(7) Object-oriented design principle three

<?php
interface process{
    public function process();
}

//播放器的编码
class playerEncode implements process{
    public function process(){
        echo "encode\r\n";
    }
}

class playerOutput implements process{
    public function process(){
        echo "output\r\n";
    }
}

//调度管理器
class playProcess{
    private $message = null;
    public function __construct(){

    }
    public function callBack(event $event){
        $this->message= $event->click();
        if ($this->message instanceof process){
            $this->message->process();
        }
    }
}

//播放器的事件处理
class mp4{
    public function work(){
        $playProcess = new playProcess();
        $playProcess->callBack(new event('encode'));
        $playProcess->callBack(new event('output'));
    }
}

//事件处理类
class event{
    private $m;

    public function __construct($me){
        $this->m = $me;
    }

    public function click(){
        switch($this->m){
            case 'encode':
                return new playerEncode();
                break;
            case 'output':
                return new playerOutput();
                break;
        }
    }
}

$mp4 = new mp4();
$mp4->work();