1 /*! \file exif-content.h
2 * \brief Handling EXIF IFDs
5 * Copyright (c) 2001 Lutz Mueller <lutz@users.sourceforge.net>
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 * Boston, MA 02110-1301 USA.
23 #ifndef __EXIF_CONTENT_H__
24 #define __EXIF_CONTENT_H__
28 #endif /* __cplusplus */
30 /*! Holds all EXIF tags in a single IFD */
31 typedef struct _ExifContent ExifContent;
32 typedef struct _ExifContentPrivate ExifContentPrivate;
34 #include <libexif/exif-tag.h>
35 #include <libexif/exif-entry.h>
36 #include <libexif/exif-data.h>
37 #include <libexif/exif-log.h>
38 #include <libexif/exif-mem.h>
45 /*! Data containing this content */
48 ExifContentPrivate *priv;
53 /*! Reserve memory for and initialize a new #ExifContent.
55 * \return new allocated #ExifContent, or NULL on error
57 * \see exif_content_new_mem, exif_content_unref
59 ExifContent *exif_content_new (void);
61 /*! Reserve memory for and initialize new #ExifContent using the specified
64 * \return new allocated #ExifContent, or NULL on error
66 * \see exif_content_new, exif_content_unref
68 ExifContent *exif_content_new_mem (ExifMem *);
70 /*! Increase reference counter for #ExifContent.
72 * \param[in] content #ExifContent
74 * \see exif_content_unref
76 void exif_content_ref (ExifContent *content);
78 /*! Decrease reference counter for #ExifContent.
79 * When the reference count drops to zero, free the content.
81 * \param[in] content #ExifContent
83 void exif_content_unref (ExifContent *content);
85 /*! Actually free the #ExifContent.
87 * \deprecated Should not be called directly. Use #exif_content_ref and
88 * #exif_content_unref instead.
90 * \param[in] content #ExifContent
92 void exif_content_free (ExifContent *content);
94 /*! Add an EXIF tag to an IFD.
95 * If this tag already exists in the IFD, this function does nothing.
96 * \pre The "tag" member of the entry must be set on entry.
99 * \param[in] entry EXIF entry to add
101 void exif_content_add_entry (ExifContent *c, ExifEntry *entry);
103 /*! Remove an EXIF tag from an IFD.
104 * If this tag does not exist in the IFD, this function does nothing.
107 * \param[in] e EXIF entry to remove
109 void exif_content_remove_entry (ExifContent *c, ExifEntry *e);
111 /*! Return the #ExifEntry in this IFD corresponding to the given tag.
112 * This is a pointer into a member of the #ExifContent array and must NOT be
113 * freed or unrefed by the caller.
115 * \param[in] content EXIF content for an IFD
116 * \param[in] tag EXIF tag to return
117 * \return #ExifEntry of the tag, or NULL on error
119 ExifEntry *exif_content_get_entry (ExifContent *content, ExifTag tag);
121 /*! Fix the IFD to bring it into specification. Call #exif_entry_fix on
122 * each entry in this IFD to fix existing entries, create any new entries
123 * that are mandatory in this IFD but do not yet exist, and remove any
124 * entries that are not allowed in this IFD.
126 * \param[in,out] c EXIF content for an IFD
128 void exif_content_fix (ExifContent *c);
130 typedef void (* ExifContentForeachEntryFunc) (ExifEntry *, void *user_data);
132 /*! Executes function on each EXIF tag in this IFD in turn.
133 * The tags will not necessarily be visited in numerical order.
135 * \param[in,out] content IFD over which to iterate
136 * \param[in] func function to call for each entry
137 * \param[in] user_data data to pass into func on each call
139 void exif_content_foreach_entry (ExifContent *content,
140 ExifContentForeachEntryFunc func,
143 /*! Return the IFD number in which the given #ExifContent is found.
145 * \param[in] c an #ExifContent*
146 * \return IFD number, or #EXIF_IFD_COUNT on error
148 ExifIfd exif_content_get_ifd (ExifContent *c);
150 /*! Return a textual representation of the EXIF data for a tag.
152 * \param[in] c #ExifContent* for an IFD
153 * \param[in] t #ExifTag to return
154 * \param[out] v char* buffer in which to store value
155 * \param[in] m unsigned int length of the buffer v
156 * \return the v pointer, or NULL on error
158 #define exif_content_get_value(c,t,v,m) \
159 (exif_content_get_entry (c,t) ? \
160 exif_entry_get_value (exif_content_get_entry (c,t),v,m) : NULL)
162 /*! Dump contents of the IFD to stdout.
163 * This is intended for diagnostic purposes only.
165 * \param[in] content IFD data
166 * \param[in] indent how many levels deep to indent the data
168 void exif_content_dump (ExifContent *content, unsigned int indent);
170 /*! Set the log message object for this IFD.
172 * \param[in] content IFD
173 * \param[in] log #ExifLog*
175 void exif_content_log (ExifContent *content, ExifLog *log);
179 #endif /* __cplusplus */
181 #endif /* __EXIF_CONTENT_H__ */