This commit add an optional `--screen off` command to initialize Lua
without first adding the screens. This is inconvinient for most users
since it restrict the APIs that are usable out of the box.
However, this allows AwesomeWM to work independently from the hardware.
This means that when a screen is unplugged, it is the Lua code that will
remove the screen instead of CAPI pulling the carpet from under. It also
allows to ignore some screen areas before the screen is ever created.
Combined, it makes it possible to work with screens even when they are
physically disconnected. Finally, it will allow for an awful.rules like
API to control how screens are created.
All in all, some people need this for their setup and some people might
want to do it anyway for fine grained and/or dynamaic multi-screen
setups.
This commit also adds 4 new signals to `capi` to be able to
execute code at specific points during the initialization. The commit
improves naughty error notifications to work even if problems occurs
before the screens are added.
Note that AwesomeWM will exit if no screens are created. While it would
be easy to just call `refresh_screen();` after unsetting the magic
variable, doing so would have corner cases. Better be harsher and
prevent the user from shooting themselves in the foot from not reading
the f****** manual. Code introduced in future commits will take care
of automatically calling fake_screen in the event nothing is created.
Fixes#1382
433898599d