Spinnrd is a pair of daemons to automatically rotate a device's screen to
match its orientation. It has two parts: the spinnrd system daemon that
translates accelerometer data into xrandr orientations, and the spinnr.sh
daemon that makes the xrandr and xinput calls. spinnr.sh needs to be
called for each X instance, but only one spinnrd is needed per physical
display to rotate.
- Rust; more specifically, Cargo (Cargo technically isn't necessary as long as you have the Rust compiler, but it'll save you tons of work)
- iio-sensor-proxy (For the FSAccel backend, which is the only one currently implemented)
Start a spinnrd process, probably as a service (you'll probably want to
use --daemonize). Then, have your display manager run spinnr.sh
(backgrounded) as part of its startup script. Your display should now
rotate to match your device's orientation! If you want to tweak the
sensitivity, spinnrd has a variety of command-line options for doing
this.
So why write this? Surely there's already software to do this, right?
Well, actually...
At the time I started this, I was using a Lenovo Flex 3 14" - essentially the consumer version of the enterprise Yoga. It can be used in Laptop, Stand, Easel, or Tablet configuration. However, for the last two to be usable the screen needs to rotate, and for Tablet in particular it needs to do so automatically. So I looked.
And I looked.
I found a few things, but none that worked consistently well, if at all.
And the one that worked was a GUI userspace application and didn't work for
the login manager (not, now that I think about it, that I really tried...).
So, I decided to write my own.
What you see here is the product of many man-days of effort, all to solve one niggly little problem: Why can't my screen just rotate itself like it does for Windows, macOS, iOS, and Android? It isn't 'done' and it may never be - there'll probably always be something I want to add - but the core functionality? It's there. It works. And so I present to you... spinnrd.
This actually isn't the first iteration of the whole "use Rust to rotate the screen to match the orientation". That first version was called 'spinnr', and it worked. So why rewrite it?
spinnr was written as one executable, entirely in Rust, with bindings to xrandr. And that was cool and all, but then I saw the problem. Since it bound to xrandr, it couldn't start without X. Which means you'd be running a seperate instance for each session. Not only does that mean much duplication of work, but even if I'd gotten the iio backend working, I'm pretty sure it wouldn't have worked in that case at all. So I rewrote it.
Now there's two parts:
- spinnrd is the parts of spinnr that dealt with translating accelerometer readings into physical orientations. It's written entirely in Rust and there should be at most one instance per physical screen.
- spinnr.sh is the (example) 'spinnr client', that watches for orientation changes and rotates the screen to match. It can have as many as one instance per physical screen per X server (I'm hoping to reduce this number in the future).
I'm always happy to recieve contributions - that's one of the major
benefits of open-source software, you're not alone. If you want an idea on
where to get started, check for open issues and take a look at
roadmap.md. I'll try to get a Trello up and running as well.