Hi,

there have been some recent changes in notification-daemon and the way
it is started. It previously was started via dbus activation on-demand.
This had the unpleasant side effect, that shipping different
notification systems either had to conflict with each other or divert
the dbus service file (or ship it under a different dbus service file
name where it no longer was clear which service would be started then).

In GNOME 3, the notification system is integrated into gnome-shell itself,
which is komparable with how kdebase-workspace does it.

As a consequence, the dbus service file was removed from
notification-daemon, as this could otherwise lead to a race when
gnome-shell is started [1]. In the GNOME 3 fallback or GNOME 2 case, we
start notification-daemon via the session manager now.

For GNOME 2, we ship a autostart file in gnome-session 2 in
/usr/share/gnome/autostart. gnome-session 3 will start
notification-daemon in the fallback case and we also ship a XDG
autostart file, which should handle non-GNOME environments.

It currently lists:
OnlyShowIn=LXDE;OPENBOX;GNOME;
AutostartCondition=GNOME3 unless-session gnome

I.e. XFCE is explicitly excluded, as I assumed that for XFCE the
preferred notification system is xfce4-notifyd.

We have been discussing that on IRC for a while, and we came to the
conclusion, that it should be up to the individual desktop environment
to depend on its notification system of choice.
The notification daemons should no longer be started via dbus activation
and instead by the session manager, so we have a defined and reliabe
behaviour.

If you can agree with that, please update xfce4-notifyd accordingly and
make the xfce4 metapackage depend/recommend xfce4-notifyd.

I also think, that individual applications should not directly depend on
notification-daemon directly. But this should be discussed / fixed
independently from this bug.

Cheers,
Michael


[1]
http://git.gnome.org/browse/notification-daemon/commit/?id=1ad20d22098bc7718614a8a87744a2c22d5438d0

I have to admit I'm still puzzled by that. Back in time, it seemed like
seamless activation through dbus was the way to go and that autostarting
was bad.

I'm not completely against the change (though it's really upstream call)
but what do we lose in the transition?

Regards,

Am 02.09.2011 07:56, schrieb Yves-Alexis Perez:

Curious, so you have any references for that?

The notification system is no longer started on demand. I.e. you can't just kill
it anymore and have it magically restart again. Also, the notification system
will be started, wether or not it is actually used.

For KDE and GNOME3 / gnome-shell this is not really a concern, as the
notification system is builtin now.

Also, using alternative notification systems, like notify-osd, becomes a bit
harder I guess and needs explicit configuration if you want to use them (*).
But again, for KDE and GNOME3 you most likely don't want to replace the
notification system anyway.

Cheers,
Michael

(*) right now notify-osd still ships a dbus autostart file, so this is not yet
true. Will have to file a corresponding bug there.

Some answers:

[10:50:31] (mr_pouit): mmh, without dbus activation, any crash in the
                       notification daemon will let the user without
                       notifications?

And, right now, xfce4-notifyd stops after some inactivity, since it'll
be automagically restarted the next time a notification happens. That'd
be broken if we remove the dbus activation.

Not sure if we could do both (ship dbus activation *and* force startup
with autostart desktop files).

Regards,

Hello

I'm using testing, normally with KDE.  After a recent update broke my
usual environment I installed XFCE as a backup.  Now that Plasma is
fixed I see that notifications there are still provided by this XFCE
service.

Reading the forwarded bug, I see where the current situation with both
autostart and dbus activation comes from.  But this bug has recently
celebrated its tenth anniversary. :)  Do DBus or systemd perhaps provide
more sophisticated ways of defining the appropriate notifications
service now?

It's not a huge problem, more like a weird quirk.  I have now masked
xfce4-notifyd.service, I hope that works.  (It was a bit annoying that
'disabling' fails silently, but that's a different matter.)

Thanks for maintaining!
-Steven