JTree problem with parents

[Olivier Legat]

Hello everyone

I've been trying to make a dynamic JTree (something that looks a little bit like this)

Just like with DynamicTree.java I made an addNode method and added 2 more methods.

public class TreeManager {
	private static TreeManager TREE_MANAGER;
	
	private DefaultMutableTreeNode rootNode;
	private DefaultTreeModel treeModel;
	private JTree tree;

	public TreeManager(MyExplorer explorer) {
		TREE_MANAGER = this;
		rootNode = new DefaultMutableTreeNode("workspace");
		treeModel = new DefaultTreeModel(rootNode);
		//treeModel.addTreeModelListener(new MyTreeModelListener());
		tree = new JTree(treeModel);
		tree.setEditable(true);
		tree.getSelectionModel().setSelectionMode
		(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
		tree.setShowsRootHandles(true);
		
		explorer.add(tree);
	}
	
	public static TreeManager get() {return TREE_MANAGER;}

	public DefaultMutableTreeNode addNode(MutableTreeNode parent,
			DefaultMutableTreeNode childNode, 
			boolean shouldBeVisible)
	{
		treeModel.insertNodeInto(childNode, parent, parent.getChildCount());
		
        if (shouldBeVisible) {
            tree.scrollPathToVisible(new TreePath(childNode.getPath()));
        }
        
		return childNode;
	}
	
	public CanvasNode addCanvas() {
		CanvasNode canvasNode = new CanvasNode();
		addNode(rootNode, canvasNode, true);
		return canvasNode;
	}
	
	public void removeNode(DefaultMutableTreeNode node) {
		treeModel.removeNodeFromParent(node);
	}
}

Adding a canvas works without any problems. But when I invoke removeCanvas I get this aggressive message but strangely enough the node still disappears

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: node does not have a parent.
at javax.swing.tree.DefaultTreeModel.removeNodeFromParent(Unknown Source)
at ueacad.view.explorer.TreeManager.removeNode(TreeManager.java:60)
at ueacad.view.desktop.CanvasFrame.dispose(CanvasFrame.java:54)
at javax.swing.JInternalFrame.doDefaultCloseAction(Unknown Source)
at javax.swing.plaf.basic.BasicInternalFrameTitlePane$CloseAction.actionPerformed(Unknown Source)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Is there something wrong with my add method ? Or does the error come from elsewhere?

Thanks in advance

[Rob Spoor]

Are you trying to remove the root node?

[Olivier Legat]

I don't think so :s ... I'll double-check.