Harden state and style changes

plugin-locationlayer/src/main/java/com/mapbox/mapboxsdk/plugins/locationlayer/LocationLayer.java

@@ -93,7 +93,8 @@ final class LocationLayer implements LocationLayerAnimator.OnLayerAnimationsValu
     Point.fromLngLat(Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY)
   );
   private GeoJsonSource locationSource;
-  private boolean isSourceInitialized;
+
+  private boolean isHidden;
 
   LocationLayer(MapView mapView, MapboxMap mapboxMap, LocationLayerOptions options) {
     this.mapboxMap = mapboxMap;
@@ -103,10 +104,15 @@ final class LocationLayer implements LocationLayerAnimator.OnLayerAnimationsValu
   }
 
   void initializeComponents(LocationLayerOptions options) {
-    prepareLocationSource();
     addLocationSource();
     addLayers();
     applyStyle(options);
+
+    if (isHidden) {
+      hide();
+    } else {
+      show();
+    }
   }
 
   void applyStyle(@NonNull LocationLayerOptions options) {
@@ -167,12 +173,14 @@ int getRenderMode() {
 
   void show() {
     setRenderMode(renderMode);
+    isHidden = false;
   }
 
   void hide() {
     for (String layerId : layerMap.keySet()) {
       setLayerVisibility(layerId, false);
     }
+    isHidden = true;
   }
 
   private void setLayerVisibility(String layerId, boolean visible) {
@@ -299,7 +307,7 @@ void updateForegroundBearing(float bearing) {
   // Source actions
   //
 
-  private void prepareLocationSource() {
+  private void addLocationSource() {
     locationFeature.addNumberProperty(PROPERTY_GPS_BEARING, 0f);
     locationFeature.addNumberProperty(PROPERTY_COMPASS_BEARING, 0f);
     locationFeature.addBooleanProperty(PROPERTY_LOCATION_STALE, false);
@@ -309,11 +317,8 @@ private void prepareLocationSource() {
       locationFeature,
       new GeoJsonOptions().withMaxZoom(16)
     );
-  }
 
-  private void addLocationSource() {
     mapboxMap.addSource(locationSource);
-    isSourceInitialized = true;
   }
 
   private void refreshSource() {
@@ -326,10 +331,6 @@ private void setLocationPoint(Point locationPoint) {
       locationFeature = Feature.fromGeometry(locationPoint, properties);
       locationSource.setGeoJson(locationFeature);
     }
-
-    if (!isSourceInitialized) {
-      addLocationSource();
-    }
   }
 
   //

plugin-locationlayer/src/main/java/com/mapbox/mapboxsdk/plugins/locationlayer/LocationLayerPlugin.java

@@ -71,6 +71,8 @@ public final class LocationLayerPlugin implements LifecycleObserver {
   private CameraPosition lastCameraPosition;
 
   private boolean isEnabled;
+  private boolean isStarted;
+
   private StaleStateManager staleStateManager;
   private final CopyOnWriteArrayList<OnLocationStaleListener> onLocationStaleListeners
     = new CopyOnWriteArrayList<>();
@@ -163,6 +165,16 @@ public void setLocationLayerEnabled(boolean isEnabled) {
     }
   }
 
+  /**
+   * Returns whether the plugin is enabled, meaning that location can be displayed and camera modes can be used.
+   *
+   * @return true if the plugin is enabled, false otherwise
+   * @since 0.6.0
+   */
+  public boolean isLocationLayerEnabled() {
+    return isEnabled;
+  }
+
   /**
    * Sets the camera mode, which determines how the map camera will track the rendered location.
    * <p>
@@ -441,10 +453,8 @@ public void removeOnLocationStaleListener(@NonNull OnLocationStaleListener liste
    */
   @OnLifecycleEvent(Lifecycle.Event.ON_START)
   public void onStart() {
-    enableLocationLayerPlugin();
-    if (isEnabled) {
-      mapView.addOnMapChangedListener(onMapChangedListener);
-    }
+    onLocationLayerStart();
+    mapView.addOnMapChangedListener(onMapChangedListener);
   }
 
   /**
@@ -454,17 +464,20 @@ public void onStart() {
    */
   @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
   public void onStop() {
-    disableLocationLayerPlugin();
+    onLocationLayerStop();
     mapView.removeOnMapChangedListener(onMapChangedListener);
   }
 
   void onLocationLayerStart() {
+    isStarted = true;
     if (isEnabled) {
       if (locationEngine != null) {
         locationEngine.addLocationEngineListener(locationEngineListener);
       }
       setLastLocation();
       setLastCompassHeading();
+      locationLayer.show();
+      setCameraMode(locationLayerCamera.getCameraMode());
     }
     if (mapboxMap != null) {
       mapboxMap.addOnCameraMoveListener(onCameraMoveListener);
@@ -476,6 +489,8 @@ void onLocationLayerStart() {
   }
 
   void onLocationLayerStop() {
+    isStarted = false;
+    locationLayer.hide();
     staleStateManager.onStop();
     compassManager.onStop();
     locationLayerAnimator.cancelAllAnimations();
@@ -522,13 +537,11 @@ private void initializeLocationEngine() {
   private void enableLocationLayerPlugin() {
     isEnabled = true;
     onLocationLayerStart();
-    locationLayer.show();
   }
 
   private void disableLocationLayerPlugin() {
     isEnabled = false;
     onLocationLayerStop();
-    locationLayer.hide();
   }
 
   private void updateMapWithOptions(final LocationLayerOptions options) {
@@ -547,7 +560,7 @@ private void updateMapWithOptions(final LocationLayerOptions options) {
    * @since 0.1.0
    */
   private void updateLocation(final Location location) {
-    if (location == null || !isEnabled) {
+    if (location == null || !isStarted) {
       return;
     }
     staleStateManager.updateLatestLocationTime();
@@ -649,8 +662,6 @@ public void onMapChanged(int change) {
       } else if (change == MapView.DID_FINISH_LOADING_STYLE) {
         locationLayer.initializeComponents(options);
         locationLayerCamera.initializeOptions(options);
-        setRenderMode(locationLayer.getRenderMode());
-        setCameraMode(locationLayerCamera.getCameraMode());
         onLocationLayerStart();
       }
     }