Addressed most of PR comments

app/src/main/java/com/mapbox/services/android/navigation/testapp/activity/navigationui/EmbeddedNavigationActivity.java

@@ -91,7 +91,7 @@ private void fetchRoute() {
       .destination(DESTINATION)
       .alternatives(true)
       .build()
-      .getRoute(new NavigationRoute.SimplifiedCallback() {
+      .getRoute(new SimplifiedCallback() {
         @Override
         public void onResponse(Call<DirectionsResponse> call, Response<DirectionsResponse> response) {
           DirectionsRoute directionsRoute = response.body().routes().get(0);

app/src/main/java/com/mapbox/services/android/navigation/testapp/activity/navigationui/NavigationViewActivity.java

@@ -271,7 +271,7 @@ private void fetchRoute() {
       .alternatives(true);
     setFieldsFromSharedPreferences(builder);
     builder.build()
-      .getRoute(new NavigationRoute.SimplifiedCallback() {
+      .getRoute(new SimplifiedCallback() {
         @Override
         public void onResponse(Call<DirectionsResponse> call, Response<DirectionsResponse> response) {
           if (validRouteResponse(response)) {
@@ -292,11 +292,11 @@ public void onResponse(Call<DirectionsResponse> call, Response<DirectionsRespons
 
   private void setFieldsFromSharedPreferences(NavigationRoute.Builder builder) {
     builder
-      .language(getLanguage())
-      .voiceUnits(getUnitType());
+      .language(getLanguageFromSharedPreferences())
+      .voiceUnits(getUnitTypeFromSharedPreferences());
   }
 
-  private String getUnitType() {
+  private String getUnitTypeFromSharedPreferences() {
     SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
     String defaultUnitType = getString(R.string.default_unit_type);
     String unitType = sharedPreferences.getString(getString(R.string.unit_type_key), defaultUnitType);
@@ -307,23 +307,23 @@ private String getUnitType() {
     return unitType;
   }
 
-  private String getLanguage() {
+  private String getLanguageFromSharedPreferences() {
     SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
     String defaultLanguage = getString(R.string.default_locale);
     String language = sharedPreferences.getString(getString(R.string.language_key), defaultLanguage);
     if (language.equals(defaultLanguage)) {
-      language = localeUtils.getDeviceLanguage(this);
+      language = localeUtils.inferDeviceLanguage(this);
     }
 
     return language;
   }
 
-  private boolean getShouldSimulateRoute() {
+  private boolean getShouldSimulateRouteFromSharedPreferences() {
     SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
     return sharedPreferences.getBoolean(getString(R.string.simulate_route_key), false);
   }
 
-  private String getRouteProfile() {
+  private String getRouteProfileFromSharedPreferences() {
     SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
     return sharedPreferences.getString(
       getString(R.string.route_profile_key), DirectionsCriteria.PROFILE_DRIVING_TRAFFIC
@@ -337,8 +337,8 @@ private void launchNavigationWithRoute() {
     }
 
     NavigationLauncherOptions.Builder optionsBuilder = NavigationLauncherOptions.builder()
-      .shouldSimulateRoute(getShouldSimulateRoute())
-      .directionsProfile(getRouteProfile());
+      .shouldSimulateRoute(getShouldSimulateRouteFromSharedPreferences())
+      .directionsProfile(getRouteProfileFromSharedPreferences());
 
     optionsBuilder.directionsRoute(route);
 

app/src/main/java/com/mapbox/services/android/navigation/testapp/activity/navigationui/NavigationViewSettingsActivity.java

@@ -11,9 +11,9 @@
 import com.mapbox.services.android.navigation.testapp.R;
 
 public class NavigationViewSettingsActivity extends PreferenceActivity {
-  SharedPreferences.OnSharedPreferenceChangeListener listener;
-  public static final String UNIT_TYPE_CHANGED = "unit_type_changed";
-  public static final String LANGUAGE_CHANGED = "language_changed";
+  private SharedPreferences.OnSharedPreferenceChangeListener listener;
+  static final String UNIT_TYPE_CHANGED = "unit_type_changed";
+  static final String LANGUAGE_CHANGED = "language_changed";
 
   @Override
   public void onCreate(Bundle savedInstanceState) {

app/src/main/java/com/mapbox/services/android/navigation/testapp/activity/navigationui/SimplifiedCallback.java

@@ -0,0 +1,17 @@
+package com.mapbox.services.android.navigation.testapp.activity.navigationui;
+
+import com.mapbox.api.directions.v5.models.DirectionsResponse;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import timber.log.Timber;
+
+/**
+ * Helper class to reduce redundant logging code when no other action is taken in onFailure
+ */
+public abstract class SimplifiedCallback implements Callback<DirectionsResponse> {
+  @Override
+  public void onFailure(Call<DirectionsResponse> call, Throwable throwable) {
+    Timber.e(throwable, throwable.getMessage());
+  }
+}

app/src/main/java/com/mapbox/services/android/navigation/testapp/activity/navigationui/WaypointNavigationActivity.java

@@ -164,7 +164,7 @@ private void fetchRoute(Point origin, Point destination) {
       .destination(destination)
       .alternatives(true)
       .build()
-      .getRoute(new NavigationRoute.SimplifiedCallback() {
+      .getRoute(new SimplifiedCallback() {
         @Override
         public void onResponse(Call<DirectionsResponse> call, Response<DirectionsResponse> response) {
           startNavigation(response.body().routes().get(0));

app/src/main/java/com/mapbox/services/android/navigation/testapp/activity/navigationui/fragment/NavigationFragment.java

@@ -13,6 +13,7 @@
 import com.mapbox.geojson.Point;
 import com.mapbox.mapboxsdk.Mapbox;
 import com.mapbox.services.android.navigation.testapp.R;
+import com.mapbox.services.android.navigation.testapp.activity.navigationui.SimplifiedCallback;
 import com.mapbox.services.android.navigation.ui.v5.NavigationView;
 import com.mapbox.services.android.navigation.ui.v5.NavigationViewOptions;
 import com.mapbox.services.android.navigation.ui.v5.OnNavigationReadyCallback;
@@ -128,7 +129,7 @@ private void fetchRoute(Point origin, Point destination) {
       .origin(origin)
       .destination(destination)
       .build()
-      .getRoute(new NavigationRoute.SimplifiedCallback() {
+      .getRoute(new SimplifiedCallback() {
         @Override
         public void onResponse(Call<DirectionsResponse> call, Response<DirectionsResponse> response) {
           DirectionsRoute directionsRoute = response.body().routes().get(0);

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/NavigationActivity.java

@@ -18,8 +18,6 @@
  */
 public class NavigationActivity extends AppCompatActivity implements OnNavigationReadyCallback, NavigationListener {
 
-  private static final String EMPTY_STRING = "";
-
   private NavigationView navigationView;
   private boolean isRunning;
 

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/NavigationView.java

@@ -544,7 +544,8 @@ private void establish(NavigationViewOptions options) {
   }
 
   private void establishLanguage(NavigationViewOptions options) {
-    String language = new LocaleUtils().getNonNullLocale(getContext(), options.directionsRoute().voiceLanguage());
+    LocaleUtils localeUtils = new LocaleUtils();
+    String language = localeUtils.getNonEmptyLanguage(getContext(), options.directionsRoute().voiceLanguage());
     instructionView.setLanguage(language);
     summaryBottomSheet.setLanguage(language);
   }

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/NavigationViewModel.java

@@ -159,7 +159,9 @@ void initializeEventDispatcher(NavigationViewEventDispatcher navigationViewEvent
   void initializeNavigation(NavigationViewOptions options) {
     MapboxNavigationOptions navigationOptions = options.navigationOptions();
     navigationOptions = navigationOptions.toBuilder().isFromNavigationUi(true).build();
-    initLocaleInfo(options);
+    LocaleUtils localeUtils = new LocaleUtils();
+    initLanguage(options, localeUtils);
+    initUnitType(options, localeUtils);
     initTimeFormat(navigationOptions);
     initVoiceInstructions();
     if (!isRunning) {
@@ -197,8 +199,11 @@ private void initNavigationLocationEngine() {
     locationEngineConductor = new LocationEngineConductor(locationEngineCallback);
   }
 
-  private void initLocaleInfo(NavigationUiOptions options) {
-    language = new LocaleUtils().getNonNullLocale(getApplication(), options.directionsRoute().voiceLanguage());
+  private void initLanguage(NavigationUiOptions options, LocaleUtils localeUtils) {
+    language = localeUtils.getNonEmptyLanguage(getApplication(), options.directionsRoute().voiceLanguage());
+  }
+
+  private void initUnitType(NavigationUiOptions options, LocaleUtils localeUtils) {
     unitType = options.directionsRoute().routeOptions().voiceUnits();
   }
 

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/InstructionModel.java

@@ -21,8 +21,7 @@ public class InstructionModel {
   private String language;
   private String unitType;
 
-  public InstructionModel(Context context, RouteProgress progress,
-                          String language, String unitType) {
+  public InstructionModel(Context context, RouteProgress progress, String language, String unitType) {
     this.progress = progress;
     this.language = language;
     this.unitType = unitType;

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/InstructionStepResources.java

@@ -26,10 +26,10 @@ class InstructionStepResources {
   private boolean shouldShowThenStep;
   private DistanceUtils distanceUtils;
   private String language;
-  private @DirectionsCriteria.VoiceUnitCriteria String unitType;
+  @DirectionsCriteria.VoiceUnitCriteria
+  private String unitType;
 
-  InstructionStepResources(Context context, RouteProgress progress, String language,
-                           String unitType) {
+  InstructionStepResources(Context context, RouteProgress progress, String language, String unitType) {
     formatStepDistance(context, progress, language, unitType);
     extractStepResources(progress);
   }
@@ -101,7 +101,6 @@ private void formatStepDistance(Context context, RouteProgress progress,
   private boolean shouldDistanceUtilsBeInitialized(String language,
                                                    @DirectionsCriteria.VoiceUnitCriteria String unitType) {
     return distanceUtils == null ||  !this.language.equals(language) || !this.unitType.equals(unitType);
-
   }
 
   private void intersectionTurnLanes(LegStep step) {

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/instruction/InstructionView.java

@@ -327,7 +327,7 @@ public void showInstructionList() {
   }
 
   /**
-   * Sets the locale to use for languages and default unit type
+   * Sets the language to use
    *
    * @param language to use
    */
@@ -348,7 +348,8 @@ public void setUnitType(@DirectionsCriteria.VoiceUnitCriteria String unitType) {
    * Inflates this layout needed for this view and initializes the locale as the device locale.
    */
   private void init() {
-    language = new LocaleUtils().getDeviceLanguage(getContext());
+    LocaleUtils localeUtils = new LocaleUtils();
+    language = localeUtils.inferDeviceLanguage(getContext());
     inflate(getContext(), R.layout.instruction_view_layout, this);
   }
 

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/route/ViewRouteFetcher.java

@@ -45,21 +45,32 @@ public void onErrorReceived(Throwable throwable) {
   /**
    * Checks the options used to launch this {@link com.mapbox.services.android.navigation.ui.v5.NavigationView}.
    * <p>
-   * Will launch with either a {@link DirectionsRoute} or pair of {@link Point}s.
+   * Will launch with a {@link DirectionsRoute}.
    *
-   * @param options holds either a set of {@link Point} coordinates or a {@link DirectionsRoute}
+   * @param options holds a {@link DirectionsRoute}
    */
   public void extractRouteOptions(NavigationViewOptions options) {
     extractRouteFromOptions(options);
   }
 
+  /**
+   * Fetches the route from the off-route event
+   *
+   * @param context to pass to route builder
+   * @param event from which the route progress is extracted
+   */
   public void fetchRouteFromOffRouteEvent(Context context, OffRouteEvent event) {
     if (OffRouteEvent.isValid(event)) {
       RouteProgress routeProgress = event.getRouteProgress();
       findRouteFromRouteProgress(context, rawLocation, routeProgress);
     }
   }
 
+  /**
+   * Updates this object's awareness of the raw location
+   *
+   * @param rawLocation to set
+   */
   public void updateRawLocation(@NonNull Location rawLocation) {
     this.rawLocation = rawLocation;
   }

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/summary/SummaryBottomSheet.java

@@ -135,7 +135,7 @@ public void hideRerouteState() {
   }
 
   /**
-   * Sets the locale to use for languages and default unit type
+   * Sets the language to use for voice language and default unit type
    *
    * @param language to use
    */
@@ -165,7 +165,7 @@ public void setTimeFormat(@NavigationTimeFormat.Type int type) {
    * Inflates this layout needed for this view and initializes the locale as the device locale.
    */
   private void init() {
-    language = new LocaleUtils().getDeviceLanguage(getContext());
+    language = new LocaleUtils().inferDeviceLanguage(getContext());
     inflate(getContext(), R.layout.summary_bottomsheet_layout, this);
   }
 

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/summary/list/InstructionListAdapter.java

@@ -27,7 +27,8 @@ public class InstructionListAdapter extends RecyclerView.Adapter<InstructionView
   private LegStep currentStep;
   private DistanceUtils distanceUtils;
   private String language;
-  private @DirectionsCriteria.VoiceUnitCriteria String unitType;
+  @DirectionsCriteria.VoiceUnitCriteria
+  private String unitType;
 
   public InstructionListAdapter() {
     stepList = new ArrayList<>();

libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/voice/AndroidSpeechPlayer.java

@@ -9,8 +9,7 @@
 import java.util.Locale;
 
 /**
- * Default player used to play voice instructions when
- * {@link com.mapbox.services.android.navigation.ui.v5.NavigationView} is launched without an AWS Cognito Pool ID.
+ * Default player used to play voice instructions when a connection to Polly is unable to be established.
  * <p>
  * This instruction player uses {@link TextToSpeech} to play voice instructions.
  *
@@ -27,6 +26,7 @@ public class AndroidSpeechPlayer implements InstructionPlayer {
    * Creates an instance of {@link AndroidSpeechPlayer}.
    *
    * @param context used to create an instance of {@link TextToSpeech}
+   * @param language to initialize locale to set
    * @since 0.6.0
    */
   AndroidSpeechPlayer(Context context, final String language) {

libandroid-navigation/src/main/java/com/mapbox/services/android/navigation/v5/navigation/NavigationRoute.java

@@ -23,7 +23,6 @@
 
 import retrofit2.Call;
 import retrofit2.Callback;
-import timber.log.Timber;
 
 
 /**
@@ -65,7 +64,8 @@ public static Builder builder(Context context) {
   public static Builder builder(Context context, LocaleUtils localeUtils) {
     return new Builder()
       .annotations(DirectionsCriteria.ANNOTATION_CONGESTION, DirectionsCriteria.ANNOTATION_DISTANCE)
-      .languageAndVoiceUnitsFromContext(context, localeUtils)
+      .language(context, localeUtils)
+      .voiceUnits(context, localeUtils)
       .profile(DirectionsCriteria.PROFILE_DRIVING_TRAFFIC);
   }
 
@@ -275,7 +275,7 @@ public Builder alternatives(@Nullable Boolean alternatives) {
      * select number of languages are currently supported, reference the table provided in the see
      * link below.
      *
-     * @param language a Locale value representing the language you'd like the instructions to be
+     * @param language a string value representing the language you'd like the instructions to be
      *                 written in when returned
      * @return this builder for chaining options together
      * @see <a href="https://www.mapbox.com/api-documentation/#instructions-languages">Supported
@@ -287,6 +287,11 @@ public Builder language(String language) {
       return this;
     }
 
+    Builder language(Context context, LocaleUtils localeUtils) {
+      directionsBuilder.language(localeUtils.inferDeviceLocale(context));
+      return this;
+    }
+
     /**
      * Whether or not to return additional metadata along the route. Possible values are:
      * {@link DirectionsCriteria#ANNOTATION_DISTANCE},
@@ -380,6 +385,11 @@ public Builder voiceUnits(@VoiceUnitCriteria String voiceUnits) {
       return this;
     }
 
+    Builder voiceUnits(Context context, LocaleUtils localeUtils) {
+      directionsBuilder.voiceUnits(localeUtils.getUnitTypeForDeviceLocale(context));
+      return this;
+    }
+
     /**
      * Exclude specific road classes such as highways, tolls, and more.
      *
@@ -430,12 +440,6 @@ public Builder baseUrl(String baseUrl) {
       return this;
     }
 
-    protected Builder languageAndVoiceUnitsFromContext(Context context, LocaleUtils localeUtils) {
-      directionsBuilder.language(localeUtils.getDeviceLocale(context))
-        .voiceUnits(localeUtils.getUnitTypeForDeviceLocale(context));
-      return this;
-    }
-
     /**
      * Optionally create a {@link Builder} based on all variables
      * from given {@link RouteOptions}.
@@ -509,14 +513,4 @@ public NavigationRoute build() {
       return new NavigationRoute(directionsBuilder.build());
     }
   }
-
-  /**
-   * Helper class to reduce redundant logging code when no other action is taken in onFailure
-   */
-  public abstract static class SimplifiedCallback implements Callback<DirectionsResponse> {
-    @Override
-    public void onFailure(Call<DirectionsResponse> call, Throwable throwable) {
-      Timber.e(throwable, throwable.getMessage());
-    }
-  }
 }