scrollspy.coffee

angular.module('jobFoundryDirectives').directive 'spy', ($location) ->
  restrict: "A"
  require: "^scrollSpy"
  link: (scope, elem, attrs, scrollSpy) ->
    attrs.spyClass ?= "current"

    elem.click ->
      scope.$apply ->
        $location.hash(attrs.spy)

    scrollSpy.addSpy
      id: attrs.spy
      in: -> elem.addClass attrs.spyClass,
      out: -> elem.removeClass attrs.spyClass

angular.module('jobFoundryDirectives').directive 'scrollSpy', ($window) ->
  restrict: 'A'
  controller: ($scope) ->
    $scope.spies = []
    @addSpy = (spyObj) -> $scope.spies.push spyObj
  link: (scope, elem, attrs) ->
    spyElems = []
    
    scope.$watch 'spies', (spies) ->
      for spy in spies
        unless spyElems[spy.id]?
          spyElems[spy.id] = elem.find('#'+spy.id)

    $($window).scroll ->
      highlightSpy = null
      for spy in scope.spies
        spy.out()

        # the elem might not have been available when it was originally cached,
        # so we check again to get another element in case this one doesn't exist.
        spyElems[spy.id] =
          if spyElems[spy.id].length is 0
            elem.find('#'+spy.id)
          else
            spyElems[spy.id]

        # the element could still not exist, so we check first to avoid errors
        if spyElems[spy.id].length isnt 0
          if (pos = spyElems[spy.id].offset().top) - $window.scrollY <= 0
            spy.pos = pos
            highlightSpy ?= spy
            if highlightSpy.pos < spy.pos
              highlightSpy = spy

      highlightSpy?.in()