Hyprland session target example

[Loara]

Describe your PR, what does it fix/add?

A simple Hyprland user session target that automatically calls graphical-session-pre.target and graphical-session.target when launched by systemctl --user. A lot of Wayland applications usually ship their own user units that depends on graphical-session.target in order to be executed only when a graphical environment is running. Hyprland doesn't automatically ships its own session target so users have to explicitly execute installed systemd units with exec-once = systemctl --user start ... without the ability of enabling/disabling them selectively without modifying each time the configuration file.

For these reasons a lot of users prefer to manually create an hyprland-session.target unit file and start it with exec-once = systemctl --user start hyprland-session.target (you can't directly start graphical-session.target via systemctl). But this approach has an important drawback: when you exit from Hyprland without logging out from your user session then neither the graphical session target nor all the unit services depending on it would stop. There are two possible ways to solve this:

• automatically integrate hyprland-session.target in Hyprland code;
• allow users to add custom hook that should be executed before Hyprland exits, currently one could do this by defining custom key bindings but this wouldn't work when hyprctl exit is called elsewhere.

For the moment I only provide a simple hyprland-session.target file which is not automatically installed by meson in order to avoid overwriting custom target units. In this way users and package managers can freely decide whenever use it or not.

Is it ready for merging, or does it need work?

Automatically works

[fufexan]

I've been thinking about adding an exec-exit hook too, but that won't work when Hyprland crashes, so it doesn't fully solve the issue.
Another thing that may help is polling pgrep Hyprland every few seconds and stopping the target when it's no longer found. It's dirty but it may work.

[Loara]

For hyprland-session.target we could solve it by simply execute Hyprland; systemctl --user stop hyprland-session.target in place of Hyprland only, so the target would be stopped whenever Hyprland exit.

A more elegant way is to write an hyprland.service unit service that both executes Hyprland and starts/stops any user unit bounded to hyprland-session.target when Hyprland exists or crashes. But at the moment I don't think Hyprland could be executed as a Systemd service.

[fufexan]

Also, related sway discussion swaywm/sway#5160.

I believe the first point you suggested might be the way to go. Additionally, distro packagers can patch https://github.com/hyprwm/Hyprland/blob/main/example/hyprland.desktop to add systemctl --user stop hyprland-session.target for systemd/other init systems.

[Loara]

I agree, the first solution is the most portable one. However, I think is a good thing to provide this hyprland-session.target file along with a patched hyprland.desktop and the following (commented) line in the default configuration file of Hyprland so that users and package managers can decide to use or not the Hyprland session target:

# exec-once = systemctl --user start hyprland-session.target