code: public void setShadowXOffset(int dimenResId) {
          int shadowXOffset = getResources().getDimensionPixelSize(dimenResId);
          if (mShadowXOffset != shadowXOffset) {
              mShadowXOffset = shadowXOffset;
              requestLayout();
              updateBackground();
          }
      }
docs: Sets the shadow x offset of the <b>FloatingActionButton</b> and invalidates its layout.
  
  @param dimenResId the resource identifier of the dimension