10-systemd-session.conf.in

# Address several issues with DBus activation and systemd user sessions
#
# 1. DBus-activated and systemd services do not share the environment with user
#    login session. In order to make the applications that have GUI or interact
#    with the compositor work as a systemd user service, certain variables must
#    be propagated to the systemd and dbus.
#    Possible (but not exhaustive) list of variables:
#    - DISPLAY - for X11 applications that are started as user session services
#    - WAYLAND_DISPLAY - similarly, this is needed for wayland-native services
#    - I3SOCK/SWAYSOCK - allow services to talk with sway using i3 IPC protocol
#
# 2. `xdg-desktop-portal` requires XDG_CURRENT_DESKTOP to be set in order to
#    select the right implementation for screenshot and screencast portals.
#    With all the numerous ways to start sway, it's not possible to rely on the
#    right value of the XDG_CURRENT_DESKTOP variable within the login session,
#    therefore the script will ensure that it is always set to `sway`.
#
# 3. GUI applications started as a systemd service (or via xdg-autostart-generator)
#    may rely on the XDG_SESSION_TYPE variable to select the backend.
#    Ensure that it is always set to `wayland`.
#
# 4. The common way to autostart a systemd service along with the desktop
#    environment is to add it to a `graphical-session.target`. However, systemd
#    forbids starting the graphical session target directly and encourages use
#    of an environment-specific target units. Therefore, the integration
#    package here provides and uses `sway-session.target` which would bind to
#    the `graphical-session.target`.
#
# 5. Stop the target and unset the variables when the compositor exits.
#
exec @execdir@/session.sh