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

From: Lars Knudsen <larsgk@gmail.com>
Date: Fri, 16 Aug 2013 11:11:00 +0200
Message-ID: <CA+jkkciZvP-AEC6ziprMT6rLZLXfOETXTvJQXK6Vy4udec-fvA@mail.gmail.com>
To: Jonas Sicking <jonas@sicking.cc>
Cc: Dhruv Chadha <Dhruv.Chadha@microsoft.com>, "Tab Atkins, Jr." <jackalmage@gmail.com>, Webapps WG <public-webapps@w3.org>

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?



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
Received on Friday, 16 August 2013 09:11:27 UTC

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