Wlroots: Delegate logind support to seatd

[emersion]

Drop our logind code, rely on seatd instead.

cc @kennylevinsen

[Conan-Kudo]

I'm not sure this is a good idea, given that seatd calls itself "alpha" right now.

Can we hold off on this until it matures more?

[kennylevinsen]

seatd calls itself "alpha" right now.

https://git.sr.ht/~kennylevinsen/seatd/commit/0d855a28f20ab3d7b2058fbe58a172a97affbde5

[Conan-Kudo]

@kennylevinsen Do you consider it stable to rely on?

[emersion]

I'm not too worried about the libseat code.

[Conan-Kudo]

Why not?

[emersion]

It's pretty similar to wlroots' code, and has been around for a while.

[emersion]

I guess the next step would be to make libseat a required dependency for wlroots, and nuke our direct session (and perhaps our session interface).

[prez]

and nuke our direct session

why? I think it is useful, for simplicity's sake.

[emersion]

Because it's code which I'd rather share with other compositors than maintain, just like e.g. libinput. It's pretty trivial to drop seatd into subprojects/ and make Meson build it as a subproject anyways.

[emersion]

libseat is now required and replaces all of our session code.

[emersion]

If you were using the direct backend and libseat is not yet packaged for your distribution, the replacement is now:

• Drop seatd into subprojects/seatd
• Run Meson with -Dseatd:builtin=enabled

And things should work just like before.