1 files changed, 97 insertions, 0 deletions
diff --git a/Src/replicant/nswasabi/MetadataChain.h b/Src/replicant/nswasabi/MetadataChain.h
new file mode 100644
index 00000000..cc6de698
--- /dev/null
+++ b/Src/replicant/nswasabi/MetadataChain.h
@@ -0,0 +1,97 @@
+#pragma once
+#include "metadata/ifc_metadata.h"
+
+
+template <class metadata_t>
+class MetadataChain : public metadata_t
+{
+public:
+	MetadataChain()
+	{
+		parent_metadata=0;
+	}
+
+	~MetadataChain()
+	{
+		if (parent_metadata)
+			parent_metadata->Release();
+	}
+	
+	static bool Unhandled(ns_error_t ret)
+	{
+		return (ret == NErr_NotImplemented || ret == NErr_Empty || ret == NErr_Unknown);
+	}
+
+	ns_error_t SetParentMetadata(ifc_metadata *new_parent_metadata)
+	{
+		if (parent_metadata)
+			parent_metadata->Release();
+		parent_metadata=new_parent_metadata;
+		if (parent_metadata)
+			parent_metadata->Retain();
+		return NErr_Success;
+	}
+protected:
+	ifc_metadata *parent_metadata;
+private:
+	ns_error_t WASABICALL Metadata_GetField(int field, unsigned int index, nx_string_t *value)
+	{
+		ns_error_t ret = metadata_t::Metadata_GetField(field, index, value);
+		if (Unhandled(ret) && parent_metadata)
+			return parent_metadata->GetField(field, index, value);
+		else
+			return ret;
+
+	}
+
+	ns_error_t WASABICALL Metadata_GetInteger(int field, unsigned int index, int64_t *value)
+	{
+		ns_error_t ret = metadata_t::Metadata_GetInteger(field, index, value);
+		if (Unhandled(ret) && parent_metadata)
+			return parent_metadata->GetInteger(field, index, value);
+		else
+			return ret;
+
+	}
+
+	ns_error_t WASABICALL Metadata_GetReal(int field, unsigned int index, double *value)
+	{
+		ns_error_t ret = metadata_t::Metadata_GetReal(field, index, value);
+		if (Unhandled(ret) && parent_metadata)
+			return parent_metadata->GetReal(field, index, value);
+		else
+			return ret;
+
+	}
+
+	ns_error_t WASABICALL Metadata_GetArtwork(int field, unsigned int index, artwork_t *artwork, data_flags_t flags)
+	{
+		ns_error_t ret = metadata_t::Metadata_GetArtwork(field, index, artwork, flags);
+		if (Unhandled(ret) && parent_metadata)
+			return parent_metadata->GetArtwork(field, index, artwork, flags);
+		else
+			return ret;
+
+	}
+
+	ns_error_t WASABICALL Metadata_GetBinary(int field, unsigned int index, nx_data_t *data)
+	{
+		ns_error_t ret = metadata_t::Metadata_GetBinary(field, index, data);
+		if (Unhandled(ret) && parent_metadata)
+			return parent_metadata->GetBinary(field, index, data);
+		else
+			return ret;
+
+	}
+
+	ns_error_t WASABICALL Metadata_GetMetadata(int field, unsigned int index, ifc_metadata **metadata)
+	{
+		ns_error_t ret = metadata_t::Metadata_GetMetadata(field, index, metadata);
+		if (Unhandled(ret) && parent_metadata)
+			return parent_metadata->GetMetadata(field, index, metadata);
+		else
+			return ret;
+
+	}
+	// TODO: ns_error_t WASABICALL Metadata_Serialize(nx_data_t *data) { return NErr_NotImplemented; }
+};