jquery.handle-scroll.js

;
(function ($, undefined) {
    $.fn.handleScroll = (upHandler, downHandler, userOptions) => {
        const options = $.extend({}, {
            debug: false
        }, userOptions);

        /**
         * Window object.
         */
        const $Window = this;
        /**
         * States if the document is already loaded.
         */
        let isLoaded = false;
        /**
         * Last scroll position.
         */
        let lastScrollTop = 0;

        jQuery(document).ready(() => {
            isLoaded = true;

            if (options.debug) {
                console.log("[handleScroll] Window loaded");
            }
        });

        $Window.on("scroll", () => {
            if (!isLoaded) {
                return;
            }

            const scrollTop = $Window.scrollTop();

            if (scrollTop > lastScrollTop) {
                if (options.debug) {
                    console.log("[handleScroll] Window scrolling down");
                }

                downHandler();
            } else {
                if (options.debug) {
                    console.log("[handleScroll] Window scrolling up");
                }

                upHandler();
            }

            lastScrollTop = scrollTop;
        });

        return $Window;
    };
})(jQuery);