Enable multiple monitor support for giving slidshow presentations in Qubes OS

User Support
1

Multiple monitors are usually detected by dom0 automatically on most of the machines I have run Qubes OS on, which is fine.

But if I wanted to use a Qubes OS machine to give a presentation inside a qube, how do I tell that qube that there are multiple monitors?

For example, I would really like to be able to use the Presenter Console in LibreOffice Impress:
image image

(In other words, have the slides on the big screen, and the Presenter Console with my notes and the next slides on my own screen in front of me)

Thank you in advance! :slight_smile:

2

How do you want to give the presentation inside a qube?
Do you plan to use some software to stream it online?
In that case maybe there is an option to capture a window instead of a desktop in this software?

3

The old-fashioned way, with a VGA cable plugged into a projector.

4

How does LibreOffice Impress with Presenter Console work?
Does it have separate windows for Presenter Console and for slides?
Or it only has separate windows if it detects multiple monitors?

5

From what I can tell, it appears to require the machine it’s running on to report that 2 displays are plugged in.

If i can tell dom0 to report to the qube that multiple displays are plugged in, that would work.

If I could get LibreOffice to put the presentation and presenter console in windows, that might also be enough for Qubes OS to display them as separate windows that I could drag across to the other physical display…

6

It works for me out of the box:
Start LibreOffice Impress in the qube based on a default debian-12-xfce template.
Create new presentation from any template.
Slide Show → Start from First Slide
Now I have 3 windows with LibreOffice Impress, Presenter Console and Presenting.
With Presenting opened on my second monitor by default.

7

It seems that you need to connect your second monitor before you start the presentation qube for it to detect it.

1 Like
8

There is also the option to always enable the presenter console.

  1. Open Expert Configuration via Tools ⇒ Options ⇒ LibreOffice ⇒ Open Export Configuration.
  2. Search for startalways.
  3. Set value of property StartAlways of the preference org.openoffice.Office.PresenterScreen/Presenter to true (double-click on the value).
9

Not to bring up an old thread, but if this is the case (which it is. I tested it successfully), then that means:

All qubes know how many displays are connected at all times…

OR

All qubes get allocated the number of displays present in dom0 on boot

I know there isn’t much that can be done to get around this, without rewriting the entire X11 stack (which I already know probably isn’t ever going to happen…too old, obsolete, too difficult, nobody could be bothered, take your pick), but still, would be nice to be able to pick and choose which qubes get access to that information…

That’s kind of where my question came from in the first place, because I genuinely thought the qubes didn’t get that type of information about displays…