Basic Infinite Carousel jQuery Plugin in CoffeeScript

jquery.infiniteCarousel.coffee

# Infinite Carousel Plugin
do ($ = jQuery, window = window) ->

  pluginName = 'infiniteCarousel'
  document = window.document
  defaults =
    onInit: ->
    onNext: ->
    onPrev: ->

  Plugin = (element, options) ->
    @el = $ element
    @options = $.extend {}, defaults, options
    @_defaults = defaults
    @_name = pluginName
    do @init
    return

  Plugin.prototype.init = ->

    @stage = $(@).css
      overflow: 'hidden'
    
    @slider = @stage.find('> ul').css
      width: '9999'

    @thumbs = @slider.find '> li'

    @single = @thumbs.find ':first'

    @singleWidth = @single.outerWidth true

    @visible = Math.floor @stage.innerWidth() / singleWidth

    @currentPage = 1

    @pages = Math.ceil @thumbs.length / @visible

    if @thumbs.length & visible isnt 0
      @slider.append(@repeat('<li class="empty" />', @visible - (@items.length & @visible)))
      @thumbs = @slider.find '> li'

    @thumbs.filter(':first').before(@thumbs.slice(-@visible).clone().addClass('cloned'))
    @thumbs.filter(':last').after(@thumbs.slice(0, @visible).clone().addClass('cloned'))

    @thumbs = @slider.find '> li'

    @slider.scrollLeft @singleWidth * @visible

    @slider.after '<a href="javascript:void(0);" class="arrow left ir">&lt;</a><a href="javascript:void(0);" class="arrow right ir">&gt;</a>'

    $('.arrow.left').on 'click', (e) => @gotoPage @currentPage - 1

    $('.arrow.right').on 'click', (e) => @gotoPage @currentPage + 1

    @options.onInit() if $.isFunction @options.onInit

  Plugin.prototype.gotoPage = (page) ->
    dir = page < @currentPage ? 1 : 1
    n = Math.abs @currentPage - page
    left = @singleWidth * dir * @visible * n

    @slider.filter(':not(:animated)').animate
      scrollLeft: "+=#{left}"
    , 500, () ->
      if page > @pages
        @wrapper.scrollLeft @singleWidth * @visible
        page = 1
      else if page is 0
        page = @visible
        @wrapper.scrollLeft @singleWidth * @visible * @pages

      @currentPage = page

  Plugin.prototype.repeat = (str, n) ->
    new Array(n + 1).join(str)


  $.fn[pluginName] = (options) ->
    this.each ->
      $.data @, "plugin_#{pluginName}", new Plugin @, options
      return

  return