libinput "mouse mode" for tablets

[Bill Spitzak]

Peter Hutterer wrote:

> this has so many more cases where it won't work correctly from the user's
> POV that it's likely easier to just have an easily accessible way of
> switching between absolute and relative mode.

I really feel this automatic switch will work perfectly and would be a 
huge improvement over how Windows and OS/X work.

An automatic switch would also be really nice if clients are able to 
restrict the tablet to a rectangle: it could enter absolute mode 
automatically when the rectangle is small enough, and go back to mouse 
mode when the client releases the tablet.

If you are really worried about it, the user control could be 3-way, 
with a default of automatic.

> other than that, there will be support for relative mouse mode on tablet
> hardware. Your general use-case is not unique, though I don't think I've
> heard of the the case of mapping a tablet area to the exact screen area
> before. Mapping it so that a square is a square, yes, but the requirement
> for exact size matches is new to me.

It is not intended to be "exact" but I may have confused things by not 
mentioning a size range. The given size is actually a maximum value for 
the smaller side of the resulting rectangle. The limits on w/h ratio 
fully control the algorithm so no minimum is needed (though I am 
assuming that the tablet is not a lot larger than the outputs).