private void updateDisplay() {
      if (mSuccessful + mFailed == mUris.length) {
        mPrefetchDiskButton.setEnabled(true);
        mPrefetchEncodedButton.setEnabled(true);
        mPrefetchBitmapButton.setEnabled(true);
      }
      mPrefetchStatus.setText(
          getString(R.string.prefetch_status, mSuccessful, mUris.length, mFailed));
    }
Fragment that illustrates how to prefetch images to disk cache so that they load faster when
finally displayed.
samples/showcase/src/main/java/com/facebook/fresco/samples/showcase/imagepipeline/ImagePipelinePrefetchFragment.java