/*
 *  File: SimpleTextEditor.java
 *  Author: Java, Java, Java
 *  Description:  This application program implements a
 *    menu-based interface for a text editor. It contains
 *    a file menu, an edit menu, and a recent-cuts menu, a
 *    dynamic menu whose options are built during the editing
 *    process.  The recent-cuts menu stores text that has been
 *    cut from the text being edited. Items from the cuts menu can be
 *    pasted into the document.
 */

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

public class SimpleTextEditor extends JFrame implements ActionListener
{
    public static final long serialVersionUID = 0;
    private JMenuBar mBar = new JMenuBar();       // Create the menu bar
    private JMenu fileMenu, editMenu, cutsMenu;           // Menu references
    private JMenuItem cutItem, copyItem, pasteItem, selectItem,recentcutItem; // Edit items
    private JMenuItem quitItem, openItem, saveItem;       // File items
    private JTextArea display = new JTextArea();          // Here's where the editing occurs                     
    private String scratchPad = "";                       // Scratch pad for cut/paste
    private Vector<String> recentCuts = new Vector<String>();
      
    /**
     *  SimpleTextEditor() constructor sets the layout for the GUI
     *  and calls methods to initialize the menus.
     */
    public SimpleTextEditor()
    {
        super("Simple Text Editor");     // Set the window title
        this.getContentPane().setLayout(new BorderLayout()); 
        this.getContentPane().add("Center", display); 
        this.getContentPane().add(new JScrollPane(display));
        display.setLineWrap(true);
        this.setJMenuBar(mBar);         // Set this program's menu bar
        initFileMenu();                 // Create the menus
        initEditMenu();    
    } // SimpleTextEditer()
   
    /**
     *  initEditMenu() creates the edit menu and adds its
     *   individual menu items. Note the each menu item
     *   is registered with an ActionListener.
     */
    private void initEditMenu() 
    {
        editMenu = new JMenu("Edit");             // Create the edit menu
        mBar.add(editMenu);                       //  and add it to menu bar
        cutItem = new JMenuItem ("Cut");          // Cut item
        cutItem.addActionListener(this);
        editMenu.add(cutItem);            
        copyItem = new JMenuItem("Copy");         // Copy item
        copyItem.addActionListener(this);
        editMenu.add(copyItem);
        pasteItem = new JMenuItem("Paste");       // Paste item
        pasteItem.addActionListener(this);   
        editMenu.add(pasteItem);
        editMenu.addSeparator();
        selectItem = new JMenuItem("Select All"); // Select item
        selectItem.addActionListener(this);  
        editMenu.add(selectItem);   
        editMenu.addSeparator();
        cutsMenu = new JMenu("Recent Cuts");      // Recent cuts submenu
        editMenu.add(cutsMenu);
    } // initEditMenu()

    /**
     *  initFileMenu() creates the file menu and adds its
     *   individual menu items. Note the each menu item
     *   is registered with an ActionListener.
     */
    private void initFileMenu() 
    {
        fileMenu = new JMenu("File");       // Create the file menu
        mBar.add(fileMenu);                 //  and add it to the menu bar
        openItem = new JMenuItem("Open");   // Open item
        openItem.addActionListener( this );
        openItem.setEnabled(false);
        fileMenu.add(openItem);
        saveItem = new JMenuItem("Save");   // Save item
        saveItem.addActionListener(this);
        saveItem.setEnabled(false);
        fileMenu.add(saveItem);  
        fileMenu.addSeparator();            // Logical separator
        quitItem = new JMenuItem("Quit");   // Quit item
        quitItem.addActionListener(this);
        fileMenu.add(quitItem);  
    } // initFileMenu()
      
    /**
     *  actionPerformed() handles the user's menu selections.
     *  @param e -- the ActionEvent that led to this method call
     */
    public void actionPerformed(ActionEvent e) 
    {
        JMenuItem m  = (JMenuItem)e.getSource();    // Get the selected menu item
        if ( m == quitItem ) 
        {                                           // Quit
            dispose();
        } else if (m == cutItem) 
        {                  // Cut the selected text
            scratchPad = display.getSelectedText(); // Copy the text to the scratchpad
            display.replaceRange("",                //  and delete 
            display.getSelectionStart(),            //  from the start of the selection
            display.getSelectionEnd());             //  to the end
            addRecentCut(scratchPad);               // Add the cut text to the cuts menu
        } else if (m == copyItem)
        {                                           // Copy the selected text to the scratchpad
            scratchPad = display.getSelectedText();
        } else if (m == pasteItem) 
        {                                           // Paste the scratchpad to the document
            display.insert(scratchPad, display.getCaretPosition());    // at the caret position
        } else if ( m == selectItem ) 
        {               
            display.selectAll();                    // Select the entire document
        } else {
            JMenuItem item = (JMenuItem)e.getSource();  // Default case is the cutsMenu
            scratchPad = item.getActionCommand();       // Put the cut back in the scratchpad
        }            
    } // actionPerformed()
   
    /**
     *  addRecentCut() adds its parameter to the recent cut menu,
     *   a menu which grows dynamically as the user cuts text from a document
     *  Recent cuts are stored in a vector. When inserting a cut into the menu
     *   the menu is first cleared (removeAll(), and then the recent cuts are
     *   inserted in last-in-first-out order. Each newly inserted cut is assigned
     *   an ActionListener.
     *  @param cut -- the text to be added as the menu item
     */
    private void addRecentCut(String cut) 
    {
        recentCuts.insertElementAt(cut,0);
        cutsMenu.removeAll();
        for (int k = 0; k < recentCuts.size(); k++) 
        {
            JMenuItem item = new JMenuItem((String)recentCuts.elementAt(k));
            cutsMenu.add( item );
            item.addActionListener(this);
        }      
    } // addRecentCut()
   
    /**
     *  main() creates an instance of the SimpleTextEditor
     */
    public static void main(String args[]) 
    {
        SimpleTextEditor f = new SimpleTextEditor(); 
        f.setSize(300, 200);  
        f.setVisible(true);
        f.addWindowListener(new WindowAdapter() 
        {   // Quit the application
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    } // main()
} // SimpleTextEditor