Linux Screensaver

A simple Linux screensaver framework, with a desktop app to manage it.

Prerequisites

• This is a Linux only screensaver framework.
• The launcher detects input using the backend that suits the current desktop (via XDG_CURRENT_DESKTOP).
  • On Gnome, input detection is handled by Mutter and both X11 and Wayland are supported.
  • On other desktops (e.g. KDE Plasma), input detection is handled by the Wayland ext-idle-notify-v1 protocol, so a Wayland session and libwayland-client are required.
• A working Go and C compiler and installed Raylib dependencies.
  • https://go.dev
  • https://github.com/gen2brain/raylib-go#requirements
• For the manager only, Qt 6 and its development files, and a C++ compiler.

How it works

The framework is modular: it is made of separate programs, each of which does one job and runs on its own.

Program	What it does
screensaver-launcher	Waits for there to be no input for a time, then runs a saver.
screensaver-*	The savers. Each draws something nice full screen and exits when input is detected. Any one can be run by hand.
screensaver-command	Sends commands to a running launcher.
screensaver-manager	An optional desktop app to choose, preview and run a saver at login.

The launcher needs nothing but the name of a saver: its timer starts and any input resets it. When it expires, the launcher runs the saver and waits for it to exit. Everything is given to it on the command line; it reads no config file, so it can be started however you like, with or without the manager. Any executable can be launched, not only the savers here.

The manager is a convenience on top: it keeps your choices in its own settings and runs the launcher with them as its options, as a systemd user service.

Install

make install

This compiles and installs the launcher, the command tool, every saver and the manager into $GOBIN (or $GOPATH/bin). That directory must be in your PATH, as the savers are run by name.

Launcher

screensaver-launcher -saver screensaver-digital-rain -timer 15m -inhibit vlc,mpv,steam

Option	Description
-saver	The screensaver to show when the timer runs out. Required.
-timer	How long to wait for input before showing it (default 15m).
-inhibit	Process names, separated by commas. While any of them is running, the saver is not shown when the timer expires; the timer simply starts again. A name matches a process whose name (as top shows it) or program file name is exactly that name.
-port	The port the command tool talks to it on (default 1337).

Add to startup

Use the Screensaver Manager to install the launcher as a systemd user service, which starts with the desktop session. Or start the launcher any other way, such as from a startup application:

screensaver-launcher -saver screensaver-game-of-life > /dev/null 2>&1

Screensaver Manager

A Qt 6 app, built with miqt, to manage the launcher. Building it needs Qt 6 and its development files.

• Screensavers lists every saver by name, with the one in use marked and selected. The selected one's preview plays beside the list. Preview runs the real saver full screen; Use This Saver makes it the one the launcher shows.
• Start Up: Install writes ~/.config/systemd/user/screensaver-launcher.service, which starts with the desktop session, and starts it. Its status is shown and kept up to date; Start, Stop and Uninstall control it, and Show after sets the timer. A launcher started some other way is pointed out, as it holds the port the service's launcher needs.
• Inhibit lists the processes that stop the saver being shown, each with whether it is running now.
• File › Settings (Ctrl+,) chooses the theme: light, dark, or following the system.

What is chosen is kept in ~/.config/screensaver-manager/settings.json. Nothing is set until you choose it. The service runs the launcher with your choices as its options (-saver, -timer, -inhibit), and each change rewrites the service and restarts the launcher if it is running.

The launcher's output goes to the journal: journalctl --user -u screensaver-launcher.service -f.

make build      # ./screensaver-manager
make run        # builds and runs it
make test       # its tests, with the race detector; the UI's run offscreen
make vet
make screenshot # draws manager/screenshot.png

Commands

You can use the command tool to send commands to the launcher to control its behaviour.

Command	Description
screensaver-command -reset	Reset the launcher timer.
screensaver-command -activate	Expires the timer and activate the specified saver.

Savers

Each saver is a directory of screen/saver, such as digital_rain, with its program in a file named for it, screensaver-digital-rain.go, and its preview in assets/images/preview.gif. make install installs a new one, and the manager lists it once it is built again, as it builds the previews into itself.

screensaver-connection-machine

screensaver-digital-rain

screensaver-game-of-life

screensaver-shader-fire

screensaver-shader-reef

screensaver-shader-star-grid

screensaver-the-thing