Exiv2::DataValue Class Reference

Value for an undefined data type. More...

#include <value.hpp>

Inheritance diagram for Exiv2::DataValue:

Public Types
typedef std::auto_ptr< DataValue >	AutoPtr
	Shortcut for a DataValue auto pointer.
Public Types inherited from Exiv2::Value
typedef std::auto_ptr< Value >	AutoPtr
	Shortcut for a Value auto pointer.

Public Member Functions
	DataValue (TypeId typeId=undefined)
	DataValue (const byte *buf, long len, ByteOrder byteOrder=invalidByteOrder, TypeId typeId=undefined)
Manipulators
virtual int	read (const byte *buf, long len, ByteOrder byteOrder=invalidByteOrder)
	Read the value from a character buffer. More...
virtual int	read (const std::string &buf)
	Set the data from a string of integer values (e.g., "0 1 2 3")
Accessors
AutoPtr	clone () const
virtual long	copy (byte *buf, ByteOrder byteOrder=invalidByteOrder) const
	Write value to a character data buffer. More...
virtual long	count () const
	Return the number of components of the value.
virtual long	size () const
	Return the size of the value in bytes.
virtual std::ostream &	write (std::ostream &os) const
	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).
virtual std::string	toString (long n) const
	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.
virtual long	toLong (long n=0) const
	Convert the n-th component of the value to a long. The behaviour of this method may be undefined if there is no n-th component. More...
virtual float	toFloat (long n=0) const
	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. More...
virtual Rational	toRational (long n=0) const
	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. More...
Public Member Functions inherited from Exiv2::Value
	Value (TypeId typeId)
	Constructor, taking a type id to initialize the base class with.
virtual	~Value ()
	Virtual destructor.
virtual int	setDataArea (const byte *buf, long len)
	Set the data area, if the value has one by copying (cloning) the buffer pointed to by buf. More...
TypeId	typeId () const
	Return the type identifier (Exif data format type).
AutoPtr	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 long	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. More...
bool	ok () const
	Check the ok status indicator. After a to<Type> conversion, this indicator shows whether the conversion was successful.

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

Detailed Description

Value for an undefined data type.

Member Function Documentation

copy()

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

virtual

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

buf	Data buffer to write to.
byteOrder	Byte order. Not needed.

Returns

Number of characters written.

Implements Exiv2::Value.

read()

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

virtual

Read the value from a character buffer.

Note

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

Parameters

buf	Pointer to the data buffer to read from
len	Number of bytes in the data buffer
byteOrder	Byte order. Not needed.

Returns

0 if successful.

Implements Exiv2::Value.

toFloat()

float Exiv2::DataValue::toFloat ( long  n = 0 ) const

virtual

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.

References Exiv2::Value::ok_.

toLong()

long Exiv2::DataValue::toLong ( long  n = 0 ) const

virtual

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

Returns

The converted value.

Implements Exiv2::Value.

References Exiv2::Value::ok_.

toRational()

Rational Exiv2::DataValue::toRational ( long  n = 0 ) const

virtual

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.

References Exiv2::Value::ok_.

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

• value.hpp
• value.cpp