Package icyllis.modernui.fragment

Class OnBackPressedCallback

java.lang.Object

icyllis.modernui.fragment.OnBackPressedCallback

public abstract class OnBackPressedCallback
extends Object

Class for handling OnBackPressedDispatcher.onBackPressed() callbacks.

This class maintains its own enabled state. Only when this callback is enabled will it receive callbacks to handleOnBackPressed().

Note that the enabled state is an additional layer on top of the LifecycleOwner passed to OnBackPressedDispatcher.addCallback(LifecycleOwner, OnBackPressedCallback) which controls when the callback is added and removed to the dispatcher.

By calling remove(), this callback will be removed from any OnBackPressedDispatcher it has been added to. It is strongly recommended to instead disable this callback to handle temporary changes in state.

Constructor Summary

Constructors

Constructor	Description
OnBackPressedCallback(boolean enabled)	Create a OnBackPressedCallback.

Method Summary

Modifier and Type	Method	Description
abstract void	handleOnBackPressed()	Callback for handling the OnBackPressedDispatcher.onBackPressed() event.
final boolean	isEnabled()	Checks whether this callback should be considered enabled.
final void	remove()	Removes this callback from any OnBackPressedDispatcher it is currently added to.
final void	setEnabled(boolean enabled)	Set the enabled state of the callback.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

OnBackPressedCallback

public OnBackPressedCallback(boolean enabled)

Create a OnBackPressedCallback.

Parameters:

enabled - The default enabled state for this callback.

See Also:

• setEnabled(boolean)

Method Details

setEnabled

@UiThread
public final void setEnabled(boolean enabled)

Set the enabled state of the callback. Only when this callback is enabled will it receive callbacks to handleOnBackPressed().

Note that the enabled state is an additional layer on top of the LifecycleOwner passed to OnBackPressedDispatcher.addCallback(LifecycleOwner, OnBackPressedCallback) which controls when the callback is added and removed to the dispatcher.

Parameters:

enabled - whether the callback should be considered enabled

isEnabled

@UiThread
public final boolean isEnabled()

Checks whether this callback should be considered enabled. Only when this callback is enabled will it receive callbacks to handleOnBackPressed().

Returns:

Whether this callback should be considered enabled.

remove

@UiThread
public final void remove()

Removes this callback from any OnBackPressedDispatcher it is currently added to.

handleOnBackPressed

@UiThread
public abstract void handleOnBackPressed()

Callback for handling the OnBackPressedDispatcher.onBackPressed() event.