package de.glossmaker.undo;

 import java.util.Stack;

 /**

  * Implementation of a common undo and redo container.

  * 

  * @author Markus Flingelli

  *

  * @param <E>

  */

 public class UndoStack<E> implements IUndoableStack<E> {

         protected Stack<E> mUndo = null;

         protected Stack<E> mRedo = null;

         protected UndoStack() {

                 mUndo = new Stack<E>();

                 mRedo = new Stack<E>();

         }

         @Override

         public int undoSize() {

                 return mUndo.size();

         }

         @Override

         public int redoSize() {

                 return mRedo.size();

         }

         @Override

         public E popUndo() {

                 return mUndo.pop();

         }

         @Override

         public E popRedo() {

                 return mRedo.pop();

         }

         @Override

         public void pushUndo(E item) {

                 mUndo.push(item);

         }

         @Override

         public void pushRedo(E item) {

                 mRedo.push(item);

         }

         @Override

         public void resetUndo() {

                 mUndo.clear();

         }

         @Override

         public void resetRedo() {

                 mRedo.clear();

         }

         @Override

         public void reset() {

                 resetUndo();

                 resetRedo();

         }

 }