Quoting Carlos:
The META_PRIORITY_EVENTS ± 1 happening below are in order to set these idles
and timeouts in a priority that is relative to the literal GDK event priority,
making those diverge is a likely way to sneakily break things.
But that's unlikely to happen, and decoupling mutter from GTK further
should make it moot, so perhaps it's alright after all.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2407>
The order and way include macros were structured was chaotic, with no
real common thread between files. Try to tidy up the mess with some
common scheme, to make things look less messy.
display.c is getting a bit crowded. Move most of the handling
out to another file, events.c.
The long-term goal is to have generic event handling here, with
backend-specific handling for the types of windows and such.