Bug 503187

Summary:	Multiple monitors on client and host machine are not utilized by KRDC
Product:	[Applications] krdc	Reporter:	Steffen W. <steffen-winkler>
Component:	general	Assignee:	Urs Wolfer <uwolfer>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	christian.stoller, ctrlaltca, dwt, mkoeditz
Priority:	NOR
Version First Reported In:	25.04.0
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Steffen W. 2025-04-22 18:05:39 UTC

When connecting with KRDC to a computer that has two monitors attached while the connecting computer also has two monitors attached, it is currently not possible to utilize both monitors on both machines. Instead only one monitor is accessible.

STEPS TO REPRODUCE
1. Connect to a PC that has two monitors attached while the PC you are connecting from also has two monitors attached to it

OBSERVED RESULT
Only one monitor is accessible. The host machine thankfully realizes that the RDP client is only using one screen so throws all windows and applications onto that monitor. Even when entering fullscreen mode only one monitor is used.

EXPECTED RESULT
There should be a button to open the other monitor - or other monitors when even more monitors are connected. If the fullscreen button is clicked the default action should be that as many monitors are utilized on the client machine as possible to display as many of the host's monitors. Each monitor obviously needs to have independent scaling from the others.

As an example for a software that is capable of this, check out Remmina. It's a bit crash prone and it can only do this on X11 but it works.

SOFTWARE/OS VERSIONS
Windows (host machine): Windows 10
Operating System: Arch Linux
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.13.0
Qt Version: 6.9.0
Kernel Version: 6.14.2-arch1-1 (64-bit)
Graphics Platform: Wayland

ADDITIONAL INFORMATION
Remmina developers currently say that they can't implement this on Wayland due to a missing feature in the Wayland protocol, which would be this one: https://gitlab.freedesktop.org/wayland/wayland-protocols/-/issues/99

Comment 1 Fabio 2025-04-22 21:13:33 UTC

Confirmed,,multi monitor support it's in our TODO list.

Comment 2 Fabio 2025-04-22 21:20:44 UTC

*** Bug 405629 has been marked as a duplicate of this bug. ***

Comment 3 Steffen W. 2025-08-19 14:08:41 UTC

Given that there is no movement in the Wayland issue and from my understanding that addition to the protocol, or something like it, is required for a fullscreen polygonal window stretching over several screens with different resolutions and sizes(*),  would it be possible to implement a solution similar to what Teamviewer is doing? You get one Window per remote screen and you can arrange them however you like? From my POV the disadvantage of that solution is still that if I'm switching from one screen/window to another screen/window I've to click once to put the focus on the new window/screen which makes it disruptive to drag a window from one screen to another.

*) that's kind of how Remmina works on X11, at least from a user's perspective.