Added in API level 18

OnWindowFocusChangeListener

interface OnWindowFocusChangeListener
android.view.ViewTreeObserver.OnWindowFocusChangeListener

Interface definition for a callback to be invoked when the view hierarchy's window focus state changes.

Summary

Public methods
abstract Unit

Callback method to be invoked when the window focus changes in the view tree.

Public methods

onWindowFocusChanged

Added in API level 18
abstract fun onWindowFocusChanged(hasFocus: Boolean): Unit

Callback method to be invoked when the window focus changes in the view tree.

Parameters
hasFocus Boolean: Set to true if the window is gaining focus, false if it is losing focus.