How to sort jTree Nodes

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Hi,
I am interested in whats the easiest way to sort jTree Nodes alphabetically. Is there any Method to do this directly or may i use something like quicksort?
Thanks for help
Mirco

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There is already a topic on this subject
http://forum.java.sun.com/thread.jsp?forum=57&thread=563889

Denis Krukovsky
http://dotuseful.sourceforge.net/

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I can't handel this classes. I didn't find out how to use them. Is there any other, maybe easier way to sort TreeNodes?

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Thanks for your feedback. What you need to do is
- create a Comparator for your nodes (I believe you know what it is?) or subclass org.dotuseful.ui.tree.SortedTreeNode and implement Comparable interface in it;
- substitute your TreeModel with org.dotuseful.ui.tree.AutomatedTreeModel;
- substitute your tree nodes with org.dotuseful.ui.tree.SortedTreeNode or its subclass, and optionally provide a Comparator for them.

Here is a sketch of a node class that you need

import org.dotuseful.ui.tree;
public class ABSortTreeNode extends SortedTreeNode implements Comparable
    public int compareTo(Object o) {
        MutableTreeNode node = (MutableTreeNode)o;
        return ((Comparable)getUserObject()).compareTo(node.getUserObject());
    }
}

So having this class, you only need to
- substitute your TreeModel with org.dotuseful.ui.tree.AutomatedTreeModel;
- substitute your tree nodes with ABSortTreeNode.

I believe this is pretty easy way to sort a tree. I would make my classes understandable for everyone, so please keep asking questions.

Denis Krukovsky
http://dotuseful.sourceforge.net/

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Hi,
The jtree nodes are sorted in jtree display.
But how to keep folders (non-leaf-nodes) and leaf-nodes sorted separately?
I�d like to have the leaf-nodes listed first under root and then all folders followed.
Any ideas? Do you have any samples related that?
Thank you for your help in advance.

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Hi,

Thank you for interest in dotuseful library. Good to have people who use our work.

I'm going to write an article about directory tree creation. Stay tuned on http://dotuseful.sourceforge.net/

For this time, what you need is to modify your Comparator or compareTo() method so your folders stay before your files.

Denis Krukovsky
http://dotuseful.sourceforge.net/

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This is not exactly what you are looking for but might give you an idea.

Hamed

/**
	 * @param root of tree
	 * @return sorted elements alphabetically
	 */
	public static DefaultMutableTreeNode sortTree(DefaultMutableTreeNode root) {
		for (int i = 0; i < root.getChildCount(); i++) {
			DefaultMutableTreeNode node = (DefaultMutableTreeNode) root
					.getChildAt(i);
			String nt = node.getUserObject().toString();
			for (int j=0; j<i; j++) {
				DefaultMutableTreeNode prevNode = (DefaultMutableTreeNode) root
				.getChildAt(j);
				String np = prevNode.getUserObject().toString();
				if (nt.compareToIgnoreCase(np)<0) {
					root.insert(node, j);
					root.insert(prevNode, i);
				}
			}
			if (node.getChildCount() > 0) {
				node = sortTree(node);
			}
		}
		return root;
	}

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This is not exactly what you are looking for but might give you an idea.

Thanks a lot for your code. It helped very much

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Thanks Hamed,

Well, I work in your code, and I post here.

  public static DefaultMutableTreeNode sortTree(DefaultMutableTreeNode root) {
        {
                 for (int i =0; i<root.getChildCount()-1; i++) {
                		DefaultMutableTreeNode node = (DefaultMutableTreeNode) root.getChildAt(i);
                        String nt = node.getUserObject().toString();

                        for (int j=i+1;j<=root.getChildCount()-1;j++)
                        {
                            	DefaultMutableTreeNode prevNode = (DefaultMutableTreeNode) root.getChildAt(j);
				                String np = prevNode.getUserObject().toString();

                            System.out.println(nt+" "+np);
                            if (nt.compareToIgnoreCase(np)>0) {

				                  	root.insert(node, j);
					                root.insert(prevNode, i);
				              }
                        }
                        if (node.getChildCount() > 0) {
				node = sortTree(node);
			}
                 }

                 return root;
        }
    }

and this code I used after include in jtree

  public  void jTreeSortingBegin()
    {
          dn = (DefaultMutableTreeNode)treeModel.getRoot();
          treeModel.reload();
          dn = sortTree(dn);
          treeModel.reload(dn);
    }

for exemple

  addObject(jTextField1.getText());
        jTreeSortingBegin();

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Thank you very much, Hamed, I only had to change your code a little, replacing

root.insert(prevNode, i);

with

break;

insert(prevNode) is not necessary as insert(node) will shift the rest of the nodes. Break is necessary to begin relocating the next child (in that case we'll be done with that one).

Edited by: Victor.E on May 27, 2009 2:38 AM