using SYNAPTICs touchpad as primitive graphics tablet

Peter Rayner prayner at
Wed Jul 14 20:42:02 PDT 2010

I originally sent this mail to Christoph Brill who suggested this

Let me give 3 sentences of background to my request.
I am a totally blind researcher who needs to look at 2-dimensional
data.  As a hobby project I'm trying to write an application to use
graphics tablets and audio output to do this. I would like to extend
this to built-in touchpads on laptops but I have to get the absolute
position of a finger on the touchpad rather than just relative

Hence my question.  The touchpad must receive absolute position
information but it appears that, at least by the time I get to pygtk,
the x,y are mapped relative so that picking a finger up and putting it
back down somewhere else doesn't change the position.  this is
what one would normally want, after all these touchpads aren't meant
to be graphics tablets, but I need absolute position.  Is
 this information made available to the X server? If so can someone
 give me a pointer to how to access it in pygtk?
thanks in advance for any help

I HAVE MOVED. Note new contact details:
Peter Rayner
room 330 
School of Earth Sciences, University of Melbourne, 3010, Vic, Australia
tel: work: +61 (0)3 8344 9708; fax: +61 (0)3 8344 7761 
mail-to: prayner at

More information about the xorg mailing list