1 files changed, 67 insertions, 12 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/location/LocationComponent.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/location/LocationComponent.java
index 7e312a8158..b6246f4abc 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/location/LocationComponent.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/location/LocationComponent.java
@@ -107,6 +107,7 @@ public final class LocationComponent {
   private LocationEngineCallback<LocationEngineResult> lastLocationEngineListener
     = new LastLocationEngineCallback(this);
 
+  @Nullable
   private CompassEngine compassEngine;
 
   private LocationLayerController locationLayerController;
@@ -146,6 +147,11 @@ public final class LocationComponent {
    */
   private boolean isLayerReady;
 
+  /**
+   * Indicates whether we are listening for compass updates.
+   */
+  private boolean isListeningToCompass;
+
   private StaleStateManager staleStateManager;
   private final CopyOnWriteArrayList<OnLocationStaleListener> onLocationStaleListeners
     = new CopyOnWriteArrayList<>();
@@ -439,6 +445,7 @@ public final class LocationComponent {
   public void setCameraMode(@CameraMode.Mode int cameraMode,
                             @Nullable OnLocationCameraTransitionListener transitionListener) {
     locationCameraController.setCameraMode(cameraMode, lastLocation, new CameraTransitionListener(transitionListener));
+    updateCompassListenerState(true);
   }
 
   /**
@@ -498,6 +505,7 @@ public final class LocationComponent {
   public void setRenderMode(@RenderMode.Mode int renderMode) {
     locationLayerController.setRenderMode(renderMode);
     updateLayerOffsets(true);
+    updateCompassListenerState(true);
   }
 
   /**
@@ -734,10 +742,12 @@ public final class LocationComponent {
    *
    * @param compassEngine to be used
    */
-  public void setCompassEngine(@NonNull CompassEngine compassEngine) {
-    this.compassEngine.removeCompassListener(compassListener);
+  public void setCompassEngine(@Nullable CompassEngine compassEngine) {
+    if (this.compassEngine != null) {
+      updateCompassListenerState(false);
+    }
     this.compassEngine = compassEngine;
-    compassEngine.addCompassListener(compassListener);
+    updateCompassListenerState(true);
   }
 
   /**
@@ -745,7 +755,7 @@ public final class LocationComponent {
    *
    * @return compass engine currently being used
    */
-  @NonNull
+  @Nullable
   public CompassEngine getCompassEngine() {
     return compassEngine;
   }
@@ -767,9 +777,11 @@ public final class LocationComponent {
    * The last known accuracy of the compass sensor, one of SensorManager.SENSOR_STATUS_*
    *
    * @return the last know compass accuracy bearing
+   * @deprecated Use {@link #getCompassEngine()}
    */
+  @Deprecated
   public float getLastKnownCompassAccuracyStatus() {
-    return compassEngine.getLastAccuracySensorStatus();
+    return compassEngine != null ? compassEngine.getLastAccuracySensorStatus() : 0;
   }
 
   /**
@@ -778,9 +790,13 @@ public final class LocationComponent {
    *
    * @param compassListener a {@link CompassListener} for listening into compass heading and
    *                        accuracy changes
+   * @deprecated Use {@link #getCompassEngine()}
    */
+  @Deprecated
   public void addCompassListener(@NonNull CompassListener compassListener) {
-    compassEngine.addCompassListener(compassListener);
+    if (compassEngine != null) {
+      compassEngine.addCompassListener(compassListener);
+    }
   }
 
   /**
@@ -788,9 +804,13 @@ public final class LocationComponent {
    *
    * @param compassListener the {@link CompassListener} which you'd like to remove from the listener
    *                        list.
+   * @deprecated Use {@link #getCompassEngine()}
    */
+  @Deprecated
   public void removeCompassListener(@NonNull CompassListener compassListener) {
-    compassEngine.removeCompassListener(compassListener);
+    if (compassEngine != null) {
+      compassEngine.removeCompassListener(compassListener);
+    }
   }
 
   /**
@@ -934,7 +954,6 @@ public final class LocationComponent {
       if (options.enableStaleState()) {
         staleStateManager.onStart();
       }
-      compassEngine.onStart();
     }
 
     if (isEnabled) {
@@ -948,6 +967,7 @@ public final class LocationComponent {
       }
       setCameraMode(locationCameraController.getCameraMode());
       setLastLocation();
+      updateCompassListenerState(true);
       setLastCompassHeading();
     }
   }
@@ -960,7 +980,9 @@ public final class LocationComponent {
     isLayerReady = false;
     locationLayerController.hide();
     staleStateManager.onStop();
-    compassEngine.onStop();
+    if (compassEngine != null) {
+      updateCompassListenerState(false);
+    }
     locationAnimatorCoordinator.cancelAllAnimations();
     if (locationEngine != null) {
       locationEngine.removeLocationUpdates(currentLocationEngineListener);
@@ -1001,8 +1023,9 @@ public final class LocationComponent {
 
     WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
     SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
-    compassEngine = new LocationComponentCompassEngine(windowManager, sensorManager);
-    compassEngine.addCompassListener(compassListener);
+    if (windowManager != null && sensorManager != null) {
+      compassEngine = new LocationComponentCompassEngine(windowManager, sensorManager);
+    }
     staleStateManager = new StaleStateManager(onLocationStaleListener, options);
 
     updateMapWithOptions(options);
@@ -1022,6 +1045,38 @@ public final class LocationComponent {
     locationEngine = internalLocationEngineProvider.getBestLocationEngine(context, false);
   }
 
+  private void updateCompassListenerState(boolean canListen) {
+    if (compassEngine != null) {
+      if (!canListen) {
+        // We shouldn't listen, simply unregistering
+        removeCompassListener(compassEngine);
+        return;
+      }
+
+      if (!isComponentInitialized || !isComponentStarted || !isEnabled) {
+        return;
+      }
+
+      if (locationCameraController.isConsumingCompass() || locationLayerController.isConsumingCompass()) {
+        // If we have a consumer, and not yet listening, then start listening
+        if (!isListeningToCompass) {
+          isListeningToCompass = true;
+          compassEngine.addCompassListener(compassListener);
+        }
+      } else {
+        // If we have no consumers, stop listening
+        removeCompassListener(compassEngine);
+      }
+    }
+  }
+
+  private void removeCompassListener(@NonNull CompassEngine engine) {
+    if (isListeningToCompass) {
+      isListeningToCompass = false;
+      engine.removeCompassListener(compassListener);
+    }
+  }
+
   private void enableLocationComponent() {
     isEnabled = true;
     onLocationLayerStart();
@@ -1091,7 +1146,7 @@ public final class LocationComponent {
   }
 
   private void setLastCompassHeading() {
-    updateCompassHeading(compassEngine.getLastHeading());
+    updateCompassHeading(compassEngine != null ? compassEngine.getLastHeading() : 0);
   }
 
   @SuppressLint("MissingPermission")