lazy.coffee

define (require) ->

  $ = require 'jquery'

  $(document).ready ->

    deferrableImages = $("img[data-src]").toArray()

    # deferrableImages = $("img[data-src]").toArray()
    loadImage = ($el, $fn) ->
      $($el).attr "src", $($el).attr "data-src"
      $($el).removeAttr "data-src"
      (if $fn then $fn() else null)

    elementInViewport = ($el) ->
      $rect = $el.getBoundingClientRect()
      $rect.top >= 0 and $rect.left >= 0 and $rect.top <= (window.innerHeight or document.documentElement.clientHeight)

    # Load images as neccesary
    findImagesToLoad = ->
      console.log 'looking...'
      imagesToCheck = deferrableImages[..]
      imagesToRecheck = []
      while imagesToCheck.length
        el = imagesToCheck.pop()
        if elementInViewport el
          loadImage el
        else
          imagesToRecheck.push el
      deferrableImages = imagesToRecheck
      unless deferrableImages.length
        $(window).unbind 'scroll', findImagesToLoad

    findImagesToLoad()
    $(window).bind "scroll", findImagesToLoad