RedoAction.java

//import the packages for using the classes in them into the program
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.undo.*;

    class RedoAction extends AbstractAction{
      Notepad notepad;

        public RedoAction(Notepad notepad){
            super("Redo");
            putValue( Action.SMALL_ICON,
                new ImageIcon(this.getClass().getResource("images/redo.gif")));
            setEnabled(false);
            this.notepad = notepad;
        }
        public void actionPerformed(ActionEvent e){
            try{
                notepad.undo.redo();
            }
            catch (CannotRedoException ex){
                System.out.println("Unable to redo: " + ex);
                ex.printStackTrace();
            }
            update();
            notepad.undoAction.update();
        }
        protected void update(){
            if(notepad.undo.canRedo()){
                setEnabled(true);
                putValue("Redo", notepad.undo.getRedoPresentationName());
            }
            else{
                setEnabled(false);
                putValue(Action.NAME, "Redo");
            }
        }
    }