code: protected float getLayoutOffset() {
          //final int offsetSign = getOffsetSign();
          final float axisSize = getViewPortSize(getOrientationAxis());
          float layoutOffset = - axisSize / 2;
          Log.d(LAYOUT, TAG, "getLayoutOffset(): dimension: %5.2f, layoutOffset: %5.2f",
                axisSize, layoutOffset);
  
          return layoutOffset;
      }
docs: Calculate the layout offset