How does Google make its scrollbars?

Question

I was just on http://www.google.com/finance and noticed on the middle of the page an awesome looking scrollbar.

How does Google create this scrollbar look/feel?

Note: this scrollbar is different than what Google used with it's Wave product.

Screenshot

UPDATE:

The scrollbar doesn't appear immediately. Do NOT refresh the page. Let the page sit ideal for a few moments until there is new news story in the world. Once a new news story appears, the new article will cause the scrollbar to appear.

Answer 1

Although others have indicated how this is done (and that was the question, thus they are the "correct" answer) I'd like to suggest an alternative answer...

Seriously consider why you would want to do this

A scrollbar would be just as easy to add by setting 2 css properties (e.g. no code required)

.container{
  height:200px;/*some fixed height*/
  overflow-y:auto;/*adds a native scrollbar, only when needed*/
}

The problem with the custom scrollbar is that it doesn't behave quite like a native one does.

• You can't click on the track to scroll the content
• You can't use the scroll-wheel on your mouse to scroll the content
• You can't use the up/down arrow keys, home, end,page up, page dn to scroll the content
• The thumbscrew doesn't change in size to reflect the amount of content that can be scrolled

These may not seem like a major issue, but changing/removing the "behavior" of UI controls that users are used to is generally not advised.

Quote from Jakob Neilsen's Usability site "Alertbox" article: "Scrolling and Scrollbars" - July 11, 2005. (emphasis mine)

Scrollbars are easy to get right. In fact, the less work you do, the better your scrollbar. Usability is almost always enhanced when you use the built-in scrollbars rather than design your own.

Answer 2

Very interesting question. I just had spare time and spent it to implement simple example of this (spent about 1 hour with a cup of tea with candies ;)). Look at this:

<script src='jquery.js'></script>
<script src='jquery-ui.js'></script>

<style>
 .frame {
  position: relative;
  top: 150px;
  left: 150px;
  width: 500px;
  height: 500px;
  overflow: hidden;
  border: 1px solid black;
 }

 .frame > div {
  border: 1px solid black;
 }

 .frame .content {
  margin-right: 0px;
  height: 498px;
  overflow: hidden;
 }

 .frame .scrollbar {
  float: right;
  width: 20px;
  text-align: center;
 }
 .frame .scrollbar .scroller {
  position: relative;
  border-right: 1px solid black;
  width: 10px;
  height: 91.8%;
 }
 .frame .scrollbar .scroll-up, .frame .scrollbar .scroll-down {
  cursor: pointer;
 }
 .frame .scrollbar .scroll-up:hover, .frame .scrollbar .scroll-down:hover {
  background: blue;
  color: White;
 }

 .frame .scroller-draggable {
  background: #EEF1F7;
  border: 1px solid #D5DFF3;
  height: 20px;
  margin-left: 1px;
  margin-right: -10px;
  cursor: pointer;
 }
</style>

<div class="frame">
 <div class="scrollbar">
  <div class="scroll-up">[^]</div>
  <div class="scroller">
   <div class="scroller-draggable"></div>
  </div>
  <div class="scroll-down">[v]</div>
 </div>
 <div class="content">
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer enim elit, tristique id tristique sed, vulputate eu libero. Nam nec lectus orci, at varius est. Aenean quis velit a lorem bibendum dignissim eu ac ipsum. Vestibulum convallis diam faucibus dolor placerat sed iaculis sapien mattis. Maecenas in velit nec mauris aliquam condimentum. Mauris porttitor magna id est ultrices dapibus. Fusce at urna felis. Quisque congue dignissim bibendum. Praesent egestas elementum ante, non condimentum libero tempor quis. Nullam fermentum tincidunt aliquam. Suspendisse nec mi velit. Nulla facilisi. Etiam vitae sem nec orci feugiat mattis a quis massa. Vivamus rutrum suscipit tempor. Proin varius interdum arcu eget auctor. Vivamus quis placerat nulla. Praesent imperdiet tempus dictum. Donec pharetra, orci ac gravida euismod, sapien tellus feugiat velit, eu egestas nunc nisi at enim. Phasellus blandit placerat neque, non rhoncus tellus commodo sit amet. Donec lectus erat, ornare sit amet venenatis id, viverra ac quam.</p>
  <p>Sed aliquet metus vitae urna vulputate in mattis orci accumsan. Quisque dictum odio ac massa aliquet porttitor. Donec accumsan tortor sit amet ante vulputate at ullamcorper arcu auctor. Aenean gravida venenatis interdum. Aliquam erat volutpat. Integer eget dui vitae eros iaculis pharetra. In aliquam volutpat tincidunt. Sed vel imperdiet eros. Ut est nunc, venenatis sed varius et, scelerisque quis mi. Nullam aliquam pretium luctus. In hac habitasse platea dictumst. Etiam nec nibh libero. Nam pellentesque accumsan justo eget gravida. Ut egestas, mauris vitae egestas convallis, nibh turpis gravida justo, sit amet tincidunt libero orci eget metus.</p>
  <p>Praesent convallis pellentesque tristique. Etiam vulputate, arcu sit amet dignissim feugiat, risus nulla adipiscing lectus, in dignissim metus mi iaculis sem. Duis pulvinar vehicula leo nec porta. Cras nisl felis, elementum sit amet commodo sit amet, gravida quis augue. Praesent pretium sapien ut orci rutrum auctor. Aliquam erat volutpat. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Sed porta mattis cursus. Duis facilisis enim quam, quis imperdiet nulla. Mauris dapibus tincidunt felis vel ultrices. Fusce ut diam lectus. In lacinia ultrices leo, ut fringilla tellus egestas eget. Ut in odio et est tristique tempor quis a orci. Integer sodales adipiscing condimentum. Ut lacinia vehicula tellus sed feugiat. Sed libero libero, vestibulum ut pharetra nec, vestibulum vel augue. Aliquam consequat nibh id nulla porta porta.</p>
  <p>Nullam ligula tortor, sollicitudin et sollicitudin a, vestibulum vel dui. Ut at facilisis nisi. Duis id ante quis augue iaculis congue. Nulla facilisi. Phasellus tincidunt condimentum nisi, ac ultricies augue ultricies et. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec id mauris a sapien suscipit adipiscing. Pellentesque accumsan pulvinar tortor et elementum. Nulla facilisi. Nulla tempor lectus et purus luctus ultricies. Phasellus aliquam, libero non ullamcorper vulputate, est lectus ultricies massa, vel tempus magna elit ac lacus. Sed id dui purus. Quisque vel erat ipsum. In in lectus diam, a tempor velit.</p>
  <p>Duis tincidunt neque quis ipsum feugiat malesuada. Sed et tortor vel nunc porta commodo. Mauris lacinia suscipit sagittis. Praesent non nibh ac elit congue sagittis vitae non dui. Nunc risus urna, sodales faucibus rhoncus at, interdum faucibus velit. Vivamus ultrices neque vehicula turpis luctus non fringilla orci aliquam. Maecenas commodo, est vitae consequat scelerisque, metus sem malesuada dolor, non tincidunt nunc turpis non arcu. Donec rutrum mi nec neque dignissim ac gravida neque dignissim. Quisque porttitor elit a ante ultrices interdum. In tempor neque vitae tellus laoreet tincidunt. Pellentesque bibendum accumsan sapien suscipit vestibulum. Nullam justo libero, consectetur id rhoncus at, vulputate eu tortor. Suspendisse mattis, erat sed viverra malesuada, sapien leo interdum leo, in adipiscing nibh purus quis diam. Sed vitae convallis purus. Maecenas leo mauris, egestas ut vehicula vel, sodales non justo. In consequat scelerisque velit, id pharetra arcu fringilla eget.</p>
  <p>Phasellus convallis porta velit at tempor. Etiam non quam tortor. Vivamus eget nulla turpis. Suspendisse potenti. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Cras sollicitudin arcu quis libero tristique vel tempus turpis eleifend. Fusce sed justo sed sem tempor mattis vel eu nulla. Phasellus hendrerit tellus et dui luctus fermentum. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Maecenas ullamcorper, dolor eu egestas tincidunt, velit nulla sollicitudin metus, a ultrices nunc diam eu ante. Suspendisse sit amet hendrerit ante. Proin viverra posuere dolor. Nullam blandit lacus quis tortor dignissim non hendrerit risus pharetra.</p>
 </div>
</div>

<script type="text/javascript">
 $(function () {
  $(".frame .scrollbar").find(".scroll-up, .scroll-down").click(function () {
   var $content = $(this).closest(".frame").children(".content");
   var dir = $(this).is(".scroll-up") ? -20 : 20;
   $content.scrollTop($content.scrollTop() + dir);
  });

  $(".frame .content")
   .bind("mousewheel", function (e) {
    $(this).scrollTop($(this).scrollTop() - e.wheelDelta);
   })
   .scroll(function (e) {
    var $scroller = $(this).closest(".frame").children(".scrollbar").children(".scroller");
    var $scrollerDraggable = $scroller.children(".scroller-draggable");

    if ($scrollerDraggable.data("isscrolling"))
     return;

    var pos = $(this).scrollTop() / ($(this)[0].scrollHeight - $(this).height());
    console.log([pos]);
    $scrollerDraggable.css("top", ($scroller.height() - $scrollerDraggable.height()) * pos);
   })

  $(".frame .scroller-draggable").draggable({
   axis: 'y',
   containment: $(".frame .scroller"),
   start: function () {
    $(this).data("isscrolling", true);
   },
   drag: function (event, ui) {
    var $scroller = $(this).closest(".scroller");
    var $content = $scroller.closest(".frame").children(".content");
    var pos = ui.position.top / ($scroller.height() - $(this).height());

    $content.scrollTop(($content[0].scrollHeight - $content.height()) * pos);
   },
   stop: function () {
    $(this).data("isscrolling", false);
   }
  });
 });
</script>

It requires JQuery and Jquery UI, and the example still has some issues, but main idea is realized. Example tested ONLY in Chrome 7. You can make a jquery plugin from it.

Answer 3

Not that I can see it, but I imagine a custom control made out of various images.

You make a track image that tiles to make up the background, top and bottom cap images to act as the forward/back buttons (with hover and depressed states) and the moveable control is usually three-part, two end-caps on either side of a tileable central area that can be resized to suit. Then you monitor drags on the control area and keep it bound within the track, and clicks (or better mousedown) on the forward/back buttons.

There are libraries like jQuery UI Slider that handle this for you if you do not wish to code it yourself.