Expanding a JTree Node on selection

Question

Hi,
I have a need to expand the node on selection in a JTree. I would like all the children to be recursively expanded and selected.
I believe the code lies somewhere with in JTree's TreeSelectionListener.
The code I have is as follows
tree.addTreeSelectionListener(new TreeSelectionListener()
public void valueChanged(TreeSelectionEvent evt)
TreePath[] paths = evt.getPaths();
for (int i=0; i<paths.length; i++)
if (evt.isAddedPath(i))
DataNode node = (DataNode)paths.getLastPathComponent();
ArrayList aList = node.children();
if( !aList.isEmpty() )
for(int j = 0; j<aList.size(); j++)
TreePath tp = paths[i].pathByAddingChild(aList.get(j));
System.out.println(tp);
tree.expandPath(tp);
}//for
}//public void ValueChanged
This does not seem to solve the problem..
Your comments or help is very much appreciated..
thanks
S

Answer 1

it does work for me (i do it in an action). what doesn't work for you?
thomas
  public RecursiveExpander() {
    menu = new JPopupMenu();
    JMenuItem expand = new JMenuItem("Expand Recursive");
    expand.addActionListener(this);
    menu.add(expand);
  public void mousePressed(MouseEvent e) {
    theTree = (JTree)e.getSource();
    currentPath = theTree.getPathForLocation(e.getX(), e.getY());
    if ((currentPath != null) &&
        !((TreeNode)currentPath.getLastPathComponent()).isLeaf() &&
        (e.getModifiers() == InputEvent.BUTTON3_MASK)) {
      menu.show(theTree, e.getX(), e.getY());
  public void actionPerformed(ActionEvent ae) {
    new Thread(this).start();
  public void run() {
    theTree.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
    try { expand(currentPath); }
    catch (OutOfMemoryError oom) {
      System.gc();
      System.err.println("RecursiveExpander: " + oom);
      JOptionPane.showMessageDialog(null, "RecursiveExpander: " + oom, "Error", JOptionPane.ERROR_MESSAGE);
    theTree.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
  private void expand(TreePath path) {
    theTree.expandPath(path);
    TreeNode start = (TreeNode)path.getLastPathComponent();
    for (int i = 0; i < start.getChildCount(); i++) {
      TreeNode node = start.getChildAt(i);
      if (!node.isLeaf()) {
        expand(path.pathByAddingChild(node));
}