I'm running Qt5.2.1 on top of Xorg with an eGalax usb touchscreen. Worked nice in Qt4.8 but in 5.1 things started to misbehave. This commit solved some of the 5.1 stuff but a apparently broke something else.
Author: Allan Sandfeld Jensen <firstname.lastname@example.org>
Date: Wed Dec 4 12:51:28 2013
Avoid duplicate emulated mouse events with XInput2
When using a touch screen on a Linux machine, we receive both touch-events
and emulated mouse events from XInput, on top of that we synthesize mouse-
events ourselves for the touch events.
This patch grabs the touch device for touch events whenever it processes
a touch-begin thereby avoiding XInput from synthesizing mouse events.
Reviewed-by: Laszlo Agocs <email@example.com>
Basically what I seeing is that the cursor does not always follow the touch-events. 95% of the times touch-events are issued the mouse cursior just stays put, but the remaining 5% of the times i moves to the touched point. Symmetry between touch,move,stationary,release looks good, but I'm suspecting that the grab introduced in the above commit is a little more tht necessary.
I ran my application with theese environment variables set.