In the Soft Home Button spec, UX proposes that, with the exception of Camera, any app in portrait orientation should not be displayed upside-down in relation to the phone hardware. This allows the user to easily identify the orientation of the phone and prevents awkward transitions and having to reverse the phone when accepting or making phone calls, returning to the home screen and other scenarios. As a result, if the phone is held upside-down in portrait, the Browser should be displayed in landscape.

For reference: here is the soft-home spec: https://bugzilla.mozilla.org/attachment.cgi?id=8473080 See the section "Placement" for details.

This is a WebAPI pollution. The only way to realize this spec is in gecko: any screen.mozLockOrientation('portrait-primary'); should be mapped to screen.mozLockOrientation('landscape'); if gecko feels there is no hardware home button. Gaia could do nothing for this requirement. And it's definitely something we should not do. Please don't do this. I will say this is WONTFIX.

Thanks Alive for the feedback. Let's discuss it with :robmac this week. It might be a tako requirement.

As an aside, the first placement implementation point of "Top Down - Portrait-Fixed" is completely possible for the system browser. We can keep the user from holding it in the upside-down orientation, and the UI will stay in the position of previously-held orientation, even if that orientation was landscape, i.e. if the user is holding it in landscape and then rotates to upside-down, the orientation will remain in landscape. The difficulty is when the user goes from primary portrait and very quickly rotates the phone to upside-down, the phone stays upside down and does not switch to landscape.

After discussing this with :robmac offline, we have decided that the implementation I discussed in comment 4 is a suitable solution. This will let us keep the system browser out of the upside-down orientation, and will also let us keep the change within Gaia only and continue to use the existing API as-is, which solves :alive's problem. I'll have a patch for review here shortly.

Comment on attachment 8476310 [details] Link to Github pull-request: https://github.com/mozilla-b2g/gaia/pull/23112 Although I still doubt some developer of 'web pages' will not know why their page is locked to these orientations.... UX should know this is only affecting the browser window but not 'any app'. And any web page is able to override this orientation lock because screen orientation is permission-less. Please communicate with UX. Also please have an unit test in app_window_test.js as well.

Rob, I need to challenge this requirement again. Please read my comment above: we cannot prevent the web page to lock the screen orientation to portrait-secondary or even unlock the screen orientation. Doing this in system app level will make web developer confused why the orientation is locked. Also we cannot control the timing of the screen orientation lock so there might be a race. That is to say, a real implementation to this needs some big gecko change as https://bugzilla.mozilla.org/show_bug.cgi?id=1043102 And the system app's behavior (lock the web page to certain orientations) needs to be documented somewhere.

Thanks, Alive. The goal here is to prevent awkward transitions during incoming calls, when returning to the home screen and from the lock screen. But it sounds like the level of effort and potential risk outweigh the potential benefits. Based on this, I'm fine with dropping this feature for now. The core apps, like dialer, contacts, mail, etc., should keep their current behaviour and not display upside-down in relation to the physical hardware. Does this make sense?

Comment on attachment 8476310 [details] Link to Github pull-request: https://github.com/mozilla-b2g/gaia/pull/23112 Removing flag based on previous comment.

Closing based on comment 9.