javascript设计模式之中介者模式

/* 

 * 小游戏演示中介者模式

 * Home 按键 1

 * Guest 按键 0

 * 半分钟内看谁按下的次数多

 *

 * 参与的对象：

 *   玩家

 *   计分板

 *   中介者

 *

 * 中介者模式使对象之间松耦合，提高了可维护性

*/



// 玩家

var Player = function (name) {

    this.name = name;

    this.point = 0;

};



Player.prototype.play = function () {

    this.point += 1;

    mediator.played(); // 每次玩家按键，中介者更新计分板

};



// 计分板

var scoreboard = {



    element: document.getElementById("result"), // 记录比分



    update: function (score) {

        var msg = "",

            i;

        for (i in score) {

            if (score.hasOwnProperty(i)) {

                msg += '<p><strong>' + i + '</strong>: ' + score[i] + '</p>';

            }

        }



        this.element.innerHTML = msg;

    }

};



// 计分人（中介者）

var mediator = {



    // 所有的玩家（player 对象）

    players: {},



    // 玩家就位

    setup: function () {



        var players = this.players;

        players.home = new Player("Home");

        players.guest = new Player("Guest");

    },



    // 计分

    played: function () {

        var players = this.players,



            score = {

                Home: players.home.point,

                Guest: players.guest.point

            };



        scoreboard.update(score);

    },



    // 游戏开始

    keypress: function (e) {



        e = e || window.event;



        if (e.which === 49) { // 按键1

            mediator.players.home.play();

            return;

        } 



        if (e.which === 48) {

            mediator.players.guest.play();

            return;

        }

    }

};





// 运行游戏

mediator.setup();

window.onkeypress = mediator.keypress;



// 游戏在30秒内结束

setTimeout(function () {

    window.onkeypress = null;

    alert("Game Over!");

}, 30000);