Input device selection on record & non-interfering repeat on systems with multiple mice

[schrmh]

Checklist

• I use the latest release of atbswp
• The issue is not existing yet

Verbose log

Not applicable / necessary for this.

Miscellaneous information

Operating System

Arch Linux x64_86

Desktop Environment/Window Manager

FVWM3 (but not that relevant here; I used xfce4 in the past but also tried whether I can get what I want on other popular WM's and DE's)

Python version

3.10.10

Description

Was asked if I would mind opening an issue with more details after I wrote that comment elsewhere:

Amazing. It would be awesome if the user could select the input device he wants to use (potential background clicks which should work on Windows, on X11 its sadly a bit of a different story but it could work).

So to go a bit further in:
On X11 you can have multiple input devices of the same type connected (xinput command will show devices and ID's).
Which means you can have multiple keyboards, each with their own layout and also multiple mice, each with their own mouse pointer on screen.

So, what I would want now are basically two things.
The first thing is that it could be defined which input device is used (however, I think pyautogui doesn't even allow this)
The second thing is what I call "background clicks". By that I mean clicks that do not let window managers set focus on windows (or even bringing them to the front), effectively interfering with e.g. some work that the user is currently doing (since you bring up automating games as a use-case for atbswp: currently the computer is barely usable for other things involving mouse clicks while atbswp is reproducing what was recorded). But that is really not that trivial to achieve.

Some resources to read on here:
jordansissel/xdotool#330 (comment) (starting here and make sure to read comments by whot, the X.Org X Server input subsystem maintainer)
https://en.wikipedia.org/wiki/Multi-Pointer_X
https://wiki.archlinux.org/title/Multi-pointer_X (in contrast to what it says here, compiz seems to have some MPX support as well and it is pretty usable; "background clicks" work there).

So yeah, that issue is very likely to not be easily resolved and might stay open that way for years.