php設(shè)計(jì)模式之備忘模式分析【星際爭霸游戲案例】

?php
  //備忘類
  class Memento
  {
    //水晶礦
    public $ore;

    //氣礦
    public $gas;

    //玩家所有的部隊(duì)對(duì)象
    public $troop;

    //玩家所有的建筑對(duì)象
    public $building;

    //構(gòu)造方法，參數(shù)為要保存的玩家的對(duì)象，這里強(qiáng)制參數(shù)的類型為Player類
    public function __construct(Player $player)
    {
      //保存這個(gè)玩家的水晶礦
      $this->ore = $player->ore;

      //保存這個(gè)玩家的氣礦
      $this->gas = $player->gas;

      //保存這個(gè)玩家所有的部隊(duì)對(duì)象
      $this->troop = $player->troop;

      //保存這個(gè)玩家所有的建筑對(duì)象
      $this->building = $player->building;
    }
  }

  //玩家的類
  class Player
  {
    //水晶礦
    public $ore;

    //氣礦
    public $gas;

    //玩家所有的部隊(duì)對(duì)象
    public $troop;

    //玩家所有的建筑對(duì)象
    public $building;

    //獲取這個(gè)玩家的備忘對(duì)象
    public function getMemento()
    {
      return new Memento($this);
    }

    //用這個(gè)玩家的備忘對(duì)象來恢復(fù)這個(gè)玩家，這里強(qiáng)制參數(shù)的類型為Memento類
    public function restore(Memento $m)
    {
      //水晶礦
      $this->ore = $m->ore;

      //氣礦
      $this->gas = $m->gas;

      //玩家所有的部隊(duì)對(duì)象
      $this->troop = $m->troop;

      //玩家所有的建筑對(duì)象
      $this->building = $m->building;
    }
  }

  //制造一個(gè)玩家
  $p1 = new Player();

  //假設(shè)他現(xiàn)在采了100水晶礦
  $p1->ore = 100;

  //我們先保存游戲，然后繼續(xù)玩游戲
  $m = $p1->getMemento();

  //假設(shè)他現(xiàn)在采了200水晶礦
  $p1->ore = 200;

  //我們現(xiàn)在載入原來保存的游戲
  $p1->restore($m);

  //輸出水晶礦，可以看到已經(jīng)變成原來保存的狀態(tài)了
  echo $p1->ore;
?>