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Proximity loading for images/social scripts
# Really this is just a proximity_sensor, it will fire whatever event you pass as an arg
# It has nothing to do with loading, that's just how we've used it so far
required = if window.lp.isMobile then 'jsmin' else 'jquery'
define [required, 'lib/extends/events'], ($, EventEmitter) ->
class ProximityLoader
for key, value of EventEmitter
@prototype[key] = value
LISTENER = '#js-row--content'
# params
# el: The listening element
# list: comma delimited list of elements to watch
# success: event to fire when the criteria is matched
# klass: Custom parameters to pass through with the success event
constructor: (args) ->
@success = args.success || ':asset/uncomment'
@klass = args.klass
@$el = $(args.el || LISTENER)
return false if @$el.length is 0
@elems = @_setUpElems(args)
@_check() # Check on load in case the user refreshes midway down the page
@_watch()
# Private
_getViewportEdge: ->
scrolled = if window.pageYOffset then window.pageYOffset else document.documentElement.scrollTop
scrolled + document.documentElement.clientHeight
_setUpElems: (args) ->
elems = []
for el in args.list.split(',')
$elems = @$el.find(el)
for $el in $elems
$el = if $.fn then $($el) else $el
elems.push({
$el: $el
top: parseInt($el.offset().top, 10)
threshold: parseInt($el.data('threshold') || 500, 10)
})
elems
_watch: ->
enableTimer = false
# Only create jquery object if necessary, otherwise we already have the node
win = if $.fn then $(window) else window
win.on 'scroll', =>
clearTimeout(enableTimer) if enableTimer
enableTimer = setTimeout =>
@_check()
, 200
_check: () ->
if @elems.length > 0
newElems = []
fold = @_getViewportEdge()
for el in @elems
if (el.top - el.threshold) <= fold
@trigger(@success, [el.$el, @klass])
else
newElems.push(el)
# Create a new array of elements that have not yet matched
@elems = newElems
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