Session

public final @NonNull CarContext getCarContext()

Returns the CarContext for this session.

The CarContext is not expected to be available until this session's is at least CREATED. Further, some instance methods within CarContext should not be called before this state has been reached. See the documentation in CarContext for details on any such restrictions.

public @NonNull Lifecycle getLifecycle()

Returns the Session's Lifecycle.

Here are some of the ways you can use the sessions's Lifecycle:

• Observe its Lifecycle by calling addObserver. You can use the androidx.lifecycle.LifecycleObserver to take specific actions whenever the Screen receives different Lifecycle.Events.
• Use this CarAppService to observe androidx.lifecycle.LiveDatas that may drive the backing data for your application.

What each lifecycle related event means for a session:

ON_CREATE

The session has just been launched, and this session is being initialized. onCreateScreen will be called at a point after this call.

onCreateScreen

The host is ready for this session to create the first Screen so that it can display its template.

ON_START

The application is now visible in the car screen.

ON_RESUME

The user can now interact with this application.

ON_PAUSE

The user can no longer interact with this application.

ON_STOP

The application is no longer visible.

ON_DESTROY

The OS has now destroyed this Session instance, and it is no longer valid.

Listeners that are added in ON_START, should be removed in ON_STOP.

Listeners that are added in ON_CREATE should be removed in ON_DESTROY.

Note lifecycle callbacks will be executed on the main thread.

public void onCarConfigurationChanged(@NonNull Configuration newConfiguration)

Notifies that the CarContext's Configuration has changed.

At the time that this function is called, the CarContext's resources object will have been updated to return resource values matching the new configuration.

Called by the system, do not call this method directly.

public abstract @NonNull Screen onCreateScreen(@NonNull Intent intent)

Requests the first Screen for the application.

Once the method returns, onGetTemplate will be called on the Screen returned, and the app will be displayed on the car screen.

To pre-seed a back stack, you can push Screens onto the stack, via push during this method call.

Called by the system, do not call this method directly.

public void onNewIntent(@NonNull Intent intent)

Notifies that the car app has received a new Intent.

Once the method returns, onGetTemplate will be called on the Screen that is on top of the Screen stack managed by the ScreenManager, and the app will be displayed on the car screen.

Often used to update the current Screen or pushing a new one on the stack, based off of the information in the intent.

Called by the system, do not call this method directly.