SystemOnBackInvokedCallbacks

Kotlin |Java

public final class SystemOnBackInvokedCallbacks
extends Object

java.lang.Object
↳	android.window.SystemOnBackInvokedCallbacks

Utility class providing OnBackInvokedCallbacks to override the default behavior when system back is invoked. e.g. Activity.finish

By registering these callbacks with the OnBackInvokedDispatcher, the system can trigger specific behaviors and play corresponding ahead-of-time animations when the back gesture is invoked.

For example, to trigger the Activity.moveTaskToBack behavior:

   OnBackInvokedDispatcher dispatcher = activity.getOnBackInvokedDispatcher();
   dispatcher.registerOnBackInvokedCallback(
       OnBackInvokedDispatcher.PRIORITY_DEFAULT,
       SystemOnBackInvokedCallbacks.moveTaskToBackCallback(activity));

Summary

Public methods
`static OnBackInvokedCallback`	`finishAndRemoveTaskCallback(Activity activity)` Get a callback to triggers `Activity.finishAndRemoveTask()` on the associated `Activity`.
`static OnBackInvokedCallback`	`moveTaskToBackCallback(Activity activity)` Get a callback to triggers `Activity.moveTaskToBack(boolean)` on the associated `Activity`, moving the task containing the activity to the background.

Public methods


        
        
        static
        
        
        OnBackInvokedCallback


      finishAndRemoveTaskCallback(Activity activity)

Get a callback to triggers Activity.finishAndRemoveTask() on the associated Activity.


        
        
        static
        
        
        OnBackInvokedCallback


      moveTaskToBackCallback(Activity activity)

Get a callback to triggers Activity.moveTaskToBack(boolean) on the associated Activity, moving the task containing the activity to the background.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public methods

finishAndRemoveTaskCallback

Added in API level 36

public static OnBackInvokedCallback finishAndRemoveTaskCallback (Activity activity)

Get a callback to triggers Activity.finishAndRemoveTask() on the associated Activity. If the activity is the root activity of its task, the entire task will be removed from the recents task. The activity will be finished in all cases. The system will play the corresponding transition animation.

Parameters
`activity`	`Activity`: The associated `Activity` This value cannot be `null`.

Returns
`OnBackInvokedCallback`	This value cannot be `null`.

See also:

Activity.finishAndRemoveTask()

moveTaskToBackCallback

Added in API level 36

public static OnBackInvokedCallback moveTaskToBackCallback (Activity activity)

Get a callback to triggers Activity.moveTaskToBack(boolean) on the associated Activity, moving the task containing the activity to the background. The system will play the corresponding transition animation, regardless of whether the activity is the root activity of the task.

Parameters
`activity`	`Activity`: The associated `Activity` This value cannot be `null`.

Returns
`OnBackInvokedCallback`	This value cannot be `null`.

See also:

Activity.moveTaskToBack(boolean)