// once complete, see if ImageView is still around and set up bitmap
    @Override
    protected void onPostExecute(FileLoader fileLoader) {
      super.onPostExecute(fileLoader);

      if (isCancelled()) {
        fileLoader = null;
      }
      if (hostFragmentReference != null) {
        final ViewerFragment hostFragment = hostFragmentReference.get();
        if (hostFragment != null) {
          if (fileLoader != null) {
            hostFragment.mFileLoader = fileLoader;
            Toast.makeText(
                    hostFragment.getActivity(),
                    "Found " + fileLoader.getNumberOfPages() + " pages",
                    Toast.LENGTH_SHORT)
                .show();
          } else {
            hostFragment.mFileLoader = null;
            if (err != null) {
              Savelog.e(TAG, "Cannot fetch pdf" + "\n" + Savelog.getStack(err));
            }
            Toast.makeText(hostFragment.getActivity(), "Data unavailable", Toast.LENGTH_SHORT)
                .show();
          }
          // Callback upon finished fetching.
          hostFragment.onFetchingCompleted();
          // Detach host fragment from this task.
          hostFragment.mFetcherTask = null;
        }
      }
      Savelog.d(TAG, debug, "AsyncTask completed.");
    }
  public void onFetchingCompleted() {
    mLoadingView.setVisibility(View.GONE);

    mListView.setVisibility(View.VISIBLE);
    mListView.setAlpha(1f);

    if (mFileLoader != null) {
      Savelog.d(TAG, debug, "bitmap page length  = " + mFileLoader.getNumberOfPages());
      if (mBitmapListAdapter == null) { // Don't reset adapter if already exists
        mBitmapListAdapter = new BitmapListAdapter(this, mFileLoader.getPageNames());
      }
      mListView.setAdapter(mBitmapListAdapter);
      mListView.setRecyclerListener(
          new RecyclerListener() {
            @Override
            public void onMovedToScrapHeap(View view) {
              final ImageView imageView = (ImageView) view.findViewById(R.id.listItem_bitmap_id);
              Savelog.d(TAG, debug, "Called recycler.");
              imageView.setImageBitmap(null);
              imageView.setTag(null);
            }
          });
    }
  }