private void showError(CharSequence error) {
   if (getActivity() == null) return;
   mFingerprintIcon.setImageResource(R.drawable.ic_fingerprint_error);
   mFingerprintStatus.setText(error);
   mFingerprintStatus.setTextColor(ContextCompat.getColor(getActivity(), R.color.warning_color));
   mFingerprintStatus.removeCallbacks(mResetErrorTextRunnable);
   mFingerprintStatus.postDelayed(mResetErrorTextRunnable, ERROR_TIMEOUT_MILLIS);
 }
 @Override
 public void onDigitusAuthenticated(Digitus digitus) {
   toggleButtonsEnabled(false);
   mFingerprintStatus.removeCallbacks(mResetErrorTextRunnable);
   mFingerprintIcon.setImageResource(R.drawable.ic_fingerprint_success);
   mFingerprintStatus.setTextColor(ContextCompat.getColor(getActivity(), R.color.success_color));
   mFingerprintStatus.setText(getResources().getString(R.string.fingerprint_success));
   mFingerprintIcon.postDelayed(
       new Runnable() {
         @Override
         public void run() {
           mCallback.onFingerprintDialogAuthenticated();
           dismiss();
         }
       },
       SUCCESS_DELAY_MILLIS);
 }