Re: [Bug 25298] How to represent VideoFacingMode if browser is not able to detect the FacingMode of the camera.

On 4/28/14 11:08 AM, Harald Alvestrand wrote:
> WRT the "default" notation: I'm unhappy with the idea of depending on 
> a proposed feature of WebIDL that last had activity on the bug in 
> 2012. That doesn't seem like it's a recipe for getting things done here.

I agree it doesn't actually block us from deciding here, so I shouldn't 
have made it a blocker. Apologies.

I propose we open two new bugs:

 1. "make facingMode a DOMString for now to avoid throwing on future
    facingModes", and
 2. "make facingMode a VideoFacingModeEnum again once default notation
    is supported".

and have the second one block on Bug 19936 
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=19936>. At that time 
we'd need to decide on "other".

I'm happy to open these if that's ok.

This is, unless we're ok with facingMode throwing on unknown values, in 
which case we don't have to do anything.


> - When reporting settings, one wants to report "something that is not 
> any of the defined states". It is a good question if there needs to be 
> a difference between "none of the above" and "I don't know" (in the 
> latter case, the camera *might* be pointing at "user" or "environment" 
> - but the browser doesn't know; in the former case, one would assume 
> that the browser knows it doesn't.)

Thanks for clarifying that "other" and "unknown" are different.

> My instinctive reaction is to go for the simplest solution:
>
> - "none of the above" can't be expressed as a constraint. It's not 
> important enough to complexify things.
> - We allow only expression of the "I don't know" semantic of a state, 
> and represent it by not returning this value in the output of 
> getSettings().
>
> Both of which need a sentence in the spec, but neither of which 
> changes the WebIDL, I think.
>
> What do people think?

I agree with undefined=unknown, and we can certainly defer deciding on 
"other".

But I'm curious what people think about UAs throwing on unknown 
facingMode enum-values, as this would most likely preclude us from ever 
adding new facingModes in the future (except perhaps as a differently 
named constraint, e.g. facingMode2, for backwards compatibilty, which is 
quite ugly).

.: Jan-Ivar :.