TreePanel.java

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;

import javax.swing.BorderFactory;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.border.Border;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeSelectionModel;

public class TreePanel implements GUI {
	private static TreePanel panel;
 private JTree tree;
 private DefaultMutableTreeNode rootNode;
 
 private JPanel treePanel;

 //singelton so only one tree can exist 
 public static TreePanel panel() {
 	if (panel == null) {
 		panel = new TreePanel();
 	}
 	
 	return panel;
 }

 public TreePanel() {
 	
 }
 
 //intialize 
 public void initialize() {
 this.rootNode = new DefaultMutableTreeNode("Root Node");
 this.tree = new JTree(rootNode);
 tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);

 this.treePanel = new JPanel();


 formatPanel();
 }
 
 //format the panel 
 public void formatPanel() {
 Border treeBorder = BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.RED), "Tree View");

 treePanel.setBorder(treeBorder);
 treePanel.setPreferredSize(new Dimension(200, 400));
 
 treePanel.setLayout(new BorderLayout());
 treePanel.add(new JScrollPane(tree));
 }
 
 //retrieves the seleceted node in a tree 
 public DefaultMutableTreeNode getSelectedNode() {
 return (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
 }
 
 //adds a group to the tree 
 public void addGroupToTree(String groupName, DefaultMutableTreeNode parentNode) {
 DefaultMutableTreeNode groupNode = new DefaultMutableTreeNode(groupName);
 parentNode.add(groupNode);
 tree.updateUI(); // Refresh the tree model to reflect the changes
 }
 
 //adds a user to the tree 
 public void addUserToTree(String userName, DefaultMutableTreeNode parentNode) {
 DefaultMutableTreeNode userNode = new DefaultMutableTreeNode(userName);
 parentNode.add(userNode);
 tree.updateUI(); // Refresh the tree model to reflect the changes
 }
 
 //renders the tree 
 public JPanel render() {
 	initialize();
 	return this.treePanel;
 }
}