code: public void onLoadTaskFinish(BitmapDrawable drawable, ImageLoadHandler handler) {
  
          mFlag &= ~STATUS_LOADING;
  
          if (null == handler) {
              return;
          }
          int errorCode = mFlag & ERROR_CODE_MASK;
          if (errorCode > 0) {
              onLoadError(errorCode, handler);
              return;
          }
  
          if (null != mImageTaskStatistics) {
              mImageTaskStatistics.s5_beforeShow();
          }
          if (mFirstImageViewHolder == null) {
              handler.onLoadFinish(this, null, drawable);
          } else {
              ImageViewHolder holder = mFirstImageViewHolder;
              do {
                  final CubeImageView imageView = holder.getImageView();
                  if (null != imageView) {
                      imageView.onLoadFinish();
                      handler.onLoadFinish(this, imageView, drawable);
                  }
              } while ((holder = holder.mNext) != null);
          }
          if (null != mImageTaskStatistics) {
              mImageTaskStatistics.s6_afterShow(ImageProvider.getBitmapSize(drawable));
              ImagePerformanceStatistics.onImageLoaded(this, mImageTaskStatistics);
          }
      }
docs: Will be called when begin load image data from dish or network
  
  @param drawable