SDDM Login Screen for KDE5

[kyonides]

SDDM Login Screen

WARNING: This guide only handles xrandr! If you're currently using wayland, you're on your own!  

Well, if you're a Linux fan, you gotta have met some KDE5 based distro that features a different login screen scheme based on QML files, namely SDDM. It does allow you to customize your login screen either by downloading themes or by editing those you've already installed on your distro. You're now supposed to be free to change even if some options show up or not or how wide a button or bar might be. Even so I encounter not a bug but a real nuisance during this customization process.

What happens if the default screen resolution for the login screen is not your preferred one? Quack! Everything looks awkward! Sadly, Melana's mapping skills can't help us here.

What do you do then?  

Look for this file:

/usr/share/sddm/scripts/Xsetup

If you found it there or in some folder called /etc/sddm/scripts/Xsetup then open it with your favorite text editor. Some Linux fans here would go demential and start a new vi like session. In my case it should suffice to open Kate, KDE's default text editor with a decent GUI.

There add a new line and enter something like this:

Code:

exec $HOME/.profile

Where $HOME should be a global variable that leads to the current user's home directory. If it doesn't work like that, replace it with something like...

Code:

exec /home/current_username/.profile

Leave an empty line and save the file. It will ask you to enter the administrator's password.

Once it's saved, create a new file called just like the file you mentioned a while ago, .profile, it should be located exactly in the same place. Then open it and enter some interesting lines there...

Code:

#!/bin/bash
xrandr --newmode "1280x768"  79.50  1280 1344 1472 1664  768 771 781 798 -hsync +vsync &&
xrandr --addmode VGA "1280x768" &&
xrandr --output VGA --mode "1280x768"

Save the file! (Blank line included!)

In this case it will reset the login screen resolution to 1280x768 automatically. If you need a different resolution plus all the technical details, you might need to use some curious tools, namely gtf or cvt, first.

At this point some forumers might start thinking why did we save those lines in a separate file? The reason is quite simple, if the Xsetup file gets corrupted, deleted or anything, the .profile file with all of our lines will still exist safely there!

Caution!
Make sure you don't pick a resolution your graphics card doesn't support! If you already did, the screen will get quite black indeed!