Qtmoko2-qte

Issue 733: Non-linear pointer moves

Reported by Adrien Dorsaz, Aug 29, 2016

From the QtMoko Report[1] announce:

> Currently the Qt-Embedded deb installs itself into /opt in 
order to not
> mess, or conflict with the non-embedded Qt variant provided by 
Debian.
> There are demos installed to /opt/qt-embedded/examples, and I 
did try
> out a few of them. They appeared to work properly, but there is 
a
> problem with touchscreen input:
> When touching the screen, Qt properly detects a mouse-press at 
the right
> location of the screen. But then when moving the pointer, it 
runs away
> in a non-linear fashion.
> I later concluded that it looks like this:
> pos_new = new_absolute_coordinates + distance_to_last_position
> This is a serious issue and needs investigating. We suspect 
that the
> Qt-Embedded LinuxTP mouse driver is doing something nasty!
> 
> If you want to play around with it, this is how:
> ```
> # set up environment
> export PATH=/opt/qt-embedded/bin:$PATH
> export LD_LIBRARY_PATH=/opt/qt-embedded/lib:$LD_LIBRARY_PATH
> export QWS_MOUSE_PROTO=linuxtp:/dev/input/touchscreen
> cd /opt/qt-embedded/examples
> # try out whatever example you like, and dont forget to pass 
the -qws commandline option
> ```

A workaround has been proposed later on the list[2]:

> On Tue Jun 14 16:41:23 CEST 2016, Josua Mayer wrote:
> 
> > When touching the screen, Qt properly detects a 
mouse-press at the right
> > location of the screen. But then when moving the pointer, 
it runs away
> > in a non-linear fashion.
> > I later concluded that it looks like this:
> > pos_new = new_absolute_coordinates + 
distance_to_last_position
> > This is a serious issue and needs investigating. We 
suspect that the
> > Qt-Embedded LinuxTP mouse driver is doing something nasty!
> 
> A quick suggestion that might not be practical: have you tried 
using the
> linuxinput driver instead?
> 
> http://doc.qt.io/qt-4.8/qt-embedded-pointer.html
> 
> For example, when I compiled Qt for the Kobo Mini, I compiled 
it with
> linuxinput support (-qt-mouse-linuxinput) and selected the 
driver using an
> environment variable at run-time:
> 
> QWS_MOUSE_PROTO=linuxinput:/dev/input/event1
> 
> I've always had difficulty with tslib but linuxinput has mostly 
worked for
> me, once I've figured out which device file it needs to read 
from.
> 
> David

Please, note that I didn't try myself to reproduce this issue. I'll 
try it later.

Adrien

[1]: 
http://lists.goldelico.com/pipermail/community/2016-June/001420.html
[2]: 
http://lists.goldelico.com/pipermail/community/2016-June/001424.html

Created: 6 years 3 months ago by Adrien Dorsaz

Status: New

Labels:
Priority:Medium
Type:Defect