Necromancer SDDM

A small Qt6/QML theme for SDDM with a dark post-apocalyptic look. The layout is kept simple so the wallpaper stays visible instead of sitting behind a large login panel.

What it includes

• Compact username and password fields
• Bordered login button
• User selection above the login form
• Session selection in the bottom-left corner
• Simple hover and menu animations
• Qt6/QML SDDM greeter
• Installer script for setting the theme up

Wallpaper

The theme was made around this 2560×1440 wallpaper from WallpaperFlare:

https://www.wallpaperflare.com/zombie-apocalypse-post-apocalypse-hackerman-hack-hacking-wallpaper-yisws/download/2560x1440

The image is not included in the repository. Download it manually and save it as:

assets/background.jpg

The filename needs to be exactly background.jpg.

Requirements

You need:

• SDDM
• A Qt6-compatible SDDM greeter
• Git
• A Linux desktop using SDDM

On Arch Linux or CachyOS, SDDM can be installed with:

sudo pacman -S sddm

If SDDM is already installed and working, there is nothing else to install.

Install

Clone the repository:

git clone https://github.com/ilhamfirmansyahhub/Linux-SDDM-Necromancer.git
cd Linux-SDDM-Necromancer

Create the assets directory and put the wallpaper there:

mkdir -p assets

After downloading the wallpaper, make sure this file exists:

assets/background.jpg

Then run the installer:

chmod +x install.sh
sudo ./install.sh

The theme is installed to:

/usr/share/sddm/themes/necromancer-sddm

and SDDM is configured to use it through:

/etc/sddm.conf.d/99-necromancer-sddm.conf

Preview

You can test the theme before logging out:

sddm-greeter-qt6 --test-mode --theme /usr/share/sddm/themes/necromancer-sddm

Depending on the distribution, the greeter executable may have a different name. You can check with:

command -v sddm-greeter
command -v sddm-greeter-qt6

Once everything looks right, log out or reboot and SDDM should load the theme normally.

Layout

The current layout is roughly:

                         Clock
                          Date

                       User selector
                       Username field
                       Password field
                          Login

[ Session selector ]

The login area is intentionally small and sits directly over the wallpaper.

Files

Main.qml          Main UI and login logic
theme.conf        Theme settings
metadata.desktop  SDDM theme metadata
install.sh        Installation script
assets/           Wallpaper file

The main UI can be adjusted in Main.qml. After making changes, run the installer again.

Uninstall

Remove the theme:

sudo rm -rf /usr/share/sddm/themes/necromancer-sddm

Remove the SDDM configuration:

sudo rm -f /etc/sddm.conf.d/99-necromancer-sddm.conf

Then choose another SDDM theme or set another theme in your SDDM configuration.

Compatibility

This theme is mainly developed and tested on Arch Linux / CachyOS with SDDM.

It should work on other distributions as long as they provide a compatible Qt6 SDDM greeter. SDDM configuration paths and package names may be different depending on the distro.

Troubleshooting

Wallpaper is not showing

Check that the file was installed:

ls -lh /usr/share/sddm/themes/necromancer-sddm/assets/background.jpg

If it is missing, copy it again:

sudo mkdir -p /usr/share/sddm/themes/necromancer-sddm/assets
sudo cp assets/background.jpg /usr/share/sddm/themes/necromancer-sddm/assets/

SDDM is not using the theme

Check the configuration:

cat /etc/sddm.conf.d/99-necromancer-sddm.conf

It should contain:

[Theme]
Current=necromancer-sddm

Also check that SDDM is enabled:

systemctl is-enabled sddm

Credits

Theme by ilhamfirmansyahhub.

Background: WallpaperFlare (link above).

License

MIT