Not for the weak-hearted

My blog has been rather empty lately. It’s not because I haven’t had anything to report, but due to the fact that many things have happened and all sorts of cool things in Plasma Active’s “Activity world” started appearing that I didn’t have the time to write about them.

Today, I’m going to write about one of the smallest things I’ve done lately that will change the world :)

startkde

startkde script had served us quite well for a long time now, and it is still the best way to start your Plasma session. But it has some downsides that we needed fixed in Plasma Active, and some features that Plasma Active doesn’t need.

So, this post is about an alternative approach to start Plasma, a new application called startactive. It is NOT a replacement of startkde, but an alternative. Meaning that it doesn’t do all the things startkde does, while it does some work that startkde doesn’t.

The design

The main goal of startactive’s design was to create a dependency-based system that starts various workspace components.

You can see the dependencies of various systems that startactive invokes in the following graph.

The blue items are meta-modules - they don’t start anything but they make it possible to keep the organization manageable.

Waiting and starting

The system starts all the free modules (modules that don’t depend on anything) at the same time (makes a nice performance boost on both single and multi-core systems), and then waits for some of them to finish until a new module becomes free. When it does, it is automatically started.

There are two ways to see when a dependency has finished its job - 1st - the usual - wait for the process to finish; and 2nd - wait for the program to register its D-Bus service. (org.kde.nepomuk.services.nepomukqueryservice for Nepomuk, org.kde.plasma-desktop for regular Plasma etc.).

Splash screen

Now, when you’re making something that doesn’t need to provide any compatibility with existing systems, you have the freedom to do the things as you see fit. So, I felt free to abandon the old splash screen engines that KDE Workspace used, but to focus only on the QML one I blogged about some time ago. It is now run in-process avoiding dirty ways of communication via X-events and such.

The missing features

startkde does a lot of things, from the initialization of the user’s .kde directory, to fonts, mouse cursors etc.

startactive doesn’t for one simple reason - all of that should be already set up on your Plasma device. All environment variables, Qt plugin locations, directory infrastructure…

Don’t try it

The code is currently located in kde:scratch/ivan/startactive and you shouldn’t use it. Unless you are a really brave soul who doesn’t care if startactive jumps out of the system and start killing kittens in your neighbourhood.

For me, it killed only two older felines, and now it has returned and manages my system with only a few smaller issues. So, if you are brave enough, then continue reading.

To test, you’ll first need to compile it and install with the same prefix as the rest of your kde system, which in turn needs to be in your PATH. Otherwise it will not work.

Then, you’ll need to adapt the module files to fit your setup and finally start the application in an empty X session.

An ordinary startactive will do - it will, by default, start the plasma active module, but if you want to run a desktop session, and change the splash screen theme, you can do something like this:

startactive --modules desktop --splash somethemename

Missing modules

If you notice that something is not started while it should, ping me here or on IRC and tell me about it.

A teaser, again. This time with std:: stuff instead of Qt. Why? Because I can :)

list <string> inputList;

// ... do something to the inputList ...

string first, second;
list <string> outputList;

(QfTuple | first, second, outputList)
                            = inputList.begin();

// or just (and it is safer)

(QfTuple | first, second, outputList)
                            = inputList;

// now, the variables first and second contain
// the first two elements of the inputList, and
// outputList contains the rest

Edit: Sorry for bumping this, WordPress seems to think changing a post title should publish it in RSS again**

QfStringList sentence;

sentence << "TZU"
         << "Anticipate"
         << "the"
         << "difficult"
         << "by"
         << "managing"
         << "the"
         << "easy";

sentence
    .foldLeft(Functions::sum);
// "TZUAnticipatethedifficultbymanagingtheeasy"

sentence
    .map(QF_FUNCTION(QString, toUpper()));
// ("TZU", "ANTICIPATE", "THE", "DIFFICULT",
//  "BY", "MANAGING", "THE", "EASY")

sentence
    .map(QF_FUNCTION(QString, length()));
// (3, 10, 3, 9, 2, 8, 3, 4)

sentence
    .map(QF_FUNCTION(QString, length()))
    .foldLeft(Functions::sum);
// 42

This is not really a KDE post, but rather something that happened and took away two days from me. So, you’re free to skip it :)

Intro

Insanely enough, I decided to completely wipe out my current system and after quite some time reinstall Debian. I completely forgot how tiresome is reinstalling everything from scratch - all the packages needed by KDE SC, all the packages needed by me, and everything else. Even more, I’m used to installing the minimal system, and then installing xorg, …

So, when the initial installation was over, I decided to make a clean KDE build (like I haven’t lost enough time already) - and after a few attempts I managed to install just enough dependencies so that the stuff I want (or work on) works without a glitch.

eeePC as a graphics card

At the time I started to get pleased by my newly refreshed and cleaned system, my screen just went blank, and after a reboot, the computer made quite a few beeps before starting to boot the OS while leaving the screen blank.

One of the capacitors on my graphic card went crazy and had blown up. Since I needed to do some work, I couldn’t allow myself to be without access to the system, and using a much slower (eee)PC with a much smaller screen while my main system lies incapacitated (or incapacitor-ated) was a no-go.

The first solution was to do an ‘ssh -X’ from eeePC and connect my big screen to it. And this worked quite well except that VGA connector didn’t want to allow the full resolution of my screen so the picture was a bit blurry.

The is in a nutshell, the power of Linux and X11.

ATI

After I finished the things I needed to do, I hurried to the last open computer-store to get a new card. The last one left in the store was ATI’s HD6450, so I didn’t have any doubts which card to get.

I have to say that I was thrilled I’m getting rid of NVidia driver problems (although I didn’t really have any :) ) and getting into AMD’s world (after all I haven’t bought a single Intel’s CPU since 80286).

But, as per Murphy’s law, while KWin worked with all fancy effects (via the openGL backend), all openGL programs decided to claim that this driver doesn’t support openGL - at all. Even the simplest examples from the ‘Computer graphics’ course I teach.

After seeking the solution on the intertubes, and trying each and every one, I almost decided to quit and leave it like that. Fortunately, after a while, I /decided/ it was the problem with the fact I need fglrx-glx package which I can’t install because it would break quite a few other packages (and thus apt would uninstall them) including some qt4 stuff which required mesa-glx.

Then I decided to do the dirty thing - to simply overwrite mesa’s libGL.so* stuff with those from fglrx. Usually, this is not really a safe thing to do, but since openGL is a C library that has to conform to a few well-defined standards, all implementations need to be binary compatible, which in turn means those can easily be interchanged.

This and a few radeon.modeset=0 sprinkled in a couple of places made my system fully functional.

Outro

This morning I even decided to tear apart all the components from the case, clean them and resemble the system (cleaning the body as well as the soul - it’s a chán/zen thing :) )

Now I have something that works and feels as a completely new system.

Ok, it is the time for me to blog from Randa and KDE Platform 11 and Nepomuk sprints.

Share-Like-Connect

One of the side effects of the /usage tracking/ is that we now know what document is currently being viewed/edited, so the Aaron’s S-L-C concept can finally come to life without using the fake dummy data.

Tasks Documents applet

This doesn’t exist yet, but when applications start reporting which documents they are showing, we’ll be able to make a fully document-oriented workspace for those that like that kind of stuff.

Zeitgeist integration

We (Nepomuk - Trueg and myself) and Zeitgeist people (Seif and Trever) had quite a few hours spent deciding the best way for the two systems to collaborate and I think we have done well. Apps that support Zeitgeist will automatically support us as well, and vice-versa. So, whether you are using a Gnome application in KDE, or KDE application in Gnome, it will just work(TM).

As you probably already know, I’m a sucker for fall-backs, so I still intend to make this work even if you disable one of the services. And it will work, but badly if you disable both of them.

Contour and Plasma Active

The thing worth mentioning is that I’m now a part-time member of the Contour team at basysKom, so you can expect these things to be finished faster than it was when I had to give focus to other non KDE-related projects.