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NavigationManager

public class NavigationManager
extends Object

java.lang.Object
   ↳ com.google.android.libraries.car.app.navigation.NavigationManager


Manager for communicating navigation related events with the host.

Navigation apps must use this interface to coordinate with the car system for navigation specific resources such as vehicle cluster and heads-up displays.

When a navigation app receives a user action to start navigating, it should call navigationStarted() to indicate it is currently navigating. When the app receives a user action to end navigation or when the destination is reached, navigationEnded() should be called.

Navigation apps must also register a NavigationManagerListener to handle callbacks to NavigationManagerListener.stopNavigation() issued by the host.

Summary

Public methods

void navigationEnded()

Notifies the host that the app has ended active navigation.

void navigationStarted()

Notifies the host that the app has started active navigation.

void setListener(NavigationManagerListener listener)

Sets a listener to start receiving navigation manager events, or null to clear the listener.

void stopNavigation()

Tells the app to stop navigating.

void updateTrip(Trip trip)

Sends the destinations, steps, and trip estimates to the host.

Inherited methods

Public methods

public void navigationEnded ()

Notifies the host that the app has ended active navigation.

Only one app may be actively navigating in the car at any time and ownership is managed by the host. The app must call this method to inform the system that it has ended navigation, for example, in response to the user cancelling navigation or upon reaching the destination.

This method is idempotent.

Throws
IllegalStateException if the current thread is not the main thread.
public void navigationStarted ()

Notifies the host that the app has started active navigation.

Only one app may be actively navigating in the car at any time and ownership is managed by the host. The app must call this method to inform the system that it has started navigation in response to user action.

This function can only called if setListener(NavigationManagerListener) has been called with a non-null value. The listener is required so that a signal to stop navigation from the host can be handled using NavigationManagerListener.stopNavigation().

This method is idempotent.

Throws
IllegalStateException if no navigation manager listener has been set.
IllegalStateException if the current thread is not the main thread.

setListener

public void setListener (NavigationManagerListener listener)

Sets a listener to start receiving navigation manager events, or null to clear the listener.

Parameters
listener NavigationManagerListener

Throws
IllegalStateException if null is passed in while navigation is started. See navigationStarted() for more info.
IllegalStateException if the current thread is not the main thread.

stopNavigation

public void stopNavigation ()

Tells the app to stop navigating.

updateTrip

public void updateTrip (Trip trip)

Sends the destinations, steps, and trip estimates to the host.

The data may be rendered at different places in the car such as the instrument cluster screen or the heads-up display.

This method should only be invoked once the navigation app has called navigationStarted(), or else the updates will be dropped by the host. Once the app has called navigationEnded() or received NavigationManagerListener.stopNavigation() it should stop sending updates.

As the location changes, and in accordance with speed and rounded distance changes, the TravelEstimates in the provided Trip should be rebuilt and this method called again. For example, when the next step is greater than 10 kilometers away and the display unit is kilometers, updates should occur roughly every kilometer.

Data provided to the cluster display depends on the vehicle capabilities. In some instances the information may not be shown at all. On some vehicles Maneuvers of unknown type may be skipped while on other displays the associated icon may be shown.

Parameters
trip Trip

Throws
HostException if the call is invoked by an app that is not declared as a navigation app in the manifest.
IllegalStateException if the call occurs when navigation is not started. See navigationStarted() for more info.
IllegalArgumentException if any of the destinations, steps, or trip position is not well formed.
IllegalStateException if the current thread is not the main thread.