WIP Add an InputTime type to use instead of u32/u64

[ids1024]

Description

I've been wondering if it would be good if time was a newtype instead of just an integer for a while.

Making the event structs in src/input using microsecond precision instead of just millisecond would presumably be a prerequisite for https://wayland.app/protocols/input-timestamps-unstable-v1.

But I ran into that trying to add wl_keyboard.warp, as an is_warp: bool field of MotionEvent. (I'm still not entirely sure on doing that vs having a separate WarpEvent; if all the logic for handling it is the same as motion events, it may make sense and save a lot of duplication). But with a fallback to send motion and a 0 relative_motion on clients not binding the latest version. relative_motion requires a microsecond time.

Going through this also reminds me that in some cases smithay synthesizes input events with a time of 0, which is probably not correct. In at least one place it synthesizes an event using CLOCK_MONOTONIC. That does match libinput (https://wayland.freedesktop.org/libinput/doc/latest/timestamps.html) but technically isn't guranteed if we had a Wayland backend. I think X also was typically CLOCK_MONOTONIC but not technically guaranteed?

I still need to update anvil/etc.

Checklist

• I agree to smithay's Developer Certificate of Origin.