Palm Programming: The Developer's Guide

Chapter 3. Designing a Solution

Now that you know about the features of the Palm OS and you have figured out what development environment you are going to use, it is time to create a new application. To do this, you first need to know what the Palm OS provides in the way of user interface elements. Second, you need a description of the elements common to every application.

From this general overview, we move to a concrete example. For this purpose, we discuss a sample application that we are going to create and then dissect in this book. We show you its design, what actions the user performs, how we prototyped it, and the design complications we encountered. Once we’ve covered the handheld portion of the application, we turn to a description of the conduit.

User Interface Elements in an Application

The Palm OS provides you with an abundance of user interface elements. The following is a description of these elements. We also show you some common examples of each type.

Alerts

Figure 3.1 contains an example of a typical alert. It is simply a modal dialog that displays a title, a message, an icon, and one or more buttons. You are responsible for setting the text of the title, the message, and the button(s). You also specify the type of alert. It can be any of the following types (ordered from mildest in consequence to most severe):

Information

This has an “i” icon. The alert provides to the user some information (for example, that an action can’t be completed). No data loss has occurred. ...