1 files changed, 47 insertions, 0 deletions
diff --git a/src/mbgl/layermanager/layer_factory.cpp b/src/mbgl/layermanager/layer_factory.cpp
new file mode 100644
index 0000000000..c7f63b8699
--- /dev/null
+++ b/src/mbgl/layermanager/layer_factory.cpp
@@ -0,0 +1,47 @@
+#include <mbgl/layermanager/layer_factory.hpp>
+
+#include <mbgl/style/conversion/constant.hpp>
+#include <mbgl/style/conversion/filter.hpp>
+#include <mbgl/style/conversion_impl.hpp>
+#include <mbgl/style/layer.hpp>
+
+namespace mbgl {
+
+optional<std::string> LayerFactory::getSource(const style::conversion::Convertible& value) const noexcept {
+    auto sourceValue = objectMember(value, "source");
+    if (!sourceValue) {
+        return nullopt;
+    }
+
+    optional<std::string> source = toString(*sourceValue);
+    if (!source) {
+        return nullopt;
+    }
+
+    return source;
+}
+
+bool LayerFactory::initSourceLayerAndFilter(style::Layer* layer, const style::conversion::Convertible& value) const noexcept {
+    auto sourceLayerValue = objectMember(value, "source-layer");
+    if (sourceLayerValue) {
+        optional<std::string> sourceLayer = toString(*sourceLayerValue);
+        if (!sourceLayer) {
+            return false;
+        }
+        layer->setSourceLayer(*sourceLayer);
+    }
+
+    auto filterValue = objectMember(value, "filter");
+    if (filterValue) {
+        style::conversion::Error error;
+        optional<style::Filter> filter = style::conversion::convert<style::Filter>(*filterValue, error);
+        if (!filter) {
+            return false;
+        }
+        layer->setFilter(*filter);
+    }
+
+    return true;
+}
+
+} // namespace mbgl