[android] refactoring LocationComponentActivationOptions based on cod…

…e review

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/location/LocationComponent.java

@@ -459,16 +459,15 @@ public void activateLocationComponent(@NonNull Context context, @NonNull Style s
     applyStyle(options);
   }
 
+  /**
+   * This method initializes the component and needs to be called before any other operations are performed.
+   * Afterwards, you can manage component's visibility by {@link #setLocationComponentEnabled(boolean)}.
+   *
+   * @param locationComponentActivationOptions a fully built {@link LocationComponentActivationOptions} object
+   */
   public void activateLocationComponent(@NonNull LocationComponentActivationOptions
                                           locationComponentActivationOptions) {
-
-    Log.d(TAG, "locationComponentActivationOptions context packageName = " + locationComponentActivationOptions.context().getPackageName());
-    Log.d(TAG, "locationComponentActivationOptions style URL = " + locationComponentActivationOptions.style().getUrl());
-    Log.d(TAG, "locationComponentActivationOptions styleRes = " + locationComponentActivationOptions.styleRes());
-
-    if (locationComponentActivationOptions.context() != null
-      && locationComponentActivationOptions.style() != null
-      && locationComponentActivationOptions.locationComponentOptions() != null) {
+    if (locationComponentActivationOptions.locationComponentOptions() != null) {
       initialize(locationComponentActivationOptions.context(), locationComponentActivationOptions.style(),
         locationComponentActivationOptions.locationComponentOptions());
     }
@@ -485,24 +484,14 @@ public void activateLocationComponent(@NonNull LocationComponentActivationOption
       setLocationEngine(null);
     }
 
-    // TODO: How to do some sort of null check on an int for locationComponentActivationOptions.styleRes() ?
-    if (locationComponentActivationOptions.styleRes() <0 &&
-      locationComponentActivationOptions.locationComponentOptions() == null
-      && locationComponentActivationOptions.context() != null) {
-
-      applyStyle(LocationComponentOptions.createFromAttributes(locationComponentActivationOptions.context(),
-        R.style.mapbox_LocationComponent));
-
-    } else if (locationComponentActivationOptions.styleRes() <0
-      && locationComponentActivationOptions.locationComponentOptions() == null
-      && locationComponentActivationOptions.context() != null) {
-
+    if (locationComponentActivationOptions.styleRes() == 0 &&
+      locationComponentActivationOptions.locationComponentOptions() == null) {
+        applyStyle(LocationComponentOptions.createFromAttributes(
+          locationComponentActivationOptions.context(), R.style.mapbox_LocationComponent));
+    } else if (locationComponentActivationOptions.styleRes() != 0) {
       applyStyle(LocationComponentOptions.createFromAttributes(locationComponentActivationOptions.context(),
         locationComponentActivationOptions.styleRes()));
-    } else if (locationComponentActivationOptions.styleRes() < 0
-      && locationComponentActivationOptions.locationComponentOptions() != null
-      && locationComponentActivationOptions.context() != null) {
-
+    } else if (locationComponentActivationOptions.locationComponentOptions() != null) {
       applyStyle(locationComponentActivationOptions.locationComponentOptions());
     }
   }

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/location/LocationComponentActivationOptions.java

@@ -9,17 +9,20 @@
 import com.mapbox.mapboxsdk.maps.Style;
 
 /**
+ * A class which holds the various options for activating the Maps SDK's {@link LocationComponent} to eventually
+ * show the device location on the map.
+ *
  * since 7.2.0
  */
 public class LocationComponentActivationOptions {
 
-  private Context context;
-  private Style style;
-  private LocationEngine locationEngine;
-  private LocationEngineRequest locationEngineRequest;
-  private LocationComponentOptions locationComponentOptions;
-  private int styleRes;
-  private boolean useDefaultLocationEngine;
+  private final Context context;
+  private final Style style;
+  private final LocationEngine locationEngine;
+  private final LocationEngineRequest locationEngineRequest;
+  private final LocationComponentOptions locationComponentOptions;
+  private final int styleRes;
+  private final boolean useDefaultLocationEngine;
 
   LocationComponentActivationOptions(@NonNull Context context, @NonNull Style style,
                                      @Nullable LocationEngine locationEngine,
@@ -51,7 +54,7 @@ public static Builder builder(@NonNull Context context, @NonNull Style fullyLoad
    *
    * @return the application's current context
    */
-  @Nullable
+  @NonNull
   public Context context() {
     return context;
   }
@@ -61,7 +64,7 @@ public Context context() {
    *
    * @return the map's fully loaded Style object
    */
-  @Nullable
+  @NonNull
   public Style style() {
     return style;
   }
@@ -95,17 +98,17 @@ public LocationComponentOptions locationComponentOptions() {
   }
 
   /**
-   * the LocationComponent style res
+   * the LocationComponent style resource (e.g. R.style.style_name)
    *
-   * @return
+   * @return the style resource.
    */
   @Nullable
   public int styleRes() {
     return styleRes;
   }
 
   /**
-   * true if you want to initialize and use the built-in location engine or false if there should be no
+   * True if you want to initialize and use the built-in location engine or false if there should be no
    * location engine initialized
    * @return whether the default LocationEngine is used
    */
@@ -133,10 +136,6 @@ public Builder(Context context, Style style) {
       this.style = style;
     }
 
-    public Builder() {
-
-    }
-
     public Builder locationEngine(LocationEngine locationEngine) {
       this.locationEngine = locationEngine;
       return this;
@@ -163,6 +162,21 @@ public Builder useDefaultLocationEngine(boolean useDefaultLocationEngine) {
     }
 
     public LocationComponentActivationOptions build() {
+      if (styleRes != 0 && locationComponentOptions != null) {
+        throw new IllegalArgumentException(
+          "You've provided both a style resource and a LocationComponentOptions object to the " +
+            "LocationComponentActivationOptions builder. You can't use both and " +
+            "you must choose one of the two to style the LocationComponent.");
+      }
+      if (context == null) {
+        throw new NullPointerException(
+          "Context in LocationComponentActivationOptions is null.");
+      }
+      if (style == null) {
+        throw new NullPointerException(
+          "Style in LocationComponentActivationOptions is null. Wait for the map to fully load before " +
+            "passing the Style object to LocationComponentActivationOptions.");
+      }
       return new LocationComponentActivationOptions(context, style, locationEngine, locationEngineRequest,
         locationComponentOptions, styleRes, useDefaultLocationEngine);
     }

platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/location/LocationComponentActivationActivity.java

@@ -13,6 +13,7 @@
 import com.mapbox.mapboxsdk.location.LocationComponent;
 import com.mapbox.mapboxsdk.location.LocationComponentActivationOptions;
 import com.mapbox.mapboxsdk.location.LocationComponentOptions;
+import com.mapbox.mapboxsdk.location.modes.CameraMode;
 import com.mapbox.mapboxsdk.location.modes.RenderMode;
 import com.mapbox.mapboxsdk.maps.MapView;
 import com.mapbox.mapboxsdk.maps.MapboxMap;
@@ -81,18 +82,18 @@ private void activateLocationComponent(@NonNull Style style) {
       .elevation(5)
       .accuracyAlpha(.6f)
       .accuracyColor(Color.GREEN)
-      .foregroundDrawable(R.drawable.mapbox_marker_icon_default)
+      .foregroundDrawable(R.drawable.mapbox_logo_helmet)
       .build();
 
     LocationComponentActivationOptions locationComponentActivationOptions = LocationComponentActivationOptions
       .builder(this, style)
-      .locationComponentOptions(locationComponentOptions)
       .useDefaultLocationEngine(true)
       .build();
 
     locationComponent.activateLocationComponent(locationComponentActivationOptions);
     locationComponent.setLocationComponentEnabled(true);
-    locationComponent.setRenderMode(RenderMode.COMPASS);
+    locationComponent.setRenderMode(RenderMode.NORMAL);
+    locationComponent.setCameraMode(CameraMode.TRACKING);
   }
 
   @Override