control center display and tablets / rotating tablets

[Alon Levy <alevy redhat com>]

Hi,

 I am playing with a new Lenovo tablet, x220t, and I've come up against
 what I think is a current gnome-control-center limitation, which I
 would like to solve. Namely, when I rotate my main display, i.e. the
 LVDS1 output that is the LCD panel of the laptop, the tablet doesn't
 rotate with it, so touching it gives the wrong location clicks.

 It is easy to solve this by setting the "Coordinate Transformation
 Matrix" property to the touch device (Henceforth this will mean all
 touch devices tied to the tablet - for the x220t there are three:
 touch, pen and eraser) to the right values - since it's an affine
 transform it can take care of all possible rotations and translations,
 including multiple monitor setups. I have a patch for doing this in
 xinput already, extending the existing map-to-output:
 http://lists.x.org/archives/xorg-devel/2012-June/031616.html

 The problem is how to recognize that a specific XInput pointer is a
 fixed tablet, and which screen it belongs to. One way of solving this
 is with a database (just a single table) of pairs of xinput pointer
 name and xrandr output names. Is there a property that already ties
 this in xinput? I couldn't find one.

 If this is a known problem and someone is already working on it, I'd
 like to help/test the solution. If not, I'm personally interested in
 solving this.

Alon