code: protected float getViewPortSize(final Axis axis) {
          float size =  mViewPort == null ? 0 : mViewPort.get(axis);
          Log.d(Log.SUBSYSTEM.LAYOUT, TAG, "getViewPortSize for %s %f mViewPort = %s", axis, size, mViewPort);
          return size;
      }
docs: Get viewport size along the axis
  @param axis {@link Axis}
  @return size