Demo: don't lock the master computer when sharing a user's screen fullscreen - #1126
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…lscreen When the master computer is itself listed among the room computers, "Share selected user's screen in fullscreen mode" sent a fullscreen demo client to the master as well. The fullscreen LockWidget grabbed keyboard and mouse and covered Veyon Master, so the teacher could neither manage nor stop the running demonstration. The master is meant to receive only the dedicated window demo started separately for its local session interface. Exclude the local host from the demo client broadcast so it is no longer also locked in fullscreen.
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Thank you very much for your helpful contribution. If you have the time, feel free to do the same for the screen lock feature. |
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OK. Can I also help you with adding Wayland support? |
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Sure, checkout the pipewire-v2 branch - most of the work is already done :-) It works on KDE with the ony limitation that veyon-server runs as session user and not as root, so users can kill it (but they can also terminate the screencast/remote desktop desktop portal operation, so it doesn't really matter). |
rautyrauty
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Jun 10, 2026
Following the same fix for the demo feature: in the ALT Education multi-teacher lab layout the teacher's computer is listed among the room computers. Locking the screen of all selected computers therefore also locked the master itself - the fullscreen LockWidget grabbed keyboard and mouse and covered Veyon Master, leaving the teacher with no way to unlock the running session. Exclude the local host from the screen lock broadcast so the master keeps control, mirroring the demo client behaviour. The local-host filtering that the demo feature already performs is moved into a ComputerControlInterfaceList::removeLocalHostInterfaces() member - promoting ComputerControlInterfaceList from a QVector alias to a QList subclass - so both features share a single implementation instead of duplicating the loop. Link: veyon#1126
tobydox
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Jun 10, 2026
Following the same fix for the demo feature: in the ALT Education multi-teacher lab layout the teacher's computer is listed among the room computers. Locking the screen of all selected computers therefore also locked the master itself - the fullscreen LockWidget grabbed keyboard and mouse and covered Veyon Master, leaving the teacher with no way to unlock the running session. Exclude the local host from the screen lock broadcast so the master keeps control, mirroring the demo client behaviour. The local-host filtering that the demo feature already performs is moved into a ComputerControlInterfaceList::removeLocalHostInterfaces() member - promoting ComputerControlInterfaceList from a QVector alias to a QList subclass - so both features share a single implementation instead of duplicating the loop. Link: #1126
tobydox
pushed a commit
that referenced
this pull request
Jun 10, 2026
Following the same fix for the demo feature: in the ALT Education multi-teacher lab layout the teacher's computer is listed among the room computers. Locking the screen of all selected computers therefore also locked the master itself - the fullscreen LockWidget grabbed keyboard and mouse and covered Veyon Master, leaving the teacher with no way to unlock the running session. Exclude the local host from the screen lock broadcast so the master keeps control, mirroring the demo client behaviour. The local-host filtering that the demo feature already performs is moved into a ComputerControlInterfaceList::removeLocalHostInterfaces() member - promoting ComputerControlInterfaceList from a QVector alias to a QList subclass - so both features share a single implementation instead of duplicating the loop. Link: #1126 (cherry picked from commit 472daa3)
tobydox
pushed a commit
that referenced
this pull request
Jun 10, 2026
Following the same fix for the demo feature: in the ALT Education multi-teacher lab layout the teacher's computer is listed among the room computers. Locking the screen of all selected computers therefore also locked the master itself - the fullscreen LockWidget grabbed keyboard and mouse and covered Veyon Master, leaving the teacher with no way to unlock the running session. Exclude the local host from the screen lock broadcast so the master keeps control, mirroring the demo client behaviour. The local-host filtering that the demo feature already performs is moved into a ComputerControlInterfaceList::removeLocalHostInterfaces() member - promoting ComputerControlInterfaceList from a QVector alias to a QList subclass - so both features share a single implementation instead of duplicating the loop. Link: #1126
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Problem
When the master computer is itself listed among the room computers — a common setup in labs where one or more teacher stations are added to the location — starting Demo → Share selected user's screen in fullscreen mode locks the master itself.
startFeature()for the user-screen demo sends a fullscreen demo client to every room computer except the selected one (userDemoControlInterfaces), and separately sends a dedicated window demo to the master's own local session so the teacher keeps control. But the master's own computer is also part ofuserDemoControlInterfaces, so it additionally receives the fullscreen client. The fullscreenLockWidgetgrabs keyboard and mouse and covers Veyon Master — the teacher can no longer switch the demonstrated user or even stop the demo. With two teacher stations, both get locked.Steps to reproduce
Fix
Exclude the local host from the fullscreen demo client broadcast. The master already receives the dedicated window demo via its local session interface — that is what lets the teacher monitor the demonstration without being locked.
Verified on ALT Education (KDE Plasma 6 / X11): after the change the presenting teacher's machine keeps a usable Veyon Master and can stop the demo, while student computers still get the fullscreen demo as before.
Downstream report: https://bugzilla.altlinux.org/41102