jQuery手风琴菜单：滚动到活动菜单项

Question

I have made an accordion menu intended to serve as an efficient mobile phone menu. I have used the jQuery 2.1.1 library for this purpose.

The part that does not work as I want it to is that concerning the body tag animation.

I want the document to scroll to active menu item instead of the nav tag, as it now does.

This is what I came up with:

 $('#menu').children('ul').on('click', '.menu-item', function(e) { if ($(window).width() < 640) { e.preventDefault(); var $menu_item = $(this).closest('li'); var $sub_menu = $menu_item.find('.sub-menu'); var $other_sub_menus = $menu_item.siblings().find('.sub-menu'); if ($sub_menu.is(':visible')) { $sub_menu.slideUp(200); $menu_item.removeClass('selected'); } else { $other_sub_menus.slideUp(200); $sub_menu.slideDown(200); $menu_item.siblings().removeClass('selected'); $menu_item.addClass('selected'); } } $('html,body').animate({ scrollTop: $(this).offset().top }, 500); console.log($(this).offset().top); }); 

 body { font-family: Arial, sans-serif; } p { font-size: 14px; line-height: 1.6; } nav ul { list-style-type: none; margin: 0; padding: 0; } #menu { max-width: 640px; } #menu ul { background: #069; } #menu ul.sub-menu { display: none; background: #fefefe; } #menu ul li a { text-decoration: none; display: block; font-size: 13px; color: #fff; padding: 0 10px; height: 32px; line-height: 30px; position: relative; border-top: 1px solid rgba(0, 0, 0, 0.1); border-bottom: 1px solid rgba(255, 255, 255, 0.1); } #menu ul.sub-menu li a { padding-left: 25px; color: #555; } #menu > ul > li > a:after { display: inline-block; vertical-align: middle; content: "\\2304"; position: absolute; right: 0; font-size: 20px; line-height: 20px; padding-bottom: 10px; width: 30px; text-align: center; top: 0; color: #fff; } #menu li.selected a:after { -webkit-transform: rotate(180deg); -moz-transform: rotate(180deg); -ms-transform: rotate(180deg); -o-transform: rotate(180deg); } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <h1>Page title</h1> <nav id="menu"> <ul> <li><a href="#" class="menu-item">Software</a> <ul class="sub-menu"> <li><a href="#">Operating systems</a></li> <li><a href="#">MS Office</a></li> <li><a href="#">Web development tools</a></li> </ul> </li> <li><a href="#" class="menu-item">Monitors &amp; screens</a> <ul class="sub-menu"> <li><a href="#">Monitors</a></li> <li><a href="#">LCD</a></li> <li><a href="#">TV</a></li> <li><a href="#">DVD players</a></li> </ul> </li> <li><a href="#" class="menu-item">Networking</a> <ul class="sub-menu"> <li><a href="#">Routers</a></li> <li><a href="#">Network Adapters</a></li> <li><a href="#">Modems</a></li> <li><a href="#">Cables</a></li> </ul> </li> <li><a href="#" class="menu-item">Print &amp; scan</a> <ul class="sub-menu"> <li><a href="#">Printers</a></li> <li><a href="#">3D printers</a></li> <li><a href="#">Scanners</a></li> </ul> </li> </ul> </nav> <p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.</p> <p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. Vestibulum erat wisi, condimentum sed, commodo vitae, ornare sit amet, wisi. Aenean fermentum, elit eget tincidunt condimentum, eros ipsum rutrum orci, sagittis tempus lacus enim ac dui. Donec non enim in turpis pulvinar facilisis. Ut felis. Praesent dapibus, neque id cursus faucibus, tortor neque egestas augue, eu vulputate magna eros eu erat. Aliquam erat volutpat. Nam dui mi, tincidunt quis, accumsan porttitor, facilisis luctus, metus</p> <p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.</p> 

UPDATE: I replaced scrollTop: $('#menu').offset().top with scrollTop: $(this).offset().top , as adviced by Kano.

It works better but not good enough. Console logging the top offset gives an aberrant value if you click multiple menu items successively .

Thank you!

Answer 1

Just change this part in your jQuery snippet:

$('body').animate({
  scrollTop: $("#menu").offset().top
}, 300);

To this:

$('body').animate({
  scrollTop: $(this).offset().top
}, 300);

That way when you're calling animate() to scroll, you're taking the offset of the clicked menu item instead of the #menu selector (which always resulted in the nav element in your case).