docs: public int getOpacity() {
  		int opacity = Math
  				.round((mPosToOpacFactor * (mBarPointerPosition - mBarPointerHaloRadius)));
  		if (opacity < 5) {
  			return 0x00;
  		} else if (opacity > 250) {
  			return 0xFF;
  		} else {
  			return opacity;
  		}
  	}