multitouch events

Jordi Polo mumismo at
Wed May 7 13:42:58 BST 2008

Answering myself once more...
 It seems that several existing applications are using multitouch events
using the TUIO protocol (

Also, it seems that no X support will be available, so I guess supporting
TUIO is the best choice.
I guess Trolltech has already a general development plan for 4.5, and I'm
sure some Trolltech's developers are in this list (Thiago?) ,  is multitouch
support in the list?

And my prior questions still apply, mainly summarized "if I work to make KDE
multitouch aware, it will be welcomed even if it will imply more code in
kdelibs and a right now limited audience ( although expected to grow to
millions at least in mobile platforms in next years)"
My first idea of merging that with KActions + send events to Apps is a
feasible good design?

On Tue, May 6, 2008 at 10:28 PM, Jordi Polo <mumismo at> wrote:

> I was wrong saying that there exist an X server implementation with
> multitouch, what there exist is a multi-pointer, multi-keyboard Xserver.
> On Tue, May 6, 2008 at 4:18 PM, Jordi Polo <mumismo at> wrote:
> >
> > Hi,
> > I have the chance to get involve in some Human interface projects but
> > want to make then as general as possible.
> >
> > == WHY ==
> > First there exist a library that let create cheap multi touch panels (
> >, they use computer vision, so
> > a lot of computing is needed and some tuning. Alternatively there are some
> > multitouch, multifinger support for the Wiimote (
> >
> > These projects use specialized libraries and are quite geek/research
> > like.
> > On the other hand, we have the new Mac Air /Mac book pro with their
> > basic multitouch gestures support.
> > And the thing that made think about all this:
> >
> >
> > Even the above article is about a patent and it doesn't mean it will
> > materialize in a product, I'd say that the next Mac whatever laptops will
> > come with a bigger trackpad with extended gestures support.
> > If they don't, with cheap (only one wiimote is needed) multitouch
> > displays available, it can be really cool if Linux/KDE leads the way on
> > interfaces innovation.
> >
> > I think the above Apple's ideas are pretty clever, use multitouch to
> > define usual GUI operations like copy or paste. Meaning no revolution is
> > needed on the UI and applications should not be wildly reworked. Also means
> > that multitouch hardware can be little by little more common place till the
> > point that we can change the UI to be more specifically multitouch (the zoom
> > idea is the first obvious thing).
> >
> > I hope you agree with me in the convenience of multitouch support. I
> > guess this can be easily flamed as not everyone will like the multitouch
> > paradigm, also  accesibility concerns can easily argued. That's why it
> > should be done gradually, trying to make it configurable, etc.  I hope that
> > it can be seen at least as interesting to be explored.
> >
> > == HOW ==
> > As I said, today multitouch programs are done with multitouch specific
> > libraries and tent to be fancy 3D stuff. I will like to include the
> > multitouch support in KDE in a way it can be easily used by normal
> > applications. In fact the support should not be limited to KDE.
> > Current Xorg has no multitouch support. It does exist a X implementation
> > that supports it and I read somewhere that someone was working on multitouch
> > Xorg but not sure about progress.
> > From my point of view, the perfect implementation would be a low level
> > library/ Xorg taking care of creating basic events from the multitouch
> > hardware (much like mouse or keyboard).
> > Those will be converted to new types of QEvents, maybe Trolltech is even
> > thinking about adding multitouch support in 4.5 for Mac platform (very wild
> > guess).
> > Since this point I am not sure what should be the best implementation.
> > In my ignorance of KDE internals I would suggest adding multitouch
> > handling to KActions, so the applications will not need to be changed. To
> > put an example, KMyWhateverApp will add a KAction copy action that is
> > activated with Ctrl+c and with the gesture two_fingers_up.
> > Gestures to show Plasma dashboard, launch krunner, etc can be managed as
> > current global shortcuts are managed.
> > Applications will of course receive multitouch QEvents (those not
> > filtered by KActions I guess), modifying the apps to use the events in
> > fancier ways is a problem of every app developers.
> >
> > As I said I want to make the whole multitouch stuff useful for OSS in
> > general instead of the "make a cool looking project" that I have being
> > offered. So for me the important point is if this kind of work is really
> > seen as useful and integrable in KDE or no. I am sorry for the hand waving
> > but I will not even start the project if it is not going to help a bigger
> > audience than my 2 reseach fellows...  So:
> > ¿What problems do you see to the general high level implementation ideas
> > above?
> > ¿Do these ideas have a place in KDE?
> > ¿If multitouch hardware is not massively available (let's say some macs
> > and maniac wiimote users only) it has the chance to be added to KDE?
> > ¿If the only way to get multitouch information is a non- Xorg related
> > library, it is implementable?
> > ¿If that library is not widely deploiyed, it is ok to include code in
> > kdelibs that use it?
> >
> > --
> > Jordi Polo Carres
> > NLP laboratory - NAIST
> >
> >
> --
> Jordi Polo Carres
> NLP laboratory - NAIST

Jordi Polo Carres
NLP laboratory - NAIST
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