Posts about kde (old posts, page 14)

2010-01-19 14:12

Happy 10th blogiversary to me!

Since yesterday this blog is ten years old so, time for some history.

It all started in advogato where you could still read it today! (Please read it here instead ;-)

Then it moved to PyDS an early python desktop blog platform with a web interface, and was hosted in PyCS, a free service.

Then PyCS kinda died, and I started generating a static blog and hosting it in my ISP's free hosting. That sucked bad.

Then I started my own company, and I had my own servers, so I started hosting it there (even today this blog is completely static HTML!)

Then PyDS started acting weird, so I wrote my own blogging software, which is a real mess, perhaps 25% finished, but it does things exactly the way I like them.

Currently, this blog is syndicated in Planeta PyAr, Planet Python, Planet Qt, Planeta LUGLI, and a couple other places.

This year, I decided to make the blog completely bilingual (English and Spanish), but I hate translating it.

According to the stats I have available, the blog is in average more popular now than ever (but yes, my most popular posts were years ago ;-)


These are the most popular pages in the last year:


  1. I need to write more about Qt and/or start flamewars with clueless IT writers
  2. I need to search for ancient material and deprecate it
  3. Having your own hosting and blogging software is neat
  4. 10 years is a lot of time: 860 posts (or 913, depending on how you count)

2009-10-23 23:27

24-hour app #1: Die Schere, a video editor

I have long known that application development is an arduous process. I have also long suspected one of the reasons it's arduous is the developer. I should be more specific, I am one of the reasons.

That's because I don't know what I am doing, and I don't mean that in the "I am a lame programmer" sense (even if that's also true somewhat), but in the sense that I literally don't know what the app should look like, or what its feature set should be.

So, I have decided to embark on a series of experiments I will call 24-hour apps.

Here are the rules:

  • I shall create a neat application, stable, useful, usable and decent-looking.
  • I shall do it in no more than 24 hours. After that time, it should be at least good enough for a preview release, if not a beta.
  • Those 24 hours can be split in two or three sessions
  • Time spent doing icons, docs, etc, counts.
  • All development shall be public (I am using github)
  • I must have a use for the resulting application, and it should be at least an adequate solution for that problem.

So, what's the first project? I call it Die Schere (The Scissors in german) and it's a video editor.

It's not a kdenlive replacement, it's just the video editor I wish I had when I needed to glue a piece of one video with a piece of another.

In the old, pre-digital world, that was done using a cutter and scotch tape. I want Die Schere to be as useful and comprehensible as that was, but useful for clumsy people like myself.

Here is a video after today's session, which lasted 8 hours:

The basic functions are there, even if lots of work is still needed.

  • You can load clips to work with them
  • You can cut clips (like using a cutter!)
  • You can choose the cut points interactively or by editing a time
  • You can arrange them (like using scotch tape!)
  • You can generate the output video

As a backend it's using mencoder, but there's no reason it shouldn't work with ffmpeg or melt if someone writes 20 lines of code.

2009-10-20 21:31

Simple KDE Trick #2: using remote desktops with avahi, krfb and krdc

Most people nowadays have more than one computer. Often, you are using one, and would like to do something in another. In this video, I will explain how trivial it is to do that without leaving your seat in a modern Linux using KDE.

We will use the following:

  • Avahi, a zeroconf implementation to let you find your computers in your network without worrying about IP addresses, DNS, etc.
  • krfb, the KDE Remote Frame Buffer. This is a program to share your desktop over the network.
  • krdc, the KDE Remote Desktop Client, a VNC, RDP client, which is what you use to see a desktop shared via krfb.

I am sure users of other operating systems or desktop environments will say they can do it just as easily. In that case, feel free to do your own videos ;-)

Keep in mind that accessing remote desktops over the internet is a whole different beast, and this solution is not meant for that case.

As usual, this video was recorded using qt-recordmydesktop. There was minor editing using mencoder.

The computer used is the original Asus eee PC 701 4G, so you can see this is not exactly a hardware-intensive operation. I find the eee's small screen is great for this kind of full-screen demo, because it's not big enough to drown the important parts.

2009-03-17 21:10

Translations coming

The spanish translations of most sessions of "PyQt by Example" are almost done, thanks to several volunteers.

Tomorrow I will upload at least one.

If anyone wants to translate them to other languages, I will be happy to include those too.

2009-03-16 10:02

Qt 4.5

Doing a routine update in my desktop, I was surprised to see Qt 4.5 is now in extra! Way to go Arch!

I had a bad start, because all fonts were broken, but after running fc-cache -fv as root and my user it looks ok again.

In fact, it fixes a bug that has been annoying me for a year.

Performance seems to be snappier. That may be a bit subjective, but things like the animations in krunner now are really quick and smooth while before they were jumpy.

And... I can try to make flash work in uRSSus! Yay!

UPDATE: it just started working:


2009-03-12 00:59

Session 5 is slightly delayed

I planned to have it ready for today, but my current consulting job (migrating a firm from Exchange to FLOSS) is getting a bit gnarly (mostly because of Outlook 2000) (Yes, I know).

It may be done this saturday, maybe next tuesday, I just don't know yet.

2008-11-01 10:16

Blogging from Latinoware again

Last night while eating one of the Python Brazil guys told me about the Lightning Talks session taking place today.

Since I am basically insane, I was convinced to do my first lightning talk:

  • In spanish in front of a purely brazilian audience
  • Creating it while having breakfast 1 hour before the event
  • After exceeding the allotted 50! minutes 2 days ago

So, in short, I was terrified. I got there, sat at the back, start listening.

I was 4th in order.

1: doctests (nice)

2: pronounceable passwords (nice)

3: MVC in gtk... I didn't understand a word, and ran out of time.

So, I am now thinking nobody will understand me at all, so I will slow down, run out of time, and will then give the worst lightning talk ever.

I'm next up. My topic: how to build a spreadsheet in 5 minutes.

Amazingly, it worked rather well, the "MC" asked me for a copy of the code, and said it was a neat example. Noone looked horrified or ROFLing, so I am at least somewhat happy about it.

Here is the code for you, too: ssin5min.tgz

I would do it again. But if I am doing it again here, I am learning portuguese first.

2008-10-30 16:59

Blogging from LatinoWare

Just finished speaking about PyQt programming in LatinoWare.

It went ok, but I ran out of time, so no Q&A, and I couldn't show about 20% of the code. :-(

Anyway, here is the code in its different stages, so you can see the "evolution" of a simple PyQt app. I will probably turn it into a real tutorial in a few days and post it.

Here is the guide I was using for myself when doing the presentation:

    1. App backend (1/
    2. Basic window with a treewidget Columns Task/Date/Tags
    3. Compile archivo .ui, show how it works
    4. Template for
    1. Load backend data in the task list
    2. Show interaction is broken
    1. Explain signals/slots
    2. Show difference between 1/ 2/
    3. Explain autoconnect, show on_lista_itemChanged
    4. Show task persistence working
    1. Fix tree decorations
    2. Make items editable
    3. Explain changes in on_lista_itemChanged
    4. Explain the problem with editing date and tags inline
    5. New idea: use a dialog to edit tasks (editor.ui)
    6. Explain layout managers
    1. Show changes in
    1. Actions
    2. Show actions in designer
    3. Show actions in
    1. Tray
    2. Show tray class in
    3. Show tray behaviour
    4. Show differences in

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