外观模式

外观模式 提供了一个统一的接口，用来访问子系统中的一群接口。外观定义了一个高层接口，让子系统更容易使用。

#include <iostream>
#include <string>


using namespace std;


struct DvdPlayer {
public:
    on() {
        cout << "DvdPlayer on" << endl;
    }
    off() {
        cout << "DvdPlayer off" << endl;
    }
    play(string movie) {
        cout << "DvdPlayer play: " << movie << endl;
    }
    stop() {
        cout << "DvdPlayer stop" << endl;
    }
};

struct Amplifier {
public:
    on() {
        cout << "Amplifier on" << endl;
    }
    off() {
        cout << "Amplifier off" << endl;
    }
    setDvd(DvdPlayer *mdvdPlayer) {
        dvdPlayer = mdvdPlayer;
        cout << "Amplifier set DvdPlayer" << endl;
    }
    setVolume(int value) {
        cout << "Amplifier set volume to " << value << endl;
    }
private:
    DvdPlayer *dvdPlayer;
};

struct Projector {
public:
    on() {
        cout << "Projector on" << endl;
    }
    off() {
        cout << "Projector off" << endl;
    }
};

struct HomeThreaterFacade {
public:
    HomeThreaterFacade(Amplifier *mamp,
        DvdPlayer *mdvd,
        Projector *mprojector) {
        amp = mamp;
        dvd = mdvd;
        projector = mprojector;
    }

    watchMovie(string movie) {
        cout << "Get ready to watch a movie..." << endl;
        projector->on();
        projector->off();
        amp->on();
        amp->setDvd(dvd);
        amp->setVolume(5);
        dvd->on();
        dvd->play(movie);
    }

    endMoive() {
        cout << "Shutting movie theater down..." << endl;
        projector->off();
        amp->off();
        dvd->stop();
        dvd->off();
    }

private:
    Amplifier *amp;
    DvdPlayer *dvd;
    Projector *projector;
};

int main(int argc, char **argv)
{
    Projector *projector = new Projector();
    Amplifier *amp = new Amplifier();
    DvdPlayer *dvd = new DvdPlayer();
    HomeThreaterFacade *threater =
        new HomeThreaterFacade(
            amp, dvd, projector);

    threater->watchMovie("freedom");
    cout << "-----------------------" << endl;
    threater->endMoive();

    delete threater;
    delete dvd;
    delete amp;
    delete projector;

    return 0;
}