7 files changed, 68 insertions, 9 deletions
diff --git a/platform/android/src/style/layers/custom_layer.cpp b/platform/android/src/style/layers/custom_layer.cpp
index 51a48520bf..61e74a9cf5 100644
--- a/platform/android/src/style/layers/custom_layer.cpp
+++ b/platform/android/src/style/layers/custom_layer.cpp
@@ -7,14 +7,10 @@
 namespace mbgl {
 namespace android {
 
-    CustomLayer::CustomLayer(jni::JNIEnv& env, jni::String layerId, jni::jlong initializeFunction, jni::jlong renderFunction, jni::jlong contextLostFunction, jni::jlong deinitializeFunction, jni::jlong context)
+    CustomLayer::CustomLayer(jni::JNIEnv& env, jni::String layerId, jni::jlong host)
         : Layer(env, std::make_unique<mbgl::style::CustomLayer>(
                 jni::Make<std::string>(env, layerId),
-                reinterpret_cast<mbgl::style::CustomLayerInitializeFunction>(initializeFunction),
-                reinterpret_cast<mbgl::style::CustomLayerRenderFunction>(renderFunction),
-                reinterpret_cast<mbgl::style::CustomLayerContextLostFunction>(contextLostFunction),
-                reinterpret_cast<mbgl::style::CustomLayerDeinitializeFunction>(deinitializeFunction),
-                reinterpret_cast<void*>(context))
+                std::unique_ptr<mbgl::style::CustomLayerHost>(reinterpret_cast<mbgl::style::CustomLayerHost*>(host)))
                 ) {
     }
 
@@ -53,7 +49,7 @@ namespace android {
         // Register the peer
         jni::RegisterNativePeer<CustomLayer>(
             env, CustomLayer::javaClass, "nativePtr",
-            std::make_unique<CustomLayer, JNIEnv&, jni::String, jni::jlong, jni::jlong, jni::jlong, jni::jlong, jni::jlong>,
+            std::make_unique<CustomLayer, JNIEnv&, jni::String, jni::jlong>,
             "initialize",
             "finalize",
             METHOD(&CustomLayer::update, "nativeUpdate"));
diff --git a/platform/android/src/style/layers/custom_layer.hpp b/platform/android/src/style/layers/custom_layer.hpp
index 9e079c1288..7eb649d923 100644
--- a/platform/android/src/style/layers/custom_layer.hpp
+++ b/platform/android/src/style/layers/custom_layer.hpp
@@ -16,7 +16,7 @@ public:
 
     static void registerNative(jni::JNIEnv&);
 
-    CustomLayer(jni::JNIEnv&, jni::String, jni::jlong, jni::jlong, jni::jlong, jni::jlong, jni::jlong);
+    CustomLayer(jni::JNIEnv&, jni::String, jni::jlong);
 
     CustomLayer(mbgl::Map&, mbgl::style::CustomLayer&);
 
diff --git a/platform/android/src/style/layers/heatmap_layer.cpp b/platform/android/src/style/layers/heatmap_layer.cpp
index 609499ec93..b3d90faab7 100644
--- a/platform/android/src/style/layers/heatmap_layer.cpp
+++ b/platform/android/src/style/layers/heatmap_layer.cpp
@@ -79,6 +79,16 @@ namespace android {
         layer.as<mbgl::style::HeatmapLayer>()->HeatmapLayer::setHeatmapIntensityTransition(options);
     }
 
+    jni::Object<jni::ObjectTag> HeatmapLayer::getHeatmapColor(jni::JNIEnv& env) {
+        using namespace mbgl::android::conversion;
+        auto propertyValue = layer.as<mbgl::style::HeatmapLayer>()->HeatmapLayer::getHeatmapColor();
+        if (propertyValue.isUndefined()) {
+            propertyValue = layer.as<mbgl::style::HeatmapLayer>()->HeatmapLayer::getDefaultHeatmapColor();
+        }
+        Result<jni::jobject*> converted = convert<jni::jobject*>(env, propertyValue);
+        return jni::Object<jni::ObjectTag>(*converted);
+    }
+
     jni::Object<jni::ObjectTag> HeatmapLayer::getHeatmapOpacity(jni::JNIEnv& env) {
         using namespace mbgl::android::conversion;
         Result<jni::jobject*> converted = convert<jni::jobject*>(env, layer.as<mbgl::style::HeatmapLayer>()->HeatmapLayer::getHeatmapOpacity());
@@ -125,6 +135,7 @@ namespace android {
             METHOD(&HeatmapLayer::getHeatmapIntensityTransition, "nativeGetHeatmapIntensityTransition"),
             METHOD(&HeatmapLayer::setHeatmapIntensityTransition, "nativeSetHeatmapIntensityTransition"),
             METHOD(&HeatmapLayer::getHeatmapIntensity, "nativeGetHeatmapIntensity"),
+            METHOD(&HeatmapLayer::getHeatmapColor, "nativeGetHeatmapColor"),
             METHOD(&HeatmapLayer::getHeatmapOpacityTransition, "nativeGetHeatmapOpacityTransition"),
             METHOD(&HeatmapLayer::setHeatmapOpacityTransition, "nativeSetHeatmapOpacityTransition"),
             METHOD(&HeatmapLayer::getHeatmapOpacity, "nativeGetHeatmapOpacity"));
diff --git a/platform/android/src/style/layers/heatmap_layer.hpp b/platform/android/src/style/layers/heatmap_layer.hpp
index 85f9f0292e..9e8908b062 100644
--- a/platform/android/src/style/layers/heatmap_layer.hpp
+++ b/platform/android/src/style/layers/heatmap_layer.hpp
@@ -39,6 +39,8 @@ public:
     void setHeatmapIntensityTransition(jni::JNIEnv&, jlong duration, jlong delay);
     jni::Object<TransitionOptions> getHeatmapIntensityTransition(jni::JNIEnv&);
 
+    jni::Object<jni::ObjectTag> getHeatmapColor(jni::JNIEnv&);
+
     jni::Object<jni::ObjectTag> getHeatmapOpacity(jni::JNIEnv&);
     void setHeatmapOpacityTransition(jni::JNIEnv&, jlong duration, jlong delay);
     jni::Object<TransitionOptions> getHeatmapOpacityTransition(jni::JNIEnv&);
diff --git a/platform/android/src/style/layers/layer.cpp b/platform/android/src/style/layers/layer.cpp
index 29530879a5..6fe6e3cb29 100644
--- a/platform/android/src/style/layers/layer.cpp
+++ b/platform/android/src/style/layers/layer.cpp
@@ -25,6 +25,7 @@
 
 // C++ -> Java conversion
 #include "../conversion/property_value.hpp"
+#include <mbgl/style/filter.hpp>
 
 #include <string>
 
@@ -134,6 +135,38 @@ namespace android {
         layer.accept(SetFilterEvaluator {std::move(*converted)});
     }
 
+    struct GetFilterEvaluator {
+        mbgl::style::Filter noop(std::string layerType) {
+            Log::Warning(mbgl::Event::JNI, "%s doesn't support filter", layerType.c_str());
+            return {};
+        }
+
+        mbgl::style::Filter operator()(style::BackgroundLayer&) { return noop("BackgroundLayer"); }
+        mbgl::style::Filter operator()(style::CustomLayer&) { return noop("CustomLayer"); }
+        mbgl::style::Filter operator()(style::RasterLayer&) { return noop("RasterLayer"); }
+        mbgl::style::Filter operator()(style::HillshadeLayer&) { return noop("HillshadeLayer"); }
+
+        template <class LayerType>
+            mbgl::style::Filter operator()(LayerType& layer) {
+            return layer.getFilter();
+        }
+    };
+
+    jni::Object<gson::JsonElement> Layer::getFilter(jni::JNIEnv& env) {
+        using namespace mbgl::style;
+        using namespace mbgl::style::conversion;
+
+        Filter filter = layer.accept(GetFilterEvaluator());
+
+        jni::Object<gson::JsonElement> converted;
+        if (filter.is<ExpressionFilter>()) {
+            ExpressionFilter filterExpression = filter.get<ExpressionFilter>();
+            mbgl::Value expressionValue = filterExpression.expression.get()->serialize();
+            converted = gson::JsonElement::New(env, expressionValue);
+        }
+        return converted;
+    }
+
     struct SetSourceLayerEvaluator {
         std::string sourceLayer;
 
@@ -208,6 +241,7 @@ namespace android {
             METHOD(&Layer::setLayoutProperty, "nativeSetLayoutProperty"),
             METHOD(&Layer::setPaintProperty, "nativeSetPaintProperty"),
             METHOD(&Layer::setFilter, "nativeSetFilter"),
+            METHOD(&Layer::getFilter, "nativeGetFilter"),
             METHOD(&Layer::setSourceLayer, "nativeSetSourceLayer"),
             METHOD(&Layer::getSourceLayer, "nativeGetSourceLayer"),
             METHOD(&Layer::getMinZoom, "nativeGetMinZoom"),
diff --git a/platform/android/src/style/layers/layer.cpp.ejs b/platform/android/src/style/layers/layer.cpp.ejs
index 1debb096a3..b08f0ec4dc 100644
--- a/platform/android/src/style/layers/layer.cpp.ejs
+++ b/platform/android/src/style/layers/layer.cpp.ejs
@@ -48,12 +48,25 @@ namespace android {
     // Property getters
 
 <% for (const property of properties) { -%>
+<% if (property.name != 'heatmap-color') { -%>
     jni::Object<jni::ObjectTag> <%- camelize(type) %>Layer::get<%- camelize(property.name) %>(jni::JNIEnv& env) {
         using namespace mbgl::android::conversion;
         Result<jni::jobject*> converted = convert<jni::jobject*>(env, layer.as<mbgl::style::<%- camelize(type) %>Layer>()-><%- camelize(type) %>Layer::get<%- camelize(property.name) %>());
         return jni::Object<jni::ObjectTag>(*converted);
     }
 
+<% } else { -%>
+    jni::Object<jni::ObjectTag> HeatmapLayer::getHeatmapColor(jni::JNIEnv& env) {
+        using namespace mbgl::android::conversion;
+        auto propertyValue = layer.as<mbgl::style::HeatmapLayer>()->HeatmapLayer::getHeatmapColor();
+        if (propertyValue.isUndefined()) {
+            propertyValue = layer.as<mbgl::style::HeatmapLayer>()->HeatmapLayer::getDefaultHeatmapColor();
+        }
+        Result<jni::jobject*> converted = convert<jni::jobject*>(env, propertyValue);
+        return jni::Object<jni::ObjectTag>(*converted);
+    }
+
+<% } -%>
 <% if (property.transition) { -%>
     jni::Object<TransitionOptions> <%- camelize(type) %>Layer::get<%- camelize(property.name) %>Transition(jni::JNIEnv& env) {
         using namespace mbgl::android::conversion;
diff --git a/platform/android/src/style/layers/layer.hpp b/platform/android/src/style/layers/layer.hpp
index 78c3f80b48..2486b0dfa6 100644
--- a/platform/android/src/style/layers/layer.hpp
+++ b/platform/android/src/style/layers/layer.hpp
@@ -3,8 +3,9 @@
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/map/map.hpp>
 #include <mbgl/style/layer.hpp>
-
+#include "../../gson/json_array.hpp"
 #include "../value.hpp"
+#include "../../gson/json_element.hpp"
 
 #include <jni/jni.hpp>
 
@@ -68,6 +69,8 @@ public:
 
     void setFilter(jni::JNIEnv&, jni::Array<jni::Object<>>);
 
+    jni::Object<gson::JsonElement> getFilter(jni::JNIEnv&);
+
     void setSourceLayer(jni::JNIEnv&, jni::String);
 
     jni::String getSourceLayer(jni::JNIEnv&);