell the tree model that you did that so that it can get the display changed. If you're using a DefaultTreeModel then you call its nodesWereInserted() method to do that.

[Brian Cole]

If you're using DefaultTreeModel then don't call
parentNode.add(newChild), but instead do
yourModel.insertNodeInto(newChild, parentNode, index)
and it will fire the events for you.

The downside is that you must supply the index.
If you want it to be the last child use
parentNode.getChildCount() as the index.

If you're not using DefaultTreeModel, then you
have to fire the events manually.