观察者Observer模式C++实现

Observer C++实现#include <string>
#include <iostream>
#include <set>

class IObserver;

class ISubject
{
public:
virtual void registerObserver(IObserver * o) = 0;
virtual void removeObserver(IObserver * o) = 0;
virtual void notifyObservers() = 0;
};

class IObserver
{
protected:
IObserver(){};
public:
virtual void update(float temp, float humidity, float pressure) = 0;

};

class IDisplayElement
{
protected:
IDisplayElement(){};
public:
virtual void display() = 0;
};

typedef std::set<IObserver *> ObserverList;
typedef std::set<IObserver *>::iterator ObserverListIter;

class WeatherData: public ISubject
{
private:
ObserverList m_Oberservers;
float m_temp;
float m_humidity;
float m_pressure;

public:
WeatherData () {};
~WeatherData () {};
virtual void registerObserver(IObserver * o)
{
m_Oberservers.insert(o);
}
virtual void removeObserver(IObserver * o)
{
ObserverListIter iter = m_Oberservers.find(o);
if (iter!=m_Oberservers.end())
{
m_Oberservers.erase(iter);
}
}
virtual void notifyObservers()
{
ObserverListIter iter = m_Oberservers.begin();
for (;iter!=m_Oberservers.end();iter ++ )
{
// notify All Observers
IObserver * pObserver = static_cast<IObserver *>(* iter);
pObserver->update(m_temp,m_humidity,m_pressure);
}
}
void measurementsChanged()
{
notifyObservers();
}

void setMeasurements(float temp, float humidity, float pressure)
{
m_temp = temp;
m_humidity = humidity;
m_pressure = pressure;
measurementsChanged();
}

};

class CurrentConditionsDisplay:public IObserver,public IDisplayElement
{
float m_temp;
float m_humidity;
ISubject *m_WeatherData;

public:

virtual void update(float temp, float humidity, float pressure)
{
m_temp = temp;
m_humidity = humidity;
display();
}

virtual void display()
{
std::cout << "Current Conditions:" << m_temp << ","
<< m_humidity <<std::endl;
}

};

class CurrentConditionsDisplay2:public IObserver,public IDisplayElement
{
float m_temp;
float m_humidity;
float m_pressure;

public:

virtual void update(float temp, float humidity, float pressure)
{
m_temp = temp;
m_humidity = humidity;
m_pressure = pressure;
display();
}

virtual void display()
{
std::cout << "Current Conditions2:" << m_temp << ","
<< m_humidity << "," << m_pressure <<std::endl;
}

};

int main()
{
CurrentConditionsDisplay * display1 = new CurrentConditionsDisplay();
CurrentConditionsDisplay2 * display2 = new CurrentConditionsDisplay2();

WeatherData * data = new WeatherData();
data->registerObserver( display1);
data->registerObserver (display2);

data->setMeasurements(100,0,200);
data->setMeasurements(50,50,500);

data->removeObserver(display1);

data->setMeasurements(10,10,10);

getchar();

return 0;
}