Qt SDK Updates, now with better Qt Component support

September 30, 2011 at 12:03 pm | Posted in Information, Software Development | Leave a comment

For those of you in the know, the Qt SDK has just been released on developer.nokia.com. However, as itt might not have grasped your attention, there is also an online update that adds better support for MeeGo 1.2 Harmattan to the SDK.

One very useful thing that has been added is support for the Harmattan Qt Components in the Qt Simulator, so now you can do more without the need to access a device. Here is a screenshot of the template Qt Quick component application running on a Windows 7 environment.

Qt Components running inside the Qt Simulator

Qt Components running inside the Qt Simulator

I have been reliably informed that the Qt Components now also work on the desktop. So what are you waiting for? Start updating your Qt SDK now.

Simple morse player for the N950

September 26, 2011 at 9:56 am | Posted in Software Development, Uncategorized | Leave a comment

Remember the old fashioned movies with spies and sailors going dit-dit-dah to each other. Well now you can relive that nostalgia with the “Morse Code Player (source code available below).

This application was supposed to be a quickie that just does a few simple things, but in the end it turned out to be a headache due to my limited understanding of the threading behaviour of QML and Qt C++. The core of the application consists of two C++ classes the MorsePlayer that converts text to morse, and the ToneEngine that creates a audio tone.

The MorsePlayer class is relatively straightforward QML binding class that has a bit of logic for converting text to morse, and then for call the ToneEngine to play the necessary tone. The ToneEngine class is a bit more complicated; it copies logic from the AudioOutput example for generating a simple tone. The tricky bit (that took several half days to solve) was working out that the audio handling code (ToneGenerator, QAudioOutput) needs to run in its own thread, with its own event handler othwerwise the audio output blocks. Additionally. MorsePlayer needs to send signals to the ToneEnginer otherwise the audio blocks. Another tricky bit is the use of resume and suspend to start/stop the audio output, this is simply because QAudioOutput start/stop takes too long to create the initial buffers etc.

The current code is not perfect, it still occasionally has buffer underflows (any help here would be appreciated). As an application, it needs some extra features like a way to set the morse code rate, and tone frequency. Additionally, it could do with more features like haptic feedback and other clever ideas. I could also clean up the code more (add more comments, play with the design, make it a QML plugin) so I am just releasing it “as-is” as a simple example of tone generation from QML.

A simple wiki page with historical source code.

A direct link to the source tarball.


MeeGo on an N900

August 23, 2010 at 11:10 am | Posted in Information, Software Development | Leave a comment

For those of you who have not been following the MeeGo on the N900, MeeGo has been ported to the device.  Being a cynic, I waited until I got it to work before posting about this activity.  It is not that difficult to get the MeeGo Handset UX on the device, but it may take some additional massaging (in my case I needed to flash the kernel twice).  Here is a screenshot in glorious technicolor:

There are good instructions here.  I took the easy approach and just downloaded the proprietary ready-made images from tablets-dev, used the windows 32 diskimager to write to the MicroSD card, and a linux laptop to flash the kernel.  I am sure there is an easier approach, but this one worked for me.

Ari Jaaksi’s key note at the Linux Collaboration Summit

April 14, 2010 at 9:39 pm | Posted in Information, Software Development | 1 Comment

Hi all,

Ari just delivered a key-note “MeeGo: A Free & Standard Linux OS for the Mobile Industry” and he pushed two major themes: user experience and openness.  The other thing made very clear was that the Meego platform will be more attractive to application developers, with better tools etc. to make their lives easier.

Another interesting tit-bit is his Meego to-do list:

  1. Develop in the open: This really means release code earlier than products.  This means that if you connect the dots, you can reverse architect the product characteristics, and can make your own decisions and change if you want it.
  2. Product quality and focus: For a phone there is a surprising amount of effort goes into finalization, it is a lot of work.  We need to focus on quality, it is getting easier as more people join the project.
  3. Keep governance simple: This should be based on contribution, and not a political committee.  We need it to be simple.
  4. Help others to join Meego: We have not been so good so far, this is changing with more people onboard.
  5. Move fast: Push code out earlier than we feel comfortable.

Other issues were mentioned regarding governance, etc. Basically the issue is that we are starting now and are heavily reliant on Intel/Nokia at the moment, but this will change over time as more companies will join (and a lot just did  see here).


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