/**
 * memento.h
 * Implemented by Blueprint Technologies, Inc.
 */

#ifndef _memento_h
#define _memento_h

#include <deque>
using namespace std;

/**
 * Abstract data type for this pattern.
 */

class State
{
};

/**
 * Stores internal state of the Originator object. The memento
 * may store as much or as little of the originator's state as
 * necessary at its originator's discretion.
 */

class Memento
{

private:
	State* state;

public:
	Memento(): state(0)
	{
	};

	Memento( State* state )
	{
		this -> state = state;
	}

	State* getState()
	{
		return state;
	};

	void setState( State* state )
	{
		this -> state = state;
	};

};

/**
 * Responsible for the memento's safekeeping. Never operates
 * on or examines the contents of a memento. We'll use a
 * double-ended queue for this.
 */

typedef deque< Memento* > Caretaker;

/**
 * Creates a memento containing a snapshot of its current
 * internal state. Uses the memento to restore its internal
 * state.
 */

class Originator
{

private:
	State* state;

public:
	Originator(): state(0)
	{
	};

	void setMemento( Memento* memento )
	{
		state = memento -> getState();
	};

	Memento* createMemento()
	{
		return new Memento( state );
	};

};

#endif