OnBackPressedCallback
public
abstract
class
OnBackPressedCallback
extends Object
| java.lang.Object | |
| ↳ | androidx.activity.OnBackPressedCallback |
Class for handling OnBackPressedDispatcher.onBackPressed() callbacks without
strongly coupling that implementation to a subclass of ComponentActivity.
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.
Summary
Public constructors | |
|---|---|
OnBackPressedCallback(boolean enabled)
Create a |
|
Public methods | |
|---|---|
abstract
void
|
handleOnBackPressed()
Callback for handling the |
final
boolean
|
isEnabled()
Checks whether this callback should be considered enabled. |
final
void
|
remove()
Removes this callback from any |
final
void
|
setEnabled(boolean enabled)
Set the enabled state of the callback. |
Inherited methods | |
|---|---|
Public constructors
OnBackPressedCallback
public OnBackPressedCallback (boolean enabled)
Create a OnBackPressedCallback.
| Parameters | |
|---|---|
enabled |
boolean: The default enabled state for this callback. |
See also:
Public methods
handleOnBackPressed
public abstract void handleOnBackPressed ()
Callback for handling the OnBackPressedDispatcher.onBackPressed() event.
isEnabled
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 | |
|---|---|
boolean |
Whether this callback should be considered enabled. |
remove
public final void remove ()
Removes this callback from any OnBackPressedDispatcher it is currently
added to.
setEnabled
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 |
boolean: whether the callback should be considered enabled
|