JTree Programmatic Node Expansion and Selection Probelm

[hemanthjava]

I've read plenty of java Swing forums or questions and none of them have the right answers. I am trying to dynamically select a node in a JTree by searching for it using a search panel based on its property.

My jtree allows single selection model. (SINGLE_TREE_SELECTION).

Code:

jTree.setExpandsSelectedPaths(true);
// jTree.expandPath(treePath);
jTree.setSelectionPath(treePath);
jTree.scrollPathToVisible(treePath);

I know the node is being selected and a call to jTree.getSelectionPath() shows the expected treePath. The problem is that graphically the treePath is neither expanded nor the specific searched node is highlighted.

TreePath is correct, and the node is being selected. The branch is just not being expanded and the node is not being highlighted. The node is not highlighted even when the branch is already in an expanded state.

Can anyone please help.

I am using Java 1.5

Thanks,
Bob

[hardwired]

Code:

import java.awt.*;
import java.awt.event.*;
import java.util.Enumeration;
import javax.swing.*;
import javax.swing.tree.*;

public class NodeExpansion implements ActionListener {
    JTree tree = new JTree();

    public void actionPerformed(ActionEvent e) {
        String s = e.getActionCommand();
        setExpandedState(s);
    }

    private void setExpandedState(String id) {
        DefaultMutableTreeNode root =
            (DefaultMutableTreeNode)tree.getModel().getRoot();
        Enumeration e = root.breadthFirstEnumeration();
        while(e.hasMoreElements()) {
            DefaultMutableTreeNode node = (DefaultMutableTreeNode)e.nextElement();
            if(node.getUserObject().equals(id)) {
                TreePath path = new TreePath(node.getPath());
                if(node.isLeaf()) {
                    DefaultMutableTreeNode parent =
                        (DefaultMutableTreeNode)node.getParent();
                    expandNode(new TreePath(parent.getPath()));
                } else {
                    expandNode(path);
                }
                tree.setSelectionPath(path);
                break;
            }
        }
    }

    private void expandNode(TreePath parent) {
        TreeNode node = (TreeNode)parent.getLastPathComponent();
        if (node.getChildCount() >= 0) {
            Enumeration e = node.children();
            while(e.hasMoreElements()) {
                TreeNode n = (TreeNode)e.nextElement();
                TreePath path = parent.pathByAddingChild(n);
                expandNode(path);
            }
        }
        tree.expandPath(parent);
    }

    private JPanel getContent() {
        JPanel panel = new JPanel(new GridLayout(1,0));
        panel.add(new JScrollPane(tree));
        panel.add(getRightComponent());
        return panel;
    }

    private JScrollPane getRightComponent() {
        ButtonGroup group = new ButtonGroup();
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(2,5,2,0);
        gbc.weightx = 1.0;
        gbc.anchor = GridBagConstraints.WEST;
        gbc.gridwidth = GridBagConstraints.REMAINDER;
        TreeModel model = tree.getModel();
        DefaultMutableTreeNode root = (DefaultMutableTreeNode)model.getRoot();
        Enumeration e = root.breadthFirstEnumeration();
        while(e.hasMoreElements()) {
            DefaultMutableTreeNode node = (DefaultMutableTreeNode)e.nextElement();
            String s = node.getUserObject().toString();
            JRadioButton rb = new JRadioButton(s);
            rb.setActionCommand(s);
            rb.addActionListener(this);
            group.add(rb);
            panel.add(rb, gbc);
        }
        return new JScrollPane(panel);
    }

    public static void main(String[] args) {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new NodeExpansion().getContent());
        f.setSize(500,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}