Public Types | Public Member Functions | List of all members
Exiv2::DataValue Class Reference

Value for an undefined data type. More...

#include <value.hpp>

Inheritance diagram for Exiv2::DataValue:
Inheritance graph
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Public Types

using UniquePtr = std::unique_ptr< DataValue >
Shortcut for a DataValue auto pointer.
 
- Public Types inherited from Exiv2::Value
using UniquePtr = std::unique_ptr< Value >
Shortcut for a Value auto pointer.

Public Member Functions

 DataValue (TypeId typeId=undefined)
 
 DataValue (const byte *buf, size_t len, ByteOrder byteOrder=invalidByteOrder, TypeId typeId=undefined)
 
Manipulators
int read (const byte *buf, size_t len, ByteOrder byteOrder=invalidByteOrder) override
Read the value from a character buffer.
 
int read (const std::string &buf) override
Set the data from a string of integer values (e.g., "0 1 2 3")
 
- Public Member Functions inherited from Exiv2::Value
 Value (TypeId typeId)
Constructor, taking a type id to initialize the base class with.
 
virtual ~Value ()=default
Virtual destructor.
 
virtual int setDataArea (const byte *buf, size_t len)
Set the data area, if the value has one by copying (cloning) the buffer pointed to by buf.
 
TypeId typeId () const
Return the type identifier (Exif data format type).
 
UniquePtr clone () const
Return an auto-pointer to a copy of itself (deep copy). The caller owns this copy and the auto-pointer ensures that it will be deleted.
 
std::string toString () const
Return the value as a string. Implemented in terms of write(std::ostream& os) const of the concrete class.
 
virtual size_t sizeDataArea () const
Return the size of the data area, 0 if there is none.
 
virtual DataBuf dataArea () const
Return a copy of the data area if the value has one. The caller owns this copy and DataBuf ensures that it will be deleted.
 
bool ok () const
Check the ok status indicator. After a to<Type> conversion, this indicator shows whether the conversion was successful.

Accessors

UniquePtr clone () const
 
size_t copy (byte *buf, ByteOrder byteOrder=invalidByteOrder) const override
Write value to a character data buffer.
 
size_t count () const override
Return the number of components of the value.
 
size_t size () const override
Return the size of the value in bytes.
 
std::ostream & write (std::ostream &os) const override
Write the value to an output stream. You do not usually have to use this function; it is used for the implementation of the output operator for Value, operator<<(std::ostream &os, const Value &value).
 
std::string toString (size_t n) const override
Return the n-th component of the value as a string. The behaviour of this method may be undefined if there is no n-th component.
 
int64_t toInt64 (size_t n=0) const override
Convert the n-th component of the value to an int64_t. The behaviour of this method may be undefined if there is no n-th component.
 
uint32_t toUint32 (size_t n=0) const override
Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.
 
float toFloat (size_t n=0) const override
Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.
 
Rational toRational (size_t n=0) const override
Convert the n-th component of the value to a Rational. The behaviour of this method may be undefined if there is no n-th component.

Additional Inherited Members

- Static Public Member Functions inherited from Exiv2::Value
static UniquePtr create (TypeId typeId)
A (simple) factory to create a Value type.
 
- Protected Member Functions inherited from Exiv2::Value
 Value (const Value &)=default
 
Value & operator= (const Value &)=default
Assignment operator. Protected so that it can only be used by subclasses but not directly.
 
- Protected Attributes inherited from Exiv2::Value
bool ok_ {true}
Indicates the status of the previous to<Type> conversion.

Detailed Description

Value for an undefined data type.

Member Function Documentation

◆ copy()

size_t Exiv2::DataValue::copy ( byte *  buf,
ByteOrder  byteOrder = invalidByteOrder 
) const
overridevirtual

Write value to a character data buffer.

Note
The byte order is required by the interface but not used by this method, so just use the default.

The user must ensure that the buffer has enough memory. Otherwise the call results in undefined behaviour.

Parameters
bufData buffer to write to.
byteOrderByte order. Not needed.
Returns
Number of characters written.

Implements Exiv2::Value.

◆ count()

size_t Exiv2::DataValue::count ( ) const
overridevirtual

Return the number of components of the value.

Implements Exiv2::Value.

◆ read() [1/2]

int Exiv2::DataValue::read ( const byte *  buf,
size_t  len,
ByteOrder  byteOrder = invalidByteOrder 
)
overridevirtual

Read the value from a character buffer.

Parameters
bufPointer to the data buffer to read from
lenNumber of bytes in the data buffer
byteOrderApplicable byte order (little or big endian).
Returns
0 if successful.

Implements Exiv2::Value.

◆ read() [2/2]

int Exiv2::DataValue::read ( const std::string &  buf)
overridevirtual

Set the data from a string of integer values (e.g., "0 1 2 3")

Implements Exiv2::Value.

◆ size()

size_t Exiv2::DataValue::size ( ) const
overridevirtual

Return the size of the value in bytes.

Implements Exiv2::Value.

◆ toFloat()

float Exiv2::DataValue::toFloat ( size_t  n = 0) const
overridevirtual

Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.

Returns
The converted value.

Implements Exiv2::Value.

◆ toInt64()

int64_t Exiv2::DataValue::toInt64 ( size_t  n = 0) const
overridevirtual

Convert the n-th component of the value to an int64_t. The behaviour of this method may be undefined if there is no n-th component.

Returns
The converted value.

Implements Exiv2::Value.

◆ toRational()

Rational Exiv2::DataValue::toRational ( size_t  n = 0) const
overridevirtual

Convert the n-th component of the value to a Rational. The behaviour of this method may be undefined if there is no n-th component.

Returns
The converted value.

Implements Exiv2::Value.

◆ toString()

std::string Exiv2::DataValue::toString ( size_t  n) const
overridevirtual

Return the n-th component of the value as a string. The behaviour of this method may be undefined if there is no n-th component.

Reimplemented from Exiv2::Value.

◆ toUint32()

uint32_t Exiv2::DataValue::toUint32 ( size_t  n = 0) const
overridevirtual

Convert the n-th component of the value to a float. The behaviour of this method may be undefined if there is no n-th component.

Returns
The converted value.

Implements Exiv2::Value.

◆ write()

std::ostream & Exiv2::DataValue::write ( std::ostream &  os) const
overridevirtual

Write the value to an output stream. You do not usually have to use this function; it is used for the implementation of the output operator for Value, operator<<(std::ostream &os, const Value &value).

Implements Exiv2::Value.

The documentation for this class was generated from the following file: