Functional Programming in C++

Back to code, back to the activities [code, openSUSE, Nepomuk, Zeitgeist]

Published by Ivan Čukić in the KDE development section, on 15 March 2011

I was (more than) a bit silent lately. The thing called ‘life’ happens and you get dragged away from your computer ;)

The strange thing is that lately, I’ve been doing more artwork than coding, so the new openSUSE 11.4 is fully stripe-themed and (IMO) looks awesome.

I don’t use openSUSE, but that doesn’t mean I should avoid contributing to one of the best KDE experiences out there, right? :) (Ok, this ended up being a contribution even to Gnome installs which required quite a lot more work, but I don’t really mind)

The additional thing that made my day was the openSUSE review on the Linux Action Show. Chris (one of the hosts) didn’t stick with the original theming, but chose to use the standard blue Stripes with the Slim Glow plasma theme. The only thing better than being the default is being a choice over the default. :)

Coding again

Well, after reaching the artwork stardom :), I decided it was the time to return to my true calling. The first thing in line were a few Lancelot bugs that needed attention, and that don’t depend on the future libplasma2 development. No new features yet - but stay tuned - there should be some soon.

Activities

The main reason I got involved in developing the activities system in the first place was to have different favourite applications, different usage statistics (files opened, browser history etc.) in different activities. It always seemed daft to have Inkscape, Gimp and similar in the appmenu when I’m doing some non-GUI C++ coding.

The thing that will be responsible for that kind of stuff is the kactivitymanagerd. It currently (4.6) only controls which activities exists (along with icons, names, running/stopped states…), and which one is currently selected.

The next big thing is making it track the user’s behaviour and things that are accessed on per-activity bases. At first the data was supposed to be stored in Nepomuk, but Sebastian raised concerns that it might slow down the database too much (needs to be tested) since it would require a vast amount of data to be stored.

The second option was to use Zeitgeist as proposed by Seif (the lead Z devel). Now that we have a usable Qt API for it, the second option became viable as well.

Since I’m not famous for betting all my money on one horse, I decided to refactor the current code to be able to handle different backends, and use the one(s) that is(are) available.

Features

Currently, the following is planned for the backends:

	Nepomuk	Zeitgeist
Top rated[1] files[2] per (app, activity) pair	yes	yes
Top rated files per application	yes	yes
Top rated files per activity	yes	yes
Files accessed on a specific date	no[3]	yes

Rating will be automatically calculated based on usage
Files, locations, web pages, contacts etc.
If the tests show that Nepomuk doesn’t slow down when saving each event individually, this will be a ‘yes’

No-backend support

Naturally, if you don’t want to use Nepomuk nor Zeitgeist, you’ll not get the rating goodness. But that doesn’t mean you’ll be left out - per-activity recent documents, places etc. are still a possibility.

Ok, this was a bit longer than I expected, sorry for that :)

Tino L.
Id be more impressed if the Linux Action guys werent world class douchebags who are not any better than shock jocks and who have an aversion to free/libre and spend quite a bit of time crapping on the GPL and the desktops. There is constructive criticism and there is sensationalism. With so many great Linux podcasts, it has been very easy to avoid them. This is the first mention I probably read this year. Thank god.
kboite
"different usage statistics (files opened, browser history etc.) in different activities"
What's your solution for being able to search the browser history both per activity and globally (if i dont remember on what activity i was when i suddenly googled that thing) ?
It would be more than nice to have some sort of activity inheritance/composition to handle that issue.
Imagine i've got two activities : "School" and "Internship" : they both belong to the virtual "Work" activity. Then i can track and browse the usage statistics for school related stuff or for the whole work (or global) activity.
Ivan Čukić
@<a href="#comment-25305" rel="nofollow">kboite</a>: So far, we are not planning to make a hierarchy of activities - it was considered, but it would need a hell of an UI to configure.
Essentially, handling of stuff can be: 1 - completely separate resources per activity 2 - rank the resources from current activity higher, but show others as well 3 - have the ability to tell which activities are related (if we think of a way to do it with a nice UI)
At the moment, 1 is the main solution while the others can be added later.
Ivan Čukić
@<a href="#comment-25253" rel="nofollow">Tino L.</a>: I've been watching them only for the last few episodes, and while they sometimes don't really know what they are talking about, they didn't seem rude towards free sw.
Eric Mesa
Yes, dude. This sounds awesome! I'm already itching to try activities once KDE 4.6 hits the official Fedora repos because it makes a lot of sense for my workflow. Your idea makes it make even more sense and is a great reason for those that don't need activities now to switch to using activities over virtual desktops. (if you only have one VD per activity)
Please do your best to get this into KDE 4.7!
gaboo
It's starting to take shape and will leverage all the cool stuff that has been happening in the 4 series. Keep it up!
Znurre
I recently started using activities (just 2 for now, development and non-development). Activity sensitive favorite applications, etc. would be an awesome addition to this! Great work, and indeed, your artwork rocks.
baxeico
Wasn't Nepomuk designed to deal with stuff like this?
I don't know what kind of storage/database is used by Zeitgeist, but it would be a pity if we needed yet another storage mechanism (we already have many).
Anyway, I can't wait to have this stuff on my desktop. I already started using activities, and I find it awesome!
uetsah
Will KRunner also use the per-activity rating information to sort results?
CSousa
Activities love... Great!
I'm already using activities for two months now and I can't stop using them even if they have a lot of small bugs.
A feature I still miss is some visual way to switch between activities and move windows around them. For example, something like Desktop Grid effect showing the running activities, and having small icons for the stopped ones.
Maybe I'll do some mockups and put them on KDE Brainstorm forum.

Imagine when all this goodies you are working are available! Activities will be a killer feature.
I bet MAC OS will copy it someday.
Ivan Čukić
@<a href="#comment-25175" rel="nofollow">baxeico</a>: It depends how you look at it :)
Nepomuk is about semantic data and meta-data. If you consider the desktop events to be a part of that, then yes.
But the potential problem is that there will be *a lot* of desktop events. The thing that needs testing is whether virtuoso/nepomuk will be able to handle that amount of data.
Zeitgeist, on the other hand, is designed with a sole purpose in mind - storing the desktop events in a sqlite database.
Ivan Čukić
@<a href="#comment-25176" rel="nofollow">uetsah</a>: It will if someone (maybe even me) implements it. It should be a priority task IMO.
@<a href="#comment-25177" rel="nofollow">CSousa</a>: The new UI (yet again :) ) is in plans. It will be one of the topics at Tokamak5.
uetsah
@Ivan: Sweet... :-)
Alejandro Nova
Speaking about this, can you replace the Lancelot usage tracking stats with Zeitgeist? I see lots of potential in Lancelot, waiting to be unlocked (the Kopete integration replaced by Telepathy, for instance).
I am already running the Zeitgeist tracking system in my KDE 4.6 setup, and I don't notice it, it's fast and eats almost no RAM.
Ivan Čukić
@<a href="#comment-25334" rel="nofollow">Alejandro Nova</a>: Well, as I suggest for all KDE apps, Lancelot will use activities service to do the usage tracking.
The current code will be removed.
The activities service can be thought of like Phonon - a thin layer above Nepomuk, Zeitgeist or a dummy recent documents model.