import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
public class TreeEvents extends JFrame implements TreeSelectionListener{
JButton addB,deleteB;
JTree tree;


DefaultMutableTreeNode leadSelection;

public TreeEvents(){
super("Tree Events Demo");
setSize(300,200);
setDefaultCloseOperation(EXIT_ON_CLOSE);

EEL eel=EEL.getInstance();
eel.addGui();

tree=new JTree();
tree.setExpandsSelectedPaths(true);
tree.setEditable(true);
getContentPane().add(new JScrollPane(tree),BorderLayout.CENTER);
tree.addTreeSelectionListener(eel);
tree.addTreeSelectionListener(this);
tree.addTreeExpansionListener(eel);
tree.addTreeWillExpandListener(eel);
tree.addPropertyChangeListener(eel);
tree.getModel().addTreeModelListener(eel);
addB=new JButton("Add a node");
deleteB=new JButton("Delete a node");
JPanel buttonP=new JPanel();
buttonP.add(addB);
buttonP.add(deleteB);
getContentPane().add(buttonP,BorderLayout.SOUTH);

addB.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae){
String nodeName=JOptionPane.showInputDialog("New node name");

if(leadSelection!=null){
leadSelection.add(new DefaultMutableTreeNode(nodeName));
((DefaultTreeModel)tree.getModel()).reload(leadSelection);
}
else{
JOptionPane.showMessageDialog(TreeEvents.this,"no parent..");
}
}
});

deleteB.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent ae){
if(leadSelection!=null){
DefaultMutableTreeNode parent=(DefaultMutableTreeNode)leadSelection.getParent();

if(parent==null){
JOptionPane.showMessageDialog(TreeEvents.this,"Can't delete root..");
}
else{
parent.remove(leadSelection);
leadSelection=null;
((DefaultTreeModel)tree.getModel()).reload(parent);
}
}
else{
JOptionPane.showMessageDialog(TreeEvents.this,"no selection..");
}
}
});

eel.showDialog();
}

public void valueChanged(TreeSelectionEvent e){
TreePath leadPath=e.getNewLeadSelectionPath();
if(leadPath!=null){
leadSelection=(DefaultMutableTreeNode)leadPath.getLastPathComponent();
}
}

public static void main(String a[])
{
TreeEvents te=new TreeEvents();
te.setVisible(true);
}
}

EEL eel=EEL.getInstance();