Book Image

BlackBerry Java Application Development

Book Image

BlackBerry Java Application Development

Overview of this book

BlackBerry Smartphone was once the domain of jet-setting business users with power suits. Now you can hardly go anywhere without seeing someone using a BlackBerry to check their messages or make a call. It's this kind of explosive growth that makes the BlackBerry ecosystem a great place to develop and market applications through the BlackBerry App World store—this book shows you how to do just that! This step-by-step guide gives you a hands-on experience of developing innovative Java applications for your BlackBerry. With the help of this book, you will learn to build your own applications to illustrate the platform, and the various capabilities that developers can use in their programs. It explores the powers of Blackberry and helps you develop professional and impressive Java applications. The book teaches how to write rich, interactive, and smart BlackBerry applications in Java. It expects the readers to know Java but not Java Mobile or the BlackBerry APIs. We will learn to build rich, interactive, and smart Java applications for the BlackBerry. The book will cover UI programming, data storage, programming network, and internet API apps. As we move on, we will learn more about the BlackBerry's device features, such as messaging, GPS, multimedia, contacts and calendar, and so on.This book also helps you build your own applications to illustrate the platform, and the various capabilities that developers can use in their programs.
Table of Contents (18 chapters)
BlackBerry Java Application Development
Credits
About the Author
Acknowledgement
About the Reviewers
Preface

CheckboxField


The CheckboxField is one of those basic fields that almost need no explanation. The CheckboxField follows many of the standard conventions in other systems, such as HTML and Windows, by placing the checkbox on the left-hand side of the screen with the label on the right. This is consistent with many other systems even if it is opposite of most other field classes in BlackBerry. A checkbox is best used to represent a Boolean value or simple on/off or yes/no values.

The checkbox itself is square and shows a nice checkmark image when the checkbox is checked. You can toggle the checkbox by pressing the Space key.

Additionally, when a CheckboxField has focus on the screen and the menu button is pressed, the framework adds a Change Option menu item to the menu in much the same way it does with the ChoiceField. Clicking on this menu item will toggle the checkbox as well.

Be sure to phrase the label in such a way as to make the choice clear. A checkbox can be used to enable a feature...