Developing Software for Symbian OS: A Beginner's Guide to Creating Symbian OS v9 Smartphone Applications in C++

Chapter 6. Strings, Buffers, and Data Collections

This chapter covers the basic string and data buffer APIs, as well as other common data organization classes. These classes are part of what is known in Symbian OS as the Base APIs, and they reside in euser.dll.

This chapter covers the following types of data classes:

• Descriptors for handling strings and binary data.

• Dynamic buffers for buffers that grow at runtime.

• Array classes.

• Other data organization classes like linked lists and circular queues.

The chapter includes numerous examples, and the complete source of the examples can be downloaded from the book's website. The examples output their results via a printf() -style function, to what is known as a text console.

Before diving into string and buffer management, let's take a look at how a text console program works. This provides an easy way to compile and run the examples in this chapter on the emulator and do experiments of your own without writing a full GUI program.

Introducing the Text Console

Symbian OS provides a text console API class called CConsoleBase that allows you to output formatted text to the screen, without the overhead of using the GUI framework. The class also accepts keyboard input. While the text console is not very useful for product software, it's excellent for learning and experimenting with non-GUI-related Symbian OS functionality.

Below is a very minimal console CPP file that outputs 'Hello' to the text console so you can get the general idea. For simplicity, ...