Add Rotate support to a driver

[Peter Hutterer]

On Sat, May 15, 2010 at 09:19:23PM +0300, yoni dana wrote:
> On Fri, May 14, 2010 at 2:16 AM, Peter Hutterer
> <peter.hutterer at who-t.net> wrote:
> > On Thu, May 13, 2010 at 10:30:17PM +0300, yoni dana wrote:
> >> Thanks for the reply. I am writing an x11 input driver. I have a
> >> looked at some x11 input driver
> >> and didn't see the XRRScreenChangeNotify  function, is there another way
> >> i can detect screen rotation so i can swap between X and Y coordinate
> >> thank you
> >
> > you need to write an X client (== application) to handle this situation.
> > input drivers don't have access to these events directly, so you won't find
> > any code in evdev/synaptics/... do handle this.
> >
> > the order of events is
> > user triggers rotation
> >   X server rotates
> >   X server sends RRNotify events
> >        your client receives event
> >        your client triggers input rotation
> >            input driver rotates.
> >
> > one question I have to ask you though - why are you writing an input driver?
> > there's a good chance that the device may be supported by evdev (of if not,
> > should be supported in the kernel instead). That's if you're on linux
> > anyway.
> >
> > Cheers,
> >  Peter
> >
> >> i have look at the synaptic and evdev driver and didn't see
> >> XRRScreenChangeNotify
> >> function, is there another wahy
> >> On Wed, May 12, 2010 at 12:52 PM, Éric Piel <E.A.B.Piel at tudelft.nl> wrote:
> >> > Op 12-05-10 07:39, yoni dana schreef:
> >> >> Hi
> >> >> i have implemented and X11 input driver,
> >> >> i need to add support to screen rotation,
> >> >> My questions is
> >> >> How can i detect screen rotation occurred
> >> >> (For Example i use xrandr -o left )
> >> > I think you can do this in a X client which listens to the
> >> > XRRScreenChangeNotify event on the root window. See the Xrandr(3) man
> >> > page for more info. Then, your client can request a change of
> >> > orientation to the input via an input property.
> >> >
> >> > Eric
> >> >
> >
> 
> Hi
> Thanks Peter for the reply, i have wrote a kernel driver,
> i will check if i can user evdev as an X11 input driver.
> My question if how can i triger the input driver to roate.
> which signal / command i have to send to the X11.

evdev has the "Evdev Axis Inversion" and the "Evdev Axis Swap" property, if
you change those it'll effectively rotate. Other drivers have other methods
to do this but they can be controlled by properties (man
XChangeDevicePropert(3) gives you a starting point)

Cheers,
  Peter