 when an element is currently being dragged.</p>
<p>A <code class="prettyprint lang-dart">drag</code> event is added to this stream as soon as the drag begins.
A <code class="prettyprint lang-dart">drag</code> event is also added to this stream at intervals while the drag
operation is still ongoing.</p>
<h2>Other resources</h2><ul><li>
<p><a href="https://github.com/dart-lang/dart-samples/tree/master/web/html5/dnd/basics">Drag and drop sample</a>
based on <a href="http://www.html5rocks.com/en/tutorials/dnd/