The Qt Ambassador Kit and my first impressions of Nokia C7

A few months ago, I submitted my personal audio player project Audactile to the Nokia’s Qt Ambassador program. They seem to have liked it and I was accepted into the program.

The good surprise is that they sent me a Qt Ambassador kit: a t-shirt, some stickers and a Nokia C7 mobile phone. The pictures I took aren’t very good, but here they are:

Qt Ambassador Kit

The stickers are beautiful and I’m thinking of where I’ll put them. :) The most attractive item is, obviously, the Nokia C7. It runs Symbian^3, and it was the very first time I could use a device with it. My first impressions:

  • The capactive touch screen is very good. I already test devices from Apple, Motorola, Sony Ericsson and HTC, and I can say that it’s very sensitive. It has support for pinch zoom on images.
  • Symbian^3’s UI is way better than its predecessors. It’s like a mix of the old Symbian (since it’s still Symbian…), iOS and Android. You have non-intrusive alerts at the top of the screen (like a desktop) instead of the old ugly rectangles that older versions of Symbian used for their notifications. The menus still are a bit confusing, but are better than my old Nokia E71’s menus.
  • The AMOLED display is very sharp, its colours are brilliant and the images look great. You have an ambient light detector that changes the display’s illumination, like my MacBook does.
  • The stereo sound from its back outputs are clear and powerful. Nokia knows how to put a good sound into its devices.
  • Its camera has 8.0MP, dual flash and face recognition. It can record videos in HD resolution, but I haven’t tested it yet.

Nokia C7 has a very powerful hardware. Its software is pretty cool and as friendly as Android IMHO (unfortunately Nokia will use Windows Phone instead of Symbian in some time…). The mobile phone was given to me with a short letter asking to develop for it, so that’s what I’ll do. I’ll try to write some Qt application for Symbian, and I’ll report any progress here. :)

Listing the packages on Debian/Ubuntu in one line

You can use dpkg to list all the packages that are selected on your Debian or Ubuntu system:

# dpkg --get-selections

But today I needed a way to list only the installed packages in just one line, so I could copy their names and use apt-get to install the same packages on another system. So I used the following command:

# dpkg --get-selections | grep "[ \t]*install$" | sed 's/[ \t]*install$//g' | awk 'BEGIN { packages = "" } { packages = packages " " $1 } END { print packages }'
acpi-support-base acpid adduser apt apt-utils [...] long list of packages [...] xsltproc xz-utils yelp zenity zlib1g zlib1g-dev

You can use the output above to easily install the same packages on another system using apt-get install <packages>.

Cool tools to avoid suffering with Windows

After two years working only with Linux and Mac OS, I received a new task that requires using Windows for two months (only two months, happily). It’s hard to get back to this bugful, unstable and confusing world: I do believe Linux and Mac OS are easier to use than Windows, that big world of icons that lead to icons that lead to icons that lead to nowhere, but I’m doing my best.

I tried to find a set of useful and free (as in “free beer” and/or as in “free speech”) tools to make my work easier. They are:

Classic Shell Setup

I don’t know why Microsoft removed the toolbar from Windows Explorer since Windows Vista, but this application tries to put it back there. It also allows you to get some customisation of Start Menu, and get a simple, fast and useful menu like the Windows 9x/ME/2000 times.


I like gedit and kate, and the native alternative for Windows is Notepad++: a good editor for plain text files, like source code.


With support for MSN/Live/whatever network, Google Talk, ICQ, etc. Pidgin is one of the best chat clients. I’d rather use it than the fancy MSN Live Messenger.


Why use iTunes or the suffering Windows Media Player if you can use Winamp? It has a clean interface, a good way to organise library (although it’s a little bit iTunesy) and a simple playlist, everything in the same screen. I really love the good and old Winamp.


Winamp can play some videos, but I think VLC is a better tool for this job. Besides, it has a great support for a huge range  of video formats and features for users with any needs and all experience levels.

Firefox 4.0 pre-beta released

Lifehacker shown a screenshot of the new Firefox 4.0 pre-beta for Windows. Here it is (Mozilla names Firefox beta versions “Minefield”):

Nice, isn’t it? So, I downloaded the new beta for Linux, and it looks like the screenshot below. I had to set the tabs to be on top; Windows version brings this for default (at least the one that I installed using Wine).

Firefox 4.0 pre-beta on Linux

Compare. The screenshot below is Firefox 3.6.4.

Firefox 3.6.4 on Linux

It’s a little far from the mockups of Firefox for Linux at Mozilla’s site. I hope I can see it soon. :)

VolumeSlider’s tooltip misbehaviour

I was developing a Qt application that makes use of a Phonon::VolumeSlider object. But after clicking the mute button beside of the VolumeSlider and verifying its tooltip, I noticed it was showing the wrong volume. A video can explain this better than me:

If you want to reproduce this problem, you can download its source code as a Qt Creator project. Please keep in mind that it’s the source code with errors!  But there’s a workaround to this problem:

1. In the class where you create the Phonon::AudioOutput whose volume is handled by the VolumeSlider, put this:

connect(audioOutput, SIGNAL(mutedChanged(bool)), this, SLOT(handleMute(bool)));
connect(audioOutput, SIGNAL(volumeChanged(qreal)), this, SLOT(handleVolume(qreal)));

2. Create the slots you used above using the following code:

void MainWindow::handleMute(bool mute) {
    if (!mute) {
void MainWindow::handleVolume(qreal volume) {
    outputVolume = volume;

3. Declare the slots and the outputVolume variable in your header file:

    qreal outputVolume;

private slots:
    void handleMute(bool mute);
    void handleVolume(qreal volume);

You can download the fixed source code. I don’t know if this behaviour is the expected in Qt, but I filed a bug for it.