Spike for scroll capturing

ScrollCapture

#= require _swipe_event

settings =
  sectionContainer: "section",
  easing: "ease",
  animationTime: 1000,
  pagination: true,
  updateURL: false,
  keyboard: true,
  beforeMove: null,
  afterMove: null,
  loop: true,
  responsiveFallback: false,
  direction : 'vertical' # 'vertical' or 'horizontal'
  transitionEndEventNames: 'transitionend webkitTransitionEnd oTransitionEnd MSTransitionEnd'


class ld.SlideScroll

  constructor: ({ container }) ->
    @$container = $(container)
    @centering = false

    scrollr = new ld.ScrollObserver(elem: @$container[0])
    scrollr.enterView =>
      @activate()



  activate: ->
    $(document).on 'mousewheel DOMMouseScroll MozMousePixelScroll', @onScroll


  deactivate: ->
    $(document).off 'mousewheel DOMMouseScroll MozMousePixelScroll', @onScroll


  onScroll: (event) =>
    event.preventDefault()
    delta = event.originalEvent.wheelDelta || -event.originalEvent.detail 
    @captureScroll(event, delta)


  captureScroll: (event, delta) ->
    if delta > 0
      @deactivate()
      return

    return if @centering

    # calculate animation speed
    if delta < -40
      duration = 200
    else if delta < -10
      duration = 500
    else
      duration = 1000

    # experimental
    currentTop = $(window).scrollTop()
    targetTop = @$container.offset().top
    deltaToTarget = targetTop - currentTop
    neededSteps = deltaToTarget / delta
    console.log "deltaToTarget #{ deltaToTarget }"
    console.log "delta #{ delta }"

    # no negative numbers
    neededSteps = neededSteps * -1 if neededSteps < 0
    console.log "neededSteps #{ neededSteps }"
    console.log "duration #{ duration }"

    @centering = true
    $('html, body').animate
      scrollTop: @$container.offset().top
    , duration