tag.cpp

FreeAMP(MP3播放)程序源代码-用来研究MP3解码

  return _impl->GetAppendedBytes();
}

size_t ID3_Tag::GetFileSize() const 
{ 
  return _impl->GetFileSize();
}

const char* ID3_Tag::GetFileName() const 
{ 
  return _impl->GetFileName().c_str();
}

/// Finds frame with given frame id
  /** Returns a pointer to the next ID3_Frame with the given ID3_FrameID;
   ** returns NULL if no such frame found.
   ** 
   ** If there are multiple frames in the tag with the same ID (which, for some
   ** frames, is allowed), then subsequent calls to Find() will return
   ** subsequent frame pointers, wrapping if necessary.
   ** 
   ** \code
   **   ID3_Frame *myFrame;
   **   if (myFrame = myTag.Find(ID3FID_TITLE))
   **   {
   **     // do something with the frame, like copy
   **     // the contents into a buffer, display the
   **     // contents in a window, etc.
   **     // ...
   **   }
   ** \endcode
   ** 
   ** You may optionally supply to more parameters ot this method, being an
   ** ID3_FieldID and a value of some sort.  Depending on the field name/ID you
   ** supply, you may supply an integer, a char* or a unicode_t* as the third
   ** parameter.  If you supply an ID3_FrameID, you must also supply a data
   ** value to compare against.
   ** 
   ** This method will then return the first frame that has a matching frame
   ** ID, and which has a field with the same name as that which you supplied
   ** in the second parameter, whose calue matches that which you supplied as
   ** the third parameter.  For example:
   ** 
   ** \code
   **   ID3_Frame *myFrame;
   **   if (myFrame = myTag.Find(ID3FID_TITLE, ID3FN_TEXT, "Nirvana"))
   **   {
   **     // found it, do something with it.
   **     // ...
   **   }
   ** \endcode
   **     
   ** This example will return the first TITLE frame and whose TEXT field is
   ** 'Nirvana'.  Currently there is no provision for things like 'contains',
   ** 'greater than', or 'less than'.  If there happens to be more than one of
   ** these frames, subsequent calls to the Find() method will return
   ** subsequent frames and will wrap around to the beginning.
   ** 
   ** Another example...
   ** 
   ** \code
   **   ID3_Frame *myFrame;
   **   if (myFrame = myTag.Find(ID3FID_COMMENT, ID3FN_TEXTENC, ID3TE_UNICODE))
   **   {
   **     // found it, do something with it.
   **     // ...
   **   }
   ** \endcode
   ** 
   ** This returns the first COMMENT frame that uses Unicode as its text
   ** encdoing.
   **  
   ** @name   Find
   ** @param  id The ID of the frame that is to be located
   ** @return A pointer to the first frame found that has the given frame id,
   **         or NULL if no such frame.
   **/
ID3_Frame* ID3_Tag::Find(ID3_FrameID id) const
{
  return _impl->Find(id);
}

/// Finds frame with given frame id, fld id, and integer data
ID3_Frame* ID3_Tag::Find(ID3_FrameID id, ID3_FieldID fld, uint32 data) const
{
  return _impl->Find(id, fld, data);
}

/// Finds frame with given frame id, fld id, and ascii data
ID3_Frame* ID3_Tag::Find(ID3_FrameID id, ID3_FieldID fld, const char* data) const
{
  String str(data);
  return _impl->Find(id, fld, str);
}

/// Finds frame with given frame id, fld id, and unicode data
ID3_Frame* ID3_Tag::Find(ID3_FrameID id, ID3_FieldID fld, const unicode_t* data) const
{
  WString str = toWString(data, ucslen(data));
  return _impl->Find(id, fld, str);
}

/** Returns the number of frames present in the tag object.
 ** 
 ** This includes only those frames that id3lib recognises.  This is used as
 ** the upper bound on calls to the GetFrame() and operator[]() methods.
 ** 
 ** \return The number of frames present in the tag object.
 **/
size_t ID3_Tag::NumFrames() const
{
  return _impl->NumFrames();
}

/** Returns a pointer to the frame with the given index; returns NULL if
 ** there is no such frame at that index.
 ** 
 ** Optionally, operator[](index_t) can be used as an alternative to this
 ** method.  Indexing is 0-based (that is, the first frame is number 0, and the
 ** last frame in a tag that holds n frames is n-1).
 ** 
 ** If you wish to have a more comlex searching facility, then at least for
 ** now you will have to devise it yourself and implement it useing these
 ** methods.
 ** 
 ** @param nIndex The index of the frame that is to be retrieved
 ** @return A pointer to the requested frame, or NULL if no such frame.
 **/
/*
ID3_Frame* ID3_Tag::GetFrameNum(index_t num) const
{
  const size_t numFrames = this->NumFrames();
  if (num >= numFrames)
  {
    return NULL;
  }

  ID3_Frame* frame = NULL;
  index_t curNum = 0;
  // search from the cursor to the end
  for (ID3_TagImpl::const_iterator cur = _impl->begin(); cur != _impl->end(); ++cur)
  {
    if (curNum++ == num)
    {
      frame = *cur;
      break;
    }
  }
  
  return frame;
}
*/

/** Returns a pointer to the frame with the given index; returns NULL if
 ** there is no such frame at that index.
 ** 
 ** @name operator[]
 ** @param index The index of the frame that is to be retrieved
 ** @return A pointer to the requested frame, or NULL if no such frame. 
 ** @see #GetFrameNum
 **/
/*
ID3_Frame* ID3_Tag::operator[](index_t index) const
{
  return this->GetFrameNum(index);
}
*/

ID3_Tag& ID3_Tag::operator=( const ID3_Tag &rTag )
{
  if (this != &rTag)
  {
    *_impl = rTag;
  }
  return *this;
}

bool ID3_Tag::HasTagType(uint16 tt) const
{
  return _impl->HasTagType(16);
}

ID3_V2Spec ID3_Tag::GetSpec() const
{
  return _impl->GetSpec();
}

bool ID3_Tag::SetSpec(ID3_V2Spec spec)
{
  return _impl->SetSpec(spec);
}

/** Analyses a buffer to determine if we have a valid ID3v2 tag header.
 ** If so, return the total number of bytes (including the header) to
 ** read so we get all of the tag
 **/
size_t ID3_Tag::IsV2Tag(const uchar* const data)
{
  ID3_MemoryReader mr(data, ID3_TagHeader::SIZE);
  return ID3_TagImpl::IsV2Tag(mr);
}

size_t ID3_Tag::IsV2Tag(ID3_Reader& reader)
{
  return ID3_TagImpl::IsV2Tag(reader);
}

/// Deprecated
void ID3_Tag::AddNewFrame(ID3_Frame* f) 
{ 
  _impl->AttachFrame(f);
}

/** Copies an array of frames to the tag.
 ** 
 ** This method copies each frame in an array to the tag.  As in 
 ** AddFrame, the tag adds a copy of the frame, and it assumes responsiblity
 ** for freeing the frames' memory when the tag goes out of scope.
 ** 
 ** \code
 **   ID3_Frame myFrames[10];
 **   myTag.AddFrames(myFrames, 10);
 ** \endcode
 ** 
 ** \sa ID3_Frame
 ** \sa ID3_Frame#AddFrame
 ** \param pNewFrames A pointer to an array of frames to be added to the tag.
 ** \param nFrames The number of frames in the array pNewFrames.
 **/
void ID3_Tag::AddFrames(const ID3_Frame *frames, size_t numFrames)
{
  for (index_t i = numFrames - 1; i >= 0; i--)
  {
    this->AddFrame(frames[i]);
  }
}

size_t ID3_Tag::Link(const char *fileInfo, bool parseID3v1, bool parseLyrics3)
{
  return _impl->Link(fileInfo, parseID3v1, parseLyrics3);
}

void ID3_Tag::SetCompression(bool b) 
{ 
  ; 
}

bool ID3_Tag::HasLyrics() const 
{ 
  return this->HasTagType(ID3TT_LYRICS);
}
bool ID3_Tag::HasV2Tag()  const 
{ 
  return this->HasTagType(ID3TT_ID3V2); 
}
bool ID3_Tag::HasV1Tag()  const 
{ 
  return this->HasTagType(ID3TT_ID3V1); 
}

/** Copies a frame to the tag.  The frame parameter can thus safely be deleted
 ** or allowed to go out of scope.
 ** 
 ** Operator<< supports the addition of a pointer to a frame object, or
 ** the frame object itself.
 **
 ** \code
 **   ID3_Frame *pFrame, frame;
 **   p_frame = &frame;
 **   myTag << pFrame;
 **   myTag << frame;
 ** \endcode
 **
 ** Both these methods copy the given frame to the tag---the tag creates its
 ** own copy of the frame.
 ** 
 ** \name operator<<
 ** \param frame The frame to be added to the tag.
 **/
ID3_Tag& ID3_Tag::operator<<(const ID3_Frame& frame)
{
  this->AddFrame(frame);
  return *this;
}


ID3_Tag& ID3_Tag::operator<<(const ID3_Frame* frame)
{
  if (frame)
  {
    this->AddFrame(frame);
  }
  return *this;
}

int32 ID3_IsTagHeader(const uchar data[ID3_TAGHEADERSIZE])
{
  size_t size = ID3_Tag::IsV2Tag(data);
  
  if (!size)
  {
    return -1;
  }
  
  return size - ID3_TagHeader::SIZE;
}


namespace
{
  class IteratorImpl : public ID3_Tag::Iterator
  {
    ID3_TagImpl::iterator _cur;
    ID3_TagImpl::iterator _end;
  public:
    IteratorImpl(ID3_TagImpl& tag)
      : _cur(tag.begin()), _end(tag.end())
    {
    }

    ID3_Frame* GetNext() 
    { 
      ID3_Frame* next = NULL;
      while (next == NULL && _cur != _end)
      {
        next = *_cur;
        ++_cur;
      }
      return next;
    }
  };

  
  class ConstIteratorImpl : public ID3_Tag::ConstIterator
  {
    ID3_TagImpl::const_iterator _cur;
    ID3_TagImpl::const_iterator _end;
  public:
    ConstIteratorImpl(ID3_TagImpl& tag)
      : _cur(tag.begin()), _end(tag.end())
    {
    }
    const ID3_Frame* GetNext() 
    { 
      ID3_Frame* next = NULL;
      while (next == NULL && _cur != _end)
      {
        next = *_cur;
        ++_cur;
      }
      return next;
    }
  };
}

ID3_Tag::Iterator* 
ID3_Tag::CreateIterator()
{
  return new IteratorImpl(*_impl);
}

ID3_Tag::ConstIterator* 
ID3_Tag::CreateIterator() const
{
  return new ConstIteratorImpl(*_impl);
}