code: public void startZoom(float endZoom) {
          mStartRTC = SystemClock.elapsedRealtime();
          mEndZoom = endZoom;
  
          mFinished = false;
          mCurrentZoom = 1f;
      }
docs: Starts a zoom from 1.0 to (1.0 + endZoom). That is, to zoom from 100% to 125%, endZoom should by 0.25f.
  
  @see android.widget.Scroller#startScroll(int, int, int, int)