add nullability annotations

core/src/main/java/com/mapzen/android/core/ApiKeyChangeListener.java

@@ -1,5 +1,7 @@
 package com.mapzen.android.core;
 
+import android.support.annotation.NonNull;
+
 /**
  * Listener for handling changes to API key.
  */
@@ -8,5 +10,5 @@ public interface ApiKeyChangeListener {
    * Called when the {@link MapzenManager}'s API key is changed.
    * @param apiKey the current API key
    */
-  void onApiKeyChanged(String apiKey);
+  void onApiKeyChanged(@NonNull String apiKey);
 }

core/src/main/java/com/mapzen/android/core/GenericHttpHandler.java

@@ -1,6 +1,7 @@
 package com.mapzen.android.core;
 
 import android.os.Build;
+import android.support.annotation.Nullable;
 
 import java.util.Map;
 
@@ -75,11 +76,11 @@ enum LogLevel {
    * Return query parameters to be appended to every request.
    * @return
    */
-  Map<String, String> queryParamsForRequest();
+  @Nullable Map<String, String> queryParamsForRequest();
 
   /**
    * Return headers to be added to every request.
    * @return
    */
-  Map<String, String> headersForRequest();
+  @Nullable Map<String, String> headersForRequest();
 }

core/src/main/java/com/mapzen/android/core/MapzenManager.java

@@ -4,6 +4,7 @@
 
 import android.content.Context;
 import android.content.res.Resources;
+import android.support.annotation.NonNull;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -42,7 +43,7 @@ public class MapzenManager {
   /**
    * Get singleton instance.
    */
-  public static MapzenManager instance(Context context) {
+  public static @NonNull MapzenManager instance(@NonNull Context context) {
     if (instance == null) {
       instance = new MapzenManager(context.getApplicationContext());
     }
@@ -55,7 +56,7 @@ public static MapzenManager instance(Context context) {
   /**
    * Creates a new instance of the manager.
    */
-  private MapzenManager(Context context) {
+  private MapzenManager(@NonNull Context context) {
     final Resources resources = context.getResources();
     if (resources != null) {
       int id = resources.getIdentifier(API_KEY_RES_NAME, API_KEY_RES_TYPE,
@@ -72,7 +73,7 @@ private MapzenManager(Context context) {
    * @throws IllegalStateException if a valid API key has not been set in code or as a string
    * resource.
    */
-  public String getApiKey() {
+  public @NonNull String getApiKey() {
     if (apiKey == null || API_KEY_DEFAULT_VALUE.equals(apiKey)) {
       throw new IllegalStateException("A valid Mapzen API key has not been provided. Please visit "
           + "https://mapzen.com/documentation/android/getting-started/ to learn how.");
@@ -84,7 +85,7 @@ public String getApiKey() {
   /**
    * Sets a new API key value. This will override any previous key including those declared in xml.
    */
-  public void setApiKey(String apiKey) {
+  public void setApiKey(@NonNull String apiKey) {
     this.apiKey = apiKey;
     notifyListeners();
   }
@@ -93,7 +94,7 @@ public void setApiKey(String apiKey) {
    * Returns the maven artifact version.
    * @return
    */
-  public static String getSdkVersion() {
+  public static @NonNull String getSdkVersion() {
     return BuildConfig.SDK_VERSION;
   }
 
@@ -102,15 +103,15 @@ public static String getSdkVersion() {
    * occur.
    * @param listener
    */
-  public void addApiKeyChangeListener(ApiKeyChangeListener listener) {
+  public void addApiKeyChangeListener(@NonNull ApiKeyChangeListener listener) {
     Collections.synchronizedList(listeners).add(listener);
   }
 
   /**
    * Removes listener from list of managed callbacks.
    * @param listener
    */
-  public void removeApiKeyChangeListener(ApiKeyChangeListener listener) {
+  public void removeApiKeyChangeListener(@NonNull ApiKeyChangeListener listener) {
     Collections.synchronizedList(listeners).remove(listener);
   }
 

core/src/main/java/com/mapzen/android/graphics/DataLayerType.java

@@ -1,5 +1,7 @@
 package com.mapzen.android.graphics;
 
+import android.support.annotation.NonNull;
+
 /**
  * Default data layers for bundled Mapzen stylesheets including Bubble Wrap, Cinnabar, and Refill.
  * Used to add client data layers to the map and optionally persist them on configuration change.
@@ -32,7 +34,7 @@ public enum DataLayerType {
    * Returns the enum's name.
    * @return
    */
-  public String toString() {
+  @NonNull public String toString() {
     return name;
   }
 }

core/src/main/java/com/mapzen/android/graphics/FeaturePickListener.java

@@ -1,5 +1,7 @@
 package com.mapzen.android.graphics;
 
+import android.support.annotation.NonNull;
+
 import java.util.Map;
 
 /**
@@ -22,5 +24,5 @@ public interface FeaturePickListener {
    * @param positionX The horizontal screen coordinate of the center of the feature
    * @param positionY The vertical screen coordinate of the center of the feature
    */
-  void onFeaturePick(Map<String, String> properties, float positionX, float positionY);
+  void onFeaturePick(@NonNull Map<String, String> properties, float positionX, float positionY);
 }

core/src/main/java/com/mapzen/android/graphics/LabelPickListener.java

@@ -2,6 +2,8 @@
 
 import com.mapzen.tangram.LabelPickResult;
 
+import android.support.annotation.NonNull;
+
 /**
  * Listener invoked when a label on the map is selected.
  */
@@ -27,5 +29,5 @@ public interface LabelPickListener {
    * @param positionY The vertical screen coordinate of the center of the feature. Will be 0 if
    * {@link LabelPickResult} is null.
    */
-  void onLabelPicked(LabelPickResult result, float positionX, float positionY);
+  void onLabelPicked(@NonNull LabelPickResult result, float positionX, float positionY);
 }

core/src/main/java/com/mapzen/android/graphics/MapView.java

@@ -106,7 +106,7 @@ private void initViews(Context context) {
   /**
    * Get the underlying Tangram map object.
    */
-  public TangramMapView getTangramMapView() {
+  @NonNull public TangramMapView getTangramMapView() {
     return tangramMapView;
   }
 
@@ -127,7 +127,7 @@ public void getMapAsync(@NonNull OnMapReadyCallback callback) {
    * @param mapStyle mapStyle that should be set.
    * @param callback listener to be invoked when map is initialized and ready to use.
    */
-  public void getMapAsync(MapStyle mapStyle, @NonNull OnMapReadyCallback callback) {
+  public void getMapAsync(@NonNull MapStyle mapStyle, @NonNull OnMapReadyCallback callback) {
     mapInitializer.init(this, mapStyle, callback);
   }
 
@@ -139,21 +139,22 @@ public void getMapAsync(MapStyle mapStyle, @NonNull OnMapReadyCallback callback)
    * @param locale used to determine language that should be used for map labels.
    * @param callback listener to be invoked when map is initialized and ready to use.
    */
-  public void getMapAsync(MapStyle mapStyle, Locale locale, @NonNull OnMapReadyCallback callback) {
+  public void getMapAsync(@NonNull MapStyle mapStyle, @NonNull Locale locale,
+      @NonNull OnMapReadyCallback callback) {
     mapInitializer.init(this, mapStyle, locale, callback);
   }
 
   /**
    * Get the compass button.
    */
-  public CompassView getCompass() {
+  @NonNull public CompassView getCompass() {
     return compass;
   }
 
   /**
    * Show compass button.
    */
-  public CompassView showCompass() {
+  @NonNull public CompassView showCompass() {
     compass.setVisibility(View.VISIBLE);
     return compass;
   }
@@ -168,14 +169,14 @@ public void hideCompass() {
   /**
    * Get the find me button.
    */
-  public ImageButton getFindMe() {
+  @NonNull public ImageButton getFindMe() {
     return findMe;
   }
 
   /**
    * Show button for finding user's location on map.
    */
-  public ImageButton showFindMe() {
+  @NonNull public ImageButton showFindMe() {
     findMe.setVisibility(View.VISIBLE);
     return findMe;
   }
@@ -190,14 +191,14 @@ public void hideFindMe() {
   /**
    * Get the zoom in button.
    */
-  public ImageButton getZoomIn() {
+  @NonNull public ImageButton getZoomIn() {
     return zoomIn;
   }
 
   /**
    * Show button for zooming in.
    */
-  public ImageButton showZoomIn() {
+  @NonNull public ImageButton showZoomIn() {
     zoomIn.setVisibility(View.VISIBLE);
     return zoomIn;
   }
@@ -212,14 +213,14 @@ public void hideZoomIn() {
   /**
    * Get the zoom out button.
    */
-  public ImageButton getZoomOut() {
+  @NonNull public ImageButton getZoomOut() {
     return zoomOut;
   }
 
   /**
    * Show button for zooming out.
    */
-  public ImageButton showZoomOut() {
+  @NonNull public ImageButton showZoomOut() {
     zoomOut.setVisibility(View.VISIBLE);
     return zoomOut;
   }
@@ -234,7 +235,7 @@ public void hideZoomOut() {
   /**
    * Return the attribution text view.
    */
-  public TextView getAttribution() {
+  @NonNull public TextView getAttribution() {
     return attribution;
   }
 
@@ -250,7 +251,7 @@ public void onDestroy() {
     getTangramMapView().onDestroy();
   }
 
-  void setMapzenMap(MapzenMap mapzenMap) {
+  void setMapzenMap(@NonNull MapzenMap mapzenMap) {
     this.mapzenMap = mapzenMap;
   }
 }