Client: Add basic support for tablet-unstable-v2

[ChangeLog][QPA plugin] Added support for drawing tablets through the
tablet-unstable-v2 protocol.

Adds support for the basic one tablet, one tool, no pads scenario.

Besides the auto tests, I tested with a Huion Kamvas Pro 16 with a simple
pressure sensitive pen with two buttons. As far as I can tell, it works the
same way as on xcb on Sway and Gnome Shell.

Also tested on a Wacom PTZ-630 with a mouse, art pen, airbrush and a stylus.

Mapped the distance event to QTabletEvent::Z and slider to
QTabletEvent::tangentialPressure.

For now we send QTabletEvents even when there's a mouse or finger on the
tablet. Those should ideally be sent as QMouseEvents/QTouchEvents, but that's
out of scope for this patch, but at least we will send synthesized mouse events
if the tablet events are not accepted.

Change-Id: I93291ffa5f00fa2bb8533eddd8d873b84a3386b8
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 1 insertions, 0 deletions

diff --git a/tests/auto/client/client.pro b/tests/auto/client/client.pro
index cda1765e3..46a3aa42e 100644
--- a/tests/auto/client/client.pro
+++ b/tests/auto/client/client.pro
@@ -11,6 +11,7 @@ SUBDIRS += \
     seatv4 \
     seatv5 \
     surface \
+    tabletv2 \
     wl_connect \
     xdgdecorationv1 \
     xdgoutput \