How to resize a custom tree node like you would a JFrame window?

Question

Hello,
I am trying to resize a custom tree node like you would a JFrame window.
As with a JFrame, when your mouse crosses the Border, the cursor should change and you are able to drag the edge to resize the node.
However, I am faced with a problem. Border cannot detect this and I dont want to use a mouse motion listener (with a large number of nodes, I fear it will be inefficient, calculating every node's position constantly).
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Insets;
import java.util.EventObject;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellEditor;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeSelectionModel;
public class ResizeNode extends JPanel {
       AnilTreeCellRenderer2 atcr;
       AnilTreeCellEditor2 atce;
       DefaultTreeModel treeModel;
       JTree tree;
       DefaultMutableTreeNode markedNode = null;
     public ResizeNode() {
            super(new BorderLayout());
               treeModel = new DefaultTreeModel(null);
               tree = new JTree(treeModel);          
              tree.setEditable(true);
               tree.getSelectionModel().setSelectionMode(
                         TreeSelectionModel.SINGLE_TREE_SELECTION);
               tree.setShowsRootHandles(true);
              tree.setCellRenderer(atcr = new AnilTreeCellRenderer2());
              tree.setCellEditor(atce = new AnilTreeCellEditor2(tree, atcr));
               JScrollPane scrollPane = new JScrollPane(tree);
               add(scrollPane,BorderLayout.CENTER);
     public void setRootNode(DefaultMutableTreeNode node) {
          treeModel.setRoot(node);
          treeModel.reload();
       public static void main(String[] args){
            ResizeNode tb = new ResizeNode();
            tb.setPreferredSize(new Dimension(400,200));
              JFrame frame = new JFrame("ResizeNode");
              frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
              frame.setContentPane(tb);
              frame.setSize(400, 200);
              frame.pack();
              frame.setVisible(true);
              tb.populate();
     private void populate() {
          TextAreaNode2 r = new TextAreaNode2(this);
           setRootNode(r);
           TextAreaNode2 a = new TextAreaNode2(this);
           treeModel.insertNodeInto(a, r, r.getChildCount());          
class AnilTreeCellRenderer2 extends DefaultTreeCellRenderer{
TreeBasic panel;
DefaultMutableTreeNode currentNode;
  public AnilTreeCellRenderer2() {
     super();
public Component getTreeCellRendererComponent
   (JTree tree, Object value, boolean selected, boolean expanded,
   boolean leaf, int row, boolean hasFocus){
     TextAreaNode2 currentNode = (TextAreaNode2)value;
     NodeGUI2 gNode = (NodeGUI2) currentNode.gNode;
    return gNode.box;
class AnilTreeCellEditor2 extends DefaultTreeCellEditor{
  DefaultTreeCellRenderer rend;
  public AnilTreeCellEditor2(JTree tree, DefaultTreeCellRenderer r){
    super(tree, r);
    rend = r;
  public Component getTreeCellEditorComponent(JTree tree, Object value,
   boolean isSelected, boolean expanded, boolean leaf, int row){
    return rend.getTreeCellRendererComponent(tree, value, isSelected, expanded,
     leaf, row, true);
  public boolean isCellEditable(EventObject event){
    return true;
class NodeGUI2 {
     final ResizeNode view;
     Box box = Box.createVerticalBox();
     final JTextArea aa = new JTextArea( 1, 5 );
     final JTextArea aaa = new JTextArea( 1, 8 );
     NodeGUI2( ResizeNode view_ ) {
          this.view = view_;
          box.add( aa );
          aa.setBorder( BorderFactory.createMatteBorder( 0, 0, 1, 0, Color.GREEN ) );
          box.add( aaa );
          box.setBorder( BorderFactory.createMatteBorder( 5, 5, 5, 5, Color.CYAN ) );
     private Dimension getEditorPreferredSize() {
          Insets insets = box.getInsets();
          Dimension boxSize = box.getPreferredSize();
          Dimension aaSize = aa.getPreferredSize();
          Dimension aaaSize = aaa.getPreferredSize();
          int height = aaSize.height + aaaSize.height + insets.top + insets.bottom;
          int width = Math.max( aaSize.width, aaaSize.width );
          if ( width < boxSize.width )
               width += insets.right + insets.left + 3;     // 3 for cursor
          return new Dimension( width, height );               
class TextAreaNode2 extends DefaultMutableTreeNode {  
     NodeGUI2 gNode;
     TextAreaNode2(ResizeNode view_) {     
          gNode = new NodeGUI2(view_);
}

Answer 1

the node on the tree is only painted on using the
renderer to do the painting work. A mouse listener
has to be added to the tree, and when moved over an
area, you have to determine if you are over the
border and which direction to update the cursor and
to know which way to resize when dragged. One of the
BasicRootPaneUI has some code that can help determine
that.Thanks for replying. What is your opinion on this alternative idea that I just had?
I am wondering if it might be easier to have a toggle button in the node that you click when you want to resize the node. Then a mouse-down and dragging the mouse will resize the node. Mouse-up will reset the toggle button, and so will mouse down in an invalid area.
Anil