lua_preferences.cpp

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/*
 * Copyright (C) 2016 - 2018 by Jyrki Vesterinen <sandgtx@gmail.com>
 * Part of the Battle for Wesnoth Project https://www.wesnoth.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY.
 *
 * See the COPYING file for more details.
 */

#include "scripting/lua_preferences.hpp"

#include "config.hpp"
#include "lua/lua.h"
#include "lua/lauxlib.h"
#include "preferences/general.hpp"
#include "scripting/lua_common.hpp"

/**
 * The __index metamethod.
 * Parameter 1: the preference table.
 * Parameter 2: preference name, must be a string.
 * Returns: preference value. If there isn't such a preference, returns nil.
 */
static int impl_preferences_get(lua_State* L)
{
    std::string preference_name = luaL_checkstring(L, 2);
    luaW_pushscalar(L, preferences::get_as_attribute(preference_name));
    return 1;
}

/**
 * The __newindex metamethod.
 * Parameter 1: the preference table.
 * Parameter 2: preference name, must be a string.
 * Parameter 3: preference value.
 * Returns nothing.
 */
static int impl_preferences_set(lua_State* L)
{
    std::string preference_name = luaL_checkstring(L, 2);
    config::attribute_value value;
    luaW_toscalar(L, 3, value);
    preferences::set(preference_name, value);
    return 0;
}

namespace lua_preferences
{
    std::string register_table(lua_State* L)
    {
        // Push the wesnoth table to the stack
        lua_getglobal(L, "wesnoth");

        // Create the preferences table
        lua_newtable(L);
        lua_pushcfunction(L, impl_preferences_get);
        lua_setfield(L, -2, "__index");
        lua_pushcfunction(L, impl_preferences_set);
        lua_setfield(L, -2, "__newindex");
        lua_pushstring(L, "src/scripting/lua_preferences.cpp");
        lua_setfield(L, -2, "__metatable");

        // Set the table as its own metatable
        lua_pushvalue(L, -1);
        lua_setmetatable(L, -2);

        // Assign the table to wesnoth.preferences
        lua_setfield(L, -2, "preferences");

        // Pop the wesnoth table from the stack
        lua_pop(L, 1);

        return "Adding preferences table...\n";
    }
}