在 Java 中手动重命名 JTree 节点

Question

I have created a jtree with the root node "RootNode" and some other nodes like "Node1","Node2", Node3".

After creation of tree I want to rename the rootnode or any other node by manually. We can rename the node dynamically by using the method

 jtee.setEditable(true);

But I want to change the name in manualy by the code level

like

 someMethod(Arg1 oldNodeName,Arg2 newNodeName)

Is there any way to do this?

Answer 1

Assuming you are using a DefaultMutableTreeNode you could just change the UserObject (whose toString() method is what is used to display the node name) by calling: setUserObject() on the node you want to change.

Answer 2

I'll assume you're using a tree with a DefaultTreeModel , using instances of DefaultMutableTreeNode .

You'll have to iterate through the tree nodes and find the one which has the oldNodeName as user object, then change its user object to newNodeName , and call the method nodeChanged of the tree model.

Answer 3

To properly rename a DefaultMutableTreeNode , you must set it's new user object as well as notify the JTree s table model the node changed so it can resize it for the shorter/longer text.

Assuming your tree is using a DefaultTreeModel , use this:

public void renameNode(JTree tree, DefaultMutableTreeNode node, Object new_user_object) {
     node.setUserObject(new_user_object);
     ((DefaultTreeModel) tree.getModel()).nodeChanged(node);
}

Answer 4

It does change the UI, if:

• you are using a DefaultTreeModel model
• you actually change the UserObject

This is to say something like this:

// TheNode is a CustomMutableTreeNode (extending DefaultMutableTreeNode)
// and points to the selected node to alter
String NewNodeName = Dlg.NewNodeName.getText();
if(!NewNodeName.isEmpty()) {
    ON.setName(NewNodeName); // ON is the real source data
    TheNode.setUserObject(NewNodeName);
    ((DefaultTreeModel)JSONTree.getModel()).nodeChanged(TheNode);
}

It took me quite a while to figure out that changing the source data (in ON) did nothing on the UI, even with a repaint();. You really have to update theUserObject (a String from the DefaultMutableTreeNode)

Once this done, it's the easiest and most elegant solution IMO.