Sort JTree

It all depends on how you are storing information in JTree.

Do you use model? If you do, how are you implementing it?

Do you use any collection to store nodes? how?

All you need to do, is to write sorting mechanism and then when you insert new node, just fire proper event like treeStructureChanged(...) or nodeChanged(...).

Let me know what you think about it.

Regards,

D

dhaval04a at 2007-7-28 19:21:42 >

This is a simple function that can sort the child nodes of a specifed parent node defined by the TreePath argument.

Copy and modify this code to suite your app. This only sorts on node but it can easily be modified to sort the entire table using recursion.

public void sortTreeNode(TreePath editPath) {

DefaultMutableTreeNode node = (DefaultMutableTreeNode)editPath.getParentPath().getLastPathComponent();

Enumeration<DefaultMutableTreeNode> children = (Enumeration<DefaultMutableTreeNode>)node.children();

Vector<DefaultMutableTreeNode> childNodes = new Vector<DefaultMutableTreeNode>();

Vector<String> nodeNames = new Vector<String>();

while( children.hasMoreElements() ) {

DefaultMutableTreeNodechild = children.nextElement() ;

nodeNames.addElement( child.getUserObject().toString() );

childNodes.addElement( child );

}

Collections.sort(nodeNames);

Vector<DefaultMutableTreeNode> sortedChildNodes = new Vector<DefaultMutableTreeNode>();

for(String nodeName: nodeNames ) {

for(DefaultMutableTreeNode child: childNodes) {

if(child.getUserObject().equals(nodeName)) {

sortedChildNodes.addElement( child );

}

}

}

node.removeAllChildren();

for(DefaultMutableTreeNode child: sortedChildNodes) {

node.add( child );

}

((DefaultTreeModel)libTree.getModel()).nodeStructureChanged( node );

childNodes.removeAllElements();

childNodes = null;

}

For your second problem, you need to consider these methods: the remove( . . ) methods under DefaultMutableTreeNode and the nodeStructureChanged(..) method in DefaultTreeModel. It is very simple to tweak and use those methods to get the results you require.

ICE

icewalker2ga at 2007-7-28 19:21:42 >

I totally agree with D, that this is not the very best solution for large tree sorting. I used this approach cause in my app, the sorting is done for only the Children of one TreeNode at a time.

This may be over your head in terms of code, but you can look at the source code provided for the JTreeTable examples on the Swing tutorials site, you'll find a good example of what D is talking about, a TreeModel with custom TreeNodes that enable sorting at the model level.

Check out: http://java.sun.com/products/jfc/tsc/articles/treetable1/index.html

http://java.sun.com/products/jfc/tsc/articles/treetable2/index.html

ICE

icewalker2ga at 2007-7-28 19:21:42 >

Well vyang,

You have very good idea about how to do sorting via ICE's reply. If you need example of what I did it, let me know at dhaval04@yahoo.com. I will be happy to give you code.

I also thanks ICE for his help and glad that we both can able to help you.

Regards,

D

dhaval04a at 2007-7-28 19:21:42 >