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>
Use the same blurb everywhere, changing from the old style MIT to the Expat
license we're using everywhere else.
Similar to bc9f16b40e
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
commit 3925936 introduced changes to container_of, this is hopefully the
last part of it.
In the linux kernel, container_of() takes a type name, and not a
variable. Without this, in some cases it is needed to declare an unused
variable in order to call container_of().
example:
return container_of(dispatch, struct fallback_dispatch, base);
instead of:
struct fallback_dispatch *p;
return container_of(dispatch, p, base);
This introduce also list_first_entry(), a simple wrapper around
container_of() to retrieve the first element of a non empty list. It
allows to simplify list_for_each() and list_for_each_safe().
Signed-off-by: Gabriel Laskar <gabriel@lse.epita.fr>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Set the dispatch type on creation, then check that whenever we try to get the
dispatch struct. This avoids a potential mismatch between the backends.
Plus, use of container_of means we're not dependent on the exact layout
anymore.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Until the kernel patches to handle LED group switching are in place we provide
the external API backed by an implementation that simply exposes one group
with one mode and no toggle buttons. This allows us to ship a libinput release
with the API in place and switch libinput later without having all the stack
above us being delayed.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Carlos Garnacho <carlosg@gnome.org>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Carlos Garnacho <carlosg@gnome.org>
