/* * Copyright (C) 2003-2009 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifndef MPD_MIXER_H #define MPD_MIXER_H #include <stdbool.h> /* * list of currently implemented mixers */ extern const struct mixer_plugin alsa_mixer; extern const struct mixer_plugin oss_mixer; struct config_param; struct mixer_plugin { /** * Alocates and configures a mixer device. */ struct mixer *(*init)(const struct config_param *param); /** * Finish and free mixer data */ void (*finish)(struct mixer *data); /** * Open mixer device */ bool (*open)(struct mixer *data); /** * Close mixer device */ void (*close)(struct mixer *data); /** * Reads the current volume. * * @return the current volume (0..100 including) or -1 on * error */ int (*get_volume)(struct mixer *mixer); /** * Sets the volume. * * @param volume the new volume (0..100 including) * @return true on success */ bool (*set_volume)(struct mixer *mixer, unsigned volume); }; struct mixer { const struct mixer_plugin *plugin; }; static inline void mixer_init(struct mixer *mixer, const struct mixer_plugin *plugin) { mixer->plugin = plugin; } struct mixer * mixer_new(const struct mixer_plugin *plugin, const struct config_param *param); void mixer_free(struct mixer *mixer); bool mixer_open(struct mixer *mixer); void mixer_close(struct mixer *mixer); static inline int mixer_get_volume(struct mixer *mixer) { return mixer->plugin->get_volume(mixer); } static inline bool mixer_set_volume(struct mixer *mixer, unsigned volume) { return mixer->plugin->set_volume(mixer, volume); } #endif