Re: [gdm-list] gdm-list Digest, Vol 116, Issue 2

[anonymous <johnandsara2 cox net>]

gdm-list-request gnome org wrote:
> Send gdm-list mailing list submissions to
>         gdm-list gnome org
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         https://mail.gnome.org/mailman/listinfo/gdm-list
> or, via email, send a message with subject or body 'help' to
>         gdm-list-request gnome org
>
> You can reach the person managing the list at
>         gdm-list-owner gnome org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of gdm-list digest..."
>
>
> Today's Topics:
>
>    1.  gdm: daemons affecting Xorg display configuration and    evdev
>       touch screen calibration (Bj?rn Gerhart)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 18 Mar 2016 00:06:50 +0100
> From: Bj?rn Gerhart <gerhart posteo de>
> To: gdm-list gnome org
> Subject: [gdm-list] gdm: daemons affecting Xorg display configuration
>         and     evdev touch screen calibration
> Message-ID: <B766024B-1DEA-45E2-B657-24910A5F9C56 posteo de>
> Content-Type: text/plain; charset=utf-8
>
> Dear list,
>
> I?m using gdm-3.14 with CentOS 7. On my system, I don?t provide a static /etc/X11/xorg.conf. Two displays are 
> connected, one of the displays is equipped with a touch screen by eGalax, which is compatible to evdev.
>
> When running gdm and gnome-shell, which is the default after el7 installation, the displays get arranged in 
> the style of the formerly ?Xinerama? automatically. So when I move the mouse to the right border of one 
> display, the cursor will appear on the left border of the other display. Furthermore, the touch screen gets 
> configured exactly the way as expected - the mouse cursor is located directly under the finger of the display 
> which is eqipped with the touch screen.
>
> Now, when I simply type ?xinit? instead from the active multi-user target (according to formerly ?runlevel 
> 3?), both displays show the same content (mirroring). But I want the simple ?xinit? to behave the same way 
> like gnome does - for dynamically configuring the displays and evdev behavior.
>
> Which are the daemons or the functionality behind the gdm resp. gnome startup mechanism, providing that 
> behavior? I want xinit to start these separately without gnome-shell, and I wonder how to achieve that.
>
> Best - Bj?rn
>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> gdm-list mailing list
> gdm-list gnome org
> https://mail.gnome.org/mailman/listinfo/gdm-list
>
>
> ------------------------------
>
> End of gdm-list Digest, Vol 116, Issue 2
> ****************************************

you've posted a query in GDM but gnome can effect "display arrangement 
and view" after gdm login, so i'm unsure GDM prevents gnome (or the X 
server) from using (ie, Xinerama).

you've said you dont "provide" an xorg.conf but obviously there is one, 
and surely that's relevant to xinerama setup on x starup

xinit runs startup scripts (in a particular search order) that many 'nix 
(ie linux) distro do not configure , infact in many releases it did not 
work at all (until re-written by end user)

gdm has startup scripts.  but also GDM polls X for touchscreen, and in 
previous versions made an invisible screen on top of the login to read 
the login, kinda a hack to support reading the login before login got 
the keys - and this was to support (ie, voice login, touch screen, etc) 
it was said

anyway you want to read about Xinerama and tools that set it up, and 
xorg.conf.  there isn't a way to use GDM code to start X without gnome 
it's very integrated to support gnome only.

(in other words, there are ways to setup Xinerama and programs that are 
helpers, but asking about GDM in a GDM forum will not lead to answers 
about those other X tools that are free of gnome dependancies)