Exiv2
metadatum.hpp
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #ifndef METADATUM_HPP_
4 #define METADATUM_HPP_
5 
6 // *****************************************************************************
7 #include "exiv2lib_export.h"
8 
9 // included header files
10 #include "value.hpp"
11 
12 // *****************************************************************************
13 // namespace extensions
14 namespace Exiv2 {
15 // *****************************************************************************
16 // class declarations
17 class ExifData;
18 
19 // *****************************************************************************
20 // class definitions
21 
26 class EXIV2API Key {
27  public:
29  using UniquePtr = std::unique_ptr<Key>;
30 
32 
33  virtual ~Key() = default;
36  Key(Key&&) = delete;
37  Key& operator=(Key&&) = delete;
39 
40 
46  [[nodiscard]] virtual std::string key() const = 0;
48  [[nodiscard]] virtual const char* familyName() const = 0;
50  [[nodiscard]] virtual std::string groupName() const = 0;
52  [[nodiscard]] virtual std::string tagName() const = 0;
54  [[nodiscard]] virtual std::string tagLabel() const = 0;
56  [[nodiscard]] virtual std::string tagDesc() const = 0;
58  [[nodiscard]] virtual uint16_t tag() const = 0;
64  [[nodiscard]] UniquePtr clone() const;
71  std::ostream& write(std::ostream& os) const {
72  return os << key();
73  }
75 
76  protected:
77  Key() = default;
78  Key(const Key&) = default;
80 
81 
85  Key& operator=(const Key&) = default;
87 
88  private:
90  [[nodiscard]] virtual Key* clone_() const = 0;
91 
92 }; // class Key
93 
95 inline std::ostream& operator<<(std::ostream& os, const Key& key) {
96  return key.write(os);
97 }
98 
103 class EXIV2API Metadatum {
104  public:
106 
107  virtual ~Metadatum() = default;
110 
112 
113 
117  virtual void setValue(const Value* pValue) = 0;
124  virtual int setValue(const std::string& buf) = 0;
126 
128 
129 
134  std::string print(const ExifData* pMetadata = nullptr) const;
146  virtual size_t copy(byte* buf, ByteOrder byteOrder) const = 0;
168  virtual std::ostream& write(std::ostream& os, const ExifData* pMetadata = nullptr) const = 0;
175  [[nodiscard]] virtual std::string key() const = 0;
177  [[nodiscard]] virtual const char* familyName() const = 0;
179  [[nodiscard]] virtual std::string groupName() const = 0;
181  [[nodiscard]] virtual std::string tagName() const = 0;
183  [[nodiscard]] virtual std::string tagLabel() const = 0;
185  [[nodiscard]] virtual std::string tagDesc() const = 0;
187  [[nodiscard]] virtual uint16_t tag() const = 0;
189  [[nodiscard]] virtual TypeId typeId() const = 0;
191  [[nodiscard]] virtual const char* typeName() const = 0;
193  [[nodiscard]] virtual size_t typeSize() const = 0;
195  [[nodiscard]] virtual size_t count() const = 0;
197  [[nodiscard]] virtual size_t size() const = 0;
199  [[nodiscard]] virtual std::string toString() const = 0;
205  [[nodiscard]] virtual std::string toString(size_t n) const = 0;
211  [[nodiscard]] virtual int64_t toInt64(size_t n = 0) const = 0;
215  [[nodiscard]] uint32_t toUint32(size_t n = 0) const;
221  [[nodiscard]] virtual float toFloat(size_t n = 0) const = 0;
227  [[nodiscard]] virtual Rational toRational(size_t n = 0) const = 0;
241  [[nodiscard]] virtual Value::UniquePtr getValue() const = 0;
255  [[nodiscard]] virtual const Value& value() const = 0;
257 
258  protected:
259  Metadatum() = default;
260  Metadatum(const Metadatum&) = default;
262 
263 
267  Metadatum& operator=(const Metadatum&) = default;
269 
270 }; // class Metadatum
271 
276 inline std::ostream& operator<<(std::ostream& os, const Metadatum& md) {
277  return md.write(os);
278 }
279 
284 EXIV2API bool cmpMetadataByTag(const Metadatum& lhs, const Metadatum& rhs);
289 EXIV2API bool cmpMetadataByKey(const Metadatum& lhs, const Metadatum& rhs);
290 
291 } // namespace Exiv2
292 
293 #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:24
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:20
A container for Exif data. This is a top-level class of the Exiv2 library. The container holds Exifda...
Definition: exif.hpp:373
ByteOrder
Type to express the byte order (little or big endian)
Definition: types.hpp:34
T getValue(const byte *buf, ByteOrder byteOrder)
Read a value of type T from the data buffer.
Definition: value.hpp:1332
TypeId
Exiv2 value type identifiers.
Definition: types.hpp:70
Abstract base class defining the Key of a metadatum. Keys are used to identify and group metadata...
Definition: metadatum.hpp:26
uint8_t byte
1 byte unsigned integer type.
Definition: types.hpp:26
std::pair< int32_t, int32_t > Rational
8 byte signed rational type.
Definition: types.hpp:31
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 value is created and set to value.
Definition: exif.cpp:147
const char * groupName(IfdId ifdId)
Return the group name for a group id.
Definition: tags_int.cpp:2477
Common interface for all types of values used with metadata.
Definition: value.hpp:33
std::unique_ptr< Key > UniquePtr
Shortcut for a Key auto pointer.
Definition: metadatum.hpp:29
Class CrwImage to access Canon CRW images. References: The Canon RAW (CRW) File Format by Phil Harv...
Definition: asfvideo.hpp:15
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:71
EXIV2API std::ostream & operator<<(std::ostream &os, const DataSet &dataSet)
Output operator for dataSet.
Definition: datasets.cpp:590
Abstract base class defining the interface to access information related to one metadata tag...
Definition: metadatum.hpp:103
virtual std::ostream & write(std::ostream &os, const ExifData *pMetadata=nullptr) const =0
Write the interpreted value to an output stream, return the stream.
std::unique_ptr< Value > UniquePtr
Shortcut for a Value auto pointer.
Definition: value.hpp:36