button remapping and drag lock?

[Peter Hutterer]

On Thu, Dec 23, 2021 at 10:30:50AM -0500, Tom Horsley wrote:
> 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 :-).

I'd argue that the best place to implement this is in the compositor [1] since
it allows for better discoverability and more flexible configuration - it is
an accessibility interface after all. 

But right now, it isn't (afaict) currently implemented in any compositor. 

Cheers,
  Peter

[1] hence why in X it's implemented in the driver which is the closest thing
to the compositor for these use-cases