Category Archives: KDE

Plasma Active

At the desktop summit, many contributors got a ExoPC from Intel, but the software on it was quite a disappointment. Meanwhile, there is an official release of Plasma Active that fills the gap. So I sat down and installed it on the ExoPC. It really works quite nice and smooth. Applications like Amarok and a browser make it usable to hear music and do some quick internet surfing. I documented the steps in order to get everything up and running.

Running Plasma Active One from the USB Stick (LIVE version)

To get a quick impression, you can download the file plasma-active-one.iso from Then, plug in a USB stick to your computer and run the comand

sudo dd if=plasma-active-one.iso of=/dev/<DEVICE> bs=1M

where <DEVICE> corresponds to the USB stick (in my case, this is sdc). When finished, plug the USB stick into the upper USB port of your ExoPC and press the power on button. Make sure to tap “BBS” immediately and choose the USB stick as boot device. After this, choose the first entry to start the live version of Plasma Active.

Note: As of 2011-10-15, a installation with this live version is not possible (even though some documentation at some point or the splash screen suggest otherwise).

Installing Plasma Active on the Hard Disk

In order to get Plasma Active on your hard disk, you first have to install openSUSE 11.4. To this end,

  1. download the 4.7 GB DVD image of openSUSE 11.4 (32 bit), and copy it on the USB stick (in my case <DEVICE> = sdc):
    sudo dd if=openSUSE-11.4-DVD-i586.iso of=/dev/<DEVICE> bs=1M
  2. plug the USB stick into the upper USB port of your ExoPC and press the power on button
  3. make sure to tap “BBS” immediately and choose the USB stick as boot device
  4. after this, choose “Installation” to start the install process (you need an external keyboard on the lower USB port)
  5. follow the installation routine, choose the KDE desktop, do the partition setup, create a new user account and finally start the installation
  6. copying files takes some time. After this, the system finally boots to proceed with the automatic configuration.
  7. Finally, the system arrives in KDE. (From now on, the USB stick is not needed anymore.)

The touch screen does not work out of the box. Hence, I restarted X from the console with /etc/init.d/xdm restart. After that, the external mouse and keyboard worked (ignore the fact that you might be greeted by 6 crashed akonadi windows).

Once you have the internet up and running, proceed with 1.5 Installation on Balsam Professional or openSUSE. This updates your kernel to properly support the touchpad and replaces the default Plasma Desktop with Plasma Active.

Kudos to the Plasma Active team and all involved contributors and supporters!

PS: Although a text editor is probably not of much use on a tablet PC, KWrite is available :-)

Line Modification System

Some days ago, Dominik implemented a line modification system in the KatePart.
For all who don’t know what that means at all (like me before the DS 2011), here some screenshots.

First, starting with a fresh loaded file:

Now, lets write some lines:

Next, after saving:

Now, lets change some stuff again:

Awesome :)

First I thought: Why to hell do I need such a feature? But after using it some days now, I think it is really VERY useful.

Yesterday I worked in parallel on code that generates integer linear programs as CPLEX files and read the output files (which are > 100000 lines) to find regressions.
I had to manually tweak the ILP files a bit to reveal the reason of my issues and it was just cool to exactly know even after save, which lines in the ILP I touched.
Normally I would have written some comments like \changed… above my modified lines in the output files, but yeah, KatePart does track such stuff now automatically ;)

Even for the much less big source files, it was nice to see:
Oh, I just tweaked that few C++ lines and it did remove the issue, maybe I should look at the lines below/above of that lines, too, for more possible problems?

Therefor: Thanks to Dominik for this nifty feature, I hope others appreciate it, too!

If you want this feature now: Use the guide at’s Get It!.

Coding Style and API Design

Once in a while, there are really interesting blogs, presentations and reports about how to do things right as software developer. This is a quick list of links about API design and coding style:

  1. Designing Qt-Style C++ APIs (Qt4), by Matthias Ettrich, 2005
  2. API Design Principles, extended version of (1), Qt Developer Network (Nokia)
  3. The Little Manual of API Design, an in-depth summary of (1) and (2), Jasmin Blanchette, 2008 (Nokia)
  4. Developing Quality Libraries, presentation of (1)-(3) on the Desktop Summit in Gran Canaria, Oliver Goffart, 2009
  5. How to Design a Good API and Why It Matters, Joshua Bloch, 2007 (Google)
  6. Qt Coding Style, good coding style not limited to Qt, Qt Developer Network (Nokia)
  7. Guidelines for KDE Development, similar to e.g. (6), KDE Techbase
  8. Hall of API Shame: Boolean Trap, Ariya Hidayat, 2011

Thanks to all the authors for sharing & happy reading!