int modifiedDGifSlurp()

in animated-gif/src/main/jni/gifimage/gif.cpp [609:671]
49 lines of code
12 McCabe index (conditional complexity)

int modifiedDGifSlurp(GifWrapper* pGifWrapper, int maxDimension, bool forceStatic) {
  GifFileType* pGifFile = pGifWrapper->get();
  GifRecordType recordType;

  pGifFile->ExtensionBlocks = NULL;
  pGifFile->ExtensionBlockCount = 0;
  bool isStop = false;
  do {
    if (DGifGetRecordType(pGifFile, &recordType) == GIF_ERROR) {
      break;
    }

    switch (recordType) {
      case IMAGE_DESC_RECORD_TYPE:
        // Set the flag whether gif is animated, but give up slurping after the first frame,
        // when static image is requested.
        if (pGifFile->ImageCount >= 1) {
          pGifWrapper->setAnimated(true);
          if (forceStatic) {
            isStop = true;
            break;
          }
        }

        // We save the byte offset where each frame begins. This allows us to avoid storing
        // the pixel data for each frame and instead decode it on the fly.
        pGifWrapper->addFrameByteOffset(pGifWrapper->getData()->getPosition());

        if (readSingleFrame(
              pGifWrapper,
              false, // Don't decode frame pixels
              true,  // Add to saved images
              maxDimension // Max dimension
              ) == GIF_ERROR) {
          isStop = true;
        }
        break;

      case EXTENSION_RECORD_TYPE:
        if (decodeExtension(pGifFile) == GIF_ERROR) {
          isStop = true;
        }
        break;

      case TERMINATE_RECORD_TYPE:
        isStop = true;
        break;

       default:    // Should be trapped by DGifGetRecordType.
        break;
      }
  } while (!isStop);
  isStop = false;

  // parse application extensions
  const int imageCount = pGifFile->ImageCount;
  ReaderLock rlock_{pGifWrapper->getSavedImagesRWLock()};
  for (int i = 0; i < imageCount; i++) {
    parseApplicationExtensions(&pGifFile->SavedImages[i], pGifWrapper);
  }

  return pGifWrapper->getFrameSize() > 0 ? GIF_OK : GIF_ERROR;
}