Good news ahead for all the people who don’t like forums in general, but still want to know what’s going on.

The Feed option has been available for a while and makes it possible to create personalized newsfeeds to follow specific forums and subforums. That’s nice, but sometimes it’s not enough.

If you follow Planet KDE you might have heard about the recent improvements on forum.kde.org, including the better search system. It’s faster, it allows you to search for common words (such as ‘kde’) and it offers more options to give more accurate results. However, that’s not all. Now it’s also possible to display the results as a newsfeed, which means that you can make highly customized feeds with posts that you’re interested in.

Below I’ll show you have to make such a feed with an example. If you want to play around with it yourself,  head to Search.

Update October 10, 2009: Feed has been removed. You can use Search to archive the same thing.

Creating a customized feed

In this example we want a newsfeed for new ideas in Brainstorm that are tagged ‘plasma’. An idea is simply a topic in the Brainstorm forum, and using the tag system we can find Plasma-related ideas that don’t necessary have the word ‘plasma’ in their title or description.

1. Go to the Search page.
2. Search Query
   Enter plasma in the tags textbox. You can enter multiple tags if you want, just remember to separate them with commas (tag1,tag2,tag3).
3. Search Options
   Select KDE Brainstorm in the list. You can select multiple forums by dragging, or clicking on the items while holding down Ctrl. We don’t want to search in subforums, so choose No for Search subforums.
   To only search for ideas (and not their comments), we choose First post of topics only in Search within. This may seem strange, but don’t worry – this will hopefully be fixed in a not too distant future.
4. Display Options
   In this example we don’t need to change any settings in this section. For now only Sort results by and Limit results to previous work for feeds.
5. RSS Options
   Finally! Choose the feed format you prefer (for example RSS 2.0) and a Style (HTML is fine if you’re unsure). You’re finished with the search options – hit the Search button.
6. Add feed to your feed reader
   Now you just have to copy the URL and use it to create a new feed in your feed reader (for example Akregator).

Adding a feed to your feed reader

Your feed reader will handle the rest, and you can stay up-to-date without visiting the forums.

By now, you should have a fairly clear idea of how to make your own custom newsfeed using the new search features. There are more plans to bring the KDE Community Forums closer to the desktop – hope you like it!

Do you remember this guy? In my previous blog post I asked the KDE community what you thought it was, and after many good guesses Kmetamorphosis finally nailed the answer: it’s for voting on questions in KDialogue.

Another person commented that “if it looks like a spinbox, it acts like a spinbox then probably it’s a spinbox. Only it doesn’t apear to be spinning”. Right, I guess we can call it a spinbox. If you’re the type who likes to spin spinboxes, I have good news for you – the first KDialogue opened recently, which means that you can spin to your heart’s content¹ over in the KDialogue forum!

Don’t forget to take the opportunity to ask Jonathan Riddell one question or four – the more spinboxes, the better right? As someone said, there are no stupid questions (as long as they follow the rules) – only good ones and less good ones. And that decision is in your hands.

Take me to the first KDialogue now »

¹ You can only vote on each question once, though.

Let’s see if you’ve done your homework lately – can you guess what this is?

Hint: it has something to do with the KDE Community Forums.

(If you’re a regular visitor to the forum channel, #kde-forum on freenode, you’re not allowed to answer. )

The end of summer

Whew, long time no see! After the summer vacation I’ve had my hands full, so I never found the motivation to sit down and write this. Sorry about the delay.

This step marks the end of summer and will show you what I’ve achieved in these two months. But first something about Qt.

The start of Qt programming

To start off, I need to say this:

Qt is easy.

When I was a child, I made some GUI applications in Visual Basic. It was very easy to get started with – you place some widgets on a form, double click on one (e.g. a pushbutton) and write some code to be run (e.g. when the pushbutton is pressed). Simple.

Even with my limited knowledge of Visual Basic, I could do pretty much. The code was usually awful – I preferred to store values in (invisible) textboxes instead of using variables, just to mention one thing – but they actually worked.

Now, I would argue that Qt is harder to get started with, probably because it uses C++ (yes I know that Qt has a lot of bindings for other languages). It’s easy to lay out widgets in Qt Designer, but it’s far from obvious what to do afterwards. The workflow is probably clearer if you use Qt Creator, but I haven’t tried it yet.

To my aid I had my books, and I soon found that I was able to do a lot in Qt that I didn’t know how to implement in Visual Basic. The Qt layout system makes it easy to lay out widgets and takes care of the position and size of widgets when you resize the window. To make an application with menubar and toolbars, you derive from QMainWindow and add a few objects and functions.

Derive. That’s something you’ll do a lot in Qt. An excellent example of object-oriented programming.

If you want an object A that have the same properties (talking about general properties, not Qt specific) as object B, but further specialized, you can derive A from B. For example, I want a cat that can play Go. Most cats can’t do that, right? A normal Cat is not enough. But I don’t need to create a new Cat from scratch, I can make the new class inherit from Cat (i.e., it is derived from Cat):

class  GoCat : public Cat
{
    Q_OBJECT

public:
    GoCat(QWidget *parent = 0);

private slots:
    void playGo();
};

This is just standard C++. Q_OBJECT is included because we want to make use of Qt’s meta-object system, including signals and slots (read more here).

In a similar fashion, we can build GUI applications by using the classes Qt provides. A Main Window with menubar, toolbar and system tray? No problem, QMainWindow takes care of it. If we want to make a custom widget that consist of two Qt widgets, for example a QSlider that’s connected to QLCDNumber like in this tutorial, we simply derive from QWidget.

MyWidget(QWidget *parent = 0); is a typical constructor declaration for derived classes. We then pass the parent pointer to the base class (the one we derive from) in the constructor:

MyWidget::MyWidget(QWidget *parent)
     : QWidget(parent)
[...]

In this example  (taken from tutorial) MyWidget is derived from QWidget, as you can see.

(Qt’s parent-child mechanism is out of scope for this article. I touched upon the subject in step 2, when I wrote about pointers in Qt).

Result

As promised I’ll show you the two Main Windows (derived from QMainWindow, of course) that I’ve done by following my two Qt books.

In The Book of Qt 4: The Art of Building Qt Applications you create a simple text editor in chapter 4. The GUI is done in Qt Designer and the final application looks like this:

CuteEditor

I liked this application. It’s simple – most of the functionality is already in QTextEdit. You need to setup the actions in the toolbar and menubar and implement a few functions functions, such as loading and saving files. Oh, and don’t forget the status bar. That’s pretty much it.

This chapter gave me a good understanding of how to create similar small applications. However, I found the part about the dock window (“Templates” in screenshot) somewhat vague and incomplete. The code wouldn’t compile for me at first – I need to look into it and see if it’s a mistake from my part.

The application in C++ GUI Programming with Qt 4 is more complex. You build a spreadsheet, completely from a text editor (chapter 3 and 4). Well, for most parts at least.

Spreadsheet

The reason I said “for most parts” is because you create some of the dialogs in Qt Designer in an earlier chapter. It’s very nice that you get to reuse them to create your Spreadsheet application and learn how dialogs work. Completing the application was also a big motivation booster – “woah, I could actually make this application”.

That’s unfortunately also the bad thing about this example – to me, it was a bit too complex and it was easy to get lost in details. Yet it’s listed under “Basic Qt”, which I find somewhat amusing.

Another thing I didn’t like was that I couldn’t compile it until I was finished. I prefer to take it in smaller steps, to be able to see what I’ve accomplished after a while. In hindsight, I should have copied example files from chapter 4 (included on CD) to test the application.

Overall I get the feeling that C++ GUI Programming with Qt 4 assumes the reader has more prior knowledge in C++ than The Book of Qt 4: The Art of Building Qt Applications. In my opinion Daniel Molkentin, the author of the latter book, gives a more expanded explanation on some topics, such as memory management (stack vs heap) and how to use Ui files created in Qt Designer. On the other hand, I also appreciate the insight Jasmin Blanchette and Mark Summerfield (authors of C++ GUI Programming with Qt 4) provides and their elegant code.

To summarize, I don’t regret getting both books – so far, I think they work pretty well as complements.

Johan Thelin has been kind enough to send me a review copy of his book, Foundations of Qt Development - thanks Johan! It’s still at my parents’ place but I’ll pick it up the next time I visit them. I’m looking forward to seeing what this book has to offer.

Final words

Everything above (mainly referring to “The start of Qt programming”) is my interpretation. If you find any errors in the text, please don’t hesitate to correct me.

Next time I’ll show you the applications I recently started working on. Simple small applications, very similar to the ones I showed above (but rewritten from scratch). I do, however, have plans to eventually turn one into a plasmoid later.

My lectures have started again, so I’ll have even less time to learn about KDE Development. That also means less frequent steps, which in unfortunate. I’ll try to keep you updated as often as my time (and motivation) allows.

Since a few people have asked me how I recorded the Plasma HowTo screencasts, I decided to post a short HowTo here. And is there any better way to show this than with an animated GIF? I can almost hear you saying “of course not!”, so here we are:

A typical record session

I use byzanz to record my desktop. It works as a GNOME panel applet but can also be used from the command line. Note that it depends on quite a lot of GNOME libraries and requires Composite to work (according to the website).

[Update October 19, 2009: I tried to remove most of the GNOME libs and byzanz still seems to run fine.]

Now back to the screencast above. I usually do the following steps:

1. Open a terminal to run the command. My terminal emulator of choice is yakuake, because it’s very easy to hide and unhide.
2. I use the following command:
   

   byzanz-record --loop --cursor --delay=delay --duration=duration filename


   where delay is the time before it starts recording, duration the duration of the animation and filename the name of the output file. --loop specifies that the animation will loop and --cursor makes sure that it also captures the mouse cursor. As an example, the command in the screencast is

   byzanz-record --loop --delay=3 --duration=8 -c plasma_howto-throw-ball


   (Don’t ask me why I use -c instead of --cursor; I don’t know myself). Enter byzanz-record --help to see all options.

3. I have a timer beside me which I start when I execute the command. After 4 seconds (3 seconds of delay + 1 second when the mouse cursor is idle) I start to do whatever I want recorded.
4. When the recording is done, I preview the file in Firefox to see if it looks good. I’m pretty strict – a small mistake and I redo the recording. For example, the ball screencast I did in the screencast is on the borderline – I accidentally move the mouse cursor one or two pixels after I’m done.

Tips

Finally here are some tips and tricks:

• I created a new user to do the recording. This has several benefits, one being that you can nuke the Plasma config files without hesitation to restore the settings to default. The command to do this is
  

  kquitapp plasma-desktop; rm $KDEHOME/share/config/plasma-desktop-appletsrc; plasma-desktop


  If the $KDEHOME environment variable isn’t set, try to replace it with ~/.kde4 or ~/.kde.

• Disable Nepomuk/Strigi and other stuff that might pop up.
• For me it didn’t work very well to record the screencast with Desktop Effects enabled. You can disable it temporary in System Settings -> Desktop Effects -> Suspend Compositing.
• Configure the task manager to only show tasks from the current desktop. As you can see in my screencast, I keep a Dolphin and a Firefox window opened on my other virtual desktop to quickly preview the results.
• Gwenview also works for viewing the GIF files. However, note that it’ll loop the animation even if they’re recorded without the --loop option. I warn you because I learned this the hard way.
• Most people probably know this, but to run the same command again you just have to press the up arrow (on your keyboard) to go back in history in the terminal – no need to copy and paste the command over and over again. Just make sure that you don’t overwrite a screencast you’re satisfied with! (Yep, it happened to me).
• As you might have noted, my filename (plasma_howto-throw-ball) doesn’t have the .gif extension. There’s actually a reason for this – to avoid overwriting good screencasts, I add the extension when I’m happy with the screencast. Then it doesn’t matter if I accidentally run the same command again without changing the output file name.
• How to find out the duration beforehand? Unfortunately I don’t have any good tips regarding this – I did it the troublesome way and timed it before recording. After doing a few screencasts I had a pretty good feeling of how long it would take.
  If the duration is too long you should be able to remove the last frames, although you have to figure it out yourself – I would just redo the screencast.

You might have seen my previous posts about Plasma HowTos in form of short screencasts. I’m happy to announce that all screencasts are recorded now and uploaded to UserBase. The full article can be found under Plasma/FAQ/HowTo.

If you don’t know what this is all about, here’s a small taste:

How to unlock your widgets

Obviously you can watch the HowTos to learn more about Plasma, but that’s not all: they can also be used to easily answer beginners’ questions in an easy-to-understand and nice-looking way. In forums, for example, you can use the same thumbnail as the one above to link to a HowTo.

Now, let’s spread the screencasts and make Plasma more comprehensible to new users!

Due to the positive feedback I received in my last post, I decided to take the experiment one step further. A page that listed all Plasma HOWTO screencasts – doesn’t that sound good?

My initial idea was to do it on my blog and eventually move it to UserBase if it was well received by the community. However, some people on IRC already voiced interest for such an article on the wiki, so here it is:

Plasma/HOWTO

Currently it’s on my own page, but the plan is to move it to Plasma/HOWTO when more screencasts have been done. As you can see, I’ve only done the first section (Widgets).

Dear KDE community, now I need your help. Are the sections strange? Do you miss a HOWTO? Should something be rearranged? Please help to improve the article! It’s a wiki, so feel free to edit it. However, if it’s something major, I would appreciate if you wrote a note under Discussion first.

Thanks everyone who commented my last post, you motivated me to continue this experiment.

Being an active member in the KDE Community Forums, I regularly see users asking how to do this and that in Plasma. My usual answer is something like “Click on cashew -> [Unlock Widgets] -> Add Widgets… -> drag widgets from the “Add Widgets” dialog to desktop/panel”. Sometimes I also refer to the Plasma FAQ.

This works, but I’ve been thinking about a more… amusing way to give the answer (in lack for a better word). Inspired by the Plasma screencasts on blip.tv, I decided to make a few screencasts. In contrast to those on blip.tv, mine are very short, direct and without any text – they’re meant to simply answer one question.

This is just an experiment, so I’ve only done three so far. I decided to record them in GIF, since most web browsers can handle it out of box. (As a result, the quality isn’t the best – you can’t get everything, right?)

Click on a thumbnail below to watch the HOWTO.

Yep, that’s it. Now I want to hear your thoughts:

• What do you think about the idea?
• Did you like the result?
• Any suggestions on how it can be improved?
• … Do you think I need to unlock the widgets every time? (Yes it gets tiring after awhile; I had to redo the recording a lot of times until I was satisfied).

I’m not very good with licenses, but Creative Commons BY sounds pretty good; that is, you’re free to share and modify. Note that the artwork in the screencasts belong to Oxygen.

For people following my The Road to KDE Devland series, I just wanted to let you know about the current status of the project. Summer holidays are almost over, and I have an exam coming up soon, which means that I haven’t had much time to study Qt or blogging recently. After the exam next week I’ll write step 4 about what I’ve accomplished in Qt – nothing big, but I promised screenshots didn’t I?

Next step is by no means the final one, but when the semester starts I’ll most likely be busy with Real Life™ again. Of course I’ll continue to give you updates of my progress, but be prepared that the time between each step will be much longer.

The interest in the series was much higher than expected. If you’re also working on becoming a KDE developer, I strongly encourage you to share your progress. If you already do, please post a link in the comments and I’ll include it in the next step. Yay.

If you’ve visited KDE Brainstorm, you might have wondered what all categories are for, or how an idea is processed when it’s been posted. So I decided to make a chart that hopefully will answer your questions:

From idea to reality

The Forum Team is constantely working on improving Brainstorm – if you have any suggestions, don’t forget to post a topic in Feedback & Questions; or, if it’s a feature request, why not post it in Brainstorm? Just don’t forget to add the tag “kde brainstorm” to make it easy for the Team to find your idea.

If you have any questions or comments regarding the chart, post a comment below.

Update September 29, 2009: The updated chart can be found in Brainstorm FAQ. Click on “Take a tour“.