Antony Pranata's Forum Nokia Blog

A New Symbian OS Book - Quick Recipes on Symbian OS

antonypr — Thu, 01 May 2008 21:39:50 +0300

It's Friday now. Is it a good time for announcement for a new book?

Today, I proudly announce a new Symbian OS book from Symbian Press, Quick Recipes on Symbian OS. The book is available for pre-order from Amazon today.

The book is authored by Michael Aubert and a bunch of other people that you may be familiar with, i.e.:

Alexey Gusev
Myself (a.k.a. antonypr)
Jo Stichbury (the author Symbian OS Explained and The Accredited Symbian Developer Primer)
Jenny Mulholland
Jukka Silvennoinen (a.k.a. symbian_yucca)
Tanzim Husain

What this book is all about? Unlike existing Symbian OS books, it is structured like recipes book. Each recipe solves one specific problem, for example: how to write data to a file, how to load JPG/PNG images, how to handle incoming message, how to dial a phone number, etc.

All the recipes are categorized in 10 different technology areas, i.e.:

File Handling
Contacts & Agenda
Networking
Messaging
Graphics and Drawing
3D Graphics
Multimedia
Telephony
Connectivity
Location-based Services

The example source code will be available soon on Symbian Press web site soon (once the book has started selling).

For now, you can download the source code of our Quick Recipes Taster booklet. The booklet is basically the stripped-down version of the book.

Using Accelerometer on Nokia N95

antonypr — Thu, 01 Nov 2007 22:58:17 +0200

The blogosphere has been hot since yesterday about accelerometer on Nokia N95. Apparently, Nokia 95 has a built-in accelerometer. You can find discussion about this on:

YouTube video showing RotateMe application on Nokia N95. It shows how to get an iPhone-like effect.
Moving Ball example from Nokia Research Center. It shows a simple moving ball application that is controlled by accelerometer.

In the latest firmware, we can even get the raw data from the accelerometer using Sensor Plug-in for S60 3rd Edition. You can download the plug-in and start experimenting with accelerometer on Nokia N95

The usage of the API is very straightforward. You just need to create an instance of CRDAccelerometer and then receives the accelerometer data from its observer, MRDAccelerometerObserver. Note that the API still has "RD" prefix in the class name and file name; so it is still an R&D version.

Having access to accelerometer raw data gives us many possibilities. For example, we can use it as control for games. Arto Holopainen has shown similar idea; but he is using human muscle to control games.

As developers, the first question that you may have is, how to process raw data from the accelerometer. You need to know about "g" unit, which is a standard unit of acceleration. There are several papers that discuss "g" unit in accelerometer, for example:

Accelerometer and How They Work - from Texas Instruments
Accelerometer Primer - from MEMSIC

Free Booklets from Symbian

antonypr — Wed, 02 May 2007 20:22:02 +0300

These free booklets from Symbian are intended for developers. They discuss various development topics in hand and consie format. They are normally less than 100 pages long. The terms "free" here mean you can download it from Symbian web site and get the printed book for free.

Currently there are 9 booklets plus some translations to Chinese and Japanese and the list is growing. Here is the current list:

Essential Symbian OS booklets

Signing Tips
Coding Tips (also available in Chinese, Japanese and Korean)
Performance Tips (also available in Chinese and Japanese)

Using Symbian OS booklets

Getting Started (also available in Chinese)
Java ME on Symbian OS
P.I.P.S
Carbide.c++
Data Sharing Tips

Essential UIQ booklets

UIQ Essentials Getting Started (also available in Chinese)

Always Remember that Mobile Device has Limited Battery Power

antonypr — Tue, 24 Apr 2007 05:30:50 +0300

Recently I had a strange problem with my Nokia E61 device. The device needs to be charged every day. I was quite sure that the battery was still okay. The device was relatively new, about 1 month old. Before it happened, I could use my device for 3 - 4 days without charging.

I thought it must be from one of the applications that I have installed recently. I suspected one of the applications that I have just installed. Then, I decided to uninstall it (I am not going to disclose the name of the application). What happened after that? The problem with my battery was solved. I can use my device normally.

Why did it happen? Apparently, the application installed a server that runs in the background. I am not sure what the server is doing, but it empties the battery very fast.

As a mobile developer, how can we avoid this? Forum Nokia has a good paper, S60 Platform Effective Power and Resource Management. I won't repeat everything here; just highlight some of the important points:

Continuous timers, ticking too frequently (for example, more than once every five seconds), can adversely affect power consumption.
If an application is moved to the background, it should, where appropriate, be paused and timers should be stopped.
The backlight shall not be kept on without a good reason. It is turned off after a short period of inactivity is to conserve power; therefore overriding the system defaults should only be done if there is a compelling reason.
Communication technologies, such as Bluetooth and WiFi, should be used carefully, as there is always some drain on the battery when any network interface is active.
The camera has to be powered off when it is no longer used. Even if the camera is not being actively used, it is still consuming power if it is not powered off.

Please, always remember that mobile device has limited battery power. It is not the same as desktop world where the power is "unlimited".

Example Code of Using XML Parser in Symbian OS

antonypr — Sat, 14 Apr 2007 00:05:09 +0300

A couple of weeks ago, I had a plan to write an article and example code of using XML parser in Symbian OS. It seems that another Forum Nokia Champion, Paul Todd had the same idea. He posted a nice article about XML parser in Symbian OS 9.x to Forum Nokia Blogs. It's good that I don't need to write the same article. :)

What I would like to share here is a complete example code of XML Parser in Symbian OS. The example code can be run on Symbian OS 8 and 9 phones, which means it can be compiled under S60 2nd Edition FP2/FP3 SDK or S60 3rd Edition SDK. I am planning to release the same example code for UIQ3 soon.

Click here to download my example code of XML parser

The example basically parses an XML file, dataexample.xml, to the main window. The content will be displayed on CEikEdwin control (see picture below).

Note that the code is written as an example; thus it is designed to be as simple as possible. Do not use it in the production code!

One more thing, this is not the official example code from Forum Nokia. It is just my personal example code.

Screenshot for Symbian OS Goes Open Source!

antonypr — Wed, 28 Feb 2007 07:24:47 +0200

Actually I don't want to reveal this today because there are still some other things to do. Unfortunately (or may be fortunately) cyke64 has smelled this new project. That's why; I decided to officially announce it today.

Ladies and gentlemen... I am proudly announcing Screenshot for Symbian OS goes open source. The source code is hosted by SourceForget.net at http://sourceforge.net/projects/screenshot-sos/. The project is distributed under GPL (General Public License) scheme.

Why do I decide to make the application as an open source project?

I want to give this application to the Symbian OS community out there. I have chosen GPL scheme to make sure that everybody can receive the copy of the binary as well as the source code free of charge.
As you may know, there are more and more Symbian OS devices coming out. Since I cannot buy and test on all of those devices, I need a way for people to helping me to debug and fix any problem and/or binary breaks.

As a starting point, I publish the source code and binary (unsigned) of the beta version of Screenshot for Symbian OS version 2.70.

I hope that my small contribution is useful for the whole Symbian OS community.

Shortcuts Tips in Carbide.c++

antonypr — Sat, 30 Dec 2006 23:40:43 +0200

After using Carbide.c++ for quite a while, I would like to summarize some shortcut tips in Carbide.c++. They should apply to both version 1.0 and 1.1 as well as Eclipse IDE. Hope you find them useful too... :)

Editing

Ctrl+F - Find/Replace.
Ctrl+K - Find next -> Be careful, it is not F3, like many other applications.
Ctrl+L - Go to line -> Be careful, it is not Ctrl+G, like many other applications.
Ctrl+Space - Code completion. For example, if you type "do" and press Ctrl+Space, the IDE will display code template for "do while" loop. Furthermore, you can display a list of class member by pressing Ctrl+Space too. Normally, they are displayed when you type ".", "->" or "::" after a member class variable. In some cases, you may need Ctrl+Space, for example when you move to another line and then come back to the previous line.
Ctrl+Shift+Up and Ctrl+Shift+Down - Go to the next or previous methods and/or functions.

Navigation

Ctrl+F6 - Navigate to the next file editor. This is always useful shortcut, especially when you are working with several files at the same time.
Ctrl+F7 - Navigate to the next view, for example you can switch from the file editor to file tree view.
Ctrl+F8 - Navigate to the next perspective, for example you can switch from the Symbian perspective to the Debug perspective.

Building and Running

Ctrl+B - Build the current project.
F11 - Debug the current project.
Ctrl+F11 - Run the current project.
Ctrl+. and Ctrl., - Go to the next and previous annotation. You may find this useful when you have several error messages from the compiler. You can use these shortcuts to walk through the list of error messages.

Debugging

Ctrl+Shift+B - Toggle breakpoint. Note that you can only use this shortcut in the Debug perspective. For some reasons (that I don't know), you cannot use this shortcut in Symbian perspective.
F5 - Step Into.
F6 - Step Over.
F8 - Resume.
Ctrl+R - Run to line.

Configuring Shortcuts

Note that you can configure shortcuts in Carbide.c++ by selecting Window | Preferences | General | Keys. This may be useful, for example if you already got used to Visual Studio's shortcuts.

How to Start Symbian OS C++ Development?

antonypr — Wed, 13 Dec 2006 07:57:21 +0200

I write this blog because so many questions at Forum Nokia Discussion, such as "How do I start Symbian OS C++ development?", "Which SDK should I use?" etc.

Download SDK

The first thing to do is download the Symbian OS C++ SDK. Which SDK to download? There are several SDKs depending on the UI platforms of the phones, i.e.:

S60. This is the platform of the most selling Symbian OS phones. Many of phones are manufactured by Nokia. S60 is mostly used in one-handed phones, but it supports full keyboard (QWERTY) too.
The S60 SDK is available at Forum Nokia. Before downloading any SDKs, check the SDK version that you need. For example, to develop applications for Nokia N95, you need S60 3rd FP1 SDK.
UIQ. This platform is mostly used in PDA-like phones that are operated with stylus. However, there are some UIQ phones operated with keyboard too. Many of UIQ phones are manufactured by Sony Ericsson.
The UIQ SDK is available at UIQ Technology.
Series 80. Series 80 is the platform for Nokia Communicator Series, such as Communicator 9500 and 9300. I am not sure about the future of Series 80 because I haven't heard any upcoming Communicator models.
The Series 80 SDK is available at Forum Nokia.

Actually, there is one more UI platform for Symbian OS, i.e. Series 90 from Nokia. Unfortunately, the platform has been discontinued. The only product that came out to the market is Nokia 7710. I don't think you should start development on Series 90 unless there is a specific need to support Nokia 7710.

Download IDE

Another question that usually comes up from developers is "Which IDE to use?" Once again, there are several IDEs supporting Symbian OS C++, i.e.:

Carbide.c++. This IDE will be the future for all Symbian OS C++ development. If you are new to Symbian OS world, I would recommend starting with Carbide.c++. Although the current version of Carbide.c++ is not perfect yet, Nokia has put a serious effort to make it better.
CodeWarrior. This is an old IDE that is originally developed by Metrowerks but then bought by Nokia. I would not recommend this IDE because Nokia may discontinue the support of CodeWarrior any time.
Visual Studio .NET 2003 + Carbide.vs. As you may know Visual Studio .NET is one of the best IDEs out there. There is plug-in from Nokia to support Symbian C++ development under Visual Studio .NET. The plug-in is called Carbide.vs.
Some people have been asking whether there is Carbide.vs for Visual Studio .NET 2005. As far as I know, the answer is no.
Linux-based IDE. If you are a fan of UNIX, there is "unofficial" tool to support Symbian C++ development in Linux platform, called sdk2unix.

As summary, if you are developing for Windows, I highly recommend to start using Carbide.c++. Note that there is a free version, called Carbide.c++ Express. The other two versions, Developers and Professional, cost some money.

Buy Books

There have been many concerns about the quality of SDK documentation, which is not good enough. That's why I would recommend buying one of Symbian OS C++ books, e.g.:

Symbian OS C++ for Mobile Phones (Symbian Press)
Developing Series 60 Applications: A Guide for Symbian OS C++ Developers (Nokia Mobile Developer Series)
The Accredited Symbian Developer Primer: Fundamentals of Symbian OS (Symbian Press) - This is actually targeted for developers who want to take Accredited Symbian Developer certificate. However, the contents are good for beginner too.

Technical Articles, Sample Codes and Forum Discussion

Sometimes books are not enough, so you may want to read some technical articles about Symbian OS C++ as well. There are several good sources, i.e.:

Forum Nokia. There are tons of technical articles and sample codes from Forum Nokia.
Sony Ericsson Developer World - Similar to Forum Nokia, but mostly for UIQ platform.
NewLC - Independent Symbian OS c++ web site that hosts many technical articles.

The last thing that I want to mention is forum discussions. Whenever you have problems or questions, you can always fire your questions to the developer communities. All the three sites above have forum discussions.

Interpreting Platform Security Error Messages in S60 3rd Edition

antonypr — Fri, 16 Jun 2006 22:38:05 +0300

If you have been reading discussions at Forum Nokia Developer Discussion Board recently, you may notice there are many questions about signing in S60 3rd Edition. It seems the new security feature in Symbian 9 has led to frustration for some developers.

I would like to share what kind of error messages I have seen when installing signed/unsigned application in S60 3rd Edition phones. There is a hint that explains what may cause a particular message. I may not be able to cover all error messages because I may not have seen all of them.

Message: Certificate error. Contact the application supplier.

Hint: You may have tried installing unsigned application. Note that signing is mandatory S60 3rd Edition. You can use self-signed certificate or developer certificate from Symbian Signed to sign your application.

Message: Unable to install. Constrained by the certificate.

Hint: This message pops up when you attempt to install developer certificate in the unsupported device. The developer certificate from Symbian Signed can only be used in a limited number of devices. Remember that you have to send your IMEIs to Symbian Signed when requesting certificate. You cannot use the certificate in other devices that is not in your IMEIs list.

Message: Required application access not granted

Hint: Check that your certificate can be used to sign all capabilities needed by your application. For example, if you use self-signed certificate, you can only sign basic set capabilities, i.e. NetworkServices, ReadUserData, WriteUserData, LocalServices and UserEnvironment. If your application requires one of the extended capabilities, for example SwEvent, you cannot sign it with self-signed certificate. In this case, apply for developer certificates from Symbian Signed.

Message: Unable to install a protected application from an untrusted supplier

Hint: If you use self-signed certificate, make sure that your application uses unprotected UID, i.e. 0xA0000000 - 0xAFFFFFFF. If you use protected UID (0x20000000 - 0x2FFFFFFF) or legacy UID (0x10000000 - 0x1FFFFFFF), you will get this message.

Message: Unable to install

Hint: This message may come up when your installation file (.sis/.sisx) copies files to other application's private folder, i.e. privateuid. Note that Symbian 9 introduces data caging concept, it means you don't have access to other application's private folder.