Added in API level 33

OnBackInvokedDispatcher


public interface OnBackInvokedDispatcher

android.window.OnBackInvokedDispatcher


Dispatcher to register OnBackInvokedCallback instances for handling back invocations. It also provides interfaces to update the attributes of OnBackInvokedCallback. Attribute updates are proactively pushed to the window manager if they change the dispatch target (a.k.a. the callback to be invoked next), or its behavior.

Summary

Constants

int PRIORITY_DEFAULT

Default priority level of OnBackInvokedCallbacks.

int PRIORITY_OVERLAY

Priority level of OnBackInvokedCallbacks for overlays such as menus and navigation drawers that should receive back dispatch before non-overlays.

Public methods

abstract void registerOnBackInvokedCallback(int priority, OnBackInvokedCallback callback)

Registers a OnBackInvokedCallback.

abstract void unregisterOnBackInvokedCallback(OnBackInvokedCallback callback)

Unregisters a OnBackInvokedCallback.

Constants

PRIORITY_DEFAULT

Added in API level 33
public static final int PRIORITY_DEFAULT

Default priority level of OnBackInvokedCallbacks.

Constant Value: 0 (0x00000000)

PRIORITY_OVERLAY

Added in API level 33
public static final int PRIORITY_OVERLAY

Priority level of OnBackInvokedCallbacks for overlays such as menus and navigation drawers that should receive back dispatch before non-overlays.

Constant Value: 1000000 (0x000f4240)

Public methods

registerOnBackInvokedCallback

Added in API level 33
public abstract void registerOnBackInvokedCallback (int priority, 
                OnBackInvokedCallback callback)

Registers a OnBackInvokedCallback. Within the same priority level, callbacks are invoked in the reverse order in which they are registered. Higher priority callbacks are invoked before lower priority ones.

Parameters
priority int: The priority of the callback. Value is PRIORITY_DEFAULT, or PRIORITY_OVERLAY Value is 0 or greater

callback OnBackInvokedCallback: The callback to be registered. If the callback instance has been already registered, the existing instance (no matter its priority) will be unregistered and registered again. This value cannot be null.

Throws
java.lang.IllegalArgumentException IllegalArgumentException} if the priority is negative.

unregisterOnBackInvokedCallback

Added in API level 33
public abstract void unregisterOnBackInvokedCallback (OnBackInvokedCallback callback)

Unregisters a OnBackInvokedCallback.

Parameters
callback OnBackInvokedCallback: The callback to be unregistered. Does nothing if the callback has not been registered. This value cannot be null.