Screen orientation and backlight sensing for the Nexus 7

[Bryce Harrington]

On Fri, Jan 18, 2013 at 12:36:00PM +0100, Oliver Grawert wrote:
> > However, to prevent adding yet another daemon with non-negligible memory 
> > footprint (~1.8M), I think behavior and various thresholds should be 
> > configurable in the Control Center GUI and the functionality added to one 
> > or several of the existing daemons written in C.
> > AFAIK there are no generic kernel and userland APIs for such sensors, 
> > save for device specific sysfs knobs so this may be a good opportunity to 
> > think about how to expose such hardware features in a device independent 
> > manner in the future.
> > 
> > Thoughts?
> 
> while i think that ambient light detection and rotation should be
> separated and implemented as gnome-settings-daemon modules and that we
> should additionally have something event driven from the kernel side
> instead of polling, i also think that this is quite a huge
> implementation task and feature freeze isn't so far out anymore ...

Yes, getting things accepted into g-s-d upstream might be too time
consuming to make it by FF.  I'm betting this is not something we'd want
to carry permanently as a distro patch, so we'd want to get it upstream
at some point.

> i think we should go with the standalone daemon for the moment, add some
> cmdline/conffile ways for configuration (feature on/off at least) and
> work out proper blueprints for 13.10. that way we have the function in
> place asap and can collect and fix bugs for it in 13.04, this will make
> sure that we have the underlying bits fully in place for 13.10 and can
> concentrate on the split into modules and UI elements...
> 
> the size is indeed a bit concerning and it would be better to just have
> it in plain C unless the go binaries can be made smaller

Would bash or python be ok?  I'm guessing this isn't performance
critical, and it looks like everything in nexus.go could be done in
either of those languages.

Btw, I've put the xrotate script into the xdiagnose package, so we can
drop it from the nexus7 image.  Work on generalizing it for other
devices is ongoing, and I'd be open to keeping it either in bash or
rewriting it into python.

Bryce