bz-sticky.src.js

(function(angular, factory) {
    if (typeof define === 'function' && define.amd) {
        define(['angular'], function(angular) {
            return factory(angular);
        });
    } else {
        return factory(angular);
    }
}(angular || null, function(angular) {
var app = angular.module('bzSticky', []);
app.run(['$window', '$rootScope', function ($window, scope) {
    if (scope._stickyElements === undefined) {
        var $win = angular.element($window);

        $win.bind('scroll.sticky', function (e) {
            var pos = $win.scrollTop();
            for (var i = 0; i < scope._stickyElements.length; i++) {

                var item = scope._stickyElements[i];

                if (!item.isStuck && pos > item.start) {
                    item.element.addClass('bz-sticky');
                    item.isStuck = true;

                    if (item.placeholder) {
                        item.placeholder = angular.element('<div></div>')
                            .css({height: item.element.outerHeight() + 'px'})
                            .insertBefore(item.element);
                    }
                }
                else if (item.isStuck && pos < item.start) {
                    item.element.removeClass('bz-sticky');
                    item.isStuck = false;

                    if (item.placeholder) {
                        item.placeholder.remove();
                        item.placeholder = true;
                    }
                }
            }
        });

        var recheckPositions = function () {
            for (var i = 0; i < scope._stickyElements.length; i++) {
                var item = scope._stickyElements[i];
                if (!item.isStuck) {
                    item.start = item.element.offset().top;
                } else if (item.placeholder) {
                    item.start = item.placeholder.offset().top;
                }
            }
        };
        $win.bind('load', recheckPositions);
        $win.bind('resize', recheckPositions);
    }
}]);
app.directive('bzSticky', ['$rootScope', function ($rootScope) {
    return {
        link: function (scope, element, attrs) {
            var item = {
                element: element,
                isStuck: false,
                placeholder: attrs.usePlaceholder !== undefined,
                start: element.offset().top
            };

            $rootScope._stickyElements = $rootScope._stickyElements || [];
            $rootScope._stickyElements.push(item);
        }
    };
}]);
    return app;
}));