From e29fd4d0ead4353ff2e03fcd793400d8e0779481 Mon Sep 17 00:00:00 2001
From: Alexander Lantsev <aunsane@gmail.com>
Date: Sat, 7 Nov 2015 18:42:19 +0000
Subject: MirLua: added metatables wrapper

git-svn-id: http://svn.miranda-ng.org/main/trunk@15697 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
---
 plugins/MirLua/src/mlua_metatable.h | 155 ++++++++++++++++++++++++++++++++++++
 1 file changed, 155 insertions(+)
 create mode 100644 plugins/MirLua/src/mlua_metatable.h

(limited to 'plugins/MirLua/src/mlua_metatable.h')

diff --git a/plugins/MirLua/src/mlua_metatable.h b/plugins/MirLua/src/mlua_metatable.h
new file mode 100644
index 0000000000..ffedc22134
--- /dev/null
+++ b/plugins/MirLua/src/mlua_metatable.h
@@ -0,0 +1,155 @@
+#ifndef _LUA_METATABLE_H_
+#define _LUA_METATABLE_H_
+
+#include <map>
+#include <string>
+
+#define LUA_TINTEGER LUA_NUMTAGS + 1
+#define LUA_TSTRINGA LUA_NUMTAGS + 2
+#define LUA_TSTRINGW LUA_NUMTAGS + 3
+
+struct MTField
+{
+	size_t offset;
+	size_t size;
+	int type;
+
+	MTField(size_t offset, size_t size, int type)
+		: offset(offset), size(size), type(type) { }
+};
+
+template<typename T>
+class MT
+{
+private:
+	static const char *name;
+	static std::map<std::string, MTField*> fields;
+
+	template<typename R> static int GetType(R T::*) { return NULL; }
+
+	template<> static int GetType(int T::*) { return LUA_TINTEGER; }
+	template<> static int GetType(unsigned int T::*) { return LUA_TINTEGER; }
+	template<> static int GetType(long T::*) { return LUA_TINTEGER; }
+	template<> static int GetType(unsigned long T::*) { return LUA_TINTEGER; }
+	template<> static int GetType(long long T::*) { return LUA_TINTEGER; }
+	template<> static int GetType(unsigned long long T::*) { return LUA_TINTEGER; }
+
+	template<> static int GetType(char* T::*) { return LUA_TSTRINGA; }
+	template<> static int GetType(wchar_t* T::*) { return LUA_TSTRINGW; }
+
+	template<typename R>
+	static R GetValue(const T *obj, size_t offset, size_t size)
+	{
+		R res;
+		memcpy(&res, ((char*)obj) + offset, size);
+		return res;
+	}
+
+	static int __new(lua_State *L)
+	{
+		T *obj = NULL;
+		T **udata = NULL;
+
+		int type = lua_type(L, 1);
+		switch (type)
+		{
+		case LUA_TLIGHTUSERDATA:
+			obj = (T*)MT::Load(L);
+			if (obj == NULL) break;
+		//case LUA_TNONE:
+			udata = (T**)lua_newuserdata(L, sizeof(T*));
+			*udata = MT::Init(obj);
+		//case LUA_TUSERDATA:
+		//	luaL_setmetatable(L, MT::name);
+		//	return 1;
+		}
+		lua_pushnil(L);
+
+		return 1;
+	}
+
+	static int __index(lua_State *L)
+	{
+		T *obj = *(T**)luaL_checkudata(L, 1, MT::name);
+		const char *key = lua_tostring(L, 2);
+
+		auto it = fields.find(key);
+		if (it == fields.end())
+		{
+			lua_pushnil(L);
+			return 1;
+		}
+
+		MTField *field = it->second;
+		size_t offset = field->offset;
+		size_t size = field->size;
+		
+		switch (field->type)
+		{
+		case LUA_TBOOLEAN:
+			lua_pushboolean(L, GetValue<bool>(obj, offset, size));
+			break;
+		case LUA_TINTEGER:
+			lua_pushinteger(L, GetValue<long long>(obj, offset, size));
+			break;
+		case LUA_TNUMBER:
+			lua_pushnumber(L, GetValue<double>(obj, offset, size));
+			break;
+		case LUA_TSTRING:
+			lua_pushstring(L, GetValue<char*>(obj, offset, size));
+			break;
+		case LUA_TSTRINGA:
+			lua_pushstring(L, ptrA(mir_utf8encode(GetValue<char*>(obj, offset, size))));
+			break;
+		case LUA_TSTRINGW:
+			lua_pushstring(L, ptrA(mir_utf8encodeW(GetValue<wchar_t*>(obj, offset, size))));
+			break;
+		default:
+			lua_pushnil(L);
+		}
+
+		return 1;
+	}
+
+	static int __gc(lua_State *L)
+	{
+		T** obj = (T**)luaL_checkudata(L, 1, MT::name);
+		MT::Free(obj);
+		return 0;
+	}
+
+	static T* Load(lua_State *L) { return (T*)lua_touserdata(L, 1); }
+	static T* Init(T *val) { return val; }
+	static void Free(T *obj) { obj = NULL; }
+
+public:
+	MT(lua_State *L, const char *tname)
+	{
+		MT::name = tname;
+
+		lua_pushcfunction(L, __new);
+		lua_setglobal(L, MT::name);
+
+		luaL_newmetatable(L, MT::name);
+		lua_pushcfunction(L, __index);
+		lua_setfield(L, -2, "__index");
+	}
+
+	template<typename R>
+	MT& Field(R T::*M, const char *name, int type = LUA_TNONE, size_t size = sizeof(R))
+	{
+		size_t offset = reinterpret_cast<size_t>(&(((T*)0)->*M));
+		if (type == LUA_TNONE) type = GetType(M);
+		if (type != LUA_TNONE)
+			fields[name] = new MTField(offset, size, type);
+		return *this;
+	}
+};
+
+template<typename T>
+const char *MT<T>::name;
+
+template<typename T>
+std::map<std::string, MTField*> MT<T>::fields;
+
+#endif //_LUA_METATABLE_H_
-- 
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