C++ CommentsFrame类代码示例

void ID3v2::Tag::setComment(const String &s)
{
  if(s.isEmpty()) {
    removeFrames("COMM");
    return;
  }

  if(!d->frameListMap["COMM"].isEmpty())
    d->frameListMap["COMM"].front()->setText(s);
  else {
    CommentsFrame *f = new CommentsFrame(d->factory->defaultTextEncoding());
    addFrame(f);
    f->setText(s);
  }
}

CommentsFrame *CommentsFrame::findByDescription(const ID3v2::Tag *tag, const String &d) // static
{
  ID3v2::FrameList comments = tag->frameList("COMM");

  for(ID3v2::FrameList::ConstIterator it = comments.begin();
      it != comments.end();
      ++it)
  {
    CommentsFrame *frame = dynamic_cast<CommentsFrame *>(*it);
    if(frame && frame->description() == d)
      return frame;
  }

  return 0;
}

String ID3v2::Tag::comment() const
{
  const FrameList &comments = d->frameListMap["COMM"];

  if(comments.isEmpty())
    return String::null;

  for(FrameList::ConstIterator it = comments.begin(); it != comments.end(); ++it)
  {
    CommentsFrame *frame = dynamic_cast<CommentsFrame *>(*it);

    if(frame && frame->description().isEmpty())
      return (*it)->toString();
  }

  return comments.front()->toString();
}

Frame *Frame::createTextualFrame(const String &key, const StringList &values) //static
{
  // check if the key is contained in the key<=>frameID mapping
  ByteVector frameID = keyToFrameID(key);
  if(!frameID.isNull()) {
    if(frameID[0] == 'T'){ // text frame
      TextIdentificationFrame *frame = new TextIdentificationFrame(frameID, String::UTF8);
      frame->setText(values);
      return frame;
    } else if((frameID[0] == 'W') && (values.size() == 1)){  // URL frame (not WXXX); support only one value
        UrlLinkFrame* frame = new UrlLinkFrame(frameID);
        frame->setUrl(values.front());
        return frame;
    }
  }
  if(key == "MUSICBRAINZ_TRACKID" && values.size() == 1) {
    UniqueFileIdentifierFrame *frame = new UniqueFileIdentifierFrame("http://musicbrainz.org", values.front().data(String::UTF8));
    return frame;
  }
  // now we check if it's one of the "special" cases:
  // -LYRICS: depending on the number of values, use USLT or TXXX (with description=LYRICS)
  if((key == "LYRICS" || key.startsWith(lyricsPrefix)) && values.size() == 1){
    UnsynchronizedLyricsFrame *frame = new UnsynchronizedLyricsFrame(String::UTF8);
    frame->setDescription(key == "LYRICS" ? key : key.substr(lyricsPrefix.size()));
    frame->setText(values.front());
    return frame;
  }
  // -URL: depending on the number of values, use WXXX or TXXX (with description=URL)
  if((key == "URL" || key.startsWith(urlPrefix)) && values.size() == 1){
    UserUrlLinkFrame *frame = new UserUrlLinkFrame(String::UTF8);
    frame->setDescription(key == "URL" ? key : key.substr(urlPrefix.size()));
    frame->setUrl(values.front());
    return frame;
  }
  // -COMMENT: depending on the number of values, use COMM or TXXX (with description=COMMENT)
  if((key == "COMMENT" || key.startsWith(commentPrefix)) && values.size() == 1){
    CommentsFrame *frame = new CommentsFrame(String::UTF8);
    if (key != "COMMENT"){
      frame->setDescription(key.substr(commentPrefix.size()));
    }
    frame->setText(values.front());
    return frame;
  }
  // if non of the above cases apply, we use a TXXX frame with the key as description
  return new UserTextIdentificationFrame(keyToTXXX(key), values, String::UTF8);
}

Frame *FrameFactory::createFrame(const ByteVector &data, uint version) const
{
  Frame::Header *header = new Frame::Header(data, version);
  ByteVector frameID = header->frameID();

  // A quick sanity check -- make sure that the frameID is 4 uppercase Latin1
  // characters.  Also make sure that there is data in the frame.

  if(!frameID.size() == (version < 3 ? 3 : 4) ||
     header->frameSize() <= 0 ||
     header->frameSize() > data.size())
  {
    delete header;
    return 0;
  }

  for(ByteVector::ConstIterator it = frameID.begin(); it != frameID.end(); it++) {
    if( (*it < 'A' || *it > 'Z') && (*it < '1' || *it > '9') ) {
      delete header;
      return 0;
    }
  }

  // TagLib doesn't mess with encrypted frames, so just treat them
  // as unknown frames.

#if HAVE_ZLIB == 0
  if(header->compression()) {
    debug("Compressed frames are currently not supported.");
    return new UnknownFrame(data, header);
  }
#endif
  if(header->encryption()) {
    debug("Encrypted frames are currently not supported.");
    return new UnknownFrame(data, header);
  }

  if(!updateFrame(header)) {
    header->setTagAlterPreservation(true);
    return new UnknownFrame(data, header);
  }

  // updateFrame() might have updated the frame ID.

  frameID = header->frameID();

  // This is where things get necissarily nasty.  Here we determine which
  // Frame subclass (or if none is found simply an Frame) based
  // on the frame ID.  Since there are a lot of possibilities, that means
  // a lot of if blocks.

  // Text Identification (frames 4.2)

  if(frameID.startsWith("T")) {
    TextIdentificationFrame *f = frameID != "TXXX"
      ? new TextIdentificationFrame(data, header)
      : new UserTextIdentificationFrame(data, header);

    if(d->useDefaultEncoding)
      f->setTextEncoding(d->defaultEncoding);

    if(frameID == "TCON")
      updateGenre(f);

    return f;
  }

  // Comments (frames 4.10)

  if(frameID == "COMM") {
    CommentsFrame *f = new CommentsFrame(data, header);
    if(d->useDefaultEncoding)
      f->setTextEncoding(d->defaultEncoding);
    return f;
  }

  // Attached Picture (frames 4.14)

  if(frameID == "APIC") {
    AttachedPictureFrame *f = new AttachedPictureFrame(data, header);
    if(d->useDefaultEncoding)
      f->setTextEncoding(d->defaultEncoding);
    return f;
  }

  // Relative Volume Adjustment (frames 4.11)

  if(frameID == "RVA2")
    return new RelativeVolumeFrame(data, header);

  // Unique File Identifier (frames 4.1)

  if(frameID == "UFID")
    return new UniqueFileIdentifierFrame(data, header);

  // General Encapsulated Object (frames 4.15)

  if(frameID == "GEOB")
    return new GeneralEncapsulatedObjectFrame(data, header);

//.........这里部分代码省略.........