/*
 * Copyright 2003-2017 The Music Player Daemon Project
 * http://www.musicpd.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; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU 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.
 */

#ifndef MPD_FILTER_OBSERVER_HXX
#define MPD_FILTER_OBSERVER_HXX

#include "check.h"

class PreparedFilter;
class Filter;

/**
 * A helper class which observes calls to a #PreparedFilter and allows
 * the caller to access the #Filter instances created by it.
 */
class FilterObserver {
	class PreparedProxy;
	class Proxy;

	PreparedProxy *proxy = nullptr;

public:
	/**
	 * @return a proxy object
	 */
	PreparedFilter *Set(PreparedFilter *pf);

	Filter *Get();
};

#endif
