RETURN_CODE menu(Draw_Engine& DE, Audio_Engine& AE, SDL_Event& event_)
{
    // Create the menu screen.
    Screen menu_screen("Screens/Menu_Screen/");

    bool exit_game = false;
    while(!exit_game)
    { // While the user hasn't exit

        while(SDL_PollEvent(&event_))
	{ // While there's events to handle

            if(event_.type == SDL_QUIT)
	    { // If the user has Xed out
                exit_game = true;
		break;
            }

	    // if user pressed "new game"
	    // call game()
	    // else if user pressed "instructions"
	    // call instructions()
	    // else if user pressed "exit"
	    // exit game

	    menu_screen.Update(event_);
	    menu_screen.Draw(DE.Get_Screen());

	    if(!DE.Draw_Screen())
	    {
	        return RC_ERROR;
	    }
        }
    }

    return RC_EXIT_PROGRAM;
}

class Screen : public Drawable, public Updateable, public Uncopyable
{
public:
	Screen();
	Screen(const std::string& directory);
	virtual ~Screen();

	virtual void Draw(SDL_Surface* screen);
	virtual void Update(const SDL_Event& event_);
protected:
	virtual void Load(const std::string& directory);
	std::vector<Base_XImage*> elements;
};

class Base_XImage : public Drawable, public Updateable, public Cloneable
{
public:
	Base_XImage();
	Base_XImage(
		const std::string& file_name_,
		int position_x,
		int position_y,
		bool is_colour_key_,
		SDL_Colour colour_key_ = SDL_Wrappers::colour(0,0,0));
	Base_XImage(const Base_XImage& rhs);
	virtual ~Base_XImage();
	
	Base_XImage& operator=(const Base_XImage& rhs);

	const std::string& Get_File_Name() const;
	const SDL_Rect& Get_Position() const;
	bool Is_Colour_Key() const;
	const SDL_Colour& Get_Colour_Key() const;
	
	virtual void Load();
	virtual void Draw(SDL_Surface* screen) = 0;
	virtual void Update(const SDL_Event& event_) = 0;
	virtual Base_XImage* Clone() const = 0;
protected:
	static void Check_Opening_Tag(const std::string& buffer);
	static void Check_Closing_Tag(const std::string& buffer);

	std::string file_name;
	SDL_Rect position;
	bool is_colour_key;
	SDL_Colour colour_key;
	SDL_Surface* surface;
};

class Observer{public:        virtual ~Observer() {}	virtual void Mouse_Click() = 0;	virtual void Mouse_Over() = 0;};

class Subject{public:	virtual ~Subject() {}protected:	std::vector<Observer*> observers;};

class Observer{public:	virtual ~Observer() {}	virtual void Notify() = 0;};class Subject{public:	virtual ~Subject() {}	virtual void Add_Observer(Observer* observer)	{		observers.push_back(observer);	}	virtual void Notify_Observers() = 0;protected:	std::vector<Observer*> observers;};class Image : public Subject{public:	Image() {}	virtual ~Image() {}	void Update(const std::string& s)	{		if(s == "mouse_click")		{			Notify_Observers();		}	}	virtual void Notify_Observers()	{		std::for_each(observers.begin(), observers.end(),			std::mem_fun(&Observer::Notify));	}};class Test_Observer : public Observer{public:	Test_Observer() {}	virtual ~Test_Observer() {}	virtual void Notify()	{		std::cout << "Observer notified." << std::endl;	}};int main(){	Image image;	Test_Observer to1;	Test_Observer to2;	image.Add_Observer(&to1);	image.Add_Observer(&to2);	std::string input;	while(input != "exit")	{		std::cin >> input;		image.Update(input);	}	return 0;}

#ifndef OBSERVABLE_H#define OBSERVABLE_H#include <vector>#include "Observer.h"class Observer;// Not an interface but complements the Observer interface.class Observable{public:	typedef enum OBSERVABLE_EVENT	{		LMB_CLICK,		RMB_CLICK,		MOUSE_OVER	};	virtual ~Observable() {}	virtual void Add_Observer(Observer* observer);	void Notify_Observers(Observable* observable, OBSERVABLE_EVENT oe);protected:	std::vector<Observer*> observers;};#endif

#include "stdafx.h"#include "Observable.h"void Observable::Notify_Observers(Observable* observable, OBSERVABLE_EVENT oe){	std::vector<Observer*>::iterator it = observers.begin();	for(; it != observers.end(); ++it)	{ // Notify each observer of the event, passing the updated observable.		(*it)->Notify(observable, oe);	}}

#ifndef OBSERVER_H#define OBSERVER_H#include "Observable.h"class Observable;class Observer{public:	virtual ~Observer() {}	virtual void Notify(Observable* observable, OBSERVABLE_EVENT oe) = 0;};#endif

void Screen::Notify(Observable* observable, void* oe){	Base_XImage::OBSERVABLE_EVENT* event_ = (Base_XImage::OBSERVABLE_EVENT*)oe;    // Do stuff...}

Screen::Screen(){}Screen::Screen(const std::string& directory){	Load(directory);}Screen::~Screen(){	for(std::vector<Base_XImage*>::iterator it = elements.begin();		it != elements.end(); ++it)	{		Base_XImage* b = *it;		delete b;	}}void Screen::Draw(SDL_Surface* screen){	std::for_each(		elements.begin(),		elements.end(), 		std::bind2nd(std::mem_fun(&Base_XImage::Draw), screen));}void Screen::Update(const SDL_Event& event_){	std::vector<Base_XImage*>::iterator it = elements.begin();	for(; it != elements.end(); ++it)	{		(*it)->Update(event_);	}}void Screen::Notify(Observable* observable, void* oe){	Base_XImage::OBSERVABLE_EVENT* event_ = (Base_XImage::OBSERVABLE_EVENT*)oe;}void Screen::Load(const std::string& directory){	std::ifstream image_file;	IO::open_read_file(image_file, directory + IMAGES_FN);	IO::read_data_clone<XImage, std::vector<Base_XImage*> >(elements, image_file);	image_file.close();	std::ifstream button_file;	IO::open_read_file(button_file, directory + BUTTONS_FN);	IO::read_data_clone<XButton, std::vector<Base_XImage*> >(elements, button_file);	button_file.close();	std::ifstream audible_button_file;	IO::open_read_file(audible_button_file, directory + AUDIBLE_BUTTONS_FN);	IO::read_data_clone<Audible_XButton, std::vector<Base_XImage*> >(elements, audible_button_file);	audible_button_file.close();	std::ifstream draggable_button_file;	IO::open_read_file(draggable_button_file, directory + DRAGGABLE_BUTTONS_FN);	IO::read_data_clone<Draggable_XButton, std::vector<Base_XImage*> >(elements, draggable_button_file);	draggable_button_file.close();}

// if user pressed "new game"	    // call game()	    // else if user pressed "instructions"	    // call instructions()	    // else if user pressed "exit"	    // exit game