Summary: Nested Classes | Ctors | Methods | Inherited Methods

CarAppExtender

Kotlin |Java

public final class CarAppExtender
extends Object implements NotificationCompat.Extender

java.lang.Object
↳	androidx.car.app.notification.CarAppExtender

---

Helper class to add car app extensions to notifications.

By default, notifications in a car screen have the properties provided by NotificationCompat.Builder. This helper class provides methods to override those properties for the car screen. However, notifications only show up in the car screen if it is extended with CarAppExtender, even if the extender does not override any properties. To create a notification with car extensions:

1. Create a NotificationCompat.Builder, setting any desired properties.
2. Create a CarAppExtender.Builder.
3. Set car-specific properties using the set methods of CarAppExtender.Builder.
4. Create a CarAppExtender by calling CarAppExtender.Builder.build().
5. Call NotificationCompat.Builder.extend(NotificationCompat.Extender) to apply the extensions to a notification.
6. Post the notification to the notification system with the NotificationManagerCompat.notify(...) methods and not the NotificationManager.notify(...) methods.

 Notification notification = new NotificationCompat.Builder(context)
         ...
         .extend(new CarAppExtender.Builder()
                 .set*(...)
                 .build())
         .build();
 

Car extensions can be accessed on an existing notification by using the CarAppExtender(Notification) constructor, and then using the get methods to access values.

The car screen UI is affected by the notification channel importance (Android O and above) or notification priority (below Android O) in the following ways:

• A heads-up-notification (HUN) will show if the importance is set to NotificationManagerCompat.IMPORTANCE_HIGH, or the priority is set to NotificationCompat.PRIORITY_HIGH or above.
• The notification center icon, which opens a screen with all posted notifications when tapped, will show a badge for a new notification if the importance is set to NotificationManagerCompat.IMPORTANCE_DEFAULT or above, or the priority is set to NotificationCompat.PRIORITY_DEFAULT or above.
• The notification entry will show in the notification center for all priority levels.

Calling CarAppExtender.Builder.setImportance(int) will override the importance for the notification in the car screen.

Calling NotificationCompat.Builder#setOnlyAlertOnce(true) will alert a high-priority notification only once in the HUN. Updating the same notification will not trigger another HUN event.

Navigation

For a navigation app's turn-by-turn (TBT) notifications, which update the same notification frequently with navigation information, the notification UI has a slightly different behavior. The app can post a TBT notification by calling NotificationCompat.Builder#setOngoing(true) and NotificationCompat.Builder#setCategory(NotificationCompat.CATEGORY_NAVIGATION).

TBT notifications behave the same as regular notifications with the following exceptions:

• The notification will not be displayed if the navigation app is not the currently active navigation app, or if the app is already displaying routing information in the navigation template.
• The heads-up-notification (HUN) can be customized with a background color through CarAppExtender.Builder.setColor(CarColor).
• The notification will not be displayed in the notification center.

In addition to that, the information in the navigation notification will be displayed in the rail widget at the bottom of the screen when the app is in the background.

Note that frequent HUNs distract the driver. The recommended practice is to update the TBT notification regularly on distance changes, which updates the rail widget, but call NotificationCompat.Builder#setOnlyAlertOnce(true) unless there is a significant navigation turn event.

Summary

Nested classes
class	CarAppExtender.Builder A builder of CarAppExtender.

Public constructors
CarAppExtender(Notification notification) Creates a CarAppExtender from the CarAppExtender of an existing notification.

Public methods
NotificationCompat.Builder	extend(NotificationCompat.Builder builder) Applies car extensions to a notification that is being built.
List<Notification.Action>	getActions() Returns the list of Notification.Action present on this car notification.
CarColor	getColor() Returns the background color of the notification or null if a default color is to be used.
PendingIntent	getContentIntent() Returns the PendingIntent to send when the notification is clicked in the car or null if not set.
CharSequence	getContentText() Returns the content text of the notification or null if not set.
CharSequence	getContentTitle() Returns the content title for the notification or null if not set.
PendingIntent	getDeleteIntent() Returns the PendingIntent to send when the notification is cleared by the user or null if not set.
int	getImportance() Returns the importance of the notification in the car screen.
Bitmap	getLargeIcon() Returns the large icon bitmap to display in the notification or null if not set.
int	getSmallIcon() Returns the resource ID of the small icon drawable to use.
static boolean	isExtended(Notification notification) Returns whether the given notification was extended with CarAppExtender.

Inherited methods
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait(long arg0, int arg1) final void wait(long arg0) final void wait()
From interface androidx.core.app.NotificationCompat.Extender abstract NotificationCompat.Builder extend(NotificationCompat.Builder builder) Apply this extender to a notification builder.

Public constructors

CarAppExtender

public CarAppExtender (Notification notification)

Creates a CarAppExtender from the CarAppExtender of an existing notification.

Parameters
notification	Notification

Public methods

extend

public NotificationCompat.Builder extend (NotificationCompat.Builder builder)

Applies car extensions to a notification that is being built.

This is typically called by NotificationCompat.Builder.extend(NotificationCompat.Extender).

Parameters
builder	NotificationCompat.Builder: the builder to be modified.

Returns
NotificationCompat.Builder	the build object for chaining.

Throws
NullPointerException	if builder is null

getActions

public List<Notification.Action> getActions ()

Returns the list of Notification.Action present on this car notification.

Returns
List<Notification.Action>

See also:

• CarAppExtender.Builder.addAction(int, CharSequence, PendingIntent)

getColor

public CarColor getColor ()

Returns the background color of the notification or null if a default color is to be used.

Returns
CarColor

See also:

• CarAppExtender.Builder.setColor(CarColor)

getContentIntent

public PendingIntent getContentIntent ()

Returns the PendingIntent to send when the notification is clicked in the car or null if not set.

Returns
PendingIntent

See also:

• CarAppExtender.Builder.setContentIntent(PendingIntent)

getContentText

public CharSequence getContentText ()

Returns the content text of the notification or null if not set.

Returns
CharSequence

See also:

• CarAppExtender.Builder.setContentText(CharSequence)

getContentTitle

public CharSequence getContentTitle ()

Returns the content title for the notification or null if not set.

Returns
CharSequence

See also:

• CarAppExtender.Builder.setContentTitle(CharSequence)

getDeleteIntent

public PendingIntent getDeleteIntent ()

Returns the PendingIntent to send when the notification is cleared by the user or null if not set.

Returns
PendingIntent

See also:

• CarAppExtender.Builder.setDeleteIntent(PendingIntent)

getImportance

public int getImportance ()

Returns the importance of the notification in the car screen.

Returns
int

See also:

• CarAppExtender.Builder.setImportance(int)

getLargeIcon

public Bitmap getLargeIcon ()

Returns the large icon bitmap to display in the notification or null if not set.

Returns
Bitmap

See also:

• CarAppExtender.Builder.setLargeIcon(Bitmap)

getSmallIcon

public int getSmallIcon ()

Returns the resource ID of the small icon drawable to use.

Returns
int

See also:

• CarAppExtender.Builder.setSmallIcon(int)

isExtended

public static boolean isExtended (Notification notification)

Returns whether the given notification was extended with CarAppExtender.

Parameters
notification	Notification

Returns
boolean

Throws
NullPointerException	if notification is null