standards - Android back button - Global history back, or menu back?

On the Android, is the expected action of the back button to navigate backward through menus, or does it just go "back" to the previous screen you came from?

I don't have an Android device to sample a number of applications to see what the norm is. I'm using phonegap to package an HTML5 app, so I need to manually handle any back button functionality.

Answer

The default behavior is to go to the previous screen no matter what it is.

• If you're deep in the menu then it takes you up a level.


• If you're in the top level of a menu it takes you back to the application.


• If you're in the main screen of an application it takes you either to the desktop or to the app, from which you launched the current one (e.g. from browser back to RSS reader).

For detailed information, see Task and Back Stack, Activity and Task Design Guidelines, and other topics about BACK button in Android Dev guide.