class Kramdown::Converter::Latex

def convert_codeblock(el, opts)
  show_whitespace = el.attr['class'].to_s =~ /\bshow-whitespaces\b/
  lang = el.attr['lang']
  if show_whitespace || lang
    options = []
    options << "showspaces=%s,showtabs=%s" % (show_whitespace ? ['true', 'true'] : ['false', 'false'])
    options << "language=#{lang}" if lang
    options << "basicstyle=\\ttfamily\\footnotesize,columns=fixed,frame=tlbr"
    id = el.attr['id']
    options << "label=#{id}" if id
    attrs = attribute_list(el)
    "#{latex_link_target(el)}\\begin{lstlisting}[#{options.join(',')}]\n#{el.value}\n\\end{lstlisting}#{attrs}\n"
  else
    "#{latex_link_target(el)}\\begin{verbatim}#{el.value}\\end{verbatim}\n"
  end
end