Pen Settings



CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource


Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource


Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.


Auto Save

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.


                <div id="knobBG">
  <div id="knob"></div>
<div id="content">
    <div class="box box1">One <div id="description">Drag me or spin the knob. Flick for momentum. Notice how it smoothly snaps to sections. </div></div>
    <div class="box box2">Two</div>
    <div class="box box3">Three</div>
    <div class="box box4">Four</div>
    <div class="box box5">Five</div>
    <div class="box box6">Six</div>
    <div class="box box7">Seven</div>
    <div class="box box8">Eight</div>
    <div class="box box9">Nine</div>


  background-color: #26292f;
#knobBG, #knob {
  background-image: url('');
#description {
#knob {
  background-image: url('');
  z-index: 1;
.box {
  padding: 10px;
#content .box {
  height: 335px;
  overflow: hidden;
  background-color: #88b6f7;
  background-color: #9a9bff;
  background-color: #bbfb94;
  background-color: #ed74c4;
  background-color: #eb984e;
  background-color: #a9eaf1;
  background-color: #dcecf1;
  background-color: pink;
  background-color: purple;


                /* fun little example using GreenSock's Draggable: */

var content = document.getElementById("content");
var knob = document.getElementById("knob");
var maxScroll = content.scrollHeight - content.offsetHeight;
var needsRotationUpdate = false;
var sections = 9;

//when the user drags the knob, we must update the scroll position. We're using the special scrollProxy object of Draggable because it allows us to overscroll (normal browser behavior won't allow it to scroll past the top/bottom). 
function onRotateKnob() { * dragKnob.rotation / -360);
  needsRotationUpdate = false;

//this method updates the knob rotation, syncing it to wherever the content's scroll position is
function updateRotation() {
  TweenMax.set(knob, {rotation:360 * (content.scrollTop / maxScroll)});
  needsRotationUpdate = false;

//if the user flicks/spins/drags with momentum, a tween is created, but if the user interacts again before the tween is done, we must kill that tweens (so as not to fight with the user). This method kills any tweens of the knob or the content's scrollProxy.
function killTweens() {
  TweenLite.killTweensOf([knob, dragContent.scrollProxy]);
content.addEventListener("mousewheel", killTweens);
content.addEventListener("DOMMouseScroll", killTweens);

//whenever the content gets scrolled (like by using the mousewheel or dragging the content), we simply set a flag indicating we need to update the knob's rotation. We use a "tick" handler later to actually trigger the update because that optimizes performance since ticks happen on requestAnimationFrame and we want to avoid thrashing
content.addEventListener("scroll", function() {
  needsRotationUpdate = true;
TweenLite.ticker.addEventListener("tick", function() {
  if (needsRotationUpdate) {

//create the knob Draggable
Draggable.create(knob, {
  bounds:{minRotation:0, maxRotation:360},
  onDrag: onRotateKnob,
  onThrowUpdate: onRotateKnob,
  snap: function(endValue) {
    var step = 360 / (sections - 1);
    return Math.round( endValue / step) * step;

//create the content Draggable
Draggable.create(content, {
  onDragStart: killTweens,
  snap: function(endValue) {
    var step = maxScroll / (sections - 1);
    console.log(Math.round( endValue / step) * -step);
    return Math.round( endValue / step) * -step;

//grab the Draggable instances for the content and the knob, and store them in variables so that we can reference them in other functions very quickly. 
var dragContent = Draggable.get(content);
var dragKnob = Draggable.get(knob);