window by dragging, when
    selecting items, and when dragging the custom time bar.
  </p>

  <p>
    Here an example on how to listen for a <code>select</code> event.
  </p>

<pre class="prettyprint lang-js">
timeline.on('select', function (properties) {
  alert('selected items: ' + properties.items);
});
</pre>

  <p>
    A listener can be removed via the function <code>off</code>:
  </p>

<pre class="prettyprint lang-js">
function onSelect (properties) {
  alert('selected items: ' + properties.items);
}