[android] fix layer ownership

3 files changed, 31 insertions, 10 deletions

diff --git a/platform/android/src/jni.cpp b/platform/android/src/jni.cpp
index 1168fb9b89..832fa436c7 100755
--- a/platform/android/src/jni.cpp
+++ b/platform/android/src/jni.cpp
@@ -1100,12 +1100,13 @@ void nativeAddLayer(JNIEnv *env, jni::jobject* obj, jlong nativeMapViewPtr, jlon
     assert(nativeLayerPtr != 0);
 
     NativeMapView *nativeMapView = reinterpret_cast<NativeMapView *>(nativeMapViewPtr);
-    Layer *layer = reinterpret_cast<Layer *>(nativeLayerPtr);
 
-    nativeMapView->getMap().addLayer(
-        layer->releaseCoreLayer(),
-        before ? mbgl::optional<std::string>(std_string_from_jstring(env, before)) : mbgl::optional<std::string>()
-    );
+    Layer *layer = reinterpret_cast<Layer *>(nativeLayerPtr);
+    try {
+        layer->addToMap(nativeMapView->getMap(), before ? mbgl::optional<std::string>(std_string_from_jstring(env, before)) : mbgl::optional<std::string>());
+    } catch (const std::runtime_error& error) {
+        jni::ThrowNew(*env, jni::FindClass(*env, "com/mapbox/mapboxsdk/style/layers/CannotAddLayerException"), error.what());
+    }
 }
 
 void nativeRemoveLayer(JNIEnv *env, jni::jobject* obj, jlong nativeMapViewPtr, jni::jstring* id) {
diff --git a/platform/android/src/style/layers/layer.cpp b/platform/android/src/style/layers/layer.cpp
index 3c1fc0af62..aa6df40470 100644
--- a/platform/android/src/style/layers/layer.cpp
+++ b/platform/android/src/style/layers/layer.cpp
@@ -32,8 +32,17 @@ namespace android {
     Layer::~Layer() {
     }
 
-    jni::String Layer::getId(jni::JNIEnv& env) {
-        return jni::Make<jni::String>(env, layer.getID());
+    void Layer::addToMap(mbgl::Map& _map, mbgl::optional<std::string> before) {
+        //Check to see if we own the layer first
+        if (!ownedLayer) {
+            throw std::runtime_error("Cannot add layer twice");
+        }
+
+        //Add layer to map
+        _map.addLayer(releaseCoreLayer(), before);
+
+        //Save pointer to the map
+        this->map = &_map;
     }
 
     std::unique_ptr<mbgl::style::Layer> Layer::releaseCoreLayer() {
@@ -41,6 +50,10 @@ namespace android {
         return std::move(ownedLayer);
     }
 
+    jni::String Layer::getId(jni::JNIEnv& env) {
+        return jni::Make<jni::String>(env, layer.getID());
+    }
+
     void Layer::setLayoutProperty(jni::JNIEnv& env, jni::String jname, jni::Object<> jvalue) {
         Value value(env, jvalue);
 
diff --git a/platform/android/src/style/layers/layer.hpp b/platform/android/src/style/layers/layer.hpp
index 024a3c38b7..01eac2280b 100644
--- a/platform/android/src/style/layers/layer.hpp
+++ b/platform/android/src/style/layers/layer.hpp
@@ -34,10 +34,9 @@ public:
 
     virtual jni::jobject* createJavaPeer(jni::JNIEnv&) = 0;
 
-    jni::String getId(jni::JNIEnv&);
+    void addToMap(mbgl::Map&, mbgl::optional<std::string>);
 
-    //Release the owned view and return it
-    std::unique_ptr<mbgl::style::Layer> releaseCoreLayer();
+    jni::String getId(jni::JNIEnv&);
 
     void setLayoutProperty(jni::JNIEnv&, jni::String, jni::Object<> value);
 
@@ -64,8 +63,16 @@ public:
     jni::Object<jni::ObjectTag> getVisibility(jni::JNIEnv&);
 
 protected:
+    //Release the owned view and return it
+    std::unique_ptr<mbgl::style::Layer> releaseCoreLayer();
+
+    //Owned layer is set when creating a new layer, before adding it to the map
     std::unique_ptr<mbgl::style::Layer> ownedLayer;
+
+    //Raw reference to the layer
     mbgl::style::Layer& layer;
+
+    //Map is set when the layer is retrieved or after adding to the map
     mbgl::Map* map;
 
 };