Exiv2::StringValueBase Class Referenceabstract

Abstract base class for a string based Value type. More...

#include <value.hpp>

Inheritance diagram for Exiv2::StringValueBase:

Public Types

typedef std::auto_ptr< StringValueBaseAutoPtr
 Shortcut for a StringValueBase auto pointer.
 
- Public Types inherited from Exiv2::Value
typedef std::auto_ptr< ValueAutoPtr
 Shortcut for a Value auto pointer.
 

Public Member Functions

Creators
 StringValueBase (TypeId typeId)
 Constructor for subclasses.
 
 StringValueBase (TypeId typeId, const std::string &buf)
 Constructor for subclasses.
 
 StringValueBase (const StringValueBase &rhs)
 Copy constructor.
 
virtual ~StringValueBase ()
 Virtual destructor.
 
Manipulators
virtual int read (const std::string &buf)
 Read the value from buf. This default implementation uses buf as it is.
 
virtual int read (const byte *buf, long len, ByteOrder byteOrder=invalidByteOrder)
 Read the value from a character buffer. More...
 
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 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...
 
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).
 
- 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 std::string toString (long n) const
 Return the n-th component of the value as a string. The default implementation returns toString(). The behaviour of this method may be undefined if there is no n-th component.
 
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.
 

Public Attributes

std::string value_
 Stores the string value.
 

Protected Member Functions

StringValueBaseoperator= (const StringValueBase &rhs)
 Assignment operator.
 
virtual StringValueBaseclone_ () const =0
 Internal virtual copy constructor.
 
- Protected Member Functions inherited from Exiv2::Value
Valueoperator= (const Value &rhs)
 Assignment operator. Protected so that it can only be used by subclasses but not directly.
 

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 Attributes inherited from Exiv2::Value
bool ok_
 Indicates the status of the previous to<Type> conversion.
 

Detailed Description

Abstract base class for a string based Value type.

Uses a std::string to store the value and implements defaults for most operations.

Member Function Documentation

◆ copy()

virtual long Exiv2::StringValueBase::copy ( byte buf,
ByteOrder  byteOrder = invalidByteOrder 
) const
virtual

Write value to a character data buffer.

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

Note
The byte order is required by the interface but not used by this method, so just use the default.
Parameters
bufData buffer to write to.
byteOrderByte order. Not used.
Returns
Number of characters written.

Implements Exiv2::Value.

Reimplemented in Exiv2::CommentValue.

◆ read()

virtual int Exiv2::StringValueBase::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
bufPointer to the data buffer to read from
lenNumber of bytes in the data buffer
byteOrderByte order. Not needed.
Returns
0 if successful.

Implements Exiv2::Value.

Reimplemented in Exiv2::CommentValue.

◆ toFloat()

virtual float Exiv2::StringValueBase::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.

◆ toLong()

virtual long Exiv2::StringValueBase::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.

◆ toRational()

virtual Rational Exiv2::StringValueBase::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.


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