// TreeDemo.java (from the Java tutorial)
// Introduction:  more about trees and models, labels, nesting swing components

import javax.swing.JTree;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.event.TreeSelectionListener;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.tree.TreeSelectionModel;
import java.io.IOException;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JFrame;
import java.awt.*;
import java.awt.event.*;

public class TreeDemo extends JFrame {
    private JPanel textPane;
    private JLabel text;

    public TreeDemo() {
        super("TreeDemo");

        //Create the nodes.
        DefaultMutableTreeNode top = new DefaultMutableTreeNode("The Java Series");
        createNodes(top);

        //Create a tree that allows one selection at a time.
        final JTree tree = new JTree(top);
        tree.getSelectionModel().setSelectionMode
                (TreeSelectionModel.SINGLE_TREE_SELECTION);

       //Listen for when the selection changes.
        tree.addTreeSelectionListener(new TreeSelectionListener() {
            public void valueChanged(TreeSelectionEvent e) {
                DefaultMutableTreeNode node = (DefaultMutableTreeNode)
                                   tree.getLastSelectedPathComponent();

                if (node == null) return;

                Object nodeInfo = node.getUserObject();
                if (node.isLeaf()) {
                    BookInfo book = (BookInfo)nodeInfo;
                    displayText(book.bookName);

                } else {
                    displayText("directory:  " + (String)nodeInfo);
                }

            }
        }); 


        //Create the scroll pane and add the tree to it.
        JScrollPane treeView = new JScrollPane(tree);

        //Create the text viewing pane.
     	text = new JLabel();
		textPane = new JPanel();
		textPane.add(text);


        //Add the scroll panes to a split pane.
        JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
        splitPane.setTopComponent(treeView);
        splitPane.setBottomComponent(textPane);

        Dimension minimumSize = new Dimension(100, 50);
        treeView.setMinimumSize(minimumSize);
        splitPane.setDividerLocation(100);

        splitPane.setPreferredSize(new Dimension(500, 300));

        //Add the split pane to this frame.
        getContentPane().add(splitPane, BorderLayout.CENTER);
    }

    private class BookInfo {
        public String bookName;

        public BookInfo(String book) {
            bookName = book;

        }

        public String toString() {
            return bookName;
        }
    }


    private void displayText(String s) {
            text.setText(s);
    }

    private void createNodes(DefaultMutableTreeNode top) {
        DefaultMutableTreeNode category;
        DefaultMutableTreeNode book;

        category = new DefaultMutableTreeNode("Books for Java Programmers");
        top.add(category);

        //original Tutorial
        book = new DefaultMutableTreeNode(new BookInfo
            ("The Java Tutorial: Object-Oriented Programming for the Internet"));
        category.add(book);

        //Tutorial Continued
        book = new DefaultMutableTreeNode(new BookInfo
            ("The Java Tutorial Continued: The Rest of the JDK"));
        category.add(book);

        //JFC Swing Tutorial
        book = new DefaultMutableTreeNode(new BookInfo
            ("The JFC Swing Tutorial: A Guide to Constructing GUIs"));
        category.add(book);

        //Arnold/Gosling
        book = new DefaultMutableTreeNode(new BookInfo
            ("The Java Programming Language"));
        category.add(book);

        //FAQ
        book = new DefaultMutableTreeNode(new BookInfo(
            "The Java FAQ"));
        category.add(book);

        //Chan/Lee
        book = new DefaultMutableTreeNode(new BookInfo
            ("The Java Class Libraries: An Annotated Reference"));
        category.add(book);

        //Threads
        book = new DefaultMutableTreeNode(new BookInfo
            ("Concurrent Programming in Java: Design Principles and Patterns"));
        category.add(book);

        category = new DefaultMutableTreeNode("Books for Java Implementers");
        top.add(category);

        //VM
        book = new DefaultMutableTreeNode(new BookInfo
            ("The Java Virtual Machine Specification"));
        category.add(book);

        //Language Spec
        book = new DefaultMutableTreeNode(new BookInfo
            ("The Java Language Specification"));
        category.add(book);
    }

    public static void main(String[] args) {
        JFrame frame = new TreeDemo();

        // add an event to the window to close it!
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        frame.pack();
        frame.setVisible(true);
    }
}