Intent to implement and ship: window.orientation and orientationchange event

[William Chen]

*Summary*: window.orientation returns a value corresponding to the screen
orientation. The orientationchange event is fired when the orientation of
the viewport is changed. These features are non-standard but have been
implemented by other browser vendors on mobile platforms leading to
widespread usage on major websites. In order to improve web compatibility,
these features are also going to be implemented by Gecko on mobile
platforms and we are also working on standardizing the feature. Web authors
should avoid these features because the values returned by
window.orientation are unreliable as it means different things across
different platforms. Instead, authors should use the ScreenOrientation API
which offers the more functionality and better specified behavior.

*Bug*: https://bugzilla.mozilla.org/show_bug.cgi?id=920734

*Link to standard*: https://compat.spec.whatwg.org/#dom-window-orientation

*Platform coverage*: Firefox for Android and Firefox OS.

*Estimated or target release*: Firefox 44

These features are currently implemented by the stock Android browser,
Safari on iOS, Chrome for Android and Internet Explorer on Windows Phone.

[Jonas Sicking]

As someone pushing for the ScreenOrientation API, I agree with this
intent nonetheless.

It *might* be worth warning about this property being inconsistent,
and that it's better for users to use the ScreenOrientation API. But I
think it's really only worth doing if this is something that other
browsers agree to do as well.

/ Jonas

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[Mounir Lamouri]

FWIW, this is the usage of window.orientation in the wild recorded by
Chrome:
https://www.chromestatus.com/metrics/feature/timeline/popularity/285

However, Google's internal tools allow me to see the repartition between
platforms and this seen a lot by Chrome Android users.

Should we add this to the Screen Orientation specification?

-- Mounir

[Jonas Sicking]

On Tue, Oct 20, 2015 at 2:49 AM, Mounir Lamouri <mou...@lamouri.fr> wrote:
> Should we add this to the Screen Orientation specification?

I think so yes.

/ Jonas

[Mike Taylor]

I also think so. In my mind the Compat Standard should be transitional
in nature, rather than something we maintain forever.

Ideally the "standard" equivalents (or logical parent specs or whatever)
will take in what's specced there as historical APIs or aliases needed
for compatibility with the de-facto web.

--
Mike Taylor
Web Compat, Mozilla