Gof's weblog Blog de Olivier Goffart

I tend to have lot of windows: between 50 and 100 windows spreads over 9 virtual desktops. My taskbar only show the windows from the current virtual desktop (I don't understand why this is not the default yet).

Switching from desktop to desktop is very fast, but in KDE 4.1, the taskbar take several seconds to update the windows. This is not acceptable for my use. This blog will explain how I did to make it fast and use this as an example/tutorial on how to profile with valgrind/callgrind so KDE developers can keep their applications fast...

Everything is in the title.

^[1]

I have just started my first job. I had the chance to be hired by Trolltech. I'm now working in the Oslo office, in the Qt development team. Actually I'm working on fixings bugs on widgets and dialogs.

Working for Trolltech is wonderful so far.

Long time ago (end of 2006) I developed a patch to use your webcam with the Kopete Jabber plugin. I used the MSN webcam code 'as it' and wrapped it into XMPP XML. ^[1]

Here is the patch against Kopete 0.12 (in KDE 3.5) for those who want it: http://bepointbe.be/files/jabber_webcam.diff

Anyway, it has several negative issue

• This is not a XMPP standard, so it only work with person who have applied the same patch.
• It would be difficult for other client to include it (It was easy in Kopete because Kopete has an MSN implementation).
• Because of that I do not plan to include it in any official release.
• It doesn't use jingle, this is totally unrelated.

The only positive issue of this protocol is that it would be easy to implement it in the MSN gateway. But this has no real interest since only Kopete support it, and Kopete support MSN natively

It could also make happy linuxers that want to use their webcam without using the evil MSN. But they could also use other free conferencing software such as Ekiga.

I've just finished my last year at the university, and got my diploma last week.

Now, I'm looking for a fun job.

I would be interrested to work in a foreign country (from Belgium). In a small company, with fun ambiance.

My interest are embedded or low level programming, but I'm open to almost everything as long as it is in development sector.

Continuing working on free software would also please me, specially for KDE.

As a free software developper, I have acquired a great programming experience. And my studies has provided me deep theoretical knowledge.

If you know a company that could interrest me, or if you are interrested by my profile, just contact me.

Get my CV

In the jabber world, almost every connection between different entities (clients and servers) are encrypted using TLS. But some people claim that it's not enough, because the server can still read the messages. The solution, for paranoic people that can't trust their server, is to use end to end (e2e) encryption, such as OTR.

OTR (for Off The Record messaging) is a protocol that make the e2e encryption easy. But it is vulnerable to the man in the middle attack, specially because the server can read and modify all messages. To prevent against this attack, user must check carefully the peer's fingerprint using another media, but honestly, who does that ?

Recently, Michael Zanetti announced he was working on an implementation of OTR for Kopete.
I have now a working implementation of OTR on the hand. And I decided to break it

That's why I wrote mod_otr . It is a module for ejabberd, which do the man in the middle attack at server level. It will intercept message and decrypt them. It can be used in combination with the mod_logmnesia module which log all messages.

The problem I have with e2e encryption is that it make impossible some other desirable feature such as automatic message history on the server. ^[1] All the proposals of an easy to use e2e encryption suffer from the same problem. The lambda user don't really care about privacy, so they will never check their fingerprints.

Download

The source code of mod_otr is there:
http://bepointbe.be/files/mod_otr-20070329.tar.gz

The instructions about how to install are in the README file

In KDE3, KNotify was already a very powerfull tool used for desktop notification. From the developer point of view this is done in few lines of code. And the advanced user may do almost everything.

Anyway there was still few limitations: The application had no control over the notification once it is fired. No way to add link on the popup or having persistant notification. In Kopete, we had to fork knotify and do some hack in order to add the "chat" link in the popup.

That's why, for KDE4 , I rewritten KNotify almost entirely. It has already more feature than the previous one. I did not anyway redesigned the UI yet. The popup is still as ugly as before, and the configure dialog as complex. But this will probably be improved later.

I've decided to blog about it in order to let developper know about possible stuff in their application.

You probably all know Jabber as an instant messageing protocol. And if you still don't use it, I recommend you to try

But people know less that XMPP (the protocol behind Jabber) is more than just instant messaging. XMPP is a protocol that simply allow you to exchange XML fragments between clients. So possibilities are infinite.

With this post, I want to show to others KDE developers some of the XMPP possibilities that could improve KDE.

KDE4 is a good time to think more about Instant messaging integration into the Desktop. I'm writing this blog entry to help me and others to understand our needs and how we should proceed.

The desktop integration consits of several level:

• In the Address Book : It helps to manage instant messaging information with others personal info. and eventually allow to start a chat or know the online status in real time from the address book interface
• In the Mail client : It consist of showing the online status of the contact we viewing a mail, and add the possibility to reply with an instant message instead of by mail.
• In the File manager : It is the possibility to send a file to a contact easily from the file manager.
• Much others: Now Listening, Web Authentication, Playing games, Voice and video, ...

The first three case are those that interest me in this post. I'll explain how they are done in KDE3, and after I'll see some others approach

Read Next...

So I'm now at planet KDE.

For those who don't know me, I'm a developper of Kopete, but i do some other work over kde, especially in kdelibs, like KNotify or few kde4 work

I don't blog often, and I was only blogging in french until now. (And I will continue, but of course french post will not appear on planetkde) But I have some upcomming posts about the Instant Messageing integration that I'd like to see visible to everybody.