1 files changed, 63 insertions, 0 deletions
diff --git a/Runtime/Misc/UserList.h b/Runtime/Misc/UserList.h
new file mode 100644
index 0000000..7999ba9
--- /dev/null
+++ b/Runtime/Misc/UserList.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#include "Runtime/Utilities/dynamic_array.h"
+#include "Runtime/Utilities/NonCopyable.h"
+#include "Runtime/Modules/ExportModules.h"
+
+class MessageIdentifier;
+
+// A UserList can be connected to other UserLists or UserListNodes.
+// A UserListNode is simply the optimized case of a single-element list.
+// The connected lists are symmetrical and can send messages in both directions.
+// Deleting a node or list will disconnect it from the graph.
+
+class EXPORT_COREMODULE UserListBase : public NonCopyable
+{
+public:
+	Object* GetTarget () { return m_Target; }
+
+protected:
+	UserListBase (Object* target) : m_Target(target) {}
+	struct Entry
+	{
+		Entry() : other(NULL), indexInOther(-1) {}
+		UserListBase* other;
+		int indexInOther;
+	};	
+	Object* m_Target;
+};
+
+class UserListNode : public UserListBase
+{
+public:
+	UserListNode (Object* target) : UserListBase(target) {}
+	~UserListNode () { Clear(); }
+
+	void Clear ();
+	bool IsConnected () const { return m_Entry.other != NULL; }
+
+private:
+	friend class UserList;
+	Entry m_Entry;
+};
+
+class EXPORT_COREMODULE UserList : public UserListBase
+{
+public:
+	UserList (Object* target) : UserListBase(target) {}
+	~UserList () { Clear(); }
+	
+	void Clear ();
+	void Reserve (size_t size);
+	void AddUser (UserListNode& other);
+	void AddUser (UserList& other);
+	void SendMessage (const MessageIdentifier& msg);
+	size_t GetSize () const { return m_Entries.size(); }
+
+private:
+	friend class UserListNode;
+	Entry& GetEntryInOther (int index);
+	void RemoveIndex (int index);
+
+	dynamic_array<Entry> m_Entries;
+};