#12228 NORM 4-softw: xo-4: zforce driver change x/y position

Zarro Boogs per Child bugtracker at laptop.org
Tue Oct 23 09:12:27 EDT 2012

#12228: xo-4: zforce driver change x/y position
 Reporter:  godiard      |                 Owner:            
     Type:  defect       |                Status:  new       
 Priority:  normal       |             Milestone:  4-software
Component:  touchscreen  |               Version:  4-B1      
 Keywords:               |           Next_action:  diagnose  
 Verified:  0            |   Deployment_affected:            
Blockedby:               |              Blocking:            
 With the zforce driver, if the user keep the finger without movement
 touching the screen, gtk receives changes in the x/y position of 1 pixel.
 If a activity process every change, as a drawing application, this issue
 can trigger a lot of events.

 In Paint activity we do:

         # the touch driver trigger many events sensing movements up and
         # by only a pixel. This code caches the last position and ignores
         # the movement if is not bigger than one pixel to avoid redraws
         if abs(x - self._last_x_touch) > 1 or \
             abs(y > self._last_y_touch) > 1:
             self._last_x_touch = x
             self._last_y_touch = y

 Should be good if this can be solved in the driver

Ticket URL: <http://dev.laptop.org/ticket/12228>
One Laptop Per Child <http://laptop.org/>
OLPC bug tracking system

More information about the Bugs mailing list