UI
The user interface is one of the most important elements of a BlackBerry® device application. The UI is how BlackBerry device users interact with your application, and gives users access to the features and functionality of your application.
- Easy to use: The UI should make it easy for users to navigate your application and access important features.
- Logical: The layout and placement of UI components should make sense, and the purpose of each component on a screen should be clear.
- Functional: The UI components that you use in your application should function properly when users interact with them, and there should be no unnecessary or unused components.
- Visually appealing: The UI should appear polished and attractive.
You can use the classes and interfaces that are included in the BlackBerry® Java® SDK to create UIs for your applications. There are three main packages that you can use to create UIs:
- The net.rim.device.api.ui package contains the fundamental classes that are used for all UI applications.
- The net.rim.device.api.ui.component package contains classes for many prebuilt UI components, such as buttons, check boxes, and text fields.
- The net.rim.device.api.ui.container package contains classes that you can use to arrange UI components, such as managers.
If you don't find a component that fits your requirements, you can extend these classes to create your own custom UI components.


For more information about UI design principles and best practices, visit www.blackberry.com/go/uiguidelines to read the UI Guidelines.