int y = getFontMetrics().getHeight() * (oldFirstLine - newFirstLine); offGfx.copyArea(0,0,offImg.getWidth(this),offImg.getHeight(this),0,y);
	public void scrollRepaint(int oldFirstLine, int newFirstLine)	{		if(offGfx == null)			return;		int y = getFontMetrics().getHeight() * (oldFirstLine - newFirstLine);		offGfx.copyArea(0,0,offImg.getWidth(this),offImg.getHeight(this),0,y);		int visibleLines = textArea.getVisibleLines();		if(oldFirstLine < newFirstLine)		{			invalidateLineRange(oldFirstLine + visibleLines - 1,				newFirstLine + visibleLines + 1);		}		else		{			invalidateLineRange(newFirstLine, oldFirstLine);		}	}