Re: Supporting Portrait-First and Landscape-First devices in HTML5 Device Orientation

Hi,

I know, I've mentioned this before - but why don't we just define one
(hardware) direction as "0 degrees" (e.g. "portrait up"), align all the
orientation specs and keep things simple for everyone?

ref
http://lists.w3.org/Archives/Public/public-webapps/2013AprJun/0063.html


br
Lars





On Fri, Aug 16, 2013 at 5:03 AM, Jonas Sicking <jonas@sicking.cc> wrote:

>
> On Aug 15, 2013 5:11 PM, "Dhruv Chadha" <Dhruv.Chadha@microsoft.com>
> wrote:
> >
> > Tab,
> >
> > We sympathize with the goal of creating a simple programming model for
> developers but we don’t believe that is what is currently specified on the
> device and screen orientation specs (as we stated in our earlier response
> to Jonas).  Our proposal maps existing native implementations done by iOS,
> Android, and Windows.  These native APIs provide capabilities to discover
> the native orientation of the device and to remap the coordinate system
> based on the user selected orientation.
> >
> > We believe that mapping the coordinates to the current screen
> orientation would generate the following issues:
> > - Changes the design of the API as defined by current draft of the
> device orientation spec and will break interoperability with current
> implementations
>
> I agree this is a problem.
>
> > - If the browser’s orientation is not locked, rotating the device would
> reset the coordinates back to 0 in the reference axis for each 90 degree
> rotation since the browser App UI would rotate as well
>
> Why is this bad? Maybe I'm not understanding the concern?
>
> > - Does not provide flexibility.  What happens if the developer is not
> interested in automatically re-mapping the coordinate system?  They
> wouldn’t have an ability to change this behavior.
>
> What are the use cases for wanting to allow the screen to reorient while
> at the same time not adjusting the coordinate system? Are these use cases
> more common than the cases where you would want to adjust the coordinate
> system?
>
> A potential solution is to add a separate set of events exactly like the
> current DeviceOrientation events, but that are relative to the screen
> orientation rather than the device orientation. Sadly that might be the
> only way to keep compatibility with existing deployed implementations,
> while still keeping a decent API.
>
> > - the alpha value (+Z) for device orientation should always be aligned
> to the input from the compass (i.e. hardware sensors) unless the developer
> requests a re-mapping
>
> I don't understand this. Could you provide an example or describe in more
> detail?
>
> / Jonas
>