How to hide div when scrolling down and then show scroll up

Question

I want to make the case for showing and hiding menu like the picture.

You can see in the following image there is a tree part. First part when you open the page the right bottom side menu will still showing.

When you scroll down then the menu will fadeIn, and when you sroll up then the menu will fadeOut.

The facebook and tumblr doing like this. I want to learn how can they do this. Anyone can tell me little example or something.

I created this DEMO from codepen.io but it is only header think and also there is a problem when scroll up.

var previousScroll = 0, // previous scroll position
        menuOffset = 54, // height of menu (once scroll passed it, menu is hidden)
        detachPoint = 650, // point of detach (after scroll passed it, menu is fixed)
        hideShowOffset = 6; // scrolling value after which triggers hide/show menu
    // on scroll hide/show menu
    $(window).scroll(function() {
      if (!$('nav').hasClass('expanded')) {
        var currentScroll = $(this).scrollTop(), // gets current scroll position
            scrollDifference = Math.abs(currentScroll - previousScroll); // calculates how fast user is scrolling
        // if scrolled past menu
        if (currentScroll > menuOffset) {
          // if scrolled past detach point add class to fix menu
          if (currentScroll > detachPoint) {
            if (!$('nav').hasClass('detached'))
              $('nav').addClass('detached');
          }
          // if scrolling faster than hideShowOffset hide/show menu
          if (scrollDifference >= hideShowOffset) {
            if (currentScroll > previousScroll) {
              // scrolling down; hide menu
              if (!$('nav').hasClass('invisible'))
                $('nav').addClass('invisible');
            } else {
              // scrolling up; show menu
              if ($('nav').hasClass('invisible'))
                $('nav').removeClass('invisible');
            }
          }
        } else {
          // only remove “detached” class if user is at the top of document (menu jump fix)
          if (currentScroll <= 0){
            $('nav').removeClass();
          }
        }
        // if user is at the bottom of document show menu
        if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight) {
          $('nav').removeClass('invisible');
        }
        // replace previous scroll position with new one
        previousScroll = currentScroll;
      }
    })
    // shows/hides navigation’s popover if class "expanded"
    $('nav').on('click touchstart', function(event) {
      showHideNav();
      event.preventDefault();
    })
    // clicking anywhere inside navigation or heading won’t close navigation’s popover
    $('#navigation').on('click touchstart', function(event){
        event.stopPropagation();
    })
    // checks if navigation’s popover is shown
    function showHideNav() {
      if ($('nav').hasClass('expanded')) {
        hideNav();
      } else {
        showNav();
      }
    }
    // shows the navigation’s popover
    function showNav() {
      $('nav').removeClass('invisible').addClass('expanded');
      $('#container').addClass('blurred');
      window.setTimeout(function(){$('body').addClass('no_scroll');}, 200); // Firefox hack. Hides scrollbar as soon as menu animation is done
      $('#navigation a').attr('tabindex', ''); // links inside navigation should be TAB selectable
    }
    // hides the navigation’s popover
    function hideNav() {
      $('#container').removeClass('blurred');
      window.setTimeout(function(){$('body').removeClass();}, 10); // allow animations to start before removing class (Firefox)
      $('nav').removeClass('expanded');
      $('#navigation a').attr('tabindex', '-1'); // links inside hidden navigation should not be TAB selectable
      $('.icon').blur(); // deselect icon when navigation is hidden
    }
    // keyboard shortcuts
    $('body').keydown(function(e) {
      // menu accessible via TAB as well
      if ($("nav .icon").is(":focus")) {
        // if ENTER/SPACE show/hide menu
        if (e.keyCode === 13 || e.keyCode === 32) {
          showHideNav();
          e.preventDefault();
        }
      }
      // if ESC show/hide menu
      if (e.keyCode === 27 || e.keyCode === 77) {
        showHideNav();
        e.preventDefault();
      }
    })

Answer 1

You might be looking for something like this? Whenever you scroll, it checks how far you've scrolled and in what direction from your previous scroll position.

var previousScroll = 0;
$(window).scroll(function(event){
   var scroll = $(this).scrollTop();
   if (scroll > previousScroll){
       // downscroll code
   } else {
      // upscroll code
   }
   previousScroll = scroll;
});

Here's a little complimentary JSFuddle with some modification and live action application of that script: https://jsfiddle.net/d00h1zmn/4/