倒计时 帮助函数

[sailei1]

/*  
    // example:
    var timer = new TimerCountDown(6),
        delegateLoop = function(){
            // this -> timer
            log('delegate loop',this.getMs());
        },
        delegateStop = function(){
            // this -> timer
            log('delegate stop',this);
            this.destroy();
        };
    log(timer);
    // 注册 TimerCountDown.EVENT_STAOP & TimerCountDown.EVENT_LOOP 两个事件
    timer.on(TimerCountDown.EVENT_STAOP,delegateStop);
    timer.on(TimerCountDown.EVENT_LOOP,delegateLoop);
    // 开始计时
    timer.run();
    // 2秒后撤销 TimerCountDown.EVENT_LOOP 事件
    setTimeout(function(){
        timer.off(TimerCountDown.EVENT_LOOP,delegateLoop);
    }, 2000);
*/

(function(){
    'use strict';
    //var hasMobileUtils = window.MobileUtils ? true : false,
    var log = function(){ if(TimerCountDown.debug) { console.log.apply(console,arguments);}};

    /**
    * 计时器
    * @param sec Number 秒数
    */
    var TimerCountDown = function(sec){
        this.reset(sec);
    },
    methods = {
        /**
        * @param type String  广播事件类型 TimerCountDown.EVENT_LOOP || TimerCountDown.EVENT_STAOP
        * @param fun Function 注册广播 (* 建议不要指定匿名函数，否则撤销不了注册的事件) 
        */
        on: function(type,fun){
            if(typeof fun == 'function' && (type == TimerCountDown.EVENT_LOOP || type == TimerCountDown.EVENT_STAOP)){
                this.__delegates__.push({type:type,delegate:fun});
                return;
            }
            log('TimerCountDown->on: 参数不合法!!');
        },
        /**
        * @param type String
        * @param fun Function
        */
        off: function(type,fun){
            log('TimerCountDown->off: type: ' + type + '; delegate: ' + fun);
            for(var i=0,len = this.__delegates__.length; i<len;i++){
                var delegateObj = this.__delegates__[i];
                if(delegateObj.type == type && delegateObj.delegate == fun){
                    this.__delegates__.splice(i,1);
                }
            }
        },
        /**
        * Get Millisecond 毫秒
        * return number
        */
        getMs: function(){
            return this.__ms__;
        },
        /**
        * Get second 秒
        * return number
        */
        getSec: function(){
            return this.__sec__;
        },
        /**
        * Get Minutes 分钟
        * return number
        */
        getMin: function(){
            return this.__min__;
        },
        /**
        * Get hour 小时
        * return number
        */
        getHr: function(){
            return this.__hr__;
        },
        /**
        * start timer 启动计时器
        */
        run: function(){
            log('TimerCountDown->run: 启动计时器');
            var that = this,
                _handler = function(){
                    that.__ms__ -= 1000;
                    that.reset(that.__ms__/1000);
                    that.__fire__(TimerCountDown.EVENT_LOOP);
                    if(that.__ms__ > 0){ that.__time__ = setTimeout(_handler, 1000);}
                    else{ that.stop(true);}
                };
            that.__time__ = setTimeout(_handler, 0);
        },
        /**
        * stop timer 停止计时器
        */
        stop: function(fire){
            log('TimerCountDown->stop: 停止计时器');
            clearTimeout(this.__time__);
            if(fire){
            this.__fire__(TimerCountDown.EVENT_STAOP);}
        },
        /**
        * @param sec Number 秒数
        */
        reset: function(sec){

            sec = typeof sec == 'number' ? sec : 0;
            if(sec < 0) { log('TimerCountDown->reset: sec 参数不合法',sec); return;}

            var _sec_ = sec % 60,
                _min_ = parseInt(sec / 60);

            this.__ms__  = sec * 1000;
            this.__sec__ = _sec_ == 0 ? 0 : _sec_;
            this.__min__ = _min_;
            this.__hr__  = parseInt(_min_ / 60);

            log(JSON.stringify({ms:this.__ms__,sec:this.__sec__,min:_min_,hr:this.__hr__}));
        },
        /**
        * destroy 销毁实例对象
        */
        destroy: function(){

            clearTimeout(this.__time__);
            this.__time__ = 0;
            for(var i=0,len = this.__delegates__.length; i<len;i++){
                var delegateObj = this.__delegates__[i];
                this.__delegates__.slice(i,1);
                delegateObj.type = null;
                delegateObj.delegate = null;
                delete delegateObj.type;
                delete delegateObj.delegate;
                delegateObj = null;
            }
            log('TimerCountDown->destroy: 销毁实例对象;',this.__delegates__);
        },
        __fire__: function(type){

            for(var i=0,len = this.__delegates__.length; i<len;i++){
                var delegateObj = this.__delegates__[i];
                if(delegateObj.type == type){
                    delegateObj.delegate.call(this);
                }
            }
        },

        __ms__:   0,
        __sec__:  0,
        __min__:  0,
        __hr__:   0,
        __time__: 0,
        __delegates__: []
    };

    // TimerCountDown Event: Singler
    TimerCountDown.EVENT_LOOP   = 'event-loop';
    TimerCountDown.EVENT_STAOP  = 'event-stop';
    // debug true is output msg
    //TimerCountDown.debug      = true;

    methods.constructor = TimerCountDown;
    TimerCountDown.prototype = methods;

    // support require
    if(typeof define === 'function' && (define.amd || define.cmd)){ define(function(){ return TimerCountDown;});}
})();