A blog by Jonas Finnemann Jensen

May 19, 2012
TabControl: Plugin for switching tabs in gedit
Filed under: Computer,English,Linux by jonasfj at 4:11 am

Whilst gedit isn’t the fastest, smartest or most fancy editor out there, I often find my self using it. With toolbars hidden and menu bar gone (unity), gedit is a neat little thing. It always works, and whilst it lacks many features compared to vim, the features gedit does offer, never pops up because I accidentally pressed some key.

The one thing about gedit that I do however feel is missing, is the ability to modify shortcuts. For example switching tabs with “Ctrl + Tab” and “Ctrl + Shift + Tab”, and closing tabs with “Ctrl + F4″, feels as natural as browsing the web in Firefox.

Luckily, it’s possible to install plugins for gedit, I recently found a plugin call Control Your Tabs, that allows you to switch tabs with “Ctrl + Tab”. However, it does tab switch in most recently used order, instead of switching tabs by order in tabview.

I had a quick look at the source for Control Your Tabs, which turned out to be slightly complicated. While I could hack the source to fit my needs, it turned out to be faster and simpler to just write my own gedit plugin.
So here it is TabControl, 50 lines of python now hosted at github.

The plugin switches tabs with “Ctrl (+ Shift) + Tab” based on their order in the tabview. And on top of this it allows you to close the current tab using “Ctrl + F4″. You can find files and installation instructions in the github repository.

The plugin is really short and simple, so if  you want a shuffle feature for switch tabs (or whatever), this could be a good place to start. Otherwise I’d definitely recommend taking a look at the gedit plugin documentation.

August 24, 2010
Turning OpenOffice Math into a visual formula editor
Filed under: English,LibreOffice,Linux by jonasfj at 2:40 am

I’ve spend most my summer working on my GSoC project, which was to create a visual formula editor for OpenOffice Math. Currently, formulas are entered in OpenOffice Math using a plaintext command language, this can be efficent and easy for power users, however, it’s an absolute show stopper for most casual users. So I’ve spend my summer writing a visual formula editor for OpenOffice Math, you can see demonstration here:

I participated in GSoC for Go OpenOffice, which is a project that maintains a set of patches on top of OpenOffice. Go OpenOffice is the OpenOffice version distributed with OpenSuSE, Ubuntu and other distros, it is allegedly a lot better than the official OpenOffice release. And also available for Windows.

Hacking OpenOffice have been a very exciting experience. I haven’t worked on a project so large and complex before. It easily takes 2 hours to build OpenOffice and the sources and binaries fills about 13 GiB. Luckily I didn’t have to rebuild everytime I had to test something.

The visual formula editor, see video above, is not production ready yet. That is it needs extensive testing and a few extra features… However, I plan to keep working on it. You can read more about it’s features and current status here.

I don’t think I’ll keep updating that wiki page, but rather post some updates here once in a while. If you are eager to help test this feature when it comes that far, feel free to leave a comment with your email…

August 26, 2009
Working on Pwytter in Google Summe of Code
Filed under: Computer,English,Linux,Pwytter by jonasfj at 12:44 am

This summer I’ve been working on Pwytter as a part of Google Summer of Code. My project was to separate the backend from the frontend and make a new user interface with PyQt. In my original propsal, I also wanted to do a GTK frontend, however, this was dropped in exchange for a more polished Qt frontend (I do have the basics for a GTK frontend lying around, if anybody is interested, but it’s far from usable).

While writing a backend for Pwytter I also created some abstractions for micro-blogging services, so that Pwytter supports multiple accounts and multiple services (currently Twitter and With this new backend all the messages are also cached in an sqlite database, enabling Pwytter for work while offline.


I also added theming support to the Qt frontend I wrote for Pwytter, above is a screenshot of Pwytter running the “Twitter-like” theme (as you can see have also be translated, so far only to Danish). Pwytter uses WebKit to display tweets, users and other types of content, thus themes can customize the GUI using HTML templates and Qt stylesheets. Documentation for writing such themes can be found in the project wiki, I plan to write an article on subject when this Pwytter branch is released. So far this Pwytter branch is still under development, and interested developers can find install instructions in the project wiki.

December 15, 2008
RaptorMail, an encrypting GMail client
Filed under: Computer,Linux,School by jonasfj at 2:30 am

Tomorrow, I’m finally turning in my P1 project, that’s the first semester project, at Aalborg University. The project is about RSA, and usability of encrypting email clients, and as a part of the project we’ve implemented an encrypting email client for GMail. In Python, with PyGTK and SQLite as backend, e.g. access mail while not online.

Anyway, I thought I’d publish the report here for anyone to stumble upon. Honestly it’s not that great, it’s written in English and is subject to some serious gramma issues, as we’ve been pretty busy actually getting it ready… For those who does not know what a P1 project at AAU is, it is a project conducted by a group of 4-7 students. Most of the education at AAU, happens through these kind of projects, which is kind of nice and gives a lot of freedom. But just for the record, I have not written the entire report myself, so do not blame me all the horror that may be found within it… :)

Enough about the report, during the project we also wrote an encrypting GMail client, called RaptorMail – don’t ask why. A GMail client is actually quite interesting, if I managed to find the time, it would be real nice to nail the last few bugs and integrate it with GPG… An application to access GMail through a non-webinterface while still maintaining the same feature set would be nice to have. And cacheing all mail for offline usage is an absolute killer-feature.

But I’m afraid I have a lot of other small projects on my mind too, so actually getting it out there is probably not going to happen. But if anybody is looking for a way to synchronize and interface GMail with a local database from Python the “gmail_cache” module I’ve written for this project is fairly comprehensive and well documented.

December 29, 2007
SimpleECDSA, a simple implementation of ECDSA in C
Filed under: Computer,English,Linux,School by jonasfj at 2:32 pm

2 weeks ago I did a school project on ECDSA (Elliptic Curve Digital Signature Algorithm). At HTX we have to do a project that goes beyond the curriculum, we must combine two subjects and do an individual project about something we find interesting. I decided to combine mathematics and programming in a project about ECDSA. Personally I think it was great fun, but perhaps I have a twisted sense of humor :)

Anyway, I’ve publish my report here, it’s in Danish though. But I did also write an implementation of ECDSA in C. The implementation is called SimpleECDSA, though I must admit it not very Simple anymore. It uses GMP as integer library, and uses the standardized curves cryptographic operations.

The comments in my source is in English, though I did translate them to Danish, before delivering my paper. Anyway, I still have the source with English comments, so I thought I’d post the source here.

As I had a little spare time this holiday I’ve configured the source with the GNU build system. It my first tarball created with Autotools, and it’s mostly hacked together of snippets from the automake and autoconf manual. But it works and the package compiles, and “./configure” complains if GMP isn’t present. I did also manage to get “make check” to run my internal tests, so I think it’s pretty good, considering the fact that is my first package build with autotools.

If you’ve any comments, bug-reports or questions to my packaging or SimpleECDSA, feel free to leave a comment. SimpleECDSA is ofcourse released under GNU GPLv3, and can be downloaded here:

August 30, 2007
Volume normalization with Amarok
Filed under: English,Linux,TheLastRipper by jonasfj at 10:08 pm

Some users of TheLastRipper has requested integrated volume nomalization (Issue 61). While I admit that I’ve noticed the volume changes between tracks, I’ve never really bordered to find a solution. But since others had similar issues, I decided to take a look at it. I ended up looking at ReplayGain, a project that aims to add a tag, containing volume information, to all songs. Then read the tag at playback and determine the volume. Though the value of the tag must be calculated first.

As this seams like a big feature, and as argued by Andreas in the issue tread, it’s probably not a feature for TheLastRipper. Nevertheless it doesn’t mean that the problem should be fixed, just that it should be done elsewhere. This is also good, since you entire music collection doesn’t necessarily origin from TheLastRipper. The solution is to implement this feature at playback level, meaning in your audio player.

For those of us running Ubuntu and using Amarok, this can be done easily. First open Amarok, choose “script-management”, Click download new scripts. This will open a dialog showing the newest, most popular and most downloaded script for Amarok. Just install the script called ReplayGain. Once this is installed you’ll have to install some dependencies with Synaptic. I’ll try to list those I think is needed: python-kde3, mp3gain, vorbisgain, flac, python-xml

If you enter the script-management in Amarok again, you can enable the ReplayGain script. Enable it, select it and click “Settings”, you can tweak the ReplayGain script a little here. Once your done with that leave the settings, and ReplayGain will print a small popup, telling you which optional dependencies you are missing. I’ve probably forgot to list some of them, you may find them in Synaptic if you think you need them. Though I haven’t found “aacgain” or “replaygain” in the Ubuntu repositories.

Well, you don’t need “replaygain” or “AACGain”, unless you, like me, have AAC music. Actually I’ve just bought my first AAC music from iTunes. I haven’t used iTunes before, but I thought I’d give it a try since they started releasing DRM-free content. So I installed iTunes in my virtual machine, and copied the AAC files back to my Ubuntu system after they were downloaded. First I must say, the quality of iTunes plus files are very good, and the files has ID3v2 tags (other mp3’s I’ve bought online did!). It’s sad that iTunes doesn’t run on Linux, Apple could at least offer a web interface for iTunes plus.

Well, if you have AAC encoded music, you’ll need AACGain, it’s not in Ubuntu or Debian repositories. Actually I couldn’t find any .deb packages for it anywhere. So I decided to make my own. You may download my ACCGain package here. Feel free to contact me if you want the source package.

Once you’re done installing dependencies, and have enabled the ReplayGain Amarok script, you can right click in your playlist and choose “Apply Replaygain tags”, I selected “To entire collection using album tags” it took a while but the volume was automatically determined by Amarok afterwards.

July 27, 2007
Min installation af Ubuntu 7.04 Feisty Fawn
Filed under: Computer,Dansk,Linux by jonasfj at 1:24 pm

Jeg ved godt at feisty fawn har været ude et stykke tid, men jeg ville ikke opgradere under mine eksamener og lige pludselig havde jeg sommerferie og sommer job… Derfor var det først her i weekenden at jeg fik installeret feisty fawn. Jeg valgte installation frem for opgradering, da jeg havde leget lidt mere med min edgy installation end hvad godt er.

Installationen var nem og hurtig, det hele gik meget smerte frit. Denne gang var network-manager allerede konfigureret lige efter installation. En lille sjov detalje:
Kort efter at have installeret Ubuntu kunne jeg læse på at toshiba havde tilbage kaldt flere batterier. Senere på aften havde Ubuntu opdaget at min laptop var en toshiba og den gav mig en fin advarsel om at mit batteri kunne være tilbage kaldt. Advarselen så sådan ud:

Ubunut Toshiba recall message

Som det kan ses var den på dansk, og kom forholdvis kort tid efter nyheden om batterierne. Jeg synes det er en fed service fra Ubuntu. Jeg kan hilse og sige at min Windows partition ikke kan finde ud af at advarer mig, og det selvom den er fuld af bloatware fra Toshiba (Bruger den kun til legacy applikationer og end smule Windows udvikling). Det skal lige siges at mit batteri ikke var tilbage kaldt, men det var tæt på.

Det eneste problem jeg havde efter installation af Ubuntu Feisty Fawn var sove funktionen, eller det der hedder “afbryd” når man logger ud at gnome, når jeg kom tilbage efter en suspendering til ram virkede det trådløs netværk ikke. Jeg kunne ikke komme på trådløst netværk med min IPW2200. Jeg kiggede lidt på nettet og det vidste sig at hvis man tilføjer “ipw2200″ til modules i /etc/default/acpi-support, så bliver driveren reloaded efter suspendering. Altså ALT+F2 skriv “gksu gedit /etc/default/acpi-support” ENTER, find linjen MODULES=”” og ændre den til MODULES=”ipw2200″ og gem.

En anden lille ting man måske kunne tænke sig at gøre efter installationen af Ubuntu, er at installere pam-keyring. Gnome-Keyring spørger normalt om din hoved adgangskode til nøgleringen, hver eneste gang et program skal have fat i et password som er gemt. F.eks. network-manager der bruger gnome-keyring til at gemme passwords i. Ved installation af pam-keyring vil standart nøgleringen blive låst op ved login. Det er vigtigt at din nøglering har sammen password som det du bruger til at logge ind med. Derefter skal du installere pam-keyring med synaptic eller bare “sudo apt-get install pam-keyring”, og tilføje følgende linjer til filen /etc/pam.d/gdm :

auth optional try_first_pass
session optional

Hvis man går lidt op i hvordan systemet ser ud, kan man installere en thumbnailer til openoffice filer. Jeg fandt en god en i en tråd på ubuntuforums, den benytter et thumbnail af openoffice dokumentet og sætter et lille gennemsigtigt ikon hen over billedet, så man kan se om der er tale om et tekst dokument, en præsentation eller et regneark. Jeg har opsummeret tråden fra ubuntuforums til et lille arkiv med installation instrukser. Resultatet ser sådan ud:

ooo2-thumbnailer Test

April 8, 2007
Howto: Export Monodoc to GoogleCode Wiki
Filed under: Computer,English,Linux,TheLastRipper by jonasfj at 12:39 am

Lately I’ve been working on a small project called TheLastRipper, hosted on A few days ago I started wondering about how to document a Mono/.Net application, not because there’s much to document in TheLastRipper or worth documenting for that matter. Anyway I ended up looking at some pages in the Mono wiki, it seams the best way of generating documentation, wasn’t by using documentations comments handled by the C# compilers /doc argument. This is the method most (former) Windows developers are familiar with, once documentation comments have been exported to Xml by the C# compiler, it can be generate into a CHM file using programs like ndoc. Instead the Mono project generates documentation from binaries, which gives them Xml files containing all methods, classes etc. Later on you’ll then be able to fill out the empty comments. This way documentation of code development have been completely separated.

You can read the discussion between the two different documentation formats in Mono wiki. I’ve chosen a middle path, by exporting my current documentation comments to monodoc. I won’t discuss the process of documenting an application using monodoc, the process is already well documented in the Mono wiki article I’ve linked to a few times. What I will discuss is how to parse you monodoc Xml to WikiMarkup that can be hosted on GoogleCode. Mono already comes with an application to parse monodoc to plain html, called monodocs2html. I’ve made a modification of the application, resulting in monodocs2wiki. If you have your documentation as monodoc Xml you can parse it to WikiMarkup, by doing following:

  1. Download: monodocs2wiki
  2. Extract the
  3. Checkout the /wiki/ directory from your GoogleCode svn repository
  4. Run: ./monodocs2wiki -source:./docs/ -dest:./wiki/

    Where ./docs/ is the base path of your monodoc xml files (Containing an index.xml file). And ./wiki/ is the /wiki/ directory you checked out of svn.

  5. Commit your /wiki/ directory to svn, and view you documentation in you GoogleCode wiki.

The /wiki/ directory of your GoogleCode svn repository, contains all the pages in your GoogleCode wiki. You may wish to change a few things in the template, perhaps using a different label than just Documentation. Take a look in the README file if you what to know more about customization. The current template in the monodocs2wiki application, uses the markup used in the wikies at Google Code. You may modify it, I think it would be easy to port it to another WikiMarkup. Any questions, feel free to leave a comment or mail me…

April 7, 2007
Digital signering med GPG
Filed under: Computer,Dansk,Linux by jonasfj at 12:39 am

For et stykke tid siden byggede jeg min første deb pakke med TheLastRipper. Sådan nogle pakker skal altid underskrives digitalt, derfor legede jeg lige lidt med GPG (GNU Privacy Guard). Men jeg fik ikke rigtigt offentliggjort min public key, så det hele var lidt nytteløst. I dag har jeg så endelig fået tid til at lege lidt med GPG.

Måske jeg skulle starte helt ved bunden, GPG og/eller PGP som er den kommercielle implementering, er et system til at digitalt underskrive og/eller kryptere ting. Det virker ved at man genererer et nøgle sæt. En offentlig nøgle og en private nøgle. Data der er krypteret med den private nøgle kan kun dekrypteres med den offentlige nøgle og omvendt. Dette kaldes asynkron kryptering. Hvis jeg så kryptere en besked med min private nøgle, kan den kun dekrypteres med min offentlige nøgle. På den måde kan man verificere signaturen (normalt kryptere man ikke hele beskeden, men kun en hashsum af den). Omvendt kan en anden person også kryptere en besked med min offentlige nøgle, hvorefter beskeden kun kan dekrypteres med min private nøgle. Hvilket sikre at det kun er mig der kan læse beskeden.

Når, men jeg startede med at installere SeaHorse, en grafisk brugerflade til GPG. Derefter var det forholdvist enkelt at genererer et nøgle sæt. Man kan også tilføje et billede af sig selv til signaturen. Problemet kom da jeg ville offentliggøre min offentlige nøgle, dette gør man ved at synkronisere sin(e) nøgle(r) med en offentlig nøgle server. Men jeg kunne ikke få SeaHorse til at synkronisere med nogle af serverne, jeg fandt også en bug rapport på dette på Gnome’s BugZilla. Løsningen var faktisk ret enkel, højre klik på din nøgle og vælg “export public key”, derefter skal man blot uploade filen til f.eks. Så venter man et par timer og pludselig er alle keyservere i verden blevet synkroniseret.

Et lille tip, man kan installere et plugin til Firefox der hedder FireGPG. Så kan man verificere mail i Gmail, og alle andre hjemmesider hvor man skulle støde på nogle. Du kan f.eks. prøve om du kan verificere dette blog indlæg, du kan finde min offentlige nøgle på, bare søg efter Du kan verificer min blog post med følgende .txt fil: Digital_signering_med_GPG.txt, du skal blot åbne filen i Firefox med FireGPG installeret: Marker alt, højre klik og vælg FireGPG > Verify. Hvis denne ikke vil verificere så tjek at du har importeret min offentlige signatur og at du benytte tegnsætningen: ISO-8859-15…

February 4, 2007
Filed under: Computer,English,Linux,School,TheLastRipper by jonasfj at 11:33 pm

The last few weeks I’ve been working on a project called TheLastRipper, an audio stream ripper for It’s not all done yet, but it’s getting close. It’s written in C# and I’m planing to port it to both Windows and OS X using both MS .Net Framework and Mono. Currently there’s only a Mono/Linux client, it should be possible to port it to gtk#/Mono/Windows pretty fast, but I think I’m going to create a native Windows.Forms interface instead.

Anyway, I’m here by making the first alpha version available for testing. Now I’ve never packaged anything before, so there’s no guaranties on the package. But it’s probably better than the tarball, since the tarball only installs two .Net assemblies, and no mono wrapper script in /usr/bin/ or menu entries.
If you know anything about debian/ubuntu packaging please give me some feedback on the packaging:

By the way, the project is part of a school project I’m doing in technology about copyright, music and luxury. This is relevant because in Danish copyright law, it’s legal to rip unencrypted audio streams, like, but please don’t take my word for it, I’m not done with the project and I’ll look more into the Danish copyright laws later. The Danish Ministry of culture has a piece on copyright and audio stream ripping.

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