Re: Proposed changes to gnus-notifications.el

["Basil L. Contovounesios" <contovob@tcd.ie>]

Michael Albinus <michael.albinus@gmx.de> writes:

> The patch seems to assume that notifications-notify works
> everywhere. That's not the case, since it depends on D-Bus it runs only
> for GNU/Linux systems.

Thank you for pointing this out.  I had wondered about it while
preparing the patch but could not find a description of what happens
when notifications are not supported, other than the usual
"notifications-notify returns an integer ID".

Does notifications-notify return nil in this case?  If so, I would like
to document this.  If not, wouldn't this make sense?

What is the best way to determine whether notifications are supported by
the current Emacs instance?  I skimmed through (info "(dbus) Top") and
(info "(elisp) Desktop Notifications"), as well as through the syms of
dbusbind.c, dbus.el, and notifications.el, but did not find any clear
answers.

Currently, gnus-notifications.el checks a) directly whether
notifications-notify is fboundp, and b) indirectly whether
notifications-notify returns nil.  Even without notification support,
(a) should always be true after loading the library, right?  So the
question is whether (b) is a sufficient condition.

PS Should gnus-notifications.el be extended to support
w32-notification-notify?

PPS Would it be possible/welcome to provide a common interface for both
notifications-notify and w32-notification-notify?  At the moment it
sounds like programmers need to choose between the two depending on
system-type.

Thanks,

-- 
Basil