minetest/src/map_settings_manager.h

/*
Minetest
Copyright (C) 2010-2013 kwolekr, Ryan Kwolek <kwolekr@minetest.net>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#pragma once

#include <string>

class Settings;
struct NoiseParams;
struct MapgenParams;

/*
	MapSettingsManager is a centralized object for management (creating,
	loading, storing, saving, etc.) of config settings related to the Map.

	It has two phases: the initial r/w "gather and modify settings" state, and
	the final r/o "read and save settings" state.

	The typical use case is, in order, as follows:
	- Create a MapSettingsManager object
	- Try to load map metadata into it from the metadata file
	- Manually view and modify the current configuration as desired through a
	  Settings-like interface
	- When all modifications are finished, create a 'Parameters' object
	  containing the finalized, active parameters.  This could be passed along
	  to whichever Map-related objects that may require it.
	- Save these active settings to the metadata file when requested
*/
class MapSettingsManager {
public:
	MapSettingsManager(Settings *user_settings,
		const std::string &map_meta_path);
	~MapSettingsManager();

	// Finalized map generation parameters
	MapgenParams *mapgen_params = nullptr;

	bool getMapSetting(const std::string &name, std::string *value_out);

	bool getMapSettingNoiseParams(
		const std::string &name, NoiseParams *value_out);

	// Note: Map config becomes read-only after makeMapgenParams() gets called
	// (i.e. mapgen_params is non-NULL).  Attempts to set map config after
	// params have been finalized will result in failure.
	bool setMapSetting(const std::string &name,
		const std::string &value, bool override_meta = false);

	bool setMapSettingNoiseParams(const std::string &name,
		const NoiseParams *value, bool override_meta = false);

	bool loadMapMeta();
	bool saveMapMeta();
	MapgenParams *makeMapgenParams();

private:
	std::string m_map_meta_path;
	Settings *m_map_settings;
	Settings *m_user_settings;
};