SDDM has been the login manager default in KDE Plasma since version 5, after replacing KDM. This is not exclusive to the project, as LXQt also makes use of it. With the constant development and evolution of the environment, KDE developers have encountered a lot of limitations SDDM architectural features, which has led two developers to propose a new project for the development of a new display manager.
This is how «Plasma Login Manager» was born, a new project that is based on the idea of Improve login manager integration with the KDE Plasma desktop environment and its KWin composition server. The primary reference for this new development is GDM (GNOME Display Manager), which has achieved deep integration with GNOME thanks to its close relationship with GNOME Shell and Mutter.
SDDM is designed to display a single welcome window, loading arbitrary QML from the specified topic.
With SDDM, power management is reinvented from the ground up with a custom configuration. We can't integrate network management, power management, volume controls, or Plasma brightness controls without reinventing them in the desktop-independent backend.
SDDM already had to duplicate so much of the functionality we had in KDE, which was very frustrating when we had to maintain it.
In contrast, SDDM was conceived as a universal Qt-based solution, compatible with multiple graphical environments. However, this flexibility has hampered its full integration with KDE Plasma. The developers have identified several shortcomings, including:
- SDDM only allows for a single window for authentication, with no advanced customization options.
- It implements its own power management system, rather than integrating with KDE Plasma's native controls.
- It duplicates existing functionality in KDE, making code maintenance and troubleshooting difficult.
Plasma Login Manager Development
In response to these limitations, a prototype Plasma Login Manager has been developed that It uses a multi-process approach and a backend based on a simplified version of SDDM.Its startup mechanism is identical to the one used to start a KDE Plasma session, ensuring a smoother transition.
The visual design of the login screen has been aligned with that of the KDE screen locker, and the Configurations have been unified with the Plasma environmentThe use of QML for theme customization has been removed in favor of compatibility with existing Plasma wallpapers, color schemes, and themes.
Currently, Plasma Login Manager is available as a working prototype for testing, Although it is not yet considered suitable for the stable branch of KDE Plasma. Development is divided into independent repositories, with plans for future integration into a single package. In terms of features, the project has almost reached parity with SDDM.
Among the improvements planned to be implemented In Plasma Login Manager, the following stand out:
- Improved performance on multi-monitor setups, high pixel density displays, and HDR.
- Change keyboard layout easily.
- Virtual keyboard support, making it easy to use on touch screens.
- Support for input in Asian languages such as Chinese, Japanese, Korean, and Vietnamese.
- Backlight control for both the display and the keyboard.
- Advanced energy management, optimizing resource consumption.
- Integration with screen readers, improving accessibility.
- Bluetooth support, allowing device pairing directly from the login screen.
- Wi-Fi connectivity, with the ability to join previously known networks.
- Remote access capabilities, using VNC/RDP protocols.
Finally, if you are interested in knowing more about it, you can consult the details in the following link
For those interested in trying out the advancements of Plasma Login Manager, you can get the source code and compilation instructions from the following link. It is important to remember that the project is a prototype and is not recommended for use on your system, only in test environments (for example, on a virtual machine).