Krita, Wacom, Qt and distributions

It’s a never-ending tale of sorrow and tears… The tale of Qt, Wacom and distributions. It happens with distressing regularity that people join us on the #krita irc channel, the krita forums or the krita mailing list. Users, but also developers. Their question? “Krita doesn’t seem to support my Wacom tablet, but Gimp and MyPaint work fine!”

This is never actually caused by Krita. Krita uses Qt’s wacom support, same as for instance Maya does. The Qt Wacom api is good, the rate of events is good, we are fine with that.

The problem is that sometimes Qt breaks when a new version of the wacom drivers is released. And sometimes distributions package the wrong version of Qt and the wrong version of the Wacom drivers together. We don’t have an exact table of what works and what doesn’t work. As developers we tend to drift to distributions that are relatively good at supporting Wacom and Qt together… OpenSUSE hasn’t failed me for a couple of years now! But just check our help forum.

And then there are situations where Qt is blameless, Wacom is blameless and the distribution is really to blame. For instance, when distributions patch Qt to achieve multitouch with an experimental patch that breaks tablet support.

I’m not sure what to do about this: the bugs get reported to the distributions, and when necessary to Qt, but in the meantime, for many people Krita breaks every time they do an upgrade. And we cannot help them!