[whatwg] MediaController feedback

[Jer Noble]

On Aug 27, 2012, at 5:02 PM, Ian Hickson <ian at hixie.ch> wrote:

>> With JavaScript, it's certainly possible for a page author to play() or 
>> pause() a slaved media element directly, but that author could just as 
>> easily remove the media element from the media group / media controller.
>> 
>>> [...]
>>> 
>>> That only works if there's JavaScript doing the removing. The idea 
>>> here is that this should all work even without any JS, just with UA 
>>> UI.
>> 
>> With just the UA UI, the behavior would be exactly the same [...]
> 
> If you remove the element from the media controller, the media 
> controller's timeline changes.

So?  In the general case (alternative audio, sign-language) the timelines will be exactly the same.  If there's an edge case where a change in the timeline is a problem, a page author could hide the slaved media element (e.g. "display:none" or "element.muted = true") instead.

> It'll be quite common for there to be videos that are not currently 
> playing, e.g. sign-language tracks.

I think you're making an incorrect distinction.  The author may not want the sign-language track to *display*.  Pausing the video is one mechanism which achieves that (sort of).  Hiding it is another.  Removing the video from the MediaController and pausing it is a third.

The side effects of this particular mechanism are causing a lot of confusion.  We gave a session at WWDC about the MediaController and collected a lot of developer feedback at the labs, and the general theme was that the API didn't make sense.  Here's a good example of the kinds of bug reports we're seeing: "MediaController play() doesn't work" <https://bugs.webkit.org/show_bug.cgi?id=94786>.

> If we change anything here, I think it 
> would be the currently required UI behaviour which requires all the videos 
> to start playing when the user overrides the JS-provided controls and just 
> uses the UA controls.

This change would break the UI controls in the basic case of <video controls mediagroup="foo">.

-Jer