multi-touch-dev team mailing list archive

[Matthis R <ebaytroete@xxxxxx>]

Am 24.07.2012 20:22, schrieb Chase Douglas:
> On 07/24/2012 05:00 AM, Matthis R wrote:
> > Hello everyone,
> >
> > since I installed Ubuntu 64biz 12.04, the multitouch support for my
> > Synaptics trackpad seems to be broken.
> > When I try to "sudo mtdev-test /dev/input/event9" (which is my touchpad)
> > it throws:
> > -> error: could not grab device
> >
> > Also geistest is throwing an error saying:
> > -> error subscribing to gestures
> > -> error subscribing window 0x000000b9
> >
> > Is this a known problem with synaptics pads, am I facing a bug here, or
> > is it intended behaviour?
>
> Hi Matthis,
>
> There are two issues here. First, X will grab the touchpad evdev node. 
> This prevents mtdev-test from working. This has always been the case. 
> If you want to use mtdev directly with a touchpad, you have to 
> configure the X server so it doesn't grab the touchpad. There's 
> instructions somewhere on wiki.ubuntu.com on how to do this, but 
> generally this isn't what you want to be doing anyway.
>
> The second issue, geistest errors, is due to a change in uTouch in 
> 12.04. The previous incarnation of the uTouch stack would allow for 
> multiple clients to select for gestures and touches on a given window. 
> The new uTouch architecture, which is now built on top of the 
> multitouch support in X.org, does not allow for this. While this can 
> be seen as a regression in behavior, it actually better defines what 
> happens when multiple clients attempt to receive touch and gesture 
> events from the same window. Ideally, this shouldn't be happening.
>
> The exact error you are seeing is due to geistest by default 
> attempting to subscribe to gestures on the root window. Unity already 
> has a gesture subscription on the root window, so geistest fails. If 
> you were to run geistest under a different environment, like KDE, it 
> should succeed. What you can do instead is to run geistest on a 
> specific window. You can use xwininfo to get the window ID of a 
> specific window. Then you can pass that to geistest by using the "-w" 
> option.
>
> You might find other tools more useful for testing, however. I suggest 
> trying geisview, for example.
>
> Thanks!
>
> -- Chase
Hey Chase.

Thanks for your detailed answer - that really shed some light on the dark.
With your advice geistest is now usable with the -w switch under unity 
and, as you mentioned, its working ootb under gnome3.
But then again, geistest seems to have no function what so ever.

This is the output:
http://pastebin.com/ySi8ym5v
This stays forever - even if I'd make a linedance on my touchpad ;-)
Am I missing something fundamental again?

I'm really sorry for beeing so noobish, but I want to understand the 
basics of the multitouch stuff in general for programming purposes.

Thanks again!

Matthis