@Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
          // todo avoid autoboxing
          setDotRevealFraction(PendingRevealAnimator.this.dot,
              (Float) valueAnimator.getAnimatedValue());
        }
An Animator that animates a given dot's revealFraction i.e. scales it up
java/com/google/android/apps/authenticator/howitworks/PagingIndicator.java