gdm-extension

A gnome-shell extension for customizing GDM Login Screen for GNOME v45 and v46.

Please note that this extension is experimental and is being continously monitored on Arch Linux with gnome-shell v46. When you run the Makefile, it will reset all the gsettings/dconf for the `gdm` user. If you have other extensions enabled for gdm login screen, then you have to add the UUID of those extensions. See line numbers 106 and 113.

Warning: Though this extension is being tested since Dec 2023, In very very rare case there could be a chance of being unable to reach even to TTY. In such a case, a bootable USB is required to remove this extension. So please make sure you have a bootable USB and some experience on how to mount drives and remove files with command line. This gdm-extension installs at

/usr/local/share/gnome-shell/extensions/gdm-extension@pratap.fastmail.fm

prerequisites packages

zip
dbus-x11
systemd-container

Installation

git clone https://github.com/PRATAP-KUMAR/gdm-extension/
cd gdm-extension
sudo make install

Customize background colors, image, blur for each monitor upto 4 monitors for GDM Login Screen from the login screen itself.

Customize Shell theme, Icon theme, Fonts, Logo, Banner message for GDM Login Screen from the login screen itself.

Preview of the gdm-extension (pics from Ubuntu 24.04 GDM Login Screen)

You can customize different colors/backgrounds with different blur for multiple monitors of upto 4.

Tweaking from GDM Login Screen

On the left side topbar, there is a preferences Icon shown. Click on it and it will popup the menu.
Based on number of monitors connected, it will popup a menu for all monitors like Monitor - 1, Monitor - 2 upto 4 monitors.
For Each monitor you can choose different colors, backgroud image, blur, gradient horizontal and gradient vertical.
For Background, if you are satisfied with your shell theme, you dont need to change any thing. If you prefer to choose colors, you have to enter a valid color for example,#456789, blue etc. You must be careful while entering these.
Important is that, you have to hit Enter when you write something in the entry box.
Icon themes are collected from ["/usr/local/share/icons/", "/usr/share/icons"] directories.
Shell themes are collected from ["/usr/local/share/themes/", "/usr/share/themes"] directories.
Fonts are collected from ["/usr/local/share/fonts", "/usr/share/fonts] directories.
Fonts are filtered by FontFamilyName based on font file naming convention and StyleName is ignored by this extension.
You can choose distribution logo from ["/usr/local/share/pixmaps", "/usr/share/pixmaps]
You can tweak some system settings from the System Settings menu like tap-to-click, show date, seconds, weekday, disable user list, disable restart buttons, show banner message.
You can type banner message on the entry box provided. Make sure you hit Enter when you write something in the entry box.
Optionally you can overrride styling with extensions css file. for example
```
#panel {
  background-color: #000000;
}
```
Topbar/Panel color is black now

Hiding the Preferences Icon from GDM Login Screen

Once you enable the extension it is available for regular users too on the Login Screen. Once you set colors, background, logo, banner message etc, then to prevent tweaking from non sudo users, you can hide the extension settings icon from the topbar by clicking the Hide button at the bottom of popup menu.

Showing the Prefernces Icon

Please note that `gdm` user is named `Debian-gdm` for debian OS. If you are using Debian OS, please replace `gdm` user with `Debian-gdm` where ever applicable in below commands.

If running from tty

sudo machinectl shell gdm@ /bin/bash # check note at line number 76. gdm || Debian-gdm
gsettings set org.gnome.shell.extensions.gdm-extension hide-gdm-settings-icon false
exit

If running from terminal

xhost si:localuser:gdm # # check note at line number 76. gdm || Debian-gdm
sudo -u gdm dbus-launch gsettings set org.gnome.shell.extensions.gdm-extension hide-gdm-settings-icon false # check not at line number 76. gdm || Debian-gdm

Known Issue

When you choose to Disable Restart Buttons, the buttons are hidden as expected, but when you toggle the switch, the buttons are not shown. To sort out this, go to any tty by CTRL+AL+F4 etc and then run sudo systemctl restart gdm.service.

Troubleshoot

While customizing colors, gradient, wallpaper, or choosing shell themes or icon themes, if you encounter problems.

if you want to operate from tty you need systemd-container package installed. Some distros ship it by default.
If you dont have this package, install it first. Then run below commands.