11 files changed, 104 insertions, 30 deletions
diff --git a/include/mbgl/style/layers/background_layer.hpp b/include/mbgl/style/layers/background_layer.hpp
index 989ef54b21..61e95d2273 100644
--- a/include/mbgl/style/layers/background_layer.hpp
+++ b/include/mbgl/style/layers/background_layer.hpp
@@ -57,11 +57,17 @@ protected:
 };
 
 class BackgroundLayerFactory : public LayerFactory {
-protected:
+public:
+    BackgroundLayerFactory();
     // LayerFactory overrides.
     ~BackgroundLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static BackgroundLayerFactory* get();
+
+private:
+    static BackgroundLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/circle_layer.hpp b/include/mbgl/style/layers/circle_layer.hpp
index dd22275b85..92a6bbd92e 100644
--- a/include/mbgl/style/layers/circle_layer.hpp
+++ b/include/mbgl/style/layers/circle_layer.hpp
@@ -105,11 +105,17 @@ protected:
 };
 
 class CircleLayerFactory : public LayerFactory {
-protected:
+public:
+    CircleLayerFactory();
     // LayerFactory overrides.
     ~CircleLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static CircleLayerFactory* get();
+
+private:
+    static CircleLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/custom_layer.hpp b/include/mbgl/style/layers/custom_layer.hpp
index 4ae59dfae3..f58e41adf5 100644
--- a/include/mbgl/style/layers/custom_layer.hpp
+++ b/include/mbgl/style/layers/custom_layer.hpp
@@ -85,5 +85,19 @@ public:
     Mutable<Layer::Impl> mutableBaseImpl() const final;
 };
 
+class CustomLayerFactory : public LayerFactory {
+public:
+    CustomLayerFactory();
+    // LayerFactory overrides.
+    ~CustomLayerFactory() override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static CustomLayerFactory* get();
+
+private:
+    static CustomLayerFactory* instance;
+};
+
 } // namespace style
 } // namespace mbgl
diff --git a/include/mbgl/style/layers/fill_extrusion_layer.hpp b/include/mbgl/style/layers/fill_extrusion_layer.hpp
index fcc66e782b..bc761f2bec 100644
--- a/include/mbgl/style/layers/fill_extrusion_layer.hpp
+++ b/include/mbgl/style/layers/fill_extrusion_layer.hpp
@@ -81,11 +81,17 @@ protected:
 };
 
 class FillExtrusionLayerFactory : public LayerFactory {
-protected:
+public:
+    FillExtrusionLayerFactory();
     // LayerFactory overrides.
     ~FillExtrusionLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static FillExtrusionLayerFactory* get();
+
+private:
+    static FillExtrusionLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/fill_layer.hpp b/include/mbgl/style/layers/fill_layer.hpp
index 0c36435ffc..7ef6727691 100644
--- a/include/mbgl/style/layers/fill_layer.hpp
+++ b/include/mbgl/style/layers/fill_layer.hpp
@@ -81,11 +81,17 @@ protected:
 };
 
 class FillLayerFactory : public LayerFactory {
-protected:
+public:
+    FillLayerFactory();
     // LayerFactory overrides.
     ~FillLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static FillLayerFactory* get();
+
+private:
+    static FillLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/heatmap_layer.hpp b/include/mbgl/style/layers/heatmap_layer.hpp
index 3f53877523..e38c6ab6e1 100644
--- a/include/mbgl/style/layers/heatmap_layer.hpp
+++ b/include/mbgl/style/layers/heatmap_layer.hpp
@@ -70,11 +70,17 @@ protected:
 };
 
 class HeatmapLayerFactory : public LayerFactory {
-protected:
+public:
+    HeatmapLayerFactory();
     // LayerFactory overrides.
     ~HeatmapLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static HeatmapLayerFactory* get();
+
+private:
+    static HeatmapLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/hillshade_layer.hpp b/include/mbgl/style/layers/hillshade_layer.hpp
index 3227505f5d..e1e9a4d0a1 100644
--- a/include/mbgl/style/layers/hillshade_layer.hpp
+++ b/include/mbgl/style/layers/hillshade_layer.hpp
@@ -75,11 +75,17 @@ protected:
 };
 
 class HillshadeLayerFactory : public LayerFactory {
-protected:
+public:
+    HillshadeLayerFactory();
     // LayerFactory overrides.
     ~HillshadeLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static HillshadeLayerFactory* get();
+
+private:
+    static HillshadeLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/layer.hpp.ejs b/include/mbgl/style/layers/layer.hpp.ejs
index b19b501713..6006352eee 100644
--- a/include/mbgl/style/layers/layer.hpp.ejs
+++ b/include/mbgl/style/layers/layer.hpp.ejs
@@ -73,11 +73,17 @@ protected:
 };
 
 class <%- camelize(type) %>LayerFactory : public LayerFactory {
-protected:
+public:
+    <%- camelize(type) %>LayerFactory();
     // LayerFactory overrides.
     ~<%- camelize(type) %>LayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static <%- camelize(type) %>LayerFactory* get();
+
+private:
+    static <%- camelize(type) %>LayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/line_layer.hpp b/include/mbgl/style/layers/line_layer.hpp
index 62cca8215d..de1ed8eef1 100644
--- a/include/mbgl/style/layers/line_layer.hpp
+++ b/include/mbgl/style/layers/line_layer.hpp
@@ -126,11 +126,17 @@ protected:
 };
 
 class LineLayerFactory : public LayerFactory {
-protected:
+public:
+    LineLayerFactory();
     // LayerFactory overrides.
     ~LineLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static LineLayerFactory* get();
+
+private:
+    static LineLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/raster_layer.hpp b/include/mbgl/style/layers/raster_layer.hpp
index 27057c6af7..5cf06a7d98 100644
--- a/include/mbgl/style/layers/raster_layer.hpp
+++ b/include/mbgl/style/layers/raster_layer.hpp
@@ -87,11 +87,17 @@ protected:
 };
 
 class RasterLayerFactory : public LayerFactory {
-protected:
+public:
+    RasterLayerFactory();
     // LayerFactory overrides.
     ~RasterLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static RasterLayerFactory* get();
+
+private:
+    static RasterLayerFactory* instance;
 };
 
 } // namespace style
diff --git a/include/mbgl/style/layers/symbol_layer.hpp b/include/mbgl/style/layers/symbol_layer.hpp
index 6c0ec6ca6e..5dac5925dd 100644
--- a/include/mbgl/style/layers/symbol_layer.hpp
+++ b/include/mbgl/style/layers/symbol_layer.hpp
@@ -275,11 +275,17 @@ protected:
 };
 
 class SymbolLayerFactory : public LayerFactory {
-protected:
+public:
+    SymbolLayerFactory();
     // LayerFactory overrides.
     ~SymbolLayerFactory() override;
-    const char* type() const final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) override;
+    bool supportsType(const std::string& type) const final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
+
+    static SymbolLayerFactory* get();
+
+private:
+    static SymbolLayerFactory* instance;
 };
 
 } // namespace style