(function ($) {
    $.fn.lazyload = function (options) {
        var settings = {
            threshold: 0, failurelimit: 0, event: "scroll", effect: "show", container: window
        };
        if (options) {
            $.extend(settings, options);
        }
        var elements = this;
        if ("scroll" == settings.event) {
            $(settings.container).bind("scroll", function (event) {
                var counter = 0;
                elements.each(function () {
                    if ($.abovethetop(this, settings) || $.leftofbegin(this, settings)) { } else if (!$.belowthefold(this, settings) && !$.rightoffold(this, settings)) {
                        $(this).trigger("appear");
                    }
                    else {
                        if (counter++ > settings.failurelimit) {
                            return false;
                        }

                    }

                });
                var temp = $.grep(elements, function (element) {
                    return !element.loaded;
                });
                elements = $(temp);
            });
        }
        this.each(function () {
            var self = this;
            if (undefined == $(self).attr("original")) {
                $(self).attr("original", $(self).attr("src"));
            }
            if ("scroll" != settings.event || undefined == $(self).attr("src") || settings.placeholder == $(self).attr("src") || ($.abovethetop(self, settings) || $.leftofbegin(self, settings) || $.belowthefold(self, settings) || $.rightoffold(self, settings))) {
                if (settings.placeholder) {
                    $(self).attr("src", settings.placeholder);
                }
                else {
                    $(self).removeAttr("src");
                }
                self.loaded = false;
            }
            else {
                self.loaded = true;
            }
            $(self).one("appear", function () {
                if (!this.loaded) {
                    $("<img />").bind("load", function () {
                        $(self).hide().attr("src", $(self).attr("original"))
                        [settings.effect](settings.effectspeed);
                        self.loaded = true;
                    }).attr("src", $(self).attr("original"));
                };
            });
            if ("scroll" != settings.event) {
                $(self).bind(settings.event, function (event) {
                    if (!self.loaded) {
                        $(self).trigger("appear");
                    }

                });
            }

        });
        $(settings.container).trigger(settings.event);
        return this;
    };
    $.belowthefold = function (element, settings) {
        if (settings.container === undefined || settings.container === window) {
            var fold = $(window).height() + $(window).scrollTop();
        }
        else {
            var fold = $(settings.container).offset().top + $(settings.container).height();
        }
        return fold <= $(element).offset().top - settings.threshold;
    };
    $.rightoffold = function (element, settings) {
        if (settings.container === undefined || settings.container === window) {
            var fold = $(window).width() + $(window).scrollLeft();
        }
        else {
            var fold = $(settings.container).offset().left + $(settings.container).width();
        }
        return fold <= $(element).offset().left - settings.threshold;
    };
    $.abovethetop = function (element, settings) {
        if (settings.container === undefined || settings.container === window) {
            var fold = $(window).scrollTop();
        }
        else {
            var fold = $(settings.container).offset().top;
        }
        return fold >= $(element).offset().top + settings.threshold + $(element).height();
    };
    $.leftofbegin = function (element, settings) {
        if (settings.container === undefined || settings.container === window) {
            var fold = $(window).scrollLeft();
        }
        else {
            var fold = $(settings.container).offset().left;
        }
        return fold >= $(element).offset().left + settings.threshold + $(element).width();
    };
    $.extend($.expr[':'], {
        "below-the-fold": "$.belowthefold(a, {threshold : 0, container: window})", "above-the-fold": "!$.belowthefold(a, {threshold : 0, container: window})", "right-of-fold": "$.rightoffold(a, {threshold : 0, container: window})", "left-of-fold": "!$.rightoffold(a, {threshold : 0, container: window})"
    });
})(jQuery);