Wacom apocalypse in Qt5: just not today

Wacom apocalypse in Qt5: just not today

As the end of 2012 quickly approaches, the echoes of apocalyptic cries return to bounce off the interwebz once again. Most recently Wacom support in Qt5 got into a bit of a press coverage trouble.

Last week Ariel Molina, who works for Edis Interactive, started a thread in the Qt's development mailing list, asking if it would be better to remove Wacom for Qt5 due to a number of unresolved issues.

Ariel quoted several bug reports, some of them dating back as far as 2009. Which then got Phoronix to feature an article suggesting that Wacom tablet support might be axed from Qt5.

Naturally, it sounds like a threat to free applications such Krita that use Qt for user interface and have a lot to do with Wacom tablets (Krita isn't yet ported to Qt5, though). But wait, there's this statement made by Laszlo Agocs, senior software engineer at Nokia:

About the state of QTabletEvent in Qt 5: For platforms other than xcb this event will never be delivered. To be on par with Qt 4 somebody needs to step up and add support for Windows and OS X.

On Linux, QTabletEvents are supported, I added this a few months back using my Wacom Bamboo. It should be considered experimental though. Event delivery, position and pressure, proximity enter/leave seem to work. Other things (e.g. additional properties like tilt which I cannot test with the Bamboo) may not.

In other words, basic Wacom tablets support is already in place for Qt5 on Linux. It “just” has to be finalized for Linux, and written for Windows and Mac. In the light of this axing away the working code for one platform sounds a bit like an overstatement.

Then there's another claim that got the attention. In the initial post Ariel states:

Nobody cares about Wacom anyway, or the bug should be solved by now.

Well, earlier today Boudewijn Rempt, Krita team lead, shared this bit of information in the list:

By the way, I visited IBC in Amsterdam today and chatted with the people at the Foundry stand. Nuke and Mari are Python-Qt apps that are used all over the film industry. They also depend on Wacom support, and they told me Autodesk does depend on it for Maya as well. I wonder if those companies have commercial licenses with Digia... I mean, there clearly are more important users of Wacom support in Qt than me with Krita.

When privately asked about the perspective of Wacom in Qt, Boudewijn maintained his point of view:

I think it's a storm in a glass of water. It's clear that Qt cannot drop support for Wacom. It looks like there's been enough pushing that people have stared looking into the issue right now, so I think it'll all turn out to have been a flash in the pan.

One last question that remains to be asked is whether certain media units are going to start actually talking to free software developers they keep writing about. The observer-expectancy effect is already in effect anyway (pun intended), so why not take a risk? The developers hardly ever bite.

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  1. Interesting. How far from being widely used is Qt5?
    I saw a release date of november-12. Will it take long before applications like Krita is adapted to it?
    Does Qt need to handle tablets? How about linuxwacom? Wouldn’t that be used on a level below Qt?

  2. I don’t think Qt5 will be widely used before 2013, and since Krita will have to wait for the KDE framework libraries to be ported to Qt5, that could easily be 2014 before porting starts for real. Plenty of time for the Qt Project and Digia to implement tablet support.

    As for using linuxwacom or the X11 tablet events directly, sure, that’s possible, and we did that in Krita 1.x. But it’s a big maintenance burden for a small team that just wants to develop an application. And, of course, we’d need to implement low-level tablet support on Windows then as well. So, if Qt abstracts the tablet events into QTabletEvent and does that on X11, Wayland, Windows and OSX, we’d prefer to use that.

  3. What is Nuke and Mari, could you please add links?

  4. Alexandre Prokoudine 11 September 2012 at 12:39 pm

    Tobias, done :)

  5. Does Maya depend on QT as well?

  6. Yes, Maya is written in Qt.

  7. Digia just can’t left commercial customers as important as Autodesk or The Foundry with no support for tablets.

    A guy from digia chimed in in the mailing list saying he’s just arrived, that the tablet he used for the patch was left at Nokia but might arrive later, etc.

    This has been exaggerated by some press (Phoronix, I’m looking at you…)

  8. For Krita, it’ll be 2014 the earliest that we’ll start porting. There’s no hurry; there’s still a lot we want to do for our users that doesn’t need Qt5 at all.

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