This avoids inconsistencies between the LITEST_ enum value and the
shortname but also makes it easier to grep for any test cases that use
the same define. At the cost of the test names not looking very nice
anymore but oh well.
Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1157>
Some tablets such as those in the XP-PEN PRO series use "dials" which
are actually scrollwheels and emit EV_REL events. These should not be
emulated as rings (which are absolute) so we must expose them as a new
tablet event.
Adds LIBINPUT_EVENT_TABLET_PAD_DIAL that work largely identical as our
high-resolution wheel events (i.e. the values are in multiples or
fractions of of 120). Currently supports two dials.
This is a lot of copy/paste from the ring axes because the interface is
virtually identical. The main difference is that dials give us a v120
value in the same manner as our scroll axes.
Notes:
- REL_DIAL is mutually exclusive with REL_WHEEL, we assume the kernel
doesn't (at this point) give us devices with both. If this changes for
devices with three dials (wheel + hwheel + dial) we need to add code
for that.
- REL_DIAL does not have a high-resolution axis and we assume that any
device with REL_WHEEL_HI_RES will also have REL_HWHEEL_HI_RES (if the
second wheel exists).
- With dials being REL_DIAL or REL_WHEEL there is no possibility of
detecting a finger release (the kernel does not route EV_RELs with a
value of zero). Unless this is implemented via a side-channel - and it
doesn't look like any hardware that supports dials does that - we
cannot forward any information here. So unlike absolute rings we
cannot provide a source information here.
Closes#600
Co-authored-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/967>
