Added in API level 18

FocusObserver

abstract class FocusObserver
kotlin.Any
   ↳ android.view.WindowId.FocusObserver

Subclass for observing changes to the focus state of an WindowId. You should use the same instance of this class for observing multiple WindowId objects, since this class is fairly heavy-weight -- the base class includes all of the mechanisms for connecting to and receiving updates from the window.

Summary

Public constructors

Construct a new observer.

Public methods
abstract Unit

Called when one of the monitored windows gains input focus.

abstract Unit

Called when one of the monitored windows loses input focus.

Public constructors

FocusObserver

Added in API level 18
FocusObserver()

Construct a new observer. This observer will be configured so that all of its callbacks are dispatched on the current calling thread.

Public methods

onFocusGained

Added in API level 18
abstract fun onFocusGained(token: WindowId!): Unit

Called when one of the monitored windows gains input focus.

onFocusLost

Added in API level 18
abstract fun onFocusLost(token: WindowId!): Unit

Called when one of the monitored windows loses input focus.