SUMMARY On my Fedora 35 KDE when I use an external monitor: if the external monitor is turned off, all of the windows that were displayed on it get moved in the main one but are resized/collapsed to (very inconvenient) overlapping stripes. *** STEPS TO REPRODUCE 1. Work on the laptop with an external monitor connected 2. Turn off the external monitor, either because of its own auto power off (in case of idle) or manual turn off OBSERVED RESULT Resize of all windows into a collection of stripes (see attachment), overlapping each other. Each window needs to be manually resized to start working again. EXPECTED RESULT Normal work: Automatic move or resize of the windows of the external monitor to the same, or at least proportional, size they had in the external monitor. On turning on again the external monitor: ideally the windows should go back to their original size and position. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Fedora 35 KDE KDE Plasma Version: 5.25.4 KDE Frameworks Version: 5.96.0 Qt Version: 5.15.2 Graphic platform: X11 ADDITIONAL INFORMATION I thought this might have been caused by the different resolution of the external monitor (4K VS 1080p of the laptop, which is a Dell Latitude 5521 btw) but it also happens when the external monitor is 1080p. One of the monitors tested is a smart TV, the other is a monitor (with TV incorporated but a true monitor). Both are Samsung devices.
Do you have the PLASMA_USE_QT_SCALING=1 environment variable set?
(In reply to Nate Graham from comment #1) > Do you have the PLASMA_USE_QT_SCALING=1 environment variable set? I don't think so: ```[giampaolo@fedora ~]$ printenv PLASMA_USE_QT_SCALING [giampaolo@fedora ~]$``` Where am I supposed to set it? I found this thread https://phabricator.kde.org/T8177 which seemed to provide the proper file location, but when checking into org.kde.plasmashell.desktop I could only find these two rows: X-DBUS-ServiceName=org.kde.plasmashell and Icon=plasmashell They do not seem the same as indicated in the link. Thanks!
I may have some idea of what's going on. I managed to make this happen on Wayland by reproducing Bug 460246, and then going from mirrored to extended mode. After I did this, in System Settings > Display and Monitor, the screens were laid out in a slightly overlapping fashion, with windows transformed into vertical striped approximately the width of the overlap. So shen this happens, are you seeing that the screens are laid out in a slightly overlapping fashion on the settings page? Also, when this happens, do either of the screens have their resolution set incorrectly?
(In reply to Nate Graham from comment #3) > I may have some idea of what's going on. I managed to make this happen on > Wayland by reproducing Bug 460246, and then going from mirrored to extended > mode. After I did this, in System Settings > Display and Monitor, the > screens were laid out in a slightly overlapping fashion, with windows > transformed into vertical striped approximately the width of the overlap. > > So shen this happens, are you seeing that the screens are laid out in a > slightly overlapping fashion on the settings page? > > Also, when this happens, do either of the screens have their resolution set > incorrectly? Apologies for taking some time to reply. Went through a few remodeling days and was under water. I tested under the two Full HD setup. As explained, the bug occurs pretty much in the same way even if in the FHD/FHD the screens are side by side and in the 4K/FHD one they are 4K on top of the FHD screen. I have to be home to check the 4K/Full HD one, but I can do that as well later if required. Q1: Not as far as I know: neither in the video settings nor on the screen there seems to be misalignment/overlapping. Q2: Same: they should both be full HD screens and in the settings they appear to be properly set. Please see two screenshots of the video settings. Language is Italian, but if you need me to translate do not hesitate to ask. https://paste.pics/85719897afea8afaf3d80edf21916a3d https://paste.pics/58fd974671ad4a4392ae3248ff216c00
Ok, then you're getting the issue for a different reason from mine, which is that the screens are slightly overlapping.
What's the exact size of the windows after the problem happens? You can check in the kwin debug console (search for "kwin" in krunner to open it)
(In reply to Zamundaaa from comment #6) > What's the exact size of the windows after the problem happens? You can > check in the kwin debug console (search for "kwin" in krunner to open it) Checked on the home setup too (native FHD + 4K extended, virtually located on top of the laptop screen). Slightly different results than in the past, but not too much. In an initial phase: - Most open windows are moved back to the laptop monitor in the same size they had on the other screen (desirable/expected). - Some windows instead are moved as if there still was another screen at the bottom (the windows were on the top, extended screen. so it kind of makes sense). They are not resized though (ok, location is not ideal but the behavior is still mostly desirable/expected) - the menu bar did not show up (in the setup it showed up on the top screen, i.e. the extended one. It did not come back to the laptop) Then something happened, possibly me using Alt+Tab to move from a window to the next OR trying a print screen to understand if Plasma was still considering two monitors (*). One of those two actions triggered the resizing to stripes, so: - it did the resizing/moving as before, shrinking all of them to stripes - the menu bar still did not show up - when looking for the kwin-debug window and opening it, it did not show up, as if it went on some other screen. Turning the extended screen back on: - I can see both the menu bar and the debug screen again, but - it shrank again the only window that I had brought back to a regular size. Size for the shrank windows are 1830x157, or 1846x157, 1727x157, 1712x157, 1696x157, etc Hope this helps. It does get me a bit nuts. (Notice> I need to upgrade. Maybe I'll wait a few days to check if this bug helps? Then I'll move to F37 KDE because my install is starting to be troublesome for other reasons too) (*) The screenshot test proved that Plasma partially behaves as if the screen that was turned off was still there: the print screen shows the 4K screen on top and the capture windows, the Kde menu and the kwin-debug windows are in there. Yet, all other windows were shrank. See: https://paste.pics/09f35683a2a015ef056eeb1dad6d555f
EDIT: My previous comment #7 was taking for granted that the reader had seen all previous comments, which might not be the case. Please bear in mind the most important thing. I am describing Kwin's reaction to the second, external monitor either: 1- being suddenly turned off during normal activity, or 2- turning off during a period of inaction and not being manually turned back on before the laptop screen is activated by a mouse or keyboard event that wakes the laptop up. Both situations mess up (shrink) most of the desktop's windows, as described in comment #7. Hope that makes it clearer.
In Plasma 5.27, I can't reproduce the original issue as described, nor can I reproduce the way I was able to before by doing from Unified mode to Extended mode. The behavior is much more robust now. Let's call it fixed!
*** Bug 456709 has been marked as a duplicate of this bug. ***