OpenFn/OpenFn-Site

'use strict';

angular.module('mgcrea.bootstrap.affix', ['mgcrea.jquery'])

  .directive('bsAffix', ['$window', '$location', '$routeParams', 'dimensions',function($window, $location, $routeParams, dimensions) {

    var checkPosition = function(instance, el, options) {

      var scrollTop = window.pageYOffset;
      var scrollHeight = document.body.scrollHeight;
      var position = dimensions.offset.call(el[0]);
      var height = dimensions.height.call(el[0]);
      var offsetTop = options.offsetTop * 1;
      var offsetBottom = options.offsetBottom * 1;
      var reset = 'affix affix-top affix-bottom';
      var affix;

      if(instance.unpin !== null && (scrollTop + instance.unpin <= position.top)) {
        affix = false;
      } else if(offsetBottom && (position.top + height >= scrollHeight - offsetBottom)) {
        affix = 'bottom';
      } else if(offsetTop && scrollTop <= offsetTop) {
        affix = 'top';
      } else {
        affix = false;
      }

      if (instance.affixed === affix) return;

      instance.affixed = affix;
      instance.unpin = affix === 'bottom' ? position.top - scrollTop : null;

      el.removeClass(reset).addClass('affix' + (affix ? '-' + affix : ''));
    };

    var checkCallbacks = function(scope, instance, iElement, iAttrs) {
      if(instance.affixed) {
        if(iAttrs.onUnaffix)
          eval("scope." + iAttrs.onUnaffix);
      }
      else {
        if(iAttrs.onAffix)
          eval("scope." + iAttrs.onAffix);
      }
    };

    return {
      restrict: 'EAC',
      link: function postLink(scope, iElement, iAttrs) {
        var instance = {unpin: null};

        angular.element($window).bind('scroll', function() {
          checkPosition(instance, iElement, iAttrs);
          checkCallbacks(scope, instance, iElement, iAttrs);
        });

        angular.element($window).bind('click', function() {
          setTimeout(function() {
            checkPosition(instance, iElement, iAttrs);
            checkCallbacks(scope, instance, iElement, iAttrs);
          }, 1);
        });
      }
    };

  }]);