Exiv2
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Value for an Exif comment. More...
#include <value.hpp>
Classes | |
class | CharsetInfo |
Charset information lookup functions. Implemented as a static class. More... | |
struct | CharsetTable |
Information pertaining to the defined character sets. More... | |
Public Types | |
enum | CharsetId { ascii, jis, unicode, undefined, invalidCharsetId, lastCharsetId } |
Character set identifiers for the character sets defined by Exif. | |
typedef std::auto_ptr < CommentValue > | AutoPtr |
Shortcut for a CommentValue auto pointer. | |
Public Member Functions | |
Creators | |
CommentValue () | |
Default constructor. | |
CommentValue (const std::string &comment) | |
Constructor, uses read(const std::string& comment) | |
virtual | ~CommentValue () |
Virtual destructor. | |
Manipulators | |
int | read (const std::string &comment) |
Read the value from a comment. | |
int | read (const byte *buf, long len, ByteOrder byteOrder) |
Read the comment from a byte buffer. | |
Accessors | |
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. | |
long | copy (byte *buf, ByteOrder byteOrder) const |
Write value to a character data buffer. | |
std::ostream & | write (std::ostream &os) const |
Write the comment in a format which can be read by read(const std::string& comment). | |
std::string | comment (const char *encoding=0) const |
Return the comment (without a charset="..." prefix) | |
const char * | detectCharset (std::string &c) const |
Determine the character encoding that was used to encode the UNICODE comment value as an iconv(3) name. | |
CharsetId | charsetId () const |
Return the Exif charset id of the comment. | |
Public Attributes | |
ByteOrder | byteOrder_ |
Byte order of the comment string that was read. |
Value for an Exif comment.
This can be a plain Ascii string or a multipe byte encoded string. The comment is expected to be encoded in the character set indicated (default undefined), but this is not checked. It is left to caller to decode and encode the string to and from readable text if that is required.
std::string Exiv2::CommentValue::comment | ( | const char * | encoding = 0 | ) | const |
Return the comment (without a charset="..." prefix)
The comment is decoded to UTF-8. For Exif UNICODE comments, the function makes an attempt to correctly determine the character encoding of the value. Alternatively, the optional encoding parameter can be used to specify it.
encoding | Optional argument to specify the character encoding that the comment is encoded in, as an iconv(3) name. Only used for Exif UNICODE comments. |
References charsetId(), Exiv2::convertStringCharset(), detectCharset(), Exiv2::string, and Exiv2::StringValueBase::value_.
Referenced by Exiv2::Converter::cnvExifComment(), Exiv2::Internal::print0x9286(), Action::Print::printMetadatum(), read(), Action::FixCom::run(), and write().
Write value to a character data buffer.
The user must ensure that the buffer has enough memory. Otherwise the call results in undefined behaviour.
buf | Data buffer to write to. |
byteOrder | Byte order. Not used. |
Reimplemented from Exiv2::StringValueBase.
References byteOrder_, charsetId(), Exiv2::convertStringCharset(), Exiv2::string, and Exiv2::StringValueBase::value_.
const char * Exiv2::CommentValue::detectCharset | ( | std::string & | c | ) | const |
Determine the character encoding that was used to encode the UNICODE comment value as an iconv(3) name.
If the comment c starts with a BOM, the BOM is interpreted and removed from the string.
Todo: Implement rules to guess if the comment is UTF-8 encoded.
References byteOrder_.
Referenced by comment().
int Exiv2::CommentValue::read | ( | const std::string & | comment | ) | [virtual] |
Read the value from a comment.
The format of comment is:
[charset=["]Ascii|Jis|Unicode|Undefined["] ]comment
The default charset is Undefined.
Reimplemented from Exiv2::StringValueBase.
References byteOrder_, charsetId(), Exiv2::CommentValue::CharsetInfo::charsetIdByName(), Exiv2::CommentValue::CharsetInfo::code(), comment(), Exiv2::convertStringCharset(), EXV_WARNING, and Exiv2::string.
Referenced by CommentValue(), and read().