Created attachment 149835 [details] Login screen in two different cases are shown. NOTE Before I describe the bug in detail, I am aware that there are some scaling limitations of kwin on X11 for multiple displays. But i feel something can be done in this particular case so I request you to read all the details carefully. SUMMARY Due to xrandr issues, when multiple displays with different resolutions are connected the login screen has scaling issues. The larger display accommodates the login screen properly however the smaller display does not (see the attachment, top figure). However, i have also noticed that the cursor doesn't blink on any of the displays in the password text box. But you can still type in the password without noticing any characters in the text boxes. This means a user can skip characters and not notice his mistake at all. Overall, This becomes quite confusing visually as to which display to focus on to type the password and whether the keyboard is responsive. Thus, a solution (if possible) is to show the login screen on only one of the connected displays. GDM3 does the same thing on gnome. STEPS TO REPRODUCE 1. Connect an external monitor (2560x1440) with a larger resolution than the laptop (1920x1080) 2. Select X11 session must be default session (Kubuntu 22.04 recommended). 3. Boot the laptop into linux by pressing the turn on button or selecting linux from the dual boot menu. 4. Login into the user account. 5. Right click and select 'Configure Display Settings'. 6. Select your external monitor as primary display and Disable your Laptop display (or leave it as secondary display). 7. Save the settings and reboot to the KDE Plasma login screen. OBSERVED RESULT Both displays show a login screen scaled to resolution of external display with (2560x1440) resolution. This results in a cropped screen on the smaller display. Cursor in the password text box is missing on both monitors. If you type the password directly, no activity is visible in the text box. However, if you click in the password text box first and type the password, it behaves properly. EXPECTED RESULT Login screen should only be displayed on the primary display. Cursor should be blinking in the text box for typing the password. On the secondary(or smaller) monitor, a Properly scaled login screen with a blurred background image and date-time in the center (see external monitor output in the 2nd frame of the attachment as a reference). ---- OR ----- When an external (or larger resolution) display is connected, only the external display should show the login screen and laptop screen is disabled. Cursor should blink in the text box for typing the password. SOFTWARE/OS VERSIONS Operating System: Kubuntu 22.04 KDE Plasma Version: 5.24.4 KDE Frameworks Version: 5.92.0 Qt Version: 5.15.3 Kernel Version: 5.15.0-37-generic (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Core™ i5-8300H CPU @ 2.30GHz Memory: 15,5 GiB of RAM Graphics Processor: Mesa Intel® UHD Graphics 630 ADDITIONAL INFORMATION
KWin isn't involved here as the SDDM login screen draws everything itself, before KWin is even running. The bugs you're experiencing are in SDDM, so please report them (individually) to https://github.com/sddm/sddm/issues/
Even as an intermediate plasma user I could not have figured out that the very login screen for KDE plasma was not a part of the desktop environment. Thanks for explaining it to me. I will report it to the right project.