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/*
* Copyright (C) 2003-2011 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_TAG_HANDLER_H
#define MPD_TAG_HANDLER_H
#include "check.h"
#include "tag.h"
#include <assert.h>
/**
* A callback table for receiving metadata of a song.
*/
struct tag_handler {
/**
* Declare the duration of a song, in seconds. Do not call
* this when the duration could not be determined, because
* there is no magic value for "unknown duration".
*/
void (*duration)(unsigned seconds, void *ctx);
/**
* A tag has been read.
*
* @param the value of the tag; the pointer will become
* invalid after returning
*/
void (*tag)(enum tag_type type, const char *value, void *ctx);
/**
* A name-value pair has been read. It is the codec specific
* representation of tags.
*/
void (*pair)(const char *key, const char *value, void *ctx);
};
static inline void
tag_handler_invoke_duration(const struct tag_handler *handler, void *ctx,
unsigned seconds)
{
assert(handler != NULL);
if (handler->duration != NULL)
handler->duration(seconds, ctx);
}
static inline void
tag_handler_invoke_tag(const struct tag_handler *handler, void *ctx,
enum tag_type type, const char *value)
{
assert(handler != NULL);
assert((unsigned)type < TAG_NUM_OF_ITEM_TYPES);
assert(value != NULL);
if (handler->tag != NULL)
handler->tag(type, value, ctx);
}
static inline void
tag_handler_invoke_pair(const struct tag_handler *handler, void *ctx,
const char *name, const char *value)
{
assert(handler != NULL);
assert(name != NULL);
assert(value != NULL);
if (handler->pair != NULL)
handler->pair(name, value, ctx);
}
/**
* This #tag_handler implementation adds tag values to a #tag object
* (casted from the context pointer).
*/
extern const struct tag_handler add_tag_handler;
/**
* This #tag_handler implementation adds tag values to a #tag object
* (casted from the context pointer), and supports the has_playlist
* attribute.
*/
extern const struct tag_handler full_tag_handler;
#endif
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