Exiv2
metadatum.hpp
1 // ***************************************************************** -*- C++ -*-
2 /*
3  * Copyright (C) 2004-2021 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  */
20 #ifndef METADATUM_HPP_
21 #define METADATUM_HPP_
22 
23 // *****************************************************************************
24 #include "exiv2lib_export.h"
25 
26 // included header files
27 #include "value.hpp"
28 
29 // *****************************************************************************
30 // namespace extensions
31 namespace Exiv2 {
32 
33 // *****************************************************************************
34 // class declarations
35  class ExifData;
36 
37 // *****************************************************************************
38 // class definitions
39 
44  class EXIV2API Key {
45  public:
47  typedef std::auto_ptr<Key> AutoPtr;
48 
50 
51  virtual ~Key();
54 
56 
57 
63  virtual std::string key() const =0;
65  virtual const char* familyName() const =0;
67  virtual std::string groupName() const =0;
69  virtual std::string tagName() const =0;
71  virtual std::string tagLabel() const =0;
73  virtual uint16_t tag() const =0;
79  AutoPtr clone() const;
86  std::ostream& write(std::ostream& os) const { return os << key(); }
88 
89  protected:
91 
92 
96  Key& operator=(const Key& rhs);
98 
99  private:
101  virtual Key* clone_() const =0;
102 
103  }; // class Key
104 
106  inline std::ostream& operator<<(std::ostream& os, const Key& key)
107  {
108  return key.write(os);
109  }
110 
115  class EXIV2API Metadatum {
116  public:
118 
119  Metadatum();
122  Metadatum(const Metadatum& rhs);
124  virtual ~Metadatum();
126 
128 
129 
133  virtual void setValue(const Value* pValue) =0;
140  virtual int setValue(const std::string& buf) =0;
142 
144 
145 
150  std::string print(const ExifData* pMetadata =0) const;
162  virtual long copy(byte* buf, ByteOrder byteOrder) const =0;
184  virtual std::ostream& write(
185  std::ostream& os,
186  const ExifData* pMetadata =0
187  ) const =0;
194  virtual std::string key() const =0;
196  virtual const char* familyName() const =0;
198  virtual std::string groupName() const =0;
200  virtual std::string tagName() const =0;
202  virtual std::string tagLabel() const =0;
204  virtual uint16_t tag() const =0;
206  virtual TypeId typeId() const =0;
208  virtual const char* typeName() const =0;
210  virtual long typeSize() const =0;
212  virtual long count() const =0;
214  virtual long size() const =0;
216  virtual std::string toString() const =0;
222  virtual std::string toString(long n) const =0;
228  virtual long toLong(long n =0) const =0;
234  virtual float toFloat(long n =0) const =0;
240  virtual Rational toRational(long n =0) const =0;
254  virtual Value::AutoPtr getValue() const =0;
268  virtual const Value& value() const =0;
270 
271  protected:
273 
274 
278  Metadatum& operator=(const Metadatum& rhs);
280 
281  }; // class Metadatum
282 
287  inline std::ostream& operator<<(std::ostream& os, const Metadatum& md)
288  {
289  return md.write(os);
290  }
291 
296  EXIV2API bool cmpMetadataByTag(const Metadatum& lhs, const Metadatum& rhs);
301  EXIV2API bool cmpMetadataByKey(const Metadatum& lhs, const Metadatum& rhs);
302 
303 } // namespace Exiv2
304 
305 #endif // #ifndef METADATUM_HPP_
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:77
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:71
A container for Exif data. This is a top-level class of the Exiv2 library. The container holds Exifda...
Definition: exif.hpp:434
ByteOrder
Type to express the byte order (little or big endian)
Definition: types.hpp:102
std::pair< int32_t, int32_t > Rational
8 byte signed rational type.
Definition: types.hpp:99
T getValue(const byte *buf, ByteOrder byteOrder)
Read a value of type T from the data buffer.
Definition: value.hpp:1363
TypeId
Exiv2 value type identifiers.
Definition: types.hpp:119
Abstract base class defining the Key of a metadatum. Keys are used to identify and group metadata...
Definition: metadatum.hpp:44
uint8_t byte
1 byte unsigned integer type.
Definition: types.hpp:94
std::string toString(const T &arg)
Utility function to convert the argument of any type to a string.
Definition: types.hpp:510
Exiv2::Exifdatum & setValue(Exiv2::Exifdatum &exifDatum, const T &value)
Set the value of exifDatum to value. If the object already has a value, it is replaced. Otherwise a new ValueType<T> value is created and set to value.
Definition: exif.cpp:193
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:86
const char * groupName(IfdId ifdId)
Return the group name for a group id.
Definition: tags_int.cpp:2540
Common interface for all types of values used with metadata.
Definition: value.hpp:51
std::auto_ptr< Value > AutoPtr
Shortcut for a Value auto pointer.
Definition: value.hpp:54
Provides classes and functions to encode and decode Exif and Iptc data. The libexiv2 API consists of ...
Definition: asfvideo.hpp:36
virtual std::ostream & write(std::ostream &os, const ExifData *pMetadata=0) const =0
Write the interpreted value to an output stream, return the stream.
EXIV2API std::ostream & operator<<(std::ostream &os, const DataSet &dataSet)
Output operator for dataSet.
Definition: datasets.cpp:709
Abstract base class defining the interface to access information related to one metadata tag...
Definition: metadatum.hpp:115
std::auto_ptr< Key > AutoPtr
Shortcut for a Key auto pointer.
Definition: metadatum.hpp:47