1 files changed, 37 insertions, 0 deletions
diff --git a/src/mbgl/style/class_dictionary.hpp b/src/mbgl/style/class_dictionary.hpp
new file mode 100644
index 0000000000..ecf80be3e3
--- /dev/null
+++ b/src/mbgl/style/class_dictionary.hpp
@@ -0,0 +1,37 @@
+#ifndef MBGL_STYLE_CLASS_DICTIONARY
+#define MBGL_STYLE_CLASS_DICTIONARY
+
+#include <cstdint>
+#include <string>
+#include <unordered_map>
+
+namespace mbgl {
+
+enum class ClassID : uint32_t {
+    Fallback = 0, // These values are from the fallback properties
+    Default = 1, // These values are from the default style for a layer
+    Named = 2 // These values (and all subsequent IDs) are from a named style from the layer
+};
+
+class ClassDictionary {
+private:
+    ClassDictionary();
+
+public:
+    static ClassDictionary &Get();
+
+    // Returns an ID for a class name. If the class name does not yet have an ID, one is
+    // auto-generated and stored for future reference.
+    ClassID lookup(const std::string &class_name);
+
+    // Returns either Fallback, Default or Named, depending on the type of the class id.
+    ClassID normalize(ClassID id);
+
+private:
+    std::unordered_map<std::string, ClassID> store = { { "", ClassID::Default } };
+    uint32_t offset = 0;
+};
+
+}
+
+#endif