Qt Speed Gauge Tutorial 3 - Adding GPS

This is part 3 of my SpeedGauge ttuorial. In this part we will add GPS capability, we will explain what is PositionSource element and we will introduce some new JavaScript Math functions. Also in this tutorial you are able to download the source code for Symbian^3 and for MeeGo phones.  Hope you enjoy it.

List of my Symbian MeeGo Qt tutorials

I have decided to write a list of my tutorials for Qt for MeeGo and Symbian^3 phones. This way everything will be in one place I will update this list when I create more tutorials so you can maybe add the page to your favorites. Hit Read more to see the list

Qt Speed Gauge Tutorial 2

Hi, Here is the part 2 of our Qt SpeedGauge tutorial. In this  tutorial we will fix few things we didn't make it in our last one. We will remove ToolBar, add stops so that the needle doesn't go all the way around and we will add Spring animation to the Needle movement. This will result in a wobbly movement of needle. Also We will prevent the screen rotation. During programming I have also stumbled on an error message Cannot open output file Permission denied and collect2: Id returned 1 exit status. You can find out how I handled the situation. If I got your attention read on.

Qt SpeedGauge Tutorial 1

As I promised here is the first part of the SpeedGauge tutorial. This will be a series of tutorials. By the end of series you should know how to create an app that uses GPS of your Symbian and MeeGo Phone. As before we will use Qt Quick, QML and JavaScript for this. Firstly we will create the app for Symbian^3 phones and then we will adjust the app so it will work on MeeGo. It will need only minor adjustments.

Speed Gauge tutorial

Hi all,
New version of my app is out. SpeedGauge is now v1.2 and is available for Symbian and MeeGo. Along with it you have tutorial explaining how to develop app like that for Symbian^3 and MeeGo using Qt QML. By buying this app you will support all the tutorials I have written so far. Both versions are available for download on Ovi Store. Here is version for Symbian^3 phones and here is MeeGo Version of SpeedGauge. So stay tuned! Click on read more to find out about the app and the tutorials.

Change default icon in Qt for Symbian

So you have finally completed your application for Symbian phones using Qt. Congrats. But when you install the app on your phone you get the default icon. You are wondering "How do I change the icon of my app?". If you don't change it you will be stuck with the default green icon with letters Qt. I have also enclosed the two icons in  SVG-Tiny format for you to download and play around. In this post you will also find a link to advices from Nokia on how to create the icons for Symbian, MeeGo and their other platforms.

Amazing Alex This game is not recognized by Game Center issue

As you know Rovio published new game. It is called Amazing Alex. It's a puzzle game. The goal is to get object A and put at the place B. You have different items at your disposal.  The reason I am writing this article is the Error message that prevents people playing the game. When you install the game you get the nagging popup saying "The game is not recognized by Game Center." I am sure that Rovio is working on the fix to this but if you are looking on a quick workaround you are at the right place. View the solution by clicking Read more below...

My first s40 mobile web app

This app is only for available and visible in Croatia. It is useful in Zagreb which is capital of Croatia.

Getting started with Windows Phone developnment part 2

I have found some more resources for getting started with developing for Windows Phone. I am just putting it here so it will be easier to find it for me, and maybe for you :) You should definitely read my first article about starting to program for Windows phone 7 if you haven't already.
Getting started with Windows Phone developnment

I have found flowing resources for learning Windows Phone 7.5 :

Getting started with Windows Phone developnment

UPDATE: 06.03.2012. I have seen all the videos. I definitely recommend these for anyone that want's to start with Windows phone 7 Mango


I have found great video tutorials for getting started with Windows Phone Development. If you want to start but don't know how these will be great for you. It will explain everything from beginning like where to download Visual Studio for Windows phone, how to install it and how to develop apps for phones. These are even great videos if you are trying to learn programming in general. Programming for mobile phones is nice entry point to the world of programming.
The course is divided in four days. First day explains basics. Even if you don't understand the basics of programming the instructor will explain what are variables, how to use loops and if statements. On the fourth day you will create completely functional app that uses GPS and stores chunks of text to the phone persistent storage.
The videos are published 11th ff November 2010. That is 11/11/2010 for all those who are struggling with the names of the month like I do :) These videos don't cover Mango but it doesn't matter. All that you will learn here you can use in Mango as well. These are great place to start. You will learn C# by watching these tutorials.

Definitely check out Education tab on the create.msdn.com

cs193p fall 2011 Assignment 2 Task 1 solution - iPhone Application Developnment

Hi,
I am having pretty hard time understanding the assignment 2 of the iPhone Application Development fall 2011. Starting point for this Assignment is right after you watch The Lecture 4- Views. You can also watch Xcode and Source Code Management because the same code is entered again.  After you made modifications to the Calculator Brain you should update your app so that all of the things from Assignment 1 work here as well.

Lets get started. I will be honest here. I read the assignment few times and I didn't understood it completely. I had few questions. One of them is: how should a user enter a variable inside the Calculator's program? I was looking at the screenshots and I saw three new buttons for variables A,B and X? Does this mean there will be only three variables? After reading whole assignment few more times I think that other variables are possible via the external API. You can probably send as many as you want using the NSDictionary and variableValues from the task one. So I stopped asking myself all those questions and start programming. If you have a different explanation feel free to share it.

cs193p fall 2011 Assignment 1 - Extra credit solution - iPhone Application Developnment

Continuing with the Assignment1 of the Stanford's CS 193P iPhone Application Development.  Fall2011 edition. This time I have solved Extra Credit part of the Assignment 1. I didn't manage to find a solution to these assignments so I am not sure if they are correct. I would appreciate your ideas and thoughts in comments below. If you have missed be sure to read my previous post that solves the non Extra Credits part of the Assignment 1:

cs193p fall 2011 iPhone Application Developnment Assignment 1 solution
Once again big thank you goes to Stanford and Paul Hegarty for creating this great video tutorials.
Nuff' talking. Lets get to work.

TASK 1.
1. Implement a “backspace” button for the user to press if  they hit the wrong digit button. 
This is not intended to be “undo,” so if  they hit the wrong operation button, they are
out of  luck!  It’s up to you to decided how to handle the case where they backspace
away the entire number they are in the middle of  entering, but having the display go
completely blank is probably not very user-friendly.
My Solution:

cs193p fall 2011 iPhone Application Developnment Assignment 1 solution

I am going to post a solution to Assignment 1 from the Stanford's CS 193P iPhone Application Development. The reason I am doing this is because I want to learn. I am following the CS 193p and I am trying to learn how to develop for iPhone and iPad. I am trying to solve the Assignments and I would like to verify if my solutions are correct. I am hoping that someone will Google this out, take a look at my solution and warn me if I made a mistake. Also I tried to find a solution because I wanted to compare my solution against someone else just to be sure that mine is O.K. So I am looking forward to your advice how to improve my solution. I hope I will learn from that.
I am grateful to Stanford University and Paul Hegraty for shearing  this great learning materials for everyone to enjoy for free.
Click read more to see the solution.

Program received a signal "SIGABRT"

This article is moving away from Qt SDK, but it is still on the track with idea of development for mobile devices. You will encounter the error
Program received a signal "SIGABRT"
from the title of this article if you are playing with Xcode and you are trying to develop for iOS. If you ever received such an error you will notice that it escalates to the main.m file that most of the time you as an developer didn't even touched. There is no universal answer on how to solve error causing this but I am about to share with you a trick I learned recently that will help you find out what is causing this error. Hit read more to read the entire article.

plugin cannot be loaded for module Cannot load library The specified module could not be found.

Hi, recently I had problems with a similar error from the title of this post.  The complete error is here:
plugin cannot be loaded for module "QtMobility.sensors": Cannot load library C:/QtSDK/Simulator/Qt/mingw/imports/QtMobility/sensors/declarative_sensorsd.dll: The specified module could not be found.
     import QtMobility.sensors 1.1 
Your error can be a little bit different from this. The text colored green can be different from the one you see. It all depends what resource you are trying to access in your code. Here is another example of the problem number 2:

plugin cannot be loaded for module "QtMobility.location": Cannot load library C:/QtSDK/Simulator/Qt/mingw/imports/QtMobility/location/declarative_locationd.dll: The specified module could not be found.
     import QtMobility.location 1.2  

Another one of these errors can look like this- problem number 3:
plugin cannot be loaded for module "QtMobility.systeminfo": Cannot load library C:/QtSDK/Simulator/Qt/mingw/imports/QtMobility/systeminfo/declarative_systeminfod.dll: The specified module could not be found.
     import QtMobility.systeminfo 1.2 

At the end of this article you will solution for these and similar errors.
If you still haven't figured it out this is one of those Qt Quick tutorials. You will need Qt SDK used to program for Nokia phones, Windows, Linux and few other platforms in order to see this error. I am using Qt SDK 1.2. For a solution, continue reading this post

Nokia 803 Camera phone, is it last Symbian phone?

I have read this on GSM arena today. There are rumors that next Symbian phone will be the last one. It will be camera phone and successor to N8. I would be called Nokia 803. It will probably be announced at MWC starting 27 of February this year. So more info will flow soon.

Some of the rumors are:

How to update to Nokia Symbian Belle

It seems that the Symbian Belle update is rolling out. Nokia suite offered me to update my N8 to Belle. You have to have Nokia Suite 3.3 in order to upgrade. There is great video tutorial on how to upgrade to Nokia Belle on Nokia support YouTube channel.
Look at the Nokia Update video from this post. On the the left you can see the video that shows you why you should update. Nokia Belle Update - same phone, new experience.
Click on the read more to find out which Nokia phones can be upgraded to Belle and how to upgrade to Belle.

How to download and install Qt SDK 1.2

I have created new video for the YouTube showing you how to download and install Qt SDK 1.2 from scratch. The video is for installing on Windows 7 but if you are using Linux of Mac OS the process is the same so the video is is still worth looking.

Qt SDK is cross platform framework for creating applications. You can create apps for Windows, Linux, Mac OS but this blog focuses on apps for Symbian and MeeGo phones. Read more about Qt on Wikipedia.

Firstly you should download the installation file. You can get it:
http://www.developer.nokia.com/Develop/Qt/Tools/
just hit the blue button Download Qt SDK.

Upgrade Qt SDK 1.1.4 to Qt SDK 1.2

I have created video on how to upgrade Qt SDK 1.1.4 to Qt SDK 1.2 released 1st of February 2012. You can use this method even if you have older version of Qt SDK installed. You can check out what is new in this version in my previous post:
New Qt SDK 1.2 is available for downloa

You will know that update has completed successfully if your version after the update is Qt Creator 2.4.1 based on Qt 4.7.4. built on Jan 26 2012. To check wich version of Qt Creator you are using go toHelp > About Qt Creator.

Here goes the video. Maximize it and enjoy.

New Qt SDK 1.2 is available for download

Yesterday new Qt SKD 1.2 is released. It targets Symbian devices and Nokia N9. If you are coding for phones you will still use Qt 4.7.4 API. On the other hand if you are a desktop developer you will be able to try first release of 4.8
Nokia mentions that with new SDK 1.2 comes new Qt Creator version 2.4, but I already have that installed on my laptop and I am using Qt SDK 1.1.4. Maybe because I updated my version?
Qt Mobility API 1.2 should also be new adding support to Bluetooth and NFC. There are also 20 new Qt Mobility examples you can access from Welcome screen. Debugging agent CODA is updated to version 1.0.6. Read the full article about Qt SKD 1.2 and download installation.

Programming with Qt Quick Video presentation

While back I have posted an article about videos I found about Qt Quick and QML. They were from Qt Developer Days 2010. Today I have found a newer version of the video from October 17th 2011.
The videos are presented by: Justin Noe from ICS. I find the videos interesting and easy to follow. The examples and the presentation are the same as the last one, but slightly updated. The presenter is easy to listen. He is a native speaker and his voice won't put you to sleep :) Definitly recomend watching them if you haven't watched the video from my older posts.

Getting Started - a Qt fast track 1/4 - Overview

I am continuing my selection of Qt educational movies from Qt Developer Days. This video is more up to date then the ones I presented earlier. It is created for Qt Developer Days 2011 that took place on October 6th 2011. The video is presented by Oliver Gutbrod from e-GITS. The video presentation is broken into 4 parts.
I have just watched first part of the four. Programming for mobile phones is not covered in this video. It is just a general video for Qt cross platform programming using C++ and not QML. Watch this video if you want to learn Qt and if you are complete beginner and if you plan on program using C++. I am not going to watch parts 2,3 and 4 because this video was kind of boring and it was too long. All the interesting parts like labs and examples weren't shown :(

Topics covered in this video
00:00:00 Introduction about e-GITS
00:03:00 Overview of the presentation
00:04:12 Fundamentals of Qt
00:05:00 Qt history
00:06:00 Qt Licence
00:08:30 Qt Architecture
00:12:12 Qt Demo & Examples that come wit Qt - This is integrated in Welcome view in QtCreator now
00:15:20 Hello World Application
00:18:00 Using command line, using qmake, copliling
00:20:40 Using Qt Creator - theory
00:24:00 Hello World app using QtCreator hands on demonstration
00:29:20 Debug mode
00:32:00 Qt Documentation
00:35:00 Modules and Include files - Project file
00:46:00 Objects in Qt (QObject, Object terr
00:51:20 Creating Objects
00:54:40 QWidget Model
00:59:40 Widgets inside the widgets
01:07:00 Objects, callbacks
01:08:50 Signals & Slots


You can find the video on:
http://developer.qt.nokia.com/videos/watch/getting-started-a-qt-fast-track-1-4-overview

How to use Button from Qt Quick Components for Symbian

In this post I will present you two videos I have created. The videos are about a simple app for Symbian^3 phones. App consists of three buttons that change the color of the rectangle and the text of the Text element on the screen.
These videos will show you how to create a button and how to detect when it was pushed. You will also learn how to position elements on screen so they look good in different orientations and screen sizes. We are using Qt Quick components in this tutorial. In this article you will also find part of the source code for this project.

HelloWorld Qt App Explained part 2 of 2

While back I created video tutorial that explains code behind Hello World application for Symbian^3 phones. I am writing this post because I have decided to put the source code here. Maybe it will be convenient for someone to look at it. Only the modified files will be here.

In this video I have explained declarative part of the code inside QML file of the Qt Hello World app for Symbian^3 phones.
Covered in this episode:
- QML code explained


This post (and video featured in it) is 3nd part of 3 part whole. You should read 1st and 2nd article before reading this one.You can find them here:
Hello World for Symbian^3 with Qt Quick components done using Qt Creator
HelloWorld Qt App Explained part 1 of 2

HelloWorld Qt App Explained part 1 of 2

While back I have created a video which explains the code behind HelloWorld app for Nokia Symbian^3 phones.  I have decided to write a post about the video. In this post I will also provide the source code from the files covered in the video.

This post (and video featured in it) is 2nd part of 3 part whole. You should read first article before reading this one.You can find it here:
Hello World for Symbian^3 with Qt Quick components done using Qt Creator 

After you finished with this article you should watch part 3. You can find it here:
HelloWorld Qt App Explained part 2 of 2

In the video tutorial I will explain native code and project file of the Qt Hello World app for Symbian^3 phones.
Covered in this episode:
- project file explained: symbian:TARGET.CAPABILITY, CONFIG and SOURCES
- main.cpp file (also called native code): QApplication, QmlApplicationViewer
- using help

ReferenceError: Can't find variable: statusBar

If you get the error:
file:///C:/QtSDK/Simulator/Qt/mingw/imports/com/nokia/symbian.1.1/PageStackWindow.qml:70: ReferenceError: Can't find variable: statusBar
In the Application Output pane you shouldn't worry about it. It is probably the bug that is harmless and will be fixed soon with some future update.
It was bothering me for some time but then I read on Nokia Developer Discussion board that it is probably the bug. You can follow the post on the link below:

http://www.developer.nokia.com/Community/Discussion/showthread.php?232315-pageStack-vs-pageStackWindow-element&p=877956&viewfull=1#post877956

I also wanted to mention that Discussion Board is great place to learn new stuff and to go to if you got questions. Of course first look for an answer and only when you make sure the same question is not asked already post new question. Visit Discussion Board about Qt

Update:
This BUG is reported. You can check comments regarding it below:
https://bugreports.qt.nokia.com/browse/QTCOMPONENTS-1217
It will be fixed in next release.

Video on Animations and Visual Effects in QML

This post continues from an earlier post. Be sure to check it out
Introduction to Qt Quick and User Interaction In QML Video

We are going on with videos from Nokia Qt learning
This video will help you out with Animations and Visual Effectsin in QML.

UPDATE: I have found newer versions of this video from October 17th 2011. These two video files are replaced by 3 shorter and newer ones. You can find my newer post here:

http://mobiledevvt.blogspot.com/2012/01/programming-with-qt-quick-video.html

Here is the video:
Animations and Visual Effects (part 3/4)

Introduction to Qt Quick and User Interaction In QML Video

Hi all,

I have found few interesting video tutorials about Qt Quick and QML. Today I will present you two of them. First video is titled "Introduction to Qt Quick (part 1/4)"
I consider it useful if you want to learn Qt Quick. Video is from Qt Developer days 2010. O.K. so it is not the new video, that is true, but if you are new to Qt Quick this will help you to understand how things work. If the documentation is boring to you this video tutorial is just for you. It has few examples so you can understand what Adam is talking about. I think it is great for beginners like myself.

Second video is titled "User Interaction In QML - User Input and States (part 2/4)"
In this video you will learn:
- to receive mouse and keyboard user inputs from Qt Quick
- signal handlers and property bindings (awareness of user's actions)
- basic understanding of states and transitions

UPDATE: I have found newer versions of this video from October 17th 2011. These two video files are replaced by 3 shorter and newer ones. You can find my newer post here:
http://mobiledevvt.blogspot.com/2012/01/programming-with-qt-quick-video.html

Hello World for Symbian^3 with Qt Quick components done using Qt Creator

Tutorial shows you how to get simple Hello world app for Symbian^3 using Qt SDK and how to run it in simulator. You will learn how to
1. create new project in Qt Creator
2. update Qt creator if there are updates available
3. save your project
4. solve QML module not found issue
5. build and run project in simulator


This code is tested on Symbian Anna and Belle phones. This code was written using QtSDK 1.4.4. and Qt Creator 2.4.0 Based on Qt 4.7.4 (32 bit) Built on Dec 16 2011 at 03:25:42. At the moment of writing this text it was latest version of QtSDK available. With newer versions of Qt the code will probably change and it will get updated. If the code changes the logic behind is will stay the same so this video will be of some use to you.