Browser tab or application switch?
<p>Is it possible to differentiate between these browser events? </p>

<ul>
<li>the user has clicked on another tab in the same browser, hiding my tab which now should be paused.  </li>
<li>they have switched to another application. My tab may still be visible, in which case it should stay running.</li>
</ul>

<p>AFAICS, identical blur/focus DOM events are raised in each scenario, so they are no help to me.</p>

<p>To put it another way, is it possible to determine if a tab is actually displayed to the user?</p>

<p>(btw if it makes any difference, I don't need this to work in IE or any other non WebGL browser.)  </p>
