private void resetState() {
    if (pageCount > 0) {
      joiningFractions = new float[pageCount - 1];
      Arrays.fill(joiningFractions, 0f);
      dotRevealFractions = new float[pageCount];
      Arrays.fill(dotRevealFractions, 0f);
      retreatingJoinX1 = INVALID_FRACTION;
      retreatingJoinX2 = INVALID_FRACTION;
      selectedDotInPosition = true;
    }
  }
As this class <b>must</b> act as the {@link ViewPager.OnPageChangeListener} for the ViewPager
(as set by {@link #setViewPager(android.support.v4.view.ViewPager)}).  Applications may set a
listener here to be notified of the ViewPager events.

@param onPageChangeListener
java/com/google/android/apps/authenticator/howitworks/PagingIndicator.java