I need help to display a program window (e.g., a Firefox browser) simultaneously on two screens, with the ability to interact with at least one instance of the window.
Use case: in a university lecture hall/classroom, my desk faces the students, with my laptop on the desk. Behind me, a projector displays my laptop's output onto a wall. I have very limited possibilities to change the physical disposition of the room. Most times, I stand up and talk/show on the wall display.
Goal: I want to be able to present and interact with my laptop while seated facing the students but my laptop screen should be able to also display non-projected content.
Linux user, X11 question. Open to wayland answers, though.
What I've tried/thought of:
XrandR: a side-by-side monitor configuration doesn't solve my problem because the projector screen is physically behind me, and I can't view the projected content while seated and facing the students. And I need to keep part of my laptop screen available for other tasks (like preparing the next lecture segment), which excludes 1:1 mirror configurationspdfpc: it works well for presentations but it is limited to pdf slides and I also need to display and interact with other content, like code editors or browsers. Also, the "presenter window" has limited re-organisation features.xpra: I attempted to usexpra attach(and a server) to mirror a window, but I could not get it to work with two clients attaching from the same computer.
My other ideas streaming through OBS, ffmpeg or vnc, but I'm not sure if the performance will be OK (e.g., sufficiently quick response in the video, and not a memory-hog)
Possibly related questions:
- mirror certain windows across screens: the OBS solution is probably a good bet, but I'm a bit surprised that there is no native X11 solution
- https://unix.stackexchange.com/questions/93687/one-x-client-many-x-servers
- https://unix.stackexchange.com/questions/150289/mirror-a-single-x-application-on-a-dual-monitor-setup-with-openbox
What tools or configurations could I use?