#include <value.hpp>
Inheritance diagram for Exiv2::Value:
Public Types | |
typedef std::auto_ptr< Value > | AutoPtr |
Shortcut for a Value auto pointer. | |
Public Member Functions | |
Creators | |
Value (TypeId typeId) | |
Constructor, taking a type id to initialize the base class with. | |
virtual | ~Value () |
Virtual destructor. | |
Manipulators | |
virtual int | read (const byte *buf, long len, ByteOrder byteOrder)=0 |
Read the value from a character buffer. | |
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. | |
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. | |
Accessors | |
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 | copy (byte *buf, ByteOrder byteOrder) const =0 |
Write value to a data buffer. | |
virtual long | count () const =0 |
Return the number of components of the value. | |
virtual long | size () const =0 |
Return the size of the value in bytes. | |
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. | |
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. | |
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. | |
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. | |
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 | |
AutoPtr | create (TypeId typeId) |
A (simple) factory to create a Value type. | |
Protected Member Functions | |
Value & | operator= (const Value &rhs) |
Assignment operator. Protected so that it can only be used by subclasses but not directly. | |
Protected Attributes | |
bool | ok_ |
Indicates the status of the previous to<Type> conversion. |
The interface provides a uniform way to access values independent of their actual C++ type for simple tasks like reading the values from a string or data buffer. For other tasks, like modifying values you may need to downcast it to a specific subclass to access its interface.
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Write value to a data buffer. The user must ensure that the buffer has enough memory. Otherwise the call results in undefined behaviour.
Implemented in Exiv2::DataValue, Exiv2::StringValueBase, Exiv2::XmpValue, Exiv2::DateValue, Exiv2::TimeValue, and Exiv2::ValueType< T >. |
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A (simple) factory to create a Value type.
The following Value subclasses are created depending on typeId:
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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. Values may have a data area, which can contain additional information besides the actual value. This method is used to access such a data area.
Reimplemented in Exiv2::ValueType< T >. |
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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.
Implemented in Exiv2::DataValue, Exiv2::StringValueBase, Exiv2::AsciiValue, Exiv2::CommentValue, Exiv2::XmpValue, Exiv2::XmpTextValue, Exiv2::XmpArrayValue, Exiv2::LangAltValue, Exiv2::DateValue, Exiv2::TimeValue, and Exiv2::ValueType< T >. |
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Read the value from a character buffer.
Implemented in Exiv2::DataValue, Exiv2::StringValueBase, Exiv2::XmpValue, Exiv2::DateValue, Exiv2::TimeValue, and Exiv2::ValueType< T >. |
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Set the data area, if the value has one by copying (cloning) the buffer pointed to by buf. Values may have a data area, which can contain additional information besides the actual value. This method is used to set such a data area.
Reimplemented in Exiv2::ValueType< T >. |
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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.
Implemented in Exiv2::DataValue, Exiv2::StringValueBase, Exiv2::XmpTextValue, Exiv2::XmpArrayValue, Exiv2::LangAltValue, Exiv2::DateValue, Exiv2::TimeValue, Exiv2::ValueType< T >, Exiv2::ValueType< T >, and Exiv2::ValueType< T >.
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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.
Implemented in Exiv2::DataValue, Exiv2::StringValueBase, Exiv2::XmpTextValue, Exiv2::XmpArrayValue, Exiv2::LangAltValue, Exiv2::DateValue, Exiv2::TimeValue, Exiv2::ValueType< T >, Exiv2::ValueType< T >, and Exiv2::ValueType< T >.
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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.
Implemented in Exiv2::DataValue, Exiv2::StringValueBase, Exiv2::XmpTextValue, Exiv2::XmpArrayValue, Exiv2::LangAltValue, Exiv2::DateValue, Exiv2::TimeValue, Exiv2::ValueType< T >, Exiv2::ValueType< T >, and Exiv2::ValueType< T >.
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