Symbian and OpenC Applications

Question

I have been researching around trying to find the best way to begin developing an application which aims to analyse user's writing styles based on outgoing SMS messages. I have installed Symbian's SDK and Carbide and purchased a book on their specific style of C++ to get started. However, I was told to check out Open C for Symbian as I have some previous C experience. I have installed the plugin from http://www.forum.nokia.com/Resources_and_Information/Explore/Runtime_Platforms/Open_C_and_C++/ and tested a simple Hello, World! application with success.

Although, the initial success would lead me to believe Open C would be a better option for me, I am worried about limitations of using Open C. For example, I need to be able to access native functions of the Symbian OS to capture keystrokes while in the SMS composer. I also need to be able to run my application in the background and have it load on system startup as not to interfere with user's normal activities.

Can someone clarify if Open C can access such functions and fulfil my needs in terms of developing this specific application? Also, what are the limitations to using Oepn C in comparison to the standard Symbian C++?

Answer 1

I'm by no means a Symbian guru but we've used the Open C/C++ plugin for Symbian here. My understanding is that the plugin is simply an extension -- it gives you the standard libraries and lets you deal with familiar functions (in our case, just the simple cstring.h, and stdio.h libraries were what we were looking for).

You can still mix and match the Symbian calls and likely will have to deal with some painful conversions to get your char* into the proper "descriptor". However, you should only have to do these at the interfaces at which you're touching existing Symbian libraries (as they're going to expect descriptors, not char*s).

In our code, we have some places where we're using a remove call to delete files and in the same class, creating the detailed Symbian RFs abd RFile objects.

So yes, while we use C/C++ libraries to do some low-level stuff and a lot of string manipulation, we're also using the Web Browser Control, key input monitoring and all that.

...And yes, we need to clean up our code. :-)

Answer 2

Open C provides a set of standard C libraries for Symbian OS programs i.e. it is a library.

This means you can call Open C code and Symbian native code freely in the same program, just as with any other library, provided you respect the preconditions and assumptions that the libraries require.

This is where the complexity comes in, because the standard Symbian APIs often require things like descriptors and a working active scheduler, whereas the Open C libraries don't. But provided you're careful you can do what you want.