Android Mobile Operating System - User Agents

Action Bar

The action bar is a dedicated piece of real estate at the top of each screen that is generally persistent throughout the app. It provides several key functions:

• Makes important actions prominent and accessible in a predictable way (such as New or Search).
• Supports consistent navigation and view switching within apps.
• Reduces clutter by providing an action overflow for rarely used actions.
• Provides a dedicated space for giving your app an identity.

Action Bar

Action bar is typically split into four areas of function:

App Icon

The app icon establishes your app's identity. It can be replaced with a different logo or branding if you wish. Important: If the app is currently not displaying the top-level screen, be sure to display the Up caret to the left of the app icon, so the user can navigate up the hierarchy (aka Up Navigation and/or Navigation Pattern).

2) View Control

If your app displays data in different views, this segment of the action bar allows users to switch views. Examples of view-switching controls are drop-down menus or tab controls. For more information on view-switching, see the App Structure pattern.

If your app doesn't support different views, you can also use this space to display non-interactive content, such as an app title or longer branding information.

3) Action Buttons

Show the most important actions of your app in the actions section. Actions that don't fit in the action bar are moved automatically to the action overflow. Long-press on an icon to view the action's name.

Action Overflow

Move less often used actions to the action overflow.