Language and Libraries Support
The Palm OS is considerably different from the Windows OS in many aspects. Its underlying structure, memory model, and data storage are radically different and require an “application abstraction layer” to provide easier access to the underlying OS. This abstraction layer is provided to the VB programmer via the AppForge libraries. These libraries provide access to native Palm OS functions, including complete support for creating and maintaining Palm databases.
There is considerable support for the VB language constructs. However, there also has been a conscious effort to increase application efficiency by limiting or eliminating (i.e., ignoring) certain aspects of VB by the AppForge compiler. There are many reasons for this, but they are related to the sheer fact that mobile handheld devices are limited by available power. Applications that require the device to perform resource-intensive processes, such as continually accessing RAM, will draw more power than usual. Another power-limiting factor is the use of slower processors to conserve energy. Consequently, some Windows features were either optimized to provide satisfactory response times or were eliminated altogether.
Visual Basic Language Support
In this section, we will cover the Visual Basic functionality that is not supported by the AppForge compiler.
Object support
AppForge does allow the creation
of
user-defined classes (i.e., class modules), using the
New
keyword in the Dim
statement. ...
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