//----------------------------------------------------------------------------
//
//  Copyright (C) Intel Corporation, 2006 - 2007.
//
//  File:       ObserverPattern.h
//
//  Contents:   An implementation of the Observer design pattern.
//
//  Notes:      
//----------------------------------------------------------------------------
#ifndef _OBSERVER_PATTERN_H__
#define _OBSERVER_PATTERN_H__

#include <vector>

using namespace std;

class Observer_Pattern_Observer
{
public:
	Observer_Pattern_Observer() {}
	virtual ~Observer_Pattern_Observer() {}
	virtual int update() = 0;
};

class Observer_Pattern_Subject
{
public:
	Observer_Pattern_Subject():observers() {}

	virtual ~Observer_Pattern_Subject() {}

	virtual int attach(Observer_Pattern_Observer * observer)
	{
		observers.push_back(observer);
		return 0;
	}
	virtual int detach(Observer_Pattern_Observer * observer)
	{
		vector<Observer_Pattern_Observer *>::iterator iter;
		for (iter = observers.begin(); iter != observers.end(); ++iter)
		{
			if (*iter == observer)
			{
				observers.erase(iter);
				return 0;
			}
		}
		return -1;
	}
	virtual int notify()
	{
		vector<Observer_Pattern_Observer *>::iterator iter;
		for (iter = observers.begin(); iter != observers.end(); ++iter)
		{
			(*iter) -> update();
		}
		return 0;
	}

private:
	vector<Observer_Pattern_Observer *> observers;
};

#endif /* _OBSERVER_PATTERN_SUBJECT_H__ */