Palm Programming: The Developer's Guide

Chapter 4. Structure of an Application

The overall flow and content of a Palm OS application is the subject of this chapter. You will learn:

• The standard code routines found in every Palm application

• All about the application’s lifecycle—its starting, running, and closing

• How the application processes each event and hands it off to the appropriate manager

• How memory is organized on a Palm device; how the application can use it

• All the times that an application needs to be available to the system and how these instances are handled in the code

Terminology

Like every operating system and coding interaction, the Palm OS has it own set of necessary terminology for you to learn. Much of it may already be familiar to you from other applications you have written. We suggest that you skim through this list and concentrate on the items that are new to you. New and unique terminology is listed first.

Form

An application window (what many people would think of as a view) that usually covers the entire screen. A form optionally contains controls, text areas, and menus. In a Palm OS application, there is only one active form allowed at a time. Chapter 5, covers forms in detail.

Window

A rectangular area in which things like dialogs, forms, and menus are drawn by the application. The Window Manager makes sure that windows properly display relative to each other (for example, it has the ability to restore the old contents when a window is closed). Note in a rather Shakespearian twist of logic that all ...