[android] source list accessor + example

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapboxMap.java

@@ -291,6 +291,22 @@ public final class MapboxMap {
     nativeMapView.removeLayer(layer);
   }
 
+  /**
+   * Retrieve all the sources in the style
+   *
+   * @return all the sources in the current style
+   */
+  @UiThread
+  public List<Source> getSources() {
+    return nativeMapView.getSources();
+  }
+
+  /**
+   * Retrieve a source by id
+   *
+   * @param sourceId the source's id
+   * @return the source if present in the current style
+   */
   @Nullable
   @UiThread
   public Source getSource(@NonNull String sourceId) {

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/NativeMapView.java

@@ -782,6 +782,13 @@ final class NativeMapView {
     nativeRemoveLayer(layer.getNativePtr());
   }
 
+  public List<Source> getSources() {
+    if (isDestroyedOn("getSources")) {
+      return null;
+    }
+    return Arrays.asList(nativeGetSources());
+  }
+
   public Source getSource(@NonNull String sourceId) {
     if (isDestroyedOn("getSource")) {
       return null;
@@ -1071,6 +1078,8 @@ final class NativeMapView {
 
   private native void nativeRemoveLayer(long layerId);
 
+  private native Source[] nativeGetSources();
+
   private native Source nativeGetSource(String sourceId);
 
   private native void nativeAddSource(long nativeSourcePtr) throws CannotAddSourceException;

platform/android/MapboxGLAndroidSDKTestApp/src/androidTest/java/com/mapbox/mapboxsdk/testapp/style/RuntimeStyleTests.java

@@ -85,6 +85,26 @@ public class RuntimeStyleTests {
     onView(withId(R.id.mapView)).perform(new AddRemoveLayerAction());
   }
 
+  @Test
+  public void testListSources() {
+    ViewUtils.checkViewIsDisplayed(R.id.mapView);
+    onView(withId(R.id.mapView)).perform(new BaseViewAction() {
+
+      @Override
+      public void perform(UiController uiController, View view) {
+        MapboxMap mapboxMap = rule.getActivity().getMapboxMap();
+
+        List<Source> sources = mapboxMap.getSources();
+        assertNotNull(sources);
+        assertTrue(sources.size() > 0);
+        for (Source source: sources) {
+          assertNotNull(source);
+        }
+      }
+
+    });
+  }
+
   @Test
   public void testAddRemoveSource() {
     ViewUtils.checkViewIsDisplayed(R.id.mapView);

platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/style/RuntimeStyleActivity.java

@@ -154,6 +154,9 @@ public class RuntimeStyleActivity extends AppCompatActivity {
       case R.id.action_list_layers:
         listLayers();
         return true;
+      case R.id.action_list_sources:
+        listSources();
+        return true;
       case R.id.action_water_color:
         setWaterColor();
         return true;
@@ -211,6 +214,16 @@ public class RuntimeStyleActivity extends AppCompatActivity {
     Toast.makeText(this, builder.toString(), Toast.LENGTH_LONG).show();
   }
 
+  private void listSources() {
+    List<Source> sources = mapboxMap.getSources();
+    StringBuilder builder = new StringBuilder("Sources:");
+    for (Source source : sources) {
+      builder.append("\n");
+      builder.append(source.getId());
+    }
+    Toast.makeText(this, builder.toString(), Toast.LENGTH_LONG).show();
+  }
+
   private void setLayerInvisible() {
     String[] roadLayers = new String[] {"water"};
     for (String roadLayer : roadLayers) {

platform/android/MapboxGLAndroidSDKTestApp/src/main/res/menu/menu_runtime_style.xml

@@ -6,6 +6,10 @@
         android:id="@+id/action_list_layers"
         android:title="List all layers in the style"
         mapbox:showAsAction="never" />
+    <item
+        android:id="@+id/action_list_sources"
+        android:title="List all sources in the style"
+        mapbox:showAsAction="never" />
     <item
         android:id="@+id/action_water_color"
         android:title="Color the water"

platform/android/src/native_map_view.cpp

@@ -799,6 +799,22 @@ void NativeMapView::removeLayer(JNIEnv&, jlong layerPtr) {
     }
 }
 
+jni::Array<jni::Object<Source>> NativeMapView::getSources(JNIEnv& env) {
+    // Get the core sources
+    std::vector<style::Source*> sources = map->getSources();
+
+    // Convert
+    jni::Array<jni::Object<Source>> jSources = jni::Array<jni::Object<Source>>::New(env, sources.size(), Source::javaClass);
+    int index = 0;
+    for (auto source : sources) {
+        auto jSource = jni::Object<Source>(createJavaSourcePeer(env, *map, *source));
+        jSources.Set(env, index, jSource);
+        jni::DeleteLocalRef(env, jSource);
+        index++;
+    }
+
+    return jSources;
+}
 
 jni::Object<Source> NativeMapView::getSource(JNIEnv& env, jni::String sourceId) {
     // Find the source
@@ -1356,6 +1372,7 @@ void NativeMapView::registerNative(jni::JNIEnv& env) {
             METHOD(&NativeMapView::addLayer, "nativeAddLayer"),
             METHOD(&NativeMapView::removeLayerById, "nativeRemoveLayerById"),
             METHOD(&NativeMapView::removeLayer, "nativeRemoveLayer"),
+            METHOD(&NativeMapView::getSources, "nativeGetSources"),
             METHOD(&NativeMapView::getSource, "nativeGetSource"),
             METHOD(&NativeMapView::addSource, "nativeAddSource"),
             METHOD(&NativeMapView::removeSourceById, "nativeRemoveSourceById"),

platform/android/src/native_map_view.hpp

@@ -211,6 +211,8 @@ public:
 
     void removeLayer(JNIEnv&, jlong);
 
+    jni::Array<jni::Object<Source>> getSources(JNIEnv&);
+
     jni::Object<Source> getSource(JNIEnv&, jni::String);
 
     void addSource(JNIEnv&, jni::jlong);