code: private void centerOnCurrentItem() {
          if(!mPieData.isEmpty()) {
              PieModel current = mPieData.get(getCurrentItem());
              int targetAngle;
  
              if(mOpenClockwise) {
                  targetAngle = (mIndicatorAngle - current.getStartAngle()) - ((current.getEndAngle() - current.getStartAngle()) / 2);
                  if (targetAngle < 0 && mPieRotation > 0) targetAngle += 360;
              }
              else {
                  targetAngle = current.getStartAngle() + (current.getEndAngle() - current.getStartAngle()) / 2;
                  targetAngle += mIndicatorAngle;
                  if (targetAngle > 270 && mPieRotation < 90) targetAngle -= 360;
              }
  
              mAutoCenterAnimator.setIntValues(targetAngle);
              mAutoCenterAnimator.setDuration(AUTOCENTER_ANIM_DURATION).start();
  
          }
      }
docs: Kicks off an animation that will result in the pointer being centered in the
  pie slice of the currently selected item.