code: public int alignBox(Inline box)
      {
      	if (box instanceof InlineElement)
      	{
  	        VerticalAlign va = ((InlineElement) box).getVerticalAlign();
  	        if (va == VerticalAlign.TOP || va == VerticalAlign.BOTTOM)
  	        {
  	            return 0; //top and bottom boxes are aligned to the line box in their absolutePositions()
  	        }
  	        else
  	        {
  	            return above + computeBaselineDifference((InlineElement) box) - box.getBaselineOffset() + ((InlineElement) box).getLineboxOffset();
  	        }
      	}
      	else
      		return above - box.getBaselineOffset();
      }
docs: Aligns a new box and updates the line metrics.
  @param box the box to be placed on the line
  @return the Y distance of the box top content edge from top of this line box