/*! iScroll v5.1.2 ~ (c) 2008-2014 Matteo Spinelli ~ http://cubiq.org/license */(function (window, document, Math) {    //请求动画帧var rAF = window.requestAnimationFrame    ||    window.webkitRequestAnimationFrame    ||    window.mozRequestAnimationFrame        ||    window.oRequestAnimationFrame        ||    window.msRequestAnimationFrame        ||    function (callback) { window.setTimeout(callback, 1000 / 60); };//显示器16.7ms刷新间隔之前发生了其他绘制请求(setTimeout)，导致所有帧丢失，setTimeout的定时器值推荐最小使用16.7ms的原因（16.7 = 1000 / 60, 即每秒60帧）//requestAnimationFrame与setTimeout的不同在于，前者跟着浏览器重绘时间走，不存在后者丢帧的问题var utils = (function () {    var me = {};    var _elementStyle = document.createElement(‘div‘).style;    //获取浏览器特性前缀    var _vendor = (function () {        var vendors = [‘t‘, ‘webkitT‘, ‘MozT‘, ‘msT‘, ‘OT‘],            transform,            i = 0,            l = vendors.length;        for ( ; i < l; i++ ) {            transform = vendors[i] + ‘ransform‘;            if ( transform in _elementStyle ) return vendors[i].substr(0, vendors[i].length-1);        }        return false;    })();    //拼装样式属性名    function _prefixStyle (style) {        if ( _vendor === false ) return false;        if ( _vendor === ‘‘ ) return style;        return _vendor + style.charAt(0).toUpperCase() + style.substr(1);    }    //获取当前时间    me.getTime = Date.now || function getTime () { return new Date().getTime(); };    //对象复制    me.extend = function (target, obj) {        for ( var i in obj ) {            target[i] = obj[i];        }    };    //事件    me.addEvent = function (el, type, fn, capture) {        el.addEventListener(type, fn, !!capture);    };    me.removeEvent = function (el, type, fn, capture) {        el.removeEventListener(type, fn, !!capture);    };    //MSPointerEvent 指针事件是一些事件和相关接口，用于处理来自鼠标、手写笔或触摸屏等设备的硬件不可知的指针输入，IE10引入，IE11去掉前缀，其他浏览器都不支持指针事件。    me.prefixPointerEvent = function (pointerEvent) {        return window.MSPointerEvent ?             ‘MSPointer‘ + pointerEvent.charAt(9).toUpperCase() + pointerEvent.substr(10):            pointerEvent;    };    //deceleration减速    /**     * 根据我们的拖动返回运动的长度与耗时，用于惯性拖动判断     * @param current 当前鼠标位置     * @param start touchStart时候记录的Y（可能是X）的开始位置，但是在touchmove时候可能被重写     * @param time touchstart到手指离开时候经历的时间，同样可能被touchmove重写     * @param lowerMargin y可移动的最大距离，这个一般为计算得出 this.wrapperHeight - this.scrollerHeight     * @param wrapperSize 如果有边界距离的话就是可拖动，不然碰到0的时候便停止     * @param deceleration 匀减速     * @returns {{destination: number, duration: number}}     */    me.momentum = function (current, start, time, lowerMargin, wrapperSize, deceleration) {        var distance = current - start,            speed = Math.abs(distance) / time,            destination,            duration;        //减速变量        deceleration = deceleration === undefined ? 0.0006 : deceleration;        //减速路程        destination = current + ( speed * speed ) / ( 2 * deceleration ) * ( distance < 0 ? -1 : 1 );        //持续时间        duration = speed / deceleration;        if ( destination < lowerMargin ) {            destination = wrapperSize ? lowerMargin - ( wrapperSize / 2.5 * ( speed / 8 ) ) : lowerMargin;            distance = Math.abs(destination - current);            duration = distance / speed;        } else if ( destination > 0 ) {            destination = wrapperSize ? wrapperSize / 2.5 * ( speed / 8 ) : 0;            distance = Math.abs(current) + destination;            duration = distance / speed;        }        return {            destination: Math.round(destination),            duration: duration        };    };    var _transform = _prefixStyle(‘transform‘);    me.extend(me, {        hasTransform: _transform !== false,        hasPerspective: _prefixStyle(‘perspective‘) in _elementStyle, //透视        hasTouch: ‘ontouchstart‘ in window,        hasPointer: window.PointerEvent || window.MSPointerEvent, // IE10 is prefixed        hasTransition: _prefixStyle(‘transition‘) in _elementStyle    });    // This should find all Android browsers lower than build 535.19 (both stock browser and webview) 低版本安卓机    me.isBadAndroid = /Android /.test(window.navigator.appVersion) && !(/Chrome\/\d/.test(window.navigator.appVersion));    me.extend(me.style = {}, {        transform: _transform,        transitionTimingFunction: _prefixStyle(‘transitionTimingFunction‘),        transitionDuration: _prefixStyle(‘transitionDuration‘),        transitionDelay: _prefixStyle(‘transitionDelay‘),        transformOrigin: _prefixStyle(‘transformOrigin‘)    });    me.hasClass = function (e, c) {        var re = new RegExp("(^|\\s)" + c + "(\\s|$)");        return re.test(e.className);    };    me.addClass = function (e, c) {        if ( me.hasClass(e, c) ) {            return;        }        var newclass = e.className.split(‘ ‘);        newclass.push(c);        e.className = newclass.join(‘ ‘);    };    me.removeClass = function (e, c) {        if ( !me.hasClass(e, c) ) {            return;        }        var re = new RegExp("(^|\\s)" + c + "(\\s|$)", ‘g‘);        e.className = e.className.replace(re, ‘ ‘);    };    me.offset = function (el) {        var left = -el.offsetLeft,            top = -el.offsetTop;        // jshint -W084        while (el = el.offsetParent) {            left -= el.offsetLeft;            top -= el.offsetTop;        }        // jshint +W084        return {            left: left,            top: top        };    };    // 配合config里面的preventDefaultException属性，不对匹配到的element使用e.preventDefault()。    me.preventDefaultException = function (el, exceptions) {        for ( var i in exceptions ) {            if ( exceptions[i].test(el[i]) ) {                return true;            }        }        return false;    };    // 事件类型    me.extend(me.eventType = {}, {        touchstart: 1,        touchmove: 1,        touchend: 1,        mousedown: 2,        mousemove: 2,        mouseup: 2,        pointerdown: 3,        pointermove: 3,        pointerup: 3,        MSPointerDown: 3,        MSPointerMove: 3,        MSPointerUp: 3    });    // 缓动函数    me.extend(me.ease = {}, {        quadratic: {            style: ‘cubic-bezier(0.25, 0.46, 0.45, 0.94)‘,            fn: function (k) {                return k * ( 2 - k );            }        },        circular: {            style: ‘cubic-bezier(0.1, 0.57, 0.1, 1)‘,    // Not properly "circular" but this looks better, it should be (0.075, 0.82, 0.165, 1)            fn: function (k) {                return Math.sqrt( 1 - ( --k * k ) );            }        },        back: {            style: ‘cubic-bezier(0.175, 0.885, 0.32, 1.275)‘,            fn: function (k) {                var b = 4;                return ( k = k - 1 ) * k * ( ( b + 1 ) * k + b ) + 1;            }        },        bounce: {            style: ‘‘,            fn: function (k) {                if ( ( k /= 1 ) < ( 1 / 2.75 ) ) {                    return 7.5625 * k * k;                } else if ( k < ( 2 / 2.75 ) ) {                    return 7.5625 * ( k -= ( 1.5 / 2.75 ) ) * k + 0.75;                } else if ( k < ( 2.5 / 2.75 ) ) {                    return 7.5625 * ( k -= ( 2.25 / 2.75 ) ) * k + 0.9375;                } else {                    return 7.5625 * ( k -= ( 2.625 / 2.75 ) ) * k + 0.984375;                }            }        },        elastic: {            style: ‘‘,            fn: function (k) {                var f = 0.22,                    e = 0.4;                if ( k === 0 ) { return 0; }                if ( k == 1 ) { return 1; }                return ( e * Math.pow( 2, - 10 * k ) * Math.sin( ( k - f / 4 ) * ( 2 * Math.PI ) / f ) + 1 );            }        }    });    me.tap = function (e, eventName) {        var ev = document.createEvent(‘Event‘);        /**        只有在新创建的 Event 对象被 Document 对象或 Element 对象的 dispatchEvent() 方法分派之前，才能调用 Event.initEvent() 方法                初始化新事件对象的属性        */        ev.initEvent(eventName, true, true);        ev.pageX = e.pageX;        ev.pageY = e.pageY;        //事件触发器就是用来触发某个元素下的某个事件        e.target.dispatchEvent(ev);    };    me.click = function (e) {        var target = e.target,            ev;        //不是select/input/textarea就创建事件        if ( !(/(SELECT|INPUT|TEXTAREA)/i).test(target.tagName) ) {            ev = document.createEvent(‘MouseEvents‘);            ev.initMouseEvent(‘click‘, true, true, e.view, 1,                target.screenX, target.screenY, target.clientX, target.clientY,                e.ctrlKey, e.altKey, e.shiftKey, e.metaKey,                0, null);            ev._constructed = true;            target.dispatchEvent(ev);        }    };    return me;})();function IScroll (el, options) {    //传入的元素 必须要有子元素    this.wrapper = typeof el == ‘string‘ ? document.querySelector(el) : el;    //子元素 实际滑动元素    this.scroller = this.wrapper.children[0];    this.scrollerStyle = this.scroller.style;        // cache style for better performance    this.options = {// INSERT POINT: OPTIONS         startX: 0,        startY: 0,        //默认是Y轴上下滚动                scrollY: true,                //方向锁定阈值，比如用户点击屏幕后，x与y之间差距大于5px，判断用户的拖动意图，是x方向拖动还是y方向                directionLockThreshold: 5,                //是否有惯性缓冲动画        momentum: true,        //超出边界时候是否还能拖动                bounce: true,                //超出边界还原时间点                bounceTime: 600,                //超出边界返回的动画                bounceEasing: ‘‘,                //是否阻止默认滚动事件                preventDefault: true,                //当遇到表单元素则不阻止冒泡，而是弹出系统自带相应的输入控件                preventDefaultException: { tagName: /^(INPUT|TEXTAREA|BUTTON|SELECT)$/ },        //硬件合成 通过GPU做图形渲染        HWCompositing: true,        //使用transition        useTransition: true,        //使用transform        useTransform: true    };    for ( var i in options ) {        this.options[i] = options[i];    }    // Normalize options    this.translateZ = this.options.HWCompositing && utils.hasPerspective ? ‘ translateZ(0)‘ : ‘‘;    this.options.useTransition = utils.hasTransition && this.options.useTransition;    this.options.useTransform = utils.hasTransform && this.options.useTransform;        // 默认false，当你想保留原生垂直滚动但能够添加水平iscroll时候，设置为true，iscroll区域水平滑动时候的touch垂直移动，不会触发原生的垂直滑动    // 通常设置为：{eventPassthrough:true,scrollX:true,scrollY:false}    //     this.options.eventPassthrough = this.options.eventPassthrough === true ? ‘vertical‘ : this.options.eventPassthrough;    //当设置了eventPassthrough时候，不阻止默认的滚动事件    this.options.preventDefault = !this.options.eventPassthrough && this.options.preventDefault;    // If you want eventPassthrough I have to lock one of the axes    // eventPassthrough可以传入具体名字(vertical/horizontal)，这里更好说明了eventPassthrough的作用，对于传入的值来阻止相应轴的滑动事件    // eventPassthrough -> true -> vertical -> scrollY : false 垂直滚动忽略    this.options.scrollY = this.options.eventPassthrough == ‘vertical‘ ? false : this.options.scrollY;    this.options.scrollX = this.options.eventPassthrough == ‘horizontal‘ ? false : this.options.scrollX;    // With eventPassthrough we also need lockDirection mechanism    // freeScroll只能与scrollX一起使用 {scrollX:true,freeScroll:true}    this.options.freeScroll = this.options.freeScroll && !this.options.eventPassthrough;    this.options.directionLockThreshold = this.options.eventPassthrough ? 0 : this.options.directionLockThreshold;    // 缓动函数    this.options.bounceEasing = typeof this.options.bounceEasing == ‘string‘ ? utils.ease[this.options.bounceEasing] || utils.ease.circular : this.options.bounceEasing;        //window resize时重新获取位置    this.options.resizePolling = this.options.resizePolling === undefined ? 60 : this.options.resizePolling;    if ( this.options.tap === true ) {        this.options.tap = ‘tap‘;    }// INSERT POINT: NORMALIZATION    // Some defaults        this.x = 0;    this.y = 0;    this.directionX = 0;    this.directionY = 0;    this._events = {};// INSERT POINT: DEFAULTS    // IScroll初始化    this._init();    //     this.refresh();    // 定位到最顶最左    this.scrollTo(this.options.startX, this.options.startY);    // 代表“启用”的一个标志    this.enable();}IScroll.prototype = {    version: ‘5.1.2‘,    _init: function () {        this._initEvents();// INSERT POINT: _init    },    destroy: function () {        this._initEvents(true);        this._execEvent(‘destroy‘);    },    _transitionEnd: function (e) {        if ( e.target != this.scroller || !this.isInTransition ) {            return;        }        this._transitionTime();        if ( !this.resetPosition(this.options.bounceTime) ) {            this.isInTransition = false;            this._execEvent(‘scrollEnd‘);        }    },    _start: function (e) {        // React to left mouse button only        // 不是已经注册的事件，而且按下的不是左键，就返回不处理。        if ( utils.eventType[e.type] != 1 ) {            if ( e.button !== 0 ) {                return;            }        }        // 没有启用，返回不处理。        if ( !this.enabled || (this.initiated && utils.eventType[e.type] !== this.initiated) ) {            return;        }        // 如果 preventDefault === true 且 不是落后的安卓版本 且 不是需要过滤的target 就 阻止默认的行为        if ( this.options.preventDefault && !utils.isBadAndroid && !utils.preventDefaultException(e.target, this.options.preventDefaultException) ) {            e.preventDefault();        }        //e.touches表示的在屏幕上所有的触摸点，但事实上，绝大数手机浏览器并不支持多点触摸，所有用e.touchees[0]捕获一个触点就知足吧，        //不要再奢望获取e.touches[>0]了，这个触点的位置可以有e.touches[0].pageX获取页面x坐标（像素）；        var point = e.touches ? e.touches[0] : e,            pos;        // 事件类型        this.initiated    = utils.eventType[e.type];        this.moved    = false;    //是否移动的标志        this.distX    = 0;        //        this.distY    = 0;        //        this.directionX = 0;    //x方向移动数        this.directionY = 0;    //y方向移动数        this.directionLocked = 0;    //方向锁        // 设置运动时间        this._transitionTime();        // 开始时间        this.startTime = utils.getTime();        // 如果还在运动中        if ( this.options.useTransition && this.isInTransition ) {            this.isInTransition = false;            // 获取当前位置            pos = this.getComputedPosition();            // 滑动到当前位置 相当于停止于此处            this._translate(Math.round(pos.x), Math.round(pos.y));            // 触发滑动结束回调函数            this._execEvent(‘scrollEnd‘);        } else if ( !this.options.useTransition && this.isAnimating ) {            this.isAnimating = false;            this._execEvent(‘scrollEnd‘);        }        this.startX    = this.x;        // scroller开始位置x        this.startY    = this.y;        // scroller开始位置y        this.absStartX = this.x;        //        this.absStartY = this.y;        //        this.pointX    = point.pageX;    // 触点x        this.pointY    = point.pageY;    // 触点y        // 触发滑动前回调函数        this._execEvent(‘beforeScrollStart‘);    },    _move: function (e) {        // 禁止 or 不存在此eventType 则返回        if ( !this.enabled || utils.eventType[e.type] !== this.initiated ) {            return;        }        if ( this.options.preventDefault ) {    // increases performance on Android? TODO: check!            e.preventDefault();        }        // point 触点        var point        = e.touches ? e.touches[0] : e,            deltaX        = point.pageX - this.pointX,    // 当前触点的pagex - 开始时的pagex = 触点档次增量x            deltaY        = point.pageY - this.pointY,    // 触点增量y            timestamp    = utils.getTime(),            newX, newY,            absDistX, absDistY;        // 最近上一次的触点位置        this.pointX        = point.pageX;        this.pointY        = point.pageY;        // 触点移动的距离        this.distX        += deltaX;        this.distY        += deltaY;        absDistX        = Math.abs(this.distX);        absDistY        = Math.abs(this.distY);        // We need to move at least 10 pixels for the scrolling to initiate        // 触点至少移动10px才会触发scroll的move 并且 移动大于300ms        if ( timestamp - this.endTime > 300 && (absDistX < 10 && absDistY < 10) ) {            return;        }        // If you are scrolling in one direction lock the other        // 除非设置了freeScroll，否则将只允许同一时间一个方向滑动        if ( !this.directionLocked && !this.options.freeScroll ) {            if ( absDistX > absDistY + this.options.directionLockThreshold ) {                this.directionLocked = ‘h‘;        // lock horizontally            } else if ( absDistY >= absDistX + this.options.directionLockThreshold ) {                this.directionLocked = ‘v‘;        // lock vertically            } else {                this.directionLocked = ‘n‘;        // no lock            }        }        if ( this.directionLocked == ‘h‘ ) {            if ( this.options.eventPassthrough == ‘vertical‘ ) {                e.preventDefault();            } else if ( this.options.eventPassthrough == ‘horizontal‘ ) {                this.initiated = false;                return;            }            deltaY = 0;        } else if ( this.directionLocked == ‘v‘ ) {            if ( this.options.eventPassthrough == ‘horizontal‘ ) {                e.preventDefault();            } else if ( this.options.eventPassthrough == ‘vertical‘ ) {                this.initiated = false;                return;            }            deltaX = 0;        }        deltaX = this.hasHorizontalScroll ? deltaX : 0;        deltaY = this.hasVerticalScroll ? deltaY : 0;        // this.x this.y 是最近上一次的scroller位置        newX = this.x + deltaX;        newY = this.y + deltaY;        // Slow down if outside of the boundaries        if ( newX > 0 || newX < this.maxScrollX ) {            newX = this.options.bounce ? this.x + deltaX / 3 : newX > 0 ? 0 : this.maxScrollX;        }        if ( newY > 0 || newY < this.maxScrollY ) {            newY = this.options.bounce ? this.y + deltaY / 3 : newY > 0 ? 0 : this.maxScrollY;        }        this.directionX = deltaX > 0 ? -1 : deltaX < 0 ? 1 : 0;    // -1 手势向左   1 手势向右        this.directionY = deltaY > 0 ? -1 : deltaY < 0 ? 1 : 0; // -1 手势向上   1 手势向下        if ( !this.moved ) {            this._execEvent(‘scrollStart‘);        }        this.moved = true;        this._translate(newX, newY);/* REPLACE START: _move */        if ( timestamp - this.startTime > 300 ) {            //300ms更新一次            this.startTime = timestamp;            this.startX = this.x;            this.startY = this.y;        }/* REPLACE END: _move */    },    // touchEnd时候处理缓动    _end: function (e) {        if ( !this.enabled || utils.eventType[e.type] !== this.initiated ) {            return;        }        if ( this.options.preventDefault && !utils.preventDefaultException(e.target, this.options.preventDefaultException) ) {            e.preventDefault();        }        var point = e.changedTouches ? e.changedTouches[0] : e,            momentumX,            momentumY,            duration = utils.getTime() - this.startTime,            newX = Math.round(this.x),            newY = Math.round(this.y),            distanceX = Math.abs(newX - this.startX),    //单次移动过程的x轴移动距离            distanceY = Math.abs(newY - this.startY),            time = 0,            easing = ‘‘;        this.isInTransition = 0;        this.initiated = 0;        this.endTime = utils.getTime();        // reset if we are outside of the boundaries        // 超过了边界就重新回到边界位        if ( this.resetPosition(this.options.bounceTime) ) {            return;        }        // 坚持滑动到        this.scrollTo(newX, newY);    // ensures that the last position is rounded        // we scrolled less than 10 pixels        if ( !this.moved ) {            if ( this.options.tap ) {                utils.tap(e, this.options.tap);            }            if ( this.options.click ) {                utils.click(e);            }            this._execEvent(‘scrollCancel‘);            return;        }        if ( this._events.flick && duration < 200 && distanceX < 100 && distanceY < 100 ) {            this._execEvent(‘flick‘);            return;        }        // start momentum animation if needed        // 获取缓动的距离 和 时间 { destination ， duration }        if ( this.options.momentum && duration < 300 ) {            momentumX = this.hasHorizontalScroll ? utils.momentum(this.x, this.startX, duration, this.maxScrollX, this.options.bounce ? this.wrapperWidth : 0, this.options.deceleration) : { destination: newX, duration: 0 };            momentumY = this.hasVerticalScroll ? utils.momentum(this.y, this.startY, duration, this.maxScrollY, this.options.bounce ? this.wrapperHeight : 0, this.options.deceleration) : { destination: newY, duration: 0 };            newX = momentumX.destination;            newY = momentumY.destination;            time = Math.max(momentumX.duration, momentumY.duration);            this.isInTransition = 1;        }// INSERT POINT: _end        if ( newX != this.x || newY != this.y ) {            // change easing function when scroller goes out of the boundaries            if ( newX > 0 || newX < this.maxScrollX || newY > 0 || newY < this.maxScrollY ) {                easing = utils.ease.quadratic;            }            this.scrollTo(newX, newY, time, easing);            return;        }        this._execEvent(‘scrollEnd‘);    },    _resize: function () {        var that = this;        clearTimeout(this.resizeTimeout);        this.resizeTimeout = setTimeout(function () {            that.refresh();        }, this.options.resizePolling);    },    /**     * 重新定位     */    resetPosition: function (time) {        var x = this.x,            y = this.y;        time = time || 0;                /**        * 如果禁止水平滑动或者x大于0，x=0。如果可以滑动的情况，x应该是小于0的。        * 否则（可水平滑动），x为maxScrollX即最左        */        if ( !this.hasHorizontalScroll || this.x > 0 ) {            x = 0;        } else if ( this.x < this.maxScrollX ) {            x = this.maxScrollX;        }        /**        * 如果禁止垂直滑动或者y大于0，y=0。如果可以滑动的情况，y应该是小于0的。        * 否则（可垂直滑动），y为maxScrollY即最上        */        if ( !this.hasVerticalScroll || this.y > 0 ) {            y = 0;        } else if ( this.y < this.maxScrollY ) {            y = this.maxScrollY;        }        // 初始化时候x y 都是0 返回。        if ( x == this.x && y == this.y ) {            return false;        }        this.scrollTo(x, y, time, this.options.bounceEasing);        return true;    },    /**     * scroll关闭的标志     */    disable: function () {        this.enabled = false;    },    /**     * scroll启用的标志     */    enable: function () {        this.enabled = true;    },    /**     * 重新获取位置等参数信息     */    refresh: function () {                var rf = this.wrapper.offsetHeight;        // Force reflow        // 获取包含块的宽度/高度        this.wrapperWidth    = this.wrapper.clientWidth;        this.wrapperHeight    = this.wrapper.clientHeight;/* REPLACE START: refresh */        // 滑动区的高度/宽度        this.scrollerWidth    = this.scroller.offsetWidth;        this.scrollerHeight    = this.scroller.offsetHeight;        // 最多允许滑动的x/y        this.maxScrollX        = this.wrapperWidth - this.scrollerWidth;        this.maxScrollY        = this.wrapperHeight - this.scrollerHeight;/* REPLACE END: refresh */        // 是否可以垂直/水平滑动        this.hasHorizontalScroll    = this.options.scrollX && this.maxScrollX < 0;        this.hasVerticalScroll        = this.options.scrollY && this.maxScrollY < 0;        if ( !this.hasHorizontalScroll ) {            this.maxScrollX = 0;            this.scrollerWidth = this.wrapperWidth;        }        if ( !this.hasVerticalScroll ) {            this.maxScrollY = 0;            this.scrollerHeight = this.wrapperHeight;        }        this.endTime = 0;        this.directionX = 0;        this.directionY = 0;                // 获取包含块的offsetLeft offsetTop        this.wrapperOffset = utils.offset(this.wrapper);        this._execEvent(‘refresh‘);        this.resetPosition();// INSERT POINT: _refresh    },    /**     * 自定义事件三件套，不解释。     */    on: function (type, fn) {        if ( !this._events[type] ) {            this._events[type] = [];        }        this._events[type].push(fn);    },    off: function (type, fn) {        if ( !this._events[type] ) {            return;        }        var index = this._events[type].indexOf(fn);        if ( index > -1 ) {            this._events[type].splice(index, 1);        }    },    _execEvent: function (type) {        if ( !this._events[type] ) {            return;        }        var i = 0,            l = this._events[type].length;        if ( !l ) {            return;        }        for ( ; i < l; i++ ) {            this._events[type][i].apply(this, [].slice.call(arguments, 1));        }    },    scrollBy: function (x, y, time, easing) {        x = this.x + x;        y = this.y + y;        time = time || 0;        this.scrollTo(x, y, time, easing);    },    /**     *     * @param  x 为移动的x轴坐标     * @param y 为移动的y轴坐标     * @param time 为移动时间     * @param easing 为移动的动画效果     */    scrollTo: function (x, y, time, easing) {        easing = easing || utils.ease.circular;        this.isInTransition = this.options.useTransition && time > 0;        if ( !time || (this.options.useTransition && easing.style) ) {            this._transitionTimingFunction(easing.style);            this._transitionTime(time);            this._translate(x, y);        } else {            this._animate(x, y, time, easing.fn);        }    },    /**     * 这个方法实际上是对scrollTo的进一步封装,滚动到相应的元素区域。     * @param el 为需要滚动到的元素引用     * @param time 为滚动时间     * @param offsetX 为X轴偏移量     * @param offsetY 为Y轴偏移量     * @param easing 动画效果     */    scrollToElement: function (el, time, offsetX, offsetY, easing) {        el = el.nodeType ? el : this.scroller.querySelector(el);        if ( !el ) {            return;        }        var pos = utils.offset(el);        pos.left -= this.wrapperOffset.left;        pos.top  -= this.wrapperOffset.top;        // if offsetX/Y are true we center the element to the screen        if ( offsetX === true ) {            offsetX = Math.round(el.offsetWidth / 2 - this.wrapper.offsetWidth / 2);        }        if ( offsetY === true ) {            offsetY = Math.round(el.offsetHeight / 2 - this.wrapper.offsetHeight / 2);        }        pos.left -= offsetX || 0;        pos.top  -= offsetY || 0;        pos.left = pos.left > 0 ? 0 : pos.left < this.maxScrollX ? this.maxScrollX : pos.left;        pos.top  = pos.top  > 0 ? 0 : pos.top  < this.maxScrollY ? this.maxScrollY : pos.top;        time = time === undefined || time === null || time === ‘auto‘ ? Math.max(Math.abs(this.x-pos.left), Math.abs(this.y-pos.top)) : time;        this.scrollTo(pos.left, pos.top, time, easing);    },    // 动画运动时间    _transitionTime: function (time) {        time = time || 0;        this.scrollerStyle[utils.style.transitionDuration] = time + ‘ms‘;        // 落后的安卓机运动時間需要把0转0.001s        if ( !time && utils.isBadAndroid ) {            this.scrollerStyle[utils.style.transitionDuration] = ‘0.001s‘;        }// INSERT POINT: _transitionTime    },    _transitionTimingFunction: function (easing) {        this.scrollerStyle[utils.style.transitionTimingFunction] = easing;// INSERT POINT: _transitionTimingFunction    },    /**     * @param  x 为移动的x轴坐标     * @param  y 为移动的y轴坐标     */    _translate: function (x, y) {        if ( this.options.useTransform ) {/* REPLACE START: _translate */            this.scrollerStyle[utils.style.transform] = ‘translate(‘ + x + ‘px,‘ + y + ‘px)‘ + this.translateZ;/* REPLACE END: _translate */        } else {            x = Math.round(x);            y = Math.round(y);            this.scrollerStyle.left = x + ‘px‘;            this.scrollerStyle.top = y + ‘px‘;        }        this.x = x;        this.y = y;// INSERT POINT: _translate    },    /**     * @param  remove 是否解绑事件     */    _initEvents: function (remove) {        var eventType = remove ? utils.removeEvent : utils.addEvent,            // 是否绑定到wrapper元素上            target = this.options.bindToWrapper ? this.wrapper : window;        //旋转屏幕事件        eventType(window, ‘orientationchange‘, this);        eventType(window, ‘resize‘, this);        if ( this.options.click ) {            eventType(this.wrapper, ‘click‘, this, true);        }        // 如果没禁用鼠标，绑定鼠标事件，针对PC。        if ( !this.options.disableMouse ) {            eventType(this.wrapper, ‘mousedown‘, this);            eventType(target, ‘mousemove‘, this);            eventType(target, ‘mousecancel‘, this);            eventType(target, ‘mouseup‘, this);        }        // 针对win phone的touch事件        if ( utils.hasPointer && !this.options.disablePointer ) {            eventType(this.wrapper, utils.prefixPointerEvent(‘pointerdown‘), this);            eventType(target, utils.prefixPointerEvent(‘pointermove‘), this);            eventType(target, utils.prefixPointerEvent(‘pointercancel‘), this);            eventType(target, utils.prefixPointerEvent(‘pointerup‘), this);        }        //针对ios & Android的touch事件        if ( utils.hasTouch && !this.options.disableTouch ) {            eventType(this.wrapper, ‘touchstart‘, this);            eventType(target, ‘touchmove‘, this);            eventType(target, ‘touchcancel‘, this);            eventType(target, ‘touchend‘, this);        }        // css3动画结束后的回调事件        eventType(this.scroller, ‘transitionend‘, this);        eventType(this.scroller, ‘webkitTransitionEnd‘, this);        eventType(this.scroller, ‘oTransitionEnd‘, this);        eventType(this.scroller, ‘MSTransitionEnd‘, this);    },    getComputedPosition: function () {        //获取scroller的样式        var matrix = window.getComputedStyle(this.scroller, null),            x, y;        //两种方式 transform 和 top/left ( transform在ios下,文本输入的光标fixed )        if ( this.options.useTransform ) {            matrix = matrix[utils.style.transform].split(‘)‘)[0].split(‘, ‘);            x = +(matrix[12] || matrix[4]);            y = +(matrix[13] || matrix[5]);        } else {            x = +matrix.left.replace(/[^-\d.]/g, ‘‘);            y = +matrix.top.replace(/[^-\d.]/g, ‘‘);        }        //返回 (x ,y)  or (top ,left)        return { x: x, y: y };    },    /**     * @param  destx 为移动目的地的x轴坐标     * @param  desty 为移动目的地的y轴坐标     * @param  duration 为移动的时间     * @param  easingFn 为移动缓动函数     */    _animate: function (destX, destY, duration, easingFn) {        var that = this,            startX = this.x,            startY = this.y,            startTime = utils.getTime(),            destTime = startTime + duration;        function step () {            var now = utils.getTime(),                newX, newY,                easing;            if ( now >= destTime ) {                that.isAnimating = false;                that._translate(destX, destY);                if ( !that.resetPosition(that.options.bounceTime) ) {                    that._execEvent(‘scrollEnd‘);                }                return;            }            now = ( now - startTime ) / duration;            easing = easingFn(now);            newX = ( destX - startX ) * easing + startX;            newY = ( destY - startY ) * easing + startY;            that._translate(newX, newY);            if ( that.isAnimating ) {                rAF(step);            }        }        this.isAnimating = true;        step();    },    handleEvent: function (e) {        switch ( e.type ) {            case ‘touchstart‘:            case ‘pointerdown‘:            case ‘MSPointerDown‘:            case ‘mousedown‘:                this._start(e);                break;            case ‘touchmove‘:            case ‘pointermove‘:            case ‘MSPointerMove‘:            case ‘mousemove‘:                this._move(e);                break;            case ‘touchend‘:            case ‘pointerup‘:            case ‘MSPointerUp‘:            case ‘mouseup‘:            case ‘touchcancel‘:            case ‘pointercancel‘:            case ‘MSPointerCancel‘:            case ‘mousecancel‘:                this._end(e);                break;            case ‘orientationchange‘:            case ‘resize‘:                this._resize();                break;            case ‘transitionend‘:            case ‘webkitTransitionEnd‘:            case ‘oTransitionEnd‘:            case ‘MSTransitionEnd‘:                this._transitionEnd(e);                break;            case ‘wheel‘:            case ‘DOMMouseScroll‘:            case ‘mousewheel‘:                this._wheel(e);                break;            case ‘keydown‘:                this._key(e);                break;            case ‘click‘:                if ( !e._constructed ) {                    e.preventDefault();                    e.stopPropagation();                }                break;        }    }};IScroll.utils = utils;if ( typeof module != ‘undefined‘ && module.exports ) {    module.exports = IScroll;} else {    window.IScroll = IScroll;}})(window, document, Math);