Bug 508562

Summary:	kwin_wayland --x11-display --fullscreen does not work as expected
Product:	[Plasma] kwin	Reporter:	mike
Component:	platform-x11-nested	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	kdedev
Priority:	NOR
Version First Reported In:	6.4.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description mike 2025-08-21 15:47:26 UTC

since kwin_x11 is now gone and xrdp is only able to provide a X11 server as interim solution launching kwin_wayland seems to do the trick, but it does not go fullscreen.
Note that first the parameter itself seems not to be passed in the X11 case (only nested wayland), but also this X server would not have a window manager, don't know if that may interfere..

What would probably a nicer solution (tough probably too complex) actually query all screens (using randr) and creating an X11WindowedOutput for every "physical" display copying some edid data. What I would say is out of scope (if you agree) is changing resultution/rotating/etc

This way it would be possible to run a wayland (with Xwayland of course since the "output only" X server probably has no window manager) session over xrdp, Xvnc or any platform that has no proper drm support (or headless mode) with the benefit of actually working goodies like hidpi.

Comment 1 TraceyC 2025-08-21 22:31:20 UTC

I'd like to get more information about your use case. Can KRDP, built into Plasma, be used for your remote desktop needs?
If it doesn't work, can you detail your use case a little more?

Comment 2 mike 2025-08-22 07:07:23 UTC

This bug report is also about mentioning that the supposed and documented --fullscreen flag does not work.

that being said: KRDP in kwin_wayland sure is the right way to go on, but what I need is a terminal server environment. That means:
The user logs in with his credentials prior the session is started (the xrdp login screen)
Locally there is no display (0 displays)
Locally there might be no /dev/dri
There might be multiple users connected simuntaneosly
Firewall rules allow only one port (so even a port per user and pre-login everybody, if that would be even possible in a domain context where you need a kerberos ticket) is no solution

Sure: if t in the future plasma-login-manager would hold the rdp server, launch a new (virtual) session for remote users when they log in this might be a better solution, but that solution would probably take multiple years to be implemented and since kwin_x11 now is gone, the entire terminal server usecase is "gone" except I downgrade to lets say xfce

Comment 3 TraceyC 2025-08-22 16:55:46 UTC

Thanks for explaining your needs. I'll let the developers take it from here.