Android Action Bar Backward Compatibility

The Action Bar is a consistently formatted navigation and option selection area at the top of a screen with an overflow area at the bottom.
Key aspects of the Action Bar include:
  • It's a replacement for the menu feature.
  • It was introduced in Android 3.0 and refined in Android 4.0.
  • It's included in activities that use the Holo theme family.

Elements of the Action Bar graphic include:

  • Application icon.
  • Application name.
  • Up navigation to a parent screen.
  • Built-in tab navigation for switching between fragments.
  • Drop-down list for alternative navigation such as sort by a different criteria.
  • Important actions for a given app such as search and share.

Google has recently developed a set of classes to give the Action Bar backward compatibility for pre Android 3.0 devices.  These classes invoke the action bar design pattern on pre-API 11 devices and the built-in Action Bar on devices supporting API 11 or greater.

This is part of a larger set of capabilities for supporting application compatibility with multiple device environments including tablets and handsets and various screen sizes.