Throttle and suppress notifications

To reduce distraction while driving, heads-up notifications (HUN) provide drivers with essential and relevant information without diverting their attention to a display or mobile device. However, since HUNs can interfere with the task of driving, it's crucial to consider the advantages and disadvantages of HUNs to ensure drivers are not distracted.

Use these Android notification-specific safety features to reduce driver distraction:

• Queue and prioritize
• Throttle and pace
• Suppression

This content describes configurations and resources that pertain to platform/packages/apps/Car/Notification.

Queue and prioritize

When multiple incoming HUNs are received, the queue and prioritize mechanism displays the most important and relevant information to the driver.

To enable or disable the queue mechanism, set the boolean value for the config_suppressAndThrottleHeadsUp config.

Queued HUNs are sorted based on priority determined by the category of the notification. Specify the headsup_category_priority array in a descending order of priority.

Some time-sensitive notifications, such as CATEGORY_CALL and CATEGORY_CAR_EMERGENCY, should be displayed immediately instead of queued.

To immediately display these types of HUNs, add these categories to the headsup_category_immediate_show array.

Throttle and pace

When a user performs an action during which it would be unsafe or distracting to show HUNs, such as interacting with Assistant or Dialer, you can throttle HUNs.

To employ throttling, add the package names of apps that require attention to the allowlist (headsup_throttled_foreground_packages). This stops the queue from displaying new HUNs while the specified apps run in the foreground.

To give drivers time to focus on driving, add a time interval between the display of each HUN. This time interval (headsup_delay_duration) applies after packages from headsup_throttled_foreground_packages are moved to the background.

Suppression

HUNs that remain in the queue for an extended period can be suppressed. When HUNs become irrelevant to the driver, they can cause distraction. Instead of triggering a HUN, direct expired notifications to the Notification center. You can tailor your management of HUNs by prescribing different values for the Drive and Park states.

For the Drive state:

1. Set config_expireHeadsUpWhenDriving to true and specify the headsup_queue_expire_driving_duration_ms as the duration (in milliseconds) after the post time when the notification is to expire.

For the Park state:

1. Set config_expireHeadsUpWhenParked to true and specify the headsup_queue_expire_parked_duration_msas the duration (in milliseconds) after the post time when the notification is to expire.

In the event of a suppression, send a trailing system HUN to notify the driver. Modify the title of this notification by updating the values of hun_suppression_notification_title_drive and hun_suppression_notification_title_park

To automatically dismiss the HUN queue when the Notification center is opened:

1. Set the config_dismissHeadsUpWhenNotificationCenterOpens boolean to true.