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metadatum.hpp
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1// ***************************************************************** -*- C++ -*-
2/*
3 * Copyright (C) 2004-2018 Exiv2 authors
4 * This program is part of the Exiv2 distribution.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301 USA.
19 */
31#ifndef METADATUM_HPP_
32#define METADATUM_HPP_
33
34// *****************************************************************************
35#include "exiv2lib_export.h"
36
37// included header files
38#include "value.hpp"
39
40// *****************************************************************************
41// namespace extensions
42namespace Exiv2 {
43
44// *****************************************************************************
45// class declarations
46 class ExifData;
47
48// *****************************************************************************
49// class definitions
50
55 class EXIV2API Key {
56 public:
58 typedef std::auto_ptr<Key> AutoPtr;
59
61
62
63 virtual ~Key();
65
67
68
74 virtual std::string key() const =0;
76 virtual const char* familyName() const =0;
78 virtual std::string groupName() const =0;
80 virtual std::string tagName() const =0;
82 virtual std::string tagLabel() const =0;
84 virtual uint16_t tag() const =0;
90 AutoPtr clone() const;
97 std::ostream& write(std::ostream& os) const { return os << key(); }
99
100 protected:
102
103
107 Key& operator=(const Key& rhs);
109
110 private:
112 virtual Key* clone_() const =0;
113
114 }; // class Key
115
117 inline std::ostream& operator<<(std::ostream& os, const Key& key)
118 {
119 return key.write(os);
120 }
121
126 class EXIV2API Metadatum {
127 public:
129
130
131 Metadatum();
133 Metadatum(const Metadatum& rhs);
135 virtual ~Metadatum();
137
139
140
144 virtual void setValue(const Value* pValue) =0;
151 virtual int setValue(const std::string& buf) =0;
153
155
156
161 std::string print(const ExifData* pMetadata =0) const;
173 virtual long copy(byte* buf, ByteOrder byteOrder) const =0;
195 virtual std::ostream& write(
196 std::ostream& os,
197 const ExifData* pMetadata =0
198 ) const =0;
205 virtual std::string key() const =0;
207 virtual const char* familyName() const =0;
209 virtual std::string groupName() const =0;
211 virtual std::string tagName() const =0;
213 virtual std::string tagLabel() const =0;
215 virtual uint16_t tag() const =0;
217 virtual TypeId typeId() const =0;
219 virtual const char* typeName() const =0;
221 virtual long typeSize() const =0;
223 virtual long count() const =0;
225 virtual long size() const =0;
227 virtual std::string toString() const =0;
233 virtual std::string toString(long n) const =0;
239 virtual long toLong(long n =0) const =0;
245 virtual float toFloat(long n =0) const =0;
251 virtual Rational toRational(long n =0) const =0;
265 virtual Value::AutoPtr getValue() const =0;
279 virtual const Value& value() const =0;
281
282 protected:
284
285
289 Metadatum& operator=(const Metadatum& rhs);
291
292 }; // class Metadatum
293
298 inline std::ostream& operator<<(std::ostream& os, const Metadatum& md)
299 {
300 return md.write(os);
301 }
302
307 EXIV2API bool cmpMetadataByTag(const Metadatum& lhs, const Metadatum& rhs);
312 EXIV2API bool cmpMetadataByKey(const Metadatum& lhs, const Metadatum& rhs);
313
314} // namespace Exiv2
315
316#endif // #ifndef METADATUM_HPP_
A container for Exif data. This is a top-level class of the Exiv2 library. The container holds Exifda...
Definition exif.hpp:434
Abstract base class defining the Key of a metadatum. Keys are used to identify and group metadata.
Definition metadatum.hpp:55
virtual std::string groupName() const =0
Return the name of the group (the second part of the key)
virtual std::string key() const =0
Return the key of the metadatum as a string. The key is of the form 'familyName.groupName....
virtual std::string tagLabel() const =0
Return a label for the tag.
std::ostream & write(std::ostream &os) const
Write the key to an output stream. You do not usually have to use this function; it is used for the i...
Definition metadatum.hpp:97
virtual uint16_t tag() const =0
Return the tag number.
std::auto_ptr< Key > AutoPtr
Shortcut for a Key auto pointer.
Definition metadatum.hpp:58
virtual std::string tagName() const =0
Return the name of the tag (which is also the third part of the key)
virtual const char * familyName() const =0
Return an identifier for the type of metadata (the first part of the key)
Abstract base class defining the interface to access information related to one metadata tag.
Definition metadatum.hpp:126
virtual long size() const =0
Return the size of the value in bytes.
virtual TypeId typeId() const =0
Return the type id of the value.
virtual long typeSize() const =0
Return the size in bytes of one component of this type.
virtual Value::AutoPtr getValue() const =0
Return an auto-pointer to a copy (clone) of the value. The caller owns this copy and the auto-poiner ...
virtual int setValue(const std::string &buf)=0
Set the value to the string buf. Uses Value::read(const std::string& buf). If the metadatum does not ...
virtual long copy(byte *buf, ByteOrder byteOrder) const =0
Write value to a data buffer and return the number of bytes written.
virtual std::string toString(long n) const =0
Return the n-th component of the value converted to a string. The behaviour of the method is undefine...
virtual std::ostream & write(std::ostream &os, const ExifData *pMetadata=0) const =0
Write the interpreted value to an output stream, return the stream.
virtual uint16_t tag() const =0
Return the tag.
virtual const char * typeName() const =0
Return the name of the type.
virtual std::string tagLabel() const =0
Return a label for the tag.
virtual const char * familyName() const =0
Return the name of the metadata family (which is also the first part of the key)
virtual long toLong(long n=0) const =0
Return the n-th component of the value converted to long. The return value is -1 if the value is not ...
virtual const Value & value() const =0
Return a constant reference to the value.
virtual long count() const =0
Return the number of components in the value.
virtual std::string tagName() const =0
Return the name of the tag (which is also the third part of the key)
virtual std::string toString() const =0
Return the value as a string.
virtual std::string groupName() const =0
Return the name of the metadata group (which is also the second part of the key)
virtual float toFloat(long n=0) const =0
Return the n-th component of the value converted to float. The return value is -1 if the value is not...
virtual Rational toRational(long n=0) const =0
Return the n-th component of the value converted to Rational. The return value is -1/1 if the value i...
virtual void setValue(const Value *pValue)=0
Set the value. This method copies (clones) the value pointed to by pValue.
virtual std::string key() const =0
Return the key of the metadatum. The key is of the form 'familyName.groupName.tagName'....
Common interface for all types of values used with metadata.
Definition value.hpp:60
std::auto_ptr< Value > AutoPtr
Shortcut for a Value auto pointer.
Definition value.hpp:63
Provides classes and functions to encode and decode Exif and Iptc data. The libexiv2 API consists of ...
Definition asfvideo.hpp:36
EXIV2API std::ostream & operator<<(std::ostream &os, const DataSet &dataSet)
Output operator for dataSet.
Definition datasets.cpp:709
EXIV2API bool cmpMetadataByTag(const Metadatum &lhs, const Metadatum &rhs)
Compare two metadata by tag. Return true if the tag of metadatum lhs is less than that of rhs.
Definition metadatum.cpp:78
TypeId
Exiv2 value type identifiers.
Definition types.hpp:130
ByteOrder
Type to express the byte order (little or big endian)
Definition types.hpp:113
std::pair< int32_t, int32_t > Rational
8 byte signed rational type.
Definition types.hpp:110
EXIV2API bool cmpMetadataByKey(const Metadatum &lhs, const Metadatum &rhs)
Compare two metadata by key. Return true if the key of metadatum lhs is less than that of rhs.
Definition metadatum.cpp:84
Value interface and concrete subclasses.