main.js

(function ($) {
    //----------------------------------------
    // Essentials
    //----------------------------------------
    var windowWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;

    // breakpoints
    var $screen_xxs = 320;
    var $screen_xs = 480;
    var $screen_sm = 576;
    var $screen_md = 768;
    var $screen_lg = 991;
    var $screen_xlg = 1200;

    // find out if is touch device
    function is_touch_device() {
        return (('ontouchstart' in window)
            || (navigator.MaxTouchPoints > 0)
            || (navigator.msMaxTouchPoints > 0));
        //navigator.msMaxTouchPoints for microsoft IE backwards compatibility
    }


    // Add slideDown animation to Bootstrap dropdown when expanding.
    $('.dropdown:not(.main-nav-wrapper-wrapper)').on('show.bs.dropdown', function () {
        $(this).find('.dropdown-menu').first().stop(true, true).slideDown();
    });

    // Add slideUp animation to Bootstrap dropdown when collapsing.
    $('.dropdown:not(.main-nav-wrapper-wrapper)').on('hide.bs.dropdown', function () {
        $(this).find('.dropdown-menu').first().stop(true, true).slideUp();
    });

    //mobile dropdown
    $('.main-header .dropdown').on('show.bs.dropdown', function () {
        var windowWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
        if (windowWidth < $screen_md) {
            $('body').addClass('no-scroll');
        }

    }).on('hide.bs.dropdown', function () {
        $('body').removeClass('no-scroll');

    });

    var originalWindowWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;

    $(window).resize(function () {

        var windowWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;

        //prevent functions from recalculating on scroll on mobile. when scrolling on iphone, the bottom appears/disappears and the browser thinks this is resizing
        //execute these functions on width resize only
        if (windowWidth != originalWindowWidth) { //if width resized

        }

    });
}(jQuery));