Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;

public class Main extends JFrame {
    DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("A");

    private DefaultTreeModel m_model = new DefaultTreeModel(rootNode);

    private JTree m_tree = new JTree(m_model);

    private JButton m_addButton;

    private JButton m_delButton;

    public Main() {
        DefaultMutableTreeNode forums = new DefaultMutableTreeNode("B");
        forums.add(new DefaultMutableTreeNode("T"));
        DefaultMutableTreeNode articles = new DefaultMutableTreeNode("A");
        articles.add(new DefaultMutableTreeNode("A"));
        DefaultMutableTreeNode examples = new DefaultMutableTreeNode("E");
        examples.add(new DefaultMutableTreeNode("E"));

        rootNode.add(forums);
        rootNode.add(articles);
        rootNode.add(examples);

        m_tree.setEditable(true);
        m_tree.setSelectionRow(0);

        JScrollPane scrollPane = new JScrollPane(m_tree);
        getContentPane().add(scrollPane, BorderLayout.CENTER);

        JPanel panel = new JPanel();
        m_addButton = new JButton("Add Node");
        m_addButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                DefaultMutableTreeNode selNode = (DefaultMutableTreeNode) m_tree.getLastSelectedPathComponent();

                if (selNode == null) {
                    return;
                }

                DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("New");
                m_model.insertNodeInto(newNode, selNode, selNode.getChildCount());

                TreeNode[] nodes = m_model.getPathToRoot(newNode);
                TreePath path = new TreePath(nodes);
                m_tree.scrollPathToVisible(path);

                m_tree.setSelectionPath(path);

                m_tree.startEditingAtPath(path);
            }

        });
        panel.add(m_addButton);
        getContentPane().add(panel, BorderLayout.SOUTH);
        m_delButton = new JButton("Delete Node");
        m_delButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent event) {
                DefaultMutableTreeNode selNode = (DefaultMutableTreeNode) m_tree.getLastSelectedPathComponent();
                if (selNode == null) {
                    return;
                }
                MutableTreeNode parent = (MutableTreeNode) (selNode.getParent());
                if (parent == null) {
                    return;
                }
                MutableTreeNode toBeSelNode = (MutableTreeNode) selNode.getPreviousSibling();
                if (toBeSelNode == null) {
                    toBeSelNode = (MutableTreeNode) selNode.getNextSibling();
                }
                if (toBeSelNode == null) {
                    toBeSelNode = parent;
                }
                TreeNode[] nodes = m_model.getPathToRoot(toBeSelNode);
                TreePath path = new TreePath(nodes);
                m_tree.scrollPathToVisible(path);
                m_tree.setSelectionPath(path);
                m_model.removeNodeFromParent(selNode);
            }

        });
        panel.add(m_delButton);
        getContentPane().add(panel, BorderLayout.SOUTH);

        setSize(300, 400);
        setVisible(true);
    }

    public static void main(String[] arg) {
        new Main();
    }
}