code: private void animateProperty(int constantName, float toValue) {
          float fromValue = getValue(constantName);
          float deltaValue = toValue - fromValue;
          animatePropertyBy(constantName, fromValue, deltaValue);
      }
docs: Utility function, called by the various x(), y(), etc. methods. This stores the
  constant name for the property along with the from/delta values that will be used to
  calculate and set the property during the animation. This structure is added to the
  pending animations, awaiting the eventual start() of the underlying animator. A
  Runnable is posted to start the animation, and any pending such Runnable is canceled
  (which enables us to end up starting just one animator for all of the properties
  specified at one time).
  
  @param constantName The specifier for the property being animated
  @param toValue The value to which the property will animate