sorting node position in JTree

[Miana Husada]

Hi!
I want to rearrange node position in JTree according to the id which has been saved in each node.
For example:
Node A has 3 children: B(id=9), C(id=2), D(id=5)
the displayed tree should be: A has 3 children: Node C at index 0, node D at index 1, Node B at index 2.
could anyone please help me?
thanks a lot,
Mia

[Stan James]

I just did this method to move the currently selected child node up or down within its parent. It assumes single select mode and tree nodes are (or extend) DefaultMutableTreeNode.

public static void moveTreeNodeVertical( JTree aTree, int aDelta )
{
   DefaultMutableTreeNode lNode = getSelectedNode( aTree );
   if ( null == lNode ) return;                        // No node selected
   DefaultMutableTreeNode lParent = (DefaultMutableTreeNode)lNode.getParent();
   if ( null == lParent ) return;                      // Cannot move the Root!
   DefaultTreeModel lModel = (DefaultTreeModel)aTree.getModel();
   int lOldIndex = lModel.getIndexOfChild( lParent, lNode );
   int lNewIndex = lOldIndex + aDelta;
   if ( lNewIndex < 0 ) return;                        // Cannot move first child up
   if ( lNewIndex >= lParent.getChildCount() ) return; // Cannot move last child down
   lModel.removeNodeFromParent( lNode );
   lModel.insertNodeInto( lNode, lParent, lNewIndex );
   aTree.setSelectionPath( new TreePath( lNode.getPath() ) );
}

The JTree remove and insert methods do the moving. The rest just make sure it is ok to move.
This always inserts the node in collapsed state. I'd like to find a way to preserve the state of the node I'm moving and all of its children.

[Anthony Yulo]

DefaultMutableTreeNode node = new DefaultMutableTreeNode();

//this is your id?
Integer id = node.getUserObject();

DefaultMutableTreeNode parent = (DefaultMutableTreeNode)node.getParent();

if(parent.getChildCount() !=0)
{

for(Enumeration enum = parent.postorderEnumeration(); enum.hasMoreElements() :wink: 
{
DefaultMutableTreeNode child = (DefaultMutableTreeNode)enum.nextElement();
Integer childid = child.getUserObject();

if(id.intValue() < childid.intValue())
{

int index = parent.getIndex(child) == 0? 0  :-P	 arent.getIndex(child) -1;
parent.insert(node, parent.getIndex(index))
}

}


}


else
parent.insert(node,0);

this code ensures that when you add a node, the tree is automatically sorted...basically you compare all of the children IDS of the parent and with the node ID of the node you are currently adding... and then when node ID is less than the current traversed child ID then insert that before the current child...
i haven't compiled this code.. its only an idea...so make the proper corrections if there are errors in it...

[Anthony Yulo]

insert the line:
parent.insert(node,parent.getChildCount-1);
after the end braces of the for loop.... so if the id is greater than all of the child nodes, it will insert on the last position...
another thing, replace the yellow smiley face with a semicolon and a closing parenthesis i.e "; )" andthe green face with a colon and the letter p i.e. ": p"

[Anthony Yulo]

also please add "break;" after the last line inside the if statement.....