Application screens

An application screen is the highest-level container that you can use for your application UI. Application screens typically contain the content for your screen, including other containers and UI components. For example, application screens can contain graphics, layout managers, and buttons.

Multiple screens can be open on a BlackBerry device at one time, but users can view only one screen at a time.

Users can perform the following common actions on screens:

Action

User interaction

Move around the screen.

Move a finger on the trackpad or touch screen.

Open the menu.

Press the Menu key.

Invoke an action in the menu.

  • Click or tap the item.
  • When an item is highlighted in the menu, press the Menu key.

Switch applications.

  • Press the Alt key and the Escape key on BlackBerry devices with a physical keyboard.
  • Hold the Menu key.

Switch between portrait view and landscape view on BlackBerry devices with a touch screen.

Turn the device sideways.

Close an application.

Click Close in the menu.

Return to the Home screen without closing the application screen.

Press the End key.

Best practice: Designing application screens

  • Use a limited number of nested layouts. The more nested layouts that you use to build your screen, the longer it takes for the BlackBerry device to render the screen.
  • Prompt users with a dialog box to save any unsaved data before closing a screen.
  • Avoid hardcoding color values. The color values that you choose might not work with the theme that users have selected.

Guidelines for layout

  • Use a vertical layout for your application screens.
  • Consider arranging the UI components on application screens using the BlackBerry API layout managers.
  • On BlackBerry devices with a touch screen, verify that the screens appear correctly in both portrait and landscape view.
  • Display the most important information at the top of the screen. For example, for contact information, display the name first, followed by the email address and phone numbers. Display a field such as the Notes field last.
  • Limit the number of components that appear on the screen at one time.
  • Use line separators on a screen to separate components or to indicate a group of components.
  • Consider localization requirements as early in the design process as possible. Localization can affect the layout of screens.
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