Palm OS Programming, 2nd Edition

User Interface Elements in the Palm OS

The Palm OS provides you with an abundance of UI elements. In what follows, we give you a description of these elements. We also show you some common examples of each type and, where relevant, give you guidelines on its placement and use. (Later chapters show you how to create them and implement them in your code.)

Alerts

Figure 3-1 shows a typical alert. It is simply a modal dialog box 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 (arranged from mildest in consequence to most severe):

Notification

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

Question

This has a “?” icon. The alert asks the user a question and asks the user to confirm an action or choose from possibilities.

Warning

This has a “!” icon. It asks the user if the action is really intentional. Data loss could occur if the action is completed. The Memo Pad uses a question alert for deleting memos, since the user can choose to save an archive on the PC (thus the data is not lost). However, the system uses a Warning dialog box when the user chooses to delete an application, since after the delete, the application is completely gone. Figure 3-1 shows a warning alert.

Error

This has a stop sign icon. This ...