Java SE (Java Platform, Standard Edition)

I thought I knew how to do this, and I do seem to have this working fine for cut/copy/paste/select all keybindings CTRL X/C/V/A respectively.
However I tried to do this for CTRL X and Y undo/redo and it's not working as I intended. Can anyone see what I'm doing wrong?
I created a SSCCE based off the original example I was following from: [http://www.java2s.com/Code/Java/Swing-JFC/Undoredotextarea.htm]

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.KeyStroke;
import javax.swing.event.UndoableEditEvent;
import javax.swing.event.UndoableEditListener;
import javax.swing.undo.CannotRedoException;
import javax.swing.undo.UndoManager;

public class UndoRedoTextArea extends JFrame implements KeyListener{
    private static final long serialVersionUID = 1L;
    protected JTextArea textArea = new JTextArea();
    protected UndoManager undoManager = new UndoManager();
    protected JButton undoButton = new JButton("Undo");
    protected JButton redoButton = new JButton("Redo");

    public UndoRedoTextArea() {
        super("Undo/Redo Demo");

        undoButton.setEnabled(false);
        redoButton.setEnabled(false);

        JPanel buttonPanel = new JPanel(new GridLayout());
        buttonPanel.add(undoButton);
        buttonPanel.add(redoButton);

        JScrollPane scroller = new JScrollPane(textArea);

        getContentPane().add(buttonPanel, BorderLayout.NORTH);
        getContentPane().add(scroller, BorderLayout.CENTER);

        textArea.getDocument().addUndoableEditListener(
            new UndoableEditListener() {
                public void undoableEditHappened(UndoableEditEvent e) {
                    undoManager.addEdit(e.getEdit());
                    updateButtons();
                }
            });
		
        undoButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    undoManager.undo();
                } catch (CannotRedoException cre) {
                    cre.printStackTrace();
                }
                updateButtons();
            }
        });
		
        undoButton.addKeyListener(this);
        redoButton.addKeyListener(this);
		
        redoButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try {
                    undoManager.redo();
                } catch (CannotRedoException cre)  {
                    cre.printStackTrace();
                }
                updateButtons();
            }
        });
		
        setSize(400, 300);
        setVisible(true);
    }
	
    public void updateButtons() {
        undoButton.setText(undoManager.getUndoPresentationName());
        redoButton.setText(undoManager.getRedoPresentationName());
        undoButton.setEnabled(undoManager.canUndo());
        redoButton.setEnabled(undoManager.canRedo());
    }
	
    public static void main(String argv[]) {
        new UndoRedoTextArea();
    }
	
	
    public void keyPressed(KeyEvent e){
        if (e.equals(KeyStroke.getKeyStroke
            (KeyEvent.VK_Z, InputEvent.CTRL_DOWN_MASK))){
            // undo
            try {
                undoManager.undo();
            } catch (CannotRedoException cre)  {
                cre.printStackTrace();
            }
            updateButtons();
        }
        else if (e.equals(KeyStroke.getKeyStroke
                (KeyEvent.VK_Y, InputEvent.CTRL_DOWN_MASK))){
            // redo
            try  {
                undoManager.redo();
            } catch (CannotRedoException cre) {
                cre.printStackTrace();
            }
            updateButtons();
        }
    }
    public void keyTyped(KeyEvent e){}
    public void keyReleased(KeyEvent e){}
}

Edited by: G-Unit on Oct 24, 2010 5:30 AM