JTree Expansion

[jhon meshek]

Hi All,

How to load data instantly when i click on "+" ?

Any suggestion would be appreciated.

Thanks in Advance

[Craig Wood]

For a JTree use a DefaultTreeModel like this

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
 
public class TreeLoading implements ActionListener {
    JTree tree;
 
    public void actionPerformed(ActionEvent e) {
        DefaultTreeModel model = (DefaultTreeModel)tree.getModel();
        DefaultMutableTreeNode root = (DefaultMutableTreeNode)model.getRoot();
        int nextRow = model.getChildCount(root);
        int[] indices = new int[10];
        for(int j = nextRow, k = 0; j < nextRow+10; j++) {
            DefaultMutableTreeNode node = new DefaultMutableTreeNode("Node " + j);
            model.insertNodeInto(node, root, j);
            indices[k++] = j;
            if(j == 0)
                tree.expandRow(0);
        }
    }
 
    private JScrollPane getTreeComponent() {
        tree = new JTree();
        DefaultTreeModel model =
            new DefaultTreeModel(new DefaultMutableTreeNode("root"));
        tree.setModel(model);
        return new JScrollPane(tree);
    }
 
    private JPanel getLast() {
        JButton button = new JButton("add data");
        button.addActionListener(this);
        JPanel panel = new JPanel();
        panel.add(button);
        return panel;
    }
 
    public static void main(String[] args) {
        TreeLoading test = new TreeLoading();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(test.getTreeComponent());
        f.getContentPane().add(test.getLast(), "Last");
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}