iscroll-lite基础上增加了 scroll方法 ,最轻的基础库上把scroll方法移过来了

   parare.on('scroll', function() {
      const that = this
      paraetail.scrollTo(that.x, 0)
    })
    paraetail.on('scroll', function() {
      const that = this
      parare.scrollTo(that.x, 0)
    })
/*! iScroll v5.2.0-snapshot ~ (c) 2008-2017 Matteo Spinelli ~ http://cubiq.org/license */
/* 2021/09/17/  在iscroll-lite基础上 增加scroll方法 和官网的iscroll-lite有区别 */
;(function(window, document, Math) {
  var rAF =
    window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    window.oRequestAnimationFrame ||
    window.msRequestAnimationFrame ||
    function(callback) {
      window.setTimeout(callback, 1000 / 60)
    }

  var utils = (function() {
    var me = {}

    var _elementStyle = document.createElement('div').style
    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
    })()

    function _prefixStyle(style) {
      if (_vendor === false) return false
      if (_vendor === '') return style
      return _vendor + style.charAt(0).toUpperCase() + style.substr(1)
    }

    me.getTime =
      Date.now ||
      function getTime() {
        return new Date().getTime()
      }

    me.extend = function(target, obj) {
      for (var i in obj) {
        target[i] = obj[i]
      }
    }

    me.addEvent = function(el, type, fn, capture) {
      el.addEventListener(type, fn, !!capture)
    }

    me.removeEvent = function(el, type, fn, capture) {
      el.removeEventListener(type, fn, !!capture)
    }

    me.prefixPointerEvent = function(pointerEvent) {
      return window.MSPointerEvent
        ? 'MSPointer' +
            pointerEvent.charAt(7).toUpperCase() +
            pointerEvent.substr(8)
        : pointerEvent
    }

    me.momentum = function(
      current,
      start,
      time,
      lowerMargin,
      wrapperSize,
      deceleration
    ) {
      var distance = current - start,
        speed = Math.abs(distance) / time,
        destination,
        duration

      deceleration = deceleration === undefined ? 0.0006 : deceleration

      destination =
        current +
        ((speed * speed) / (2 * deceleration)) * (distance < 0 ? -1 : 1)
      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,
      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)
    - galaxy S2 is ok
      - 2.3.6 : `AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1`
      - 4.0.4 : `AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30`
     - galaxy S3 is badAndroid (stock brower, webview)
       `AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30`
     - galaxy S4 is badAndroid (stock brower, webview)
       `AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30`
     - galaxy S5 is OK
       `AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Mobile Safari/537.36 (Chrome/)`
     - galaxy S6 is OK
       `AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Mobile Safari/537.36 (Chrome/)`
    */
    me.isBadAndroid = (function() {
      var appVersion = window.navigator.appVersion
      // Android browser is not a chrome browser.
      if (/Android/.test(appVersion) && !/Chrome\/\d/.test(appVersion)) {
        var safariVersion = appVersion.match(/Safari\/(\d+.\d)/)
        if (
          safariVersion &&
          typeof safariVersion === 'object' &&
          safariVersion.length >= 2
        ) {
          return parseFloat(safariVersion[1]) < 535.19
        } else {
          return true
        }
      } else {
        return false
      }
    })()

    me.extend((me.style = {}), {
      transform: _transform,
      transitionTimingFunction: _prefixStyle('transitionTimingFunction'),
      transitionDuration: _prefixStyle('transitionDuration'),
      transitionDelay: _prefixStyle('transitionDelay'),
      transformOrigin: _prefixStyle('transformOrigin'),
      touchAction: _prefixStyle('touchAction')
    })

    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
      }
    }

    me.preventDefaultException = function(el, exceptions) {
      for (var i in exceptions) {
        if (exceptions[i].test(el[i])) {
          return true
        }
      }

      return false
    }

    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
    })

    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')
      ev.initEvent(eventName, true, true)
      ev.pageX = e.pageX
      ev.pageY = e.pageY
      e.target.dispatchEvent(ev)
    }

    me.click = function(e) {
      var target = e.target,
        ev

      if (!/(SELECT|INPUT|TEXTAREA)/i.test(target.tagName)) {
        // https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/initMouseEvent
        // initMouseEvent is deprecated.
        ev = document.createEvent(window.MouseEvent ? 'MouseEvents' : 'Event')
        ev.initEvent('click', true, true)
        ev.view = e.view || window
        ev.detail = 1
        ev.screenX = target.screenX || 0
        ev.screenY = target.screenY || 0
        ev.clientX = target.clientX || 0
        ev.clientY = target.clientY || 0
        ev.ctrlKey = !!e.ctrlKey
        ev.altKey = !!e.altKey
        ev.shiftKey = !!e.shiftKey
        ev.metaKey = !!e.metaKey
        ev.button = 0
        ev.relatedTarget = null
        ev._constructed = true
        target.dispatchEvent(ev)
      }
    }

    me.getTouchAction = function(eventPassthrough, addPinch) {
      var touchAction = 'none'
      if (eventPassthrough === 'vertical') {
        touchAction = 'pan-y'
      } else if (eventPassthrough === 'horizontal') {
        touchAction = 'pan-x'
      }
      if (addPinch && touchAction != 'none') {
        // add pinch-zoom support if the browser supports it, but if not (eg. Chrome <55) do nothing
        touchAction += ' pinch-zoom'
      }
      return touchAction
    }

    me.getRect = function(el) {
      if (el instanceof SVGElement) {
        var rect = el.getBoundingClientRect()
        return {
          top: rect.top,
          left: rect.left,
          width: rect.width,
          height: rect.height
        }
      } else {
        return {
          top: el.offsetTop,
          left: el.offsetLeft,
          width: el.offsetWidth,
          height: el.offsetHeight
        }
      }
    }

    return me
  })()
  function IScroll(el, options) {
    this.wrapper = typeof el == 'string' ? document.querySelector(el) : el
    this.scroller = this.wrapper.children[0]
    this.scrollerStyle = this.scroller.style // cache style for better performance

    this.options = {
      resizeScrollbars: true,

      mouseWheelSpeed: 20,

      snapThreshold: 0.334,

      // INSERT POINT: OPTIONS
      disablePointer: !utils.hasPointer,
      disableTouch: utils.hasPointer || !utils.hasTouch,
      disableMouse: utils.hasPointer || utils.hasTouch,
      startX: 0,
      startY: 0,
      scrollY: true,
      directionLockThreshold: 5,
      momentum: true,

      bounce: true,
      bounceTime: 600,
      bounceEasing: '',

      preventDefault: true,
      preventDefaultException: { tagName: /^(INPUT|TEXTAREA|BUTTON|SELECT)$/ },

      HWCompositing: true,
      useTransition: true,
      useTransform: true,
      bindToWrapper: typeof window.onmousedown === 'undefined'
    }

    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

    this.options.eventPassthrough =
      this.options.eventPassthrough === true
        ? 'vertical'
        : this.options.eventPassthrough
    this.options.preventDefault =
      !this.options.eventPassthrough && this.options.preventDefault

    // If you want eventPassthrough I have to lock one of the axes
    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
    this.options.freeScroll =
      this.options.freeScroll && !this.options.eventPassthrough
    this.options.directionLockThreshold = this.options.eventPassthrough
      ? 0
      : this.options.directionLockThreshold

    this.options.bounceEasing =
      typeof this.options.bounceEasing == 'string'
        ? utils.ease[this.options.bounceEasing] || utils.ease.circular
        : this.options.bounceEasing

    this.options.resizePolling =
      this.options.resizePolling === undefined ? 60 : this.options.resizePolling

    if (this.options.tap === true) {
      this.options.tap = 'tap'
    }

    // https://github.com/cubiq/iscroll/issues/1029
    if (!this.options.useTransition && !this.options.useTransform) {
      if (!/relative|absolute/i.test(this.scrollerStyle.position)) {
        this.scrollerStyle.position = 'relative'
      }
    }

    if (this.options.shrinkScrollbars == 'scale') {
      this.options.useTransition = false
    }

    this.options.invertWheelDirection = this.options.invertWheelDirection
      ? -1
      : 1

    if (this.options.probeType == 3) {
      this.options.useTransition = false
    }

    // INSERT POINT: NORMALIZATION

    // Some defaults
    this.x = 0
    this.y = 0
    this.directionX = 0
    this.directionY = 0
    this._events = {}

    // INSERT POINT: DEFAULTS

    this._init()
    this.refresh()

    this.scrollTo(this.options.startX, this.options.startY)
    this.enable()
  }

  IScroll.prototype = {
    version: '5.2.0-snapshot',

    _init: function() {
      this._initEvents()

      // INSERT POINT: _init
    },

    destroy: function() {
      this._initEvents(true)
      clearTimeout(this.resizeTimeout)
      this.resizeTimeout = null
      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
      if (utils.eventType[e.type] != 1) {
        // for button property
        // http://unixpapa.com/js/mouse.html
        var button
        if (!e.which) {
          /* IE case */
          button = e.button < 2 ? 0 : e.button == 4 ? 1 : 2
        } else {
          /* All others */
          button = e.button
        }
        if (button !== 0) {
          return
        }
      }

      if (
        !this.enabled ||
        (this.initiated && utils.eventType[e.type] !== this.initiated)
      ) {
        return
      }

      if (
        this.options.preventDefault &&
        !utils.isBadAndroid &&
        !utils.preventDefaultException(
          e.target,
          this.options.preventDefaultException
        )
      ) {
        e.preventDefault()
      }

      var point = e.touches ? e.touches[0] : e,
        pos

      this.initiated = utils.eventType[e.type]
      this.moved = false
      this.distX = 0
      this.distY = 0
      this.directionX = 0
      this.directionY = 0
      this.directionLocked = 0

      this.startTime = utils.getTime()

      if (this.options.useTransition && this.isInTransition) {
        this._transitionTime()
        this.isInTransition = false
        pos = this.getComputedPosition()
        this._translate(Math.round(pos.x), Math.round(pos.y))
        this._execEvent('scrollEnd')
      } else if (!this.options.useTransition && this.isAnimating) {
        this.isAnimating = false
        this._execEvent('scrollEnd')
      }

      this.startX = this.x
      this.startY = this.y
      this.absStartX = this.x
      this.absStartY = this.y
      this.pointX = point.pageX
      this.pointY = point.pageY

      this._execEvent('beforeScrollStart')
    },

    _move: function(e) {
      if (!this.enabled || utils.eventType[e.type] !== this.initiated) {
        return
      }

      if (this.options.preventDefault) {
        // increases performance on Android? TODO: check!
        e.preventDefault()
      }

      var point = e.touches ? e.touches[0] : e,
        deltaX = point.pageX - this.pointX,
        deltaY = point.pageY - this.pointY,
        timestamp = utils.getTime(),
        newX,
        newY,
        absDistX,
        absDistY

      this.pointX = point.pageX
      this.pointY = point.pageY

      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
      if (timestamp - this.endTime > 300 && absDistX < 10 && absDistY < 10) {
        return
      }

      // If you are scrolling in one direction lock the other
      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

      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
      this.directionY = deltaY > 0 ? -1 : deltaY < 0 ? 1 : 0

      if (!this.moved) {
        this._execEvent('scrollStart')
      }

      this.moved = true

      this._translate(newX, newY)

      /* REPLACE START: _move */

      if (timestamp - this.startTime > 300) {
        this.startTime = timestamp
        this.startX = this.x
        this.startY = this.y

        if (this.options.probeType == 1) {
          this._execEvent('scroll')
        }
      }

      if (this.options.probeType > 1) {
        this._execEvent('scroll')
      }
      /* REPLACE END: _move */
    },

    _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),
        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
      if (this.resetPosition(this.options.bounceTime)) {
        return
      }

      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
      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)
    },

    resetPosition: function(time) {
      var x = this.x,
        y = this.y

      time = time || 0

      if (!this.hasHorizontalScroll || this.x > 0) {
        x = 0
      } else if (this.x < this.maxScrollX) {
        x = this.maxScrollX
      }

      if (!this.hasVerticalScroll || this.y > 0) {
        y = 0
      } else if (this.y < this.maxScrollY) {
        y = this.maxScrollY
      }

      if (x == this.x && y == this.y) {
        return false
      }

      this.scrollTo(x, y, time, this.options.bounceEasing)

      return true
    },

    disable: function() {
      this.enabled = false
    },

    enable: function() {
      this.enabled = true
    },

    refresh: function() {
      utils.getRect(this.wrapper) // Force reflow

      this.wrapperWidth = this.wrapper.clientWidth
      this.wrapperHeight = this.wrapper.clientHeight

      var rect = utils.getRect(this.scroller)
      /* REPLACE START: refresh */

      this.scrollerWidth = rect.width
      this.scrollerHeight = rect.height

      this.maxScrollX = this.wrapperWidth - this.scrollerWidth
      this.maxScrollY = this.wrapperHeight - this.scrollerHeight

      /* REPLACE END: refresh */

      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

      if (utils.hasPointer && !this.options.disablePointer) {
        // The wrapper should have `touchAction` property for using pointerEvent.
        this.wrapper.style[utils.style.touchAction] = utils.getTouchAction(
          this.options.eventPassthrough,
          true
        )

        // case. not support 'pinch-zoom'
        // https://github.com/cubiq/iscroll/issues/1118#issuecomment-270057583
        if (!this.wrapper.style[utils.style.touchAction]) {
          this.wrapper.style[utils.style.touchAction] = utils.getTouchAction(
            this.options.eventPassthrough,
            false
          )
        }
      }
      this.wrapperOffset = utils.offset(this.wrapper)

      this._execEvent('refresh')

      this.resetPosition()

      // INSERT POINT: _refresh
    },

    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)
    },

    scrollTo: function(x, y, time, easing) {
      easing = easing || utils.ease.circular

      this.isInTransition = this.options.useTransition && time > 0
      var transitionType = this.options.useTransition && easing.style
      if (!time || transitionType) {
        if (transitionType) {
          this._transitionTimingFunction(easing.style)
          this._transitionTime(time)
        }
        this._translate(x, y)
      } else {
        this._animate(x, y, time, easing.fn)
      }
    },

    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
      var elRect = utils.getRect(el)
      var wrapperRect = utils.getRect(this.wrapper)
      if (offsetX === true) {
        offsetX = Math.round(elRect.width / 2 - wrapperRect.width / 2)
      }
      if (offsetY === true) {
        offsetY = Math.round(elRect.height / 2 - wrapperRect.height / 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)
    },

    _transitionTime: function(time) {
      if (!this.options.useTransition) {
        return
      }
      time = time || 0
      var durationProp = utils.style.transitionDuration
      if (!durationProp) {
        return
      }

      this.scrollerStyle[durationProp] = time + 'ms'

      if (!time && utils.isBadAndroid) {
        this.scrollerStyle[durationProp] = '0.0001ms'
        // remove 0.0001ms
        var self = this
        rAF(function() {
          if (self.scrollerStyle[durationProp] === '0.0001ms') {
            self.scrollerStyle[durationProp] = '0s'
          }
        })
      }

      // INSERT POINT: _transitionTime
    },

    _transitionTimingFunction: function(easing) {
      this.scrollerStyle[utils.style.transitionTimingFunction] = easing

      // INSERT POINT: _transitionTimingFunction
    },

    _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
    },

    _initEvents: function(remove) {
      var eventType = remove ? utils.removeEvent : utils.addEvent,
        target = this.options.bindToWrapper ? this.wrapper : window

      eventType(window, 'orientationchange', this)
      eventType(window, 'resize', this)

      if (this.options.click) {
        eventType(this.wrapper, 'click', this, true)
      }

      if (!this.options.disableMouse) {
        eventType(this.wrapper, 'mousedown', this)
        eventType(target, 'mousemove', this)
        eventType(target, 'mousecancel', this)
        eventType(target, 'mouseup', this)
      }

      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)
      }

      if (utils.hasTouch && !this.options.disableTouch) {
        eventType(this.wrapper, 'touchstart', this)
        eventType(target, 'touchmove', this)
        eventType(target, 'touchcancel', this)
        eventType(target, 'touchend', this)
      }

      eventType(this.scroller, 'transitionend', this)
      eventType(this.scroller, 'webkitTransitionEnd', this)
      eventType(this.scroller, 'oTransitionEnd', this)
      eventType(this.scroller, 'MSTransitionEnd', this)
    },

    getComputedPosition: function() {
      var matrix = window.getComputedStyle(this.scroller, null),
        x,
        y

      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, '')
      }

      return { x: x, y: y }
    },
    _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)
        }

        if (that.options.probeType == 3) {
          that._execEvent('scroll')
        }
      }

      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 (this.enabled && !e._constructed) {
            e.preventDefault()
            e.stopPropagation()
          }
          break
      }
    }
  }
  IScroll.utils = utils

  if (typeof module != 'undefined' && module.exports) {
    module.exports = IScroll
  } else if (typeof define == 'function' && define.amd) {
    define(function() {
      return IScroll
    })
  } else {
    window.IScroll = IScroll
  }
})(window, document, Math)

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