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

public class TreeWithPopup extends JPanel {
  DefaultMutableTreeNode root, node1, node2, node3;
  public TreeWithPopup() {
    MyJTree tree;
    root = new DefaultMutableTreeNode("root", true);
    node1 = new DefaultMutableTreeNode("node 1", true);
    node2 = new DefaultMutableTreeNode("node 2" , true);
    node3 = new DefaultMutableTreeNode("node 3", true);
    root.add(node1);
    node1.add(node2);
    root.add(node3);
    setLayout(new BorderLayout());
    tree = new MyJTree(root);
    add(new JScrollPane((JTree)tree),"Center");
    }

  public Dimension getPreferredSize(){
    return new Dimension(300, 300);
    }
   
  public static void main(String s[]){
    JFrame frame = new JFrame("Tree With Popup");
    TreeWithPopup panel = new TreeWithPopup();
        
    frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
    frame.setForeground(Color.black);
    frame.setBackground(Color.lightGray);
    frame.getContentPane().add(panel,"Center");

    frame.setSize(panel.getPreferredSize());
    frame.setVisible(true);
    frame.addWindowListener(new WindowCloser());
    }
}

class WindowCloser extends WindowAdapter {
  public void windowClosing(WindowEvent e) {
    Window win = e.getWindow();
    win.setVisible(false);
    System.exit(0);
    }
}

class MyJTree extends JTree implements ActionListener{
   JPopupMenu popup;
   JMenuItem mi;

   MyJTree (DefaultMutableTreeNode dmtn) {
    super(dmtn);
    // define the popup
    popup = new JPopupMenu();
    mi = new JMenuItem("Insert a children");
    mi.addActionListener(this);
    mi.setActionCommand("insert");
    popup.add(mi);
    mi = new JMenuItem("Remove this node");
    mi.addActionListener(this);
    mi.setActionCommand("remove");
    popup.add(mi);  
    popup.setOpaque(true);
    popup.setLightWeightPopupEnabled(true);

    addMouseListener (
        new MouseAdapter () {
           public void mouseReleased( MouseEvent e ) {
              if ( e.isPopupTrigger()) {
                  popup.show( (JComponent)e.getSource(), e.getX(), e.getY() );
                  }
              } 
           }
        );
     
   }
  public void actionPerformed(ActionEvent ae) {
    DefaultMutableTreeNode dmtn, node;

    TreePath path = this.getSelectionPath();
    dmtn = (DefaultMutableTreeNode) path.getLastPathComponent();
    if (ae.getActionCommand().equals("insert")) {
      node = new DefaultMutableTreeNode("children");
      dmtn.add(node);
      // thanks to Yong Zhang for the tip for refreshing the tree structure.
      ((DefaultTreeModel )this.getModel()).nodeStructureChanged((TreeNode)dmtn); 
      }
    if (ae.getActionCommand().equals("remove")) {
      node = (DefaultMutableTreeNode)dmtn.getParent();
      node.removeAllChildren();
      ((DefaultTreeModel )this.getModel()).nodeStructureChanged((TreeNode)dmtn); 
      }
    } 
  }