condition.cpp

自己写的c++实现的headfirst中的设计模式

/* *观察者模式
 */

#include <iostream>
#include <vector>

using namespace std;

class obviour
{
public:
	virtual void update(const int a,const int b)=0;
	//virtual void display()=0;
};

class condition_a:public obviour
{
private:
	int data_a;
	
public:
	void update(const int a,const int b)
	{
		data_a=a;
	}
	
	void display()
	{
		cout << data_a<<endl;
	}
};

class sum:public obviour
{
private:
	int data_a;
	int data_b;
	
public:
	void update(const int a,const int b)
	{
		data_a=a;data_b=b;
	}
	
	void display()
	{
		cout << data_a+data_b<< endl;
	}
};

class dataCenter
{
private:
	vector<obviour*> obviours;		//指针list
	int data_a;
	int data_b;
	
public:
	void regist (obviour* ob)
	{
		obviours.push_back(ob);
		update();		//注册既更新
	}
	
	void setData(const int a,const int b)
	{
		data_a=a;data_b=b;
		update();
	}
	
	void update()
	{
		unsigned int i;
		for(i=0;i<obviours.size();i++)
		{
			obviours[i]->update(data_a,data_b);
		}
	}
	
	dataCenter(int a,int b)
	{
		data_a=a;data_b=b;
	}
	
};

void condition_main()
{
	dataCenter data(1,5);
	//obviour *ca=new condition_a;
	//obviour *ab=new sum;
	
	condition_a ca;
	sum ab;
	data.regist(&ca);
	data.regist(&ab);
	
	ca.display();
	ab.display();
	
	data.setData(2,1);
	ca.display();
	ab.display();

}