pollymc/api/logic/settings/SettingsObject.h

/* Copyright 2013-2015 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <QObject>
#include <QMap>
#include <QStringList>
#include <QVariant>
#include <memory>

#include "multimc_logic_export.h"

class Setting;
class SettingsObject;

typedef std::shared_ptr<SettingsObject> SettingsObjectPtr;

/*!
 * \brief The SettingsObject handles communicating settings between the application and a
 *settings file.
 * The class keeps a list of Setting objects. Each Setting object represents one
 * of the application's settings. These Setting objects are registered with
 * a SettingsObject and can be managed similarly to the way a list works.
 *
 * \author Andrew Okin
 * \date 2/22/2013
 *
 * \sa Setting
 */
class MULTIMC_LOGIC_EXPORT SettingsObject : public QObject
{
	Q_OBJECT
public:
	class Lock
	{
	public:
		Lock(SettingsObjectPtr locked)
			:m_locked(locked)
		{
			m_locked->suspendSave();
		}
		~Lock()
		{
			m_locked->resumeSave();
		}
	private:
		SettingsObjectPtr m_locked;
	};
public:
	explicit SettingsObject(QObject *parent = 0);
	virtual ~SettingsObject();
	/*!
	 * Registers an override setting for the given original setting in this settings object
	 * gate decides if the passthrough (true) or the original (false) is used for value
	 *
	 * This will fail if there is already a setting with the same ID as
	 * the one that is being registered.
	 * \return A valid Setting shared pointer if successful.
	 */
	std::shared_ptr<Setting> registerOverride(std::shared_ptr<Setting> original, std::shared_ptr<Setting> gate);

	/*!
	 * Registers a passthorugh setting for the given original setting in this settings object
	 * gate decides if the passthrough (true) or the original (false) is used for value
	 *
	 * This will fail if there is already a setting with the same ID as
	 * the one that is being registered.
	 * \return A valid Setting shared pointer if successful.
	 */
	std::shared_ptr<Setting> registerPassthrough(std::shared_ptr<Setting> original, std::shared_ptr<Setting> gate);

	/*!
	 * Registers the given setting with this SettingsObject and connects the necessary  signals.
	 *
	 * This will fail if there is already a setting with the same ID as
	 * the one that is being registered.
	 * \return A valid Setting shared pointer if successful.
	 */
	std::shared_ptr<Setting> registerSetting(QStringList synonyms,
											 QVariant defVal = QVariant());

	/*!
	 * Registers the given setting with this SettingsObject and connects the necessary signals.
	 *
	 * This will fail if there is already a setting with the same ID as
	 * the one that is being registered.
	 * \return A valid Setting shared pointer if successful.
	 */
	std::shared_ptr<Setting> registerSetting(QString id, QVariant defVal = QVariant())
	{
		return registerSetting(QStringList(id), defVal);
	}

	/*!
	 * \brief Gets the setting with the given ID.
	 * \param id The ID of the setting to get.
	 * \return A pointer to the setting with the given ID.
	 * Returns null if there is no setting with the given ID.
	 * \sa operator []()
	 */
	std::shared_ptr<Setting> getSetting(const QString &id) const;

	/*!
	 * \brief Gets the value of the setting with the given ID.
	 * \param id The ID of the setting to get.
	 * \return The setting's value as a QVariant.
	 * If no setting with the given ID exists, returns an invalid QVariant.
	 */
	QVariant get(const QString &id) const;

	/*!
	 * \brief Sets the value of the setting with the given ID.
	 * If no setting with the given ID exists, returns false
	 * \param id The ID of the setting to change.
	 * \param value The new value of the setting.
	 * \return True if successful, false if it failed.
	 */
	bool set(const QString &id, QVariant value);

	/*!
	 * \brief Reverts the setting with the given ID to default.
	 * \param id The ID of the setting to reset.
	 */
	void reset(const QString &id) const;

	/*!
	 * \brief Checks if this SettingsObject contains a setting with the given ID.
	 * \param id The ID to check for.
	 * \return True if the SettingsObject has a setting with the given ID.
	 */
	bool contains(const QString &id);

	/*!
	 * \brief Reloads the settings and emit signals for changed settings
	 * \return True if reloading was successful
	 */
	virtual bool reload();

	virtual void suspendSave() = 0;
	virtual void resumeSave() = 0;
signals:
	/*!
	 * \brief Signal emitted when one of this SettingsObject object's settings changes.
	 * This is usually just connected directly to each Setting object's
	 * SettingChanged() signals.
	 * \param setting A reference to the Setting object that changed.
	 * \param value The Setting object's new value.
	 */
	void SettingChanged(const Setting &setting, QVariant value);

	/*!
	 * \brief Signal emitted when one of this SettingsObject object's settings resets.
	 * This is usually just connected directly to each Setting object's
	 * settingReset() signals.
	 * \param setting A reference to the Setting object that changed.
	 */
	void settingReset(const Setting &setting);

protected
slots:
	/*!
	 * \brief Changes a setting.
	 * This slot is usually connected to each Setting object's
	 * SettingChanged() signal. The signal is emitted, causing this slot
	 * to update the setting's value in the config file.
	 * \param setting A reference to the Setting object that changed.
	 * \param value The setting's new value.
	 */
	virtual void changeSetting(const Setting &setting, QVariant value) = 0;

	/*!
	 * \brief Resets a setting.
	 * This slot is usually connected to each Setting object's
	 * settingReset() signal. The signal is emitted, causing this slot
	 * to update the setting's value in the config file.
	 * \param setting A reference to the Setting object that changed.
	 */
	virtual void resetSetting(const Setting &setting) = 0;

protected:
	/*!
	 * \brief Connects the necessary signals to the given Setting.
	 * \param setting The setting to connect.
	 */
	void connectSignals(const Setting &setting);

	/*!
	 * \brief Function used by Setting objects to get their values from the SettingsObject.
	 * \param setting The
	 * \return
	 */
	virtual QVariant retrieveValue(const Setting &setting) = 0;

	friend class Setting;

private:
	QMap<QString, std::shared_ptr<Setting>> m_settings;
protected:
	bool m_suspendSave = false;
	bool m_doSave = false;
};