A file class with some useful methods for tag manipulation. More...

#include <tfile.h>

Inheritance diagram for TagLib::File:

Public Types

enum  Position { Beginning, Current, End }
 

Public Member Functions

virtual ~File ()
 
FileName name () const
 
virtual Tagtag () const =0
 
PropertyMap properties () const
 
void removeUnsupportedProperties (const StringList &properties)
 
PropertyMap setProperties (const PropertyMap &properties)
 
virtual AudioPropertiesaudioProperties () const =0
 
virtual bool save ()=0
 
ByteVector readBlock (unsigned long length)
 
void writeBlock (const ByteVector &data)
 
long find (const ByteVector &pattern, long fromOffset=0, const ByteVector &before=ByteVector())
 
long rfind (const ByteVector &pattern, long fromOffset=0, const ByteVector &before=ByteVector())
 
void insert (const ByteVector &data, unsigned long start=0, unsigned long replace=0)
 
void removeBlock (unsigned long start=0, unsigned long length=0)
 
bool readOnly () const
 
bool isOpen () const
 
bool isValid () const
 
void seek (long offset, Position p=Beginning)
 
void clear ()
 
long tell () const
 
long length ()
 

Static Public Member Functions

static bool isReadable (const char *file)
 
static bool isWritable (const char *name)
 

Protected Member Functions

 File (FileName file)
 
 File (IOStream *stream)
 
void setValid (bool valid)
 
void truncate (long length)
 

Static Protected Member Functions

static unsigned int bufferSize ()
 

Detailed Description

A file class with some useful methods for tag manipulation.

This class is a basic file class with some methods that are particularly useful for tag editors. It has methods to take advantage of ByteVector and a binary search method for finding patterns in a file.

Member Enumeration Documentation

Position in the file used for seeking.

Enumerator
Beginning 

Seek from the beginning of the file.

Current 

Seek from the current position in the file.

End 

Seek from the end of the file.

Constructor & Destructor Documentation

TagLib::File::File ( FileName  file)
protected

Construct a File object and opens the file. file should be a be a C-string in the local file system encoding.

Note
Constructor is protected since this class should only be instantiated through subclasses.
TagLib::File::File ( IOStream stream)
protected

Construct a File object and use the stream instance.

Note
TagLib will not take ownership of the stream, the caller is responsible for deleting it after the File object.
Constructor is protected since this class should only be instantiated through subclasses.

Member Function Documentation

virtual AudioProperties* TagLib::File::audioProperties ( ) const
pure virtual
static unsigned int TagLib::File::bufferSize ( )
staticprotected

Returns the buffer size that is used for internal buffering.

void TagLib::File::clear ( )

Reset the end-of-file and error flags on the file.

long TagLib::File::find ( const ByteVector pattern,
long  fromOffset = 0,
const ByteVector before = ByteVector() 
)

Returns the offset in the file that pattern occurs at or -1 if it can not be found. If before is set, the search will only continue until the pattern before is found. This is useful for tagging purposes to search for a tag before the sync frame.

Searching starts at fromOffset, which defaults to the beginning of the file.

Note
This has the practical limitation that pattern can not be longer than the buffer size used by readBlock(). Currently this is 1024 bytes.
void TagLib::File::insert ( const ByteVector data,
unsigned long  start = 0,
unsigned long  replace = 0 
)

Insert data at position start in the file overwriting replace bytes of the original content.

Note
This method is slow since it requires rewriting all of the file after the insertion point.
bool TagLib::File::isOpen ( ) const

Since the file can currently only be opened as an argument to the constructor (sort-of by design), this returns if that open succeeded.

static bool TagLib::File::isReadable ( const char *  file)
static

Returns true if file can be opened for reading. If the file does not exist, this will return false.

bool TagLib::File::isValid ( ) const

Returns true if the file is open and readable.

static bool TagLib::File::isWritable ( const char *  name)
static

Returns true if file can be opened for writing.

long TagLib::File::length ( )

Returns the length of the file.

FileName TagLib::File::name ( ) const

Returns the file name in the local file system encoding.

PropertyMap TagLib::File::properties ( ) const

Exports the tags of the file as dictionary mapping (human readable) tag names (uppercase Strings) to StringLists of tag values. Calls the according specialization in the File subclasses. For each metadata object of the file that could not be parsed into the PropertyMap format, the returned map's unsupportedData() list will contain one entry identifying that object (e.g. the frame type for ID3v2 tags). Use removeUnsupportedProperties() to remove (a subset of) them. For files that contain more than one tag (e.g. an MP3 with both an ID3v2 and an ID3v2 tag) only the most "modern" one will be exported (ID3v2 in this case). BIC: Will be made virtual in future releases.

ByteVector TagLib::File::readBlock ( unsigned long  length)

Reads a block of size length at the current get pointer.

bool TagLib::File::readOnly ( ) const

Returns true if the file is read only (or if the file can not be opened).

void TagLib::File::removeBlock ( unsigned long  start = 0,
unsigned long  length = 0 
)

Removes a block of the file starting a start and continuing for length bytes.

Note
This method is slow since it involves rewriting all of the file after the removed portion.
void TagLib::File::removeUnsupportedProperties ( const StringList properties)

Removes unsupported properties, or a subset of them, from the file's metadata. The parameter properties must contain only entries from properties().unsupportedData(). BIC: Will be mad virtual in future releases.

long TagLib::File::rfind ( const ByteVector pattern,
long  fromOffset = 0,
const ByteVector before = ByteVector() 
)

Returns the offset in the file that pattern occurs at or -1 if it can not be found. If before is set, the search will only continue until the pattern before is found. This is useful for tagging purposes to search for a tag before the sync frame.

Searching starts at fromOffset and proceeds from the that point to the beginning of the file and defaults to the end of the file.

Note
This has the practical limitation that pattern can not be longer than the buffer size used by readBlock(). Currently this is 1024 bytes.
virtual bool TagLib::File::save ( )
pure virtual

Save the file and its associated tags. This should be reimplemented in the concrete subclasses. Returns true if the save succeeds.

Warning
On UNIX multiple processes are able to write to the same file at the same time. This can result in serious file corruption. If you are developing a program that makes use of TagLib from multiple processes you must insure that you are only doing writes to a particular file from one of them.

Implemented in TagLib::MPEG::File, TagLib::FLAC::File, TagLib::TrueAudio::File, TagLib::RIFF::WAV::File, TagLib::APE::File, TagLib::MPC::File, TagLib::WavPack::File, TagLib::Ogg::FLAC::File, TagLib::Ogg::Vorbis::File, TagLib::RIFF::AIFF::File, TagLib::Ogg::Opus::File, TagLib::Ogg::Speex::File, TagLib::ASF::File, TagLib::MP4::File, TagLib::Mod::File, TagLib::S3M::File, TagLib::XM::File, TagLib::IT::File, and TagLib::Ogg::File.

void TagLib::File::seek ( long  offset,
Position  p = Beginning 
)

Move the I/O pointer to offset in the file from position p. This defaults to seeking from the beginning of the file.

See also
Position
PropertyMap TagLib::File::setProperties ( const PropertyMap properties)

Sets the tags of this File to those specified in properties. Calls the according specialization method in the subclasses of File to do the translation into the format-specific details. If some value(s) could not be written imported to the specific metadata format, the returned PropertyMap will contain those value(s). Otherwise it will be empty, indicating that no problems occurred. With file types that support several tag formats (for instance, MP3 files can have ID3v1, ID3v2, and APEv2 tags), this function will create the most appropriate one (ID3v2 for MP3 files). Older formats will be updated as well, if they exist, but won't be taken into account for the return value of this function. See the documentation of the subclass implementations for detailed descriptions. BIC: will become pure virtual in the future

void TagLib::File::setValid ( bool  valid)
protected

Marks the file as valid or invalid.

See also
isValid()
long TagLib::File::tell ( ) const

Returns the current offset within the file.

void TagLib::File::truncate ( long  length)
protected

Truncates the file to a length.

void TagLib::File::writeBlock ( const ByteVector data)

Attempts to write the block data at the current get pointer. If the file is currently only opened read only – i.e. readOnly() returns true – this attempts to reopen the file in read/write mode.

Note
This should be used instead of using the streaming output operator for a ByteVector. And even this function is significantly slower than doing output with a char[].

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