button remapping and drag lock?

[Tom Horsley]

Here is a bit of shell script which makes it possible to use my
Kensington Expert Wireless Trackball Mouse under X11:

      xinput --set-button-map "$nm" 1 8 3 4 5 6 7 2
      xinput --set-prop --type=int --format=8 "$nm" \
         'libinput Drag Lock Buttons' 2 1

The trackball is large, it sits in one place, and unless I
can make one of the buttons be a drag lock button, it is
almost impossible to use, needing to cross over both hands
or play twister with my fingers :-). (If I can use drag
lock, it is the best mouse I've ever had).

Is there any way at all to do this in wayland? I recently
tried wayland on an ubuntu 20.04 system, and could not find
anything like it.

I'd be happy to buy a couple of trackballs for wayland developers
if they'd promise to support drag lock :-).

Alternatively, perhaps you could tell me where such support
would best be implemented and I could see about implementing
it myself. Shouldn't take me more than a year to come up to speed
on the software :-).