multi-touch-dev team mailing list archive

[Duncan McGreggor <duncan.mcgreggor@xxxxxxxxxxxxx>]

-------- Original Message --------
Subject: Re: touch input rotation
Date: Tue, 29 Jun 2010 16:20:56 +0200
From: Alberto Milone <alberto.milone@xxxxxxxxxxxxx>
To: Kees Cook <kees.cook@xxxxxxxxxxxxx>
CC: Federico Mena Quintero <federico@xxxxxxxxxx>,        Bryce
Harrington <bryce@xxxxxxxxxxxxx>,        Chase Douglas
<chase.douglas@xxxxxxxxxxxxx>,        "Duncan M. McGreggor"
<duncan.mcgreggor@xxxxxxxxxxxxx>,        Rick Spencer
<rick.spencer@xxxxxxxxxxxxx>,        Rafi Rubin <rafi@xxxxxxxxxxxxxx>

On 28 June 2010 20:14, Kees Cook <kees.cook@xxxxxxxxxxxxx> wrote:
> Hi Federico,
>
> I saw your touch input rotation work[1].  I was looking at this too,
> and I think it needs to be done more generally (in gnome-desktop rather
> than g-s-d), and with XInput (rather than calling out to xsetwacom).
> I've got a patch to do it here:
>
> https://launchpad.net/bugs/599478
> http://launchpadlibrarian.net/51043158/101_rotate-touch-devices.patch
>
> Is there an upstream Gnome bug for this work?
>
> Thanks,
>
> -Kees
>
> [1]
http://git.gnome.org/browse/gnome-settings-daemon/log/?h=randr-rotate-wacom-tablet
>
> --
> Kees Cook
> Ubuntu Security Team
>

Hi all,

A few notes:

According to Rafi (who I'm subscribing) there are cases in which we
may not want to auto rotate input devices:

"Simply differentiating pen and touch is insufficient.  Most of the
wacom touch screens seem to have pen, and we would want to rotate
those pens.  We also see devices like the bamboo tablets which
identify as touch, but aren't attached to the screen and shouldn't
auto rotate. And then there's messes like ntrig devices, where we're
moving towards using evdev for touch and the wacom x driver for pen"


I think that perhaps using either a blacklist or regular expressions
to indentify devices would help. This said, I still think that we
can't get this right for all devices, therefore I recommend that we
adopt Federico's approach where a gconf key allows users to disable
automatic rotation of input devices. This is not enough but at least
it should make things less annoying for users who don't want to rotate
inputs. We might as well have a text file with the blacklist so that
users can add devices that shouldn't rotate there (this would help
OEMs a great deal).

As regards Kees' implementation in gnome-desktop, I think that it's
the right place to implement part of this feature however I think we
can do a little more than that. We could expose functions to list
devices and to get, set and list device properties in the
gnome-desktop API. I think this would make sense as it would reduce
code duplication in the touchpad plugin (in gnome-settings-daemon)
and, above all, if the Xinput API changed we would have to fix things
only in gnome-desktop (at least in theory).

Regards,

-- 
Alberto Milone
Sustaining Engineer (system)
Foundations Team
Canonical OEM Services