Re: Screen Orientation Feedback

On Mon, Aug 11, 2014 at 11:33 PM, Jonas Sicking <jonas@sicking.cc> wrote:
> On Fri, Aug 8, 2014 at 6:44 AM, Mounir Lamouri <mounir@lamouri.fr> wrote:
>> Maybe this feedback should be more for DeviceOrientation than Screen
>> Orientation. There has been a few discussions there
>> (public-geolocation).
>
> This is the type of procedural issues that I'd really rather not get
> caught in. I think it's fine to defer to the DeviceOrientation spec,
> but only if we think there's any chance of it getting added there
> anytime soon. Given that no drafts, to my knowledge, has been
> published for a DeviceOrientation v2, that does not seem to be the
> case.
>
>> Anyway. I am not convinced that adding new properties will really fix
>> how developers handle this. I asked around and it seems that native
>> platforms do not expose Device Orientation relative to the screen. I am
>> not sure why we should expose something different on the Web platform.
>
> I don't think the fact that other platforms do not supply screen
> relative orientation events is a strong technical argument for why we
> shouldn't.
>
> I'm definitely in favor of looking at what other platforms do, but not
> with the mindset that what other platforms do is the right thing to
> do, but rather to see if they have good solutions that we could learn
> from. Surely other platforms will make design mistakes, just like we
> do.
>
>> I think we should work on providing developers the right tools in order
>> for them to do the right thing.
>
> I totally agree with this. For all the use cases that I can think of
> for getting the coordinates relative to the screen is more important
> than relative to the device. This includes:
>
> * A navigation page which shows a map as well as how the device is
> oriented relative to the map.
> * A navigation page which shows a map orientated so that the on-screen
> map matches real world.
> * A game where an in-game character is controlled by tilting the
> device left and right to make the character walk left vs. right.
>
> I'm sure there are use cases where you need to know the orientation
> relative to the device rather than relative to the screen, they just
> seem to be less common to me.
>
> Given that, the right tool seems to be to provide the
> DeviceOrientation events relative to the screen and allow them to be
> compensated to be relative to the device if needed.
>
> Sadly it's too late for that. Authors already have the wrong tool as a
> default since the DeviceOrientation spec is written and implemented
> the way it is.
>
> However we can at least give authors the right tool as well, by
> introducing screeAlpha etc.
>
>> For example, without the Screen
>> Orientation API, they do not know the relative angle between the device
>> natural orientation and the screen. This API is not yet widely
>> available. Some version of it ships in Firefox and IE but is prefixed.
>> It should be in Chrome Beta soon.
>
> I don't think "the right tool to do the right thing" in this case
> means "give them coordinates in a coordinate system that they don't
> want, and then give them enough information to transform the
> coordinate into the coordinate system that they do want".
>
> I'm not arguing that we remove the relative angle that's in the spec
> right now. I'm arguing that for device orientation events, we should
> provide coordinates relative to the screen as well.

This topic was filed as an issue against the DeviceOrientation spec in
March (https://github.com/w3c/deviceorientation/issues/4).

Interest from implementers is a strong indicator to proceed with such
spec additions. Active implementer engagement around spec
clarifications and additions is quite low right now.

>
> / Jonas

Received on Tuesday, 12 August 2014 12:36:16 UTC