Week 3: Integrating GNOME Shell with Zeitgeist

["Siegfried-Angel Gevatter Pujals (RainCT)" <rainct eurion net>]

Hey,

I had the last exams on Thursday so now I've finally had some days to
start touching the Shell; not much visible stuff yet, though. Here's
what I've done those last days:

On the Zeitgeist side
------------------------------

 - Familiarized myself with the changes they did in Zeitgeist since
UDS (which is basically a complete database redesign and starting to
use Storm ORM; this broke everything and now we're still getting stuff
to work again, but on the good side the DB is more flexible now and
inspired in Xesam).

 - Finished splitting Zeitgeist into two separate project for the
engine and the GUI (I started this at UDS and moved the engine to a
new branch but still had to remove that stuff from the GUI branch).
Also other maintenance work and bug fixes which aren't relevant to the
GSoC project.

 - Renamed all D-Bus methods Zeitgeist provides (I added the D-Bus
interface before GSoC started officially) so that they use CamelCase
capitalization. Improved the GetItems function so that it provides the
functionality that I need for now (some stuff I'll need later isn't
implemented yet but the "API" already contemplates it).

On GNOME Shell
--------------------------

I've changed the "Recent Docs" panel in the sidebar so that it
displays items from Zeitgeist. Outstanding issues:
 a) Showing a proper icon (currently they only have a placeholder),
more on this below.
 b) What to display below the item's name (where the Applications have
their description)?

For the icon I've thought, they are pretty big so why don't we display
a thumbnail there? I'll need code to display thumbnails anyway once I
implement the main part of the UI (what will be shown when the user
clicks on "More..." in the overlay), so I've been looking at how I can
do this.

Because of discussion in Zeitgeist I've found out about a
specification on how to store thumbnails
http://jens.triq.net/thumbnail-spec/ (which obviously makes sense to
use instead of coming up with something new) and also something
better: http://live.gnome.org/ThumbnailerSpec, a specification for a
daemon which you can ask to generate thumbnails over D-Bus.

Apparently hildon-thumbnail
(https://stage.maemo.org/svn/maemo/projects/haf/trunk/hildon-thumbnail/)
provides a prototype daemon for this spec, so I tried it out and other
that it lacks plugins for several data types (for image/jpeg and
image/png it worked, for text/plain no) it worked fine, so as there's
at least one working implementation which can be used for now I think
I'll have a go at using the API described in ThumbnailerSpec for
requesting thumbnails. I have to talk yet to any GNOME Shell developer
about this though.

Oh, and any ideas on other ways to get icons (be it as an alternative
to this or as a fallback option) are highly welcome!

Next items
----------------

Some stuff I'm going to look at next:

 - More work on Zeitgeist (general stuff, and more work on GetItems's
features I'll need later).
 - Getting proper icons (as I've described above).
 - Replacing also the "Recent Documents" list in the overlay with
items from Zeitgeist.
 - Consider showing Recent and/or Most Used documents for the selected
application in the overlay's "More..." menu for applications.

I'll leave the "More..." section of "Recent Documents" for the end as
that's where I can do the most stuff and in many different ways, so I
want to have the most straightforward things done first.


Regards,

--
Siegfried-Angel Gevatter Pujals (RainCT)
Ubuntu Developer. Debian Contributor.