[xubuntu-users] independent desktops on 2 monitors with Xubuntu 22.04?

[Ulli Horlacher]

I have asked this first on the Xfce mailing list, because I thought it is
an easy configuration problem... but sadly: it is NOT.

I am on the way to replace a notebook running Xubuntu 18.04 with a new one
running Xubuntu 22.04. Both have a second external monitor attached.

Everything runs fine on the new notebook when using just the internal
display, but not with the second, external HDMI monitor.

I do no want the standard configuration with one $DISPLAY, but I want the
so called Zaphod mode with independent displays where I can switch the
workspaces independently.

With the default (non-Zaphod) mode, a workspace switch is done always on
both displays, together. Unusable for me.

After activating the Zaphod mode via a handcrafted xorg.conf on the new
Xubuntu 22.04 notebook I see now only on the internal display windows
and the panel, the external display is just black, BUT I can move the
mouse to it and I can see the mouse pointer! So, the external display is
recognized by X11, but I cannot start there any programs with the mouse.
Nothing is clickable.
What I can do is starting X11 programs this way from the internal display:
DISPLAY=:0.1 <program> <args...>
                                     

I discovered that the problem arrived first with Xubuntu 19:

https://bugzilla.xfce.org/show_bug.cgi?id=15116

The cause was the switch to GTK3 which does not support any longer Xfce
Zaphod mode.

Xfce 4.12 still uses GTK2 which supports Zaphod mode.

Now my question:

(How) is it possible to use Xfce 4.12 with Xubuntu 22.04?
Is some kind of downgrade possible?

I do not need any new fancy stuff coming up with the new Xfce 4.16
but I REALLY need independet workspace switching! 
My desktop work flow is based on it!


-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart         E-Mail: horlacher at tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<20230306110248.GA21974 at tik.uni-stuttgart.de>