Create helper.hpp

Author: Upbolt

helper.hpp

@@ -0,0 +1,41 @@
+#pragma once
+
+template<typename T>
+constexpr inline void set_userdata(lua_State* L, T* element) {
+	*static_cast<T**>(lua_newuserdata(L, sizeof(T*))) = element;
+}
+
+template<typename T>
+constexpr inline T* to_class_ptr(lua_State* L, int idx) {
+	return *static_cast<T**>(lua_touserdata(L, idx));
+}
+
+void set_type(lua_State* L, const char* type_name) {
+	lua_pushstring(L, type_name);
+
+	lua_pushvalue(L, -1);
+	lua_setfield(L, -3, "__type");
+
+	lua_pushcclosure(L, [](lua_State* L) {
+		lua_pushstring(L, lua_tostring(L, lua_upvalueindex(1)));
+		return 1;
+		}, 1);
+	lua_setfield(L, -2, "__tostring");
+}
+
+void assign_to_parent(lua_State* L, lib::element* element) {
+	lua_getmetatable(L, 2);
+	lua_getfield(L, -1, "__type");
+
+	const char* type = lua_tostring(L, -1);
+	lua_pop(L, 2);
+
+	if (strcmp(type, "Window") == 0) {
+		auto window = to_class_ptr<lib::window>(L, 2);
+		window->add_element(element);
+	}
+	else if (strcmp(type, "Tab") == 0) {
+		auto tab = to_class_ptr<lib::tab>(L, 2);
+		tab->add_element(element);
+	}
+}