[core][android] Introduce mbgl::style::LayerTypeInfo

The `LayerTypeInfo` contains static meta data about certain layer type.

Each layer module should have a single immutable `LayerTypeInfo` instance
for the represented layer type. Both `LayerImpl` and `LayerFactory` from the
module always refer to the same `LayerTypeInfo` instance, so address of this
instance can be used as a layer module Id during the process life time.

1 files changed, 3 insertions, 7 deletions

diff --git a/include/mbgl/style/layers/fill_layer.hpp b/include/mbgl/style/layers/fill_layer.hpp
index aeb0ba988a..52bbd054ae 100644
--- a/include/mbgl/style/layers/fill_layer.hpp
+++ b/include/mbgl/style/layers/fill_layer.hpp
@@ -83,15 +83,11 @@ protected:
 class FillLayerFactory : public LayerFactory {
 public:
     FillLayerFactory();
-    // LayerFactory overrides.
     ~FillLayerFactory() override;
-    bool supportsType(const std::string& type) const noexcept final;
-    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
-
-    static FillLayerFactory* get() noexcept;
 
-private:
-    static FillLayerFactory* instance;
+    // LayerFactory overrides.
+    const LayerTypeInfo* getTypeInfo() const noexcept final;
+    std::unique_ptr<style::Layer> createLayer(const std::string& id, const conversion::Convertible& value) final;
 };
 
 } // namespace style