count = ch.getChildrenAdded().length + ch.getChildrenRemoved().length;
count = ch.getChildrenAdded().length - ch.getChildrenRemoved().length;
	protected void updateDisplay(DocumentEvent evt)	{		DocumentEvent.ElementChange ch = evt.getChange(			document.getDefaultRootElement());		TextAreaPainter painter = textArea.getPainter();		int count;		if(ch == null)			count = 0;		else			count = ch.getChildrenAdded().length +			ch.getChildrenRemoved().length;		if(count == 0)		{			int line = getLineOfOffset(evt.getOffset());			painter.invalidateLineRange(line,line);		}		else		{			int index = ch.getIndex();			painter.invalidateLineRange(index,				document.getDefaultRootElement()				.getElementCount());			textArea.updateScrollBars();		}	}