scopesessions.org/js/custom.js

var scrolling = false;
var navigatorOpen = false;
var topButtonVisible = true;

$(document).ready(function() {

 $(function() {
  $.scrollIt();
 });


 $(".navigator-toggle").click(function() {
  if (navigatorOpen) {
   closeTopMenu();
  } else {
   openTopMenu();
  }
  navigatorOpen = !navigatorOpen;
 });

 $(".topic").click(function() {
  closeTopMenu();
 });

 function openTopMenu() {
  if (!scrolling && !navigatorOpen) {
   scrolling = true;
   $(".navigator").slideDown("slow", function() {
    scrolling = false;
    navigatorOpen = true;
   });
  }
 }

 function closeTopMenu() {
  if (!scrolling && navigatorOpen) {
   scrolling = true;
   $('.navigator').slideUp("slow", function() {
    scrolling = false;
    navigatorOpen = false;
   });
  }
 }

 function showTopButton() {
  console.log('showTopButton');
  if (!topButtonVisible) {
   $('.top-button').show("slow", function() {
    topButtonVisible = true;
   });
  }
 }

 function hideTopButton() {
  console.log('hideTopButton');
  if (topButtonVisible) {
   $('.top-button').hide("slow", function() {
    topButtonVisible = false;
   });
  }
 }

 var timeout = null;
 var navbarHeight = $('.navbar').height();

 $(window).scroll(function() {
  if (!timeout) {
   timeout = setTimeout(function() {
    clearTimeout(timeout);
    timeout = null;
    if ($(window).scrollTop() >= navbarHeight) {
     closeTopMenu();
     showTopButton();
    } else {
     hideTopButton();
    }
   }, 250);
  }
 });

});