设计模式--适配器模式

对象适配器是对象的合成关系，也可以说是类的关联关系；
对象适配器，相比于类适配器，对象适配器是通过类间的关联关系进行耦合的，因此在设计时就可以做到比较灵活，实际项目中，使用的较多；

// 目标
class IMediaPlayer{
public:

virtual void play(string fileName) = 0;    

};

// 源
class IAdvacneMediaPlayer{
public:

virtual void playVlc(string fileName) = 0;
virtual void playMp4(string fileName) = 0;    

};

class VlcPlayer : public IAdvacneMediaPlayer{
public:

virtual void playVlc(string fileName){
    cout << "playing vlc file: " << fileName << endl;
}

virtual void playMp4(string fileName){
    
}

};

class Mp4Player : public IAdvacneMediaPlayer{
public:

virtual void playVlc(string fileName){
    
}

virtual void playMp4(string fileName){
    cout << "playing mp4 file: " << fileName << endl;
}    

};

// VLC 适配器
class VlcAudioMediaAdapter : public IMediaPlayer{
public:

VlcAudioMediaAdapter(VlcPlayer* player){
    this->player = player;
}

virtual void play(string fileName){
    player->playVlc(fileName);
}

private:

VlcPlayer* player;            

};

// MP4 适配器
class Mp4AudioMediaAdapter : public IMediaPlayer{
public:

Mp4AudioMediaAdapter(Mp4Player* player){
    this->player = player;
}

virtual void play(string fileName){
    player->playMp4(fileName);
}    

private:

Mp4Player* player;        

};

int main(){

IMediaPlayer* media = new VlcAudioMediaAdapter(new VlcPlayer);    
media->play("/home/a.vlc");

media = new Mp4AudioMediaAdapter(new Mp4Player);
media->play("/home/b.mp4");

return 0;

}