Exiv2::XmpValue Class Referenceabstract

Base class for all Exiv2 values used to store XMP property values. More...

#include <value.hpp>

Inheritance diagram for Exiv2::XmpValue:

Public Types

enum  XmpArrayType { xaNone, xaAlt, xaBag, xaSeq }
 XMP array types.
 
enum  XmpStruct { xsNone, xsStruct }
 XMP structure indicator.
 
typedef std::auto_ptr< XmpValueAutoPtr
 Shortcut for a XmpValue auto pointer.
 
- Public Types inherited from Exiv2::Value
typedef std::auto_ptr< ValueAutoPtr
 Shortcut for a Value auto pointer.
 

Public Member Functions

Creators
 XmpValue (TypeId typeId)
 
Accessors
XmpArrayType xmpArrayType () const
 Return XMP array type, indicates if an XMP value is an array.
 
XmpStruct xmpStruct () const
 Return XMP struct, indicates if an XMP value is a structure.
 
virtual long size () const
 Return the size of the value in bytes.
 
virtual long copy (byte *buf, ByteOrder byteOrder=invalidByteOrder) const
 Write value to a character data buffer. More...
 
Manipulators
void setXmpArrayType (XmpArrayType xmpArrayType)
 Set the XMP array type to indicate that an XMP value is an array.
 
void setXmpStruct (XmpStruct xmpStruct=xsStruct)
 Set the XMP struct type to indicate that an XMP value is a structure.
 
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)=0
 Set the value from a string buffer. The format of the string corresponds to that of the write() method, i.e., a string obtained through the write() method can be read by this function. 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.
 
virtual long count () const =0
 Return the number of components of the value.
 
virtual std::ostream & write (std::ostream &os) const =0
 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 () 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 toLong (long n=0) const =0
 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 =0
 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 =0
 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 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.
 

Static Public Member Functions

static XmpArrayType xmpArrayType (TypeId typeId)
 Return XMP array type for an array Value TypeId, xaNone if typeId is not an XMP array value type.
 
- 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

XmpValueoperator= (const XmpValue &rhs)
 Assignment operator. Protected so that it can only be used by subclasses but not directly.
 
- 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

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

Detailed Description

Base class for all Exiv2 values used to store XMP property values.

Member Function Documentation

virtual long Exiv2::XmpValue::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.

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

Read the value from a character buffer.

Uses read(const std::string& buf)

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.

virtual int Exiv2::XmpValue::read ( const std::string &  buf)
pure virtual

Set the value from a string buffer. The format of the string corresponds to that of the write() method, i.e., a string obtained through the write() method can be read by this function.

Parameters
bufThe string to read from.
Returns
0 if successful.

Implements Exiv2::Value.

Implemented in Exiv2::LangAltValue, Exiv2::XmpArrayValue, and Exiv2::XmpTextValue.


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