☰

如何获取lstnewenvironment新建的环境的宽度？

tag-icon • tag-icon listings environments
如何获取lstnewenvironment新建的环境的宽度？

背景

我尝试新建一个环境来显示 LaTeX 代码和编译结果。我参考了siunitx.tex并作出了如下的 MWE：

\documentclass{article}
% For creating code demonstrations
% This needs access to some code-level interfaces in listings
\usepackage{listings}
\makeatletter
\lst@RequireAspects{writefile}
\newsavebox\LaTeXdemo@box
\lstnewenvironment{LaTeXdemo}[1][code and example]
  {%
    \global\let\lst@intname\@empty
    \edef\LaTeXdemo@end{%
      \expandafter\noexpand\csname LaTeXdemo@@#1@end\endcsname
    }%
    \@nameuse{LaTeXdemo@@#1}%
  }
  {\LaTeXdemo@end}
\ExplSyntaxOff
\newcommand\LaTeXdemo@new[3]{%
  \@namedef{LaTeXdemo@@#1}{#2}%
  \@namedef{LaTeXdemo@@#1@end}{#3}%
}
\newcommand*\LaTeXdemo@common{%
  \setkeys{lst}
    {%
            basicstyle         = \ttfamily\small,
            basewidth          = 0.51em,
            backgroundcolor    = \color{cyan!10},
            % rulecolor          = \color{red!10},
            frame              = shadowbox,
            frameround         = tttt,
            % framerule          = 0pt,
            gobble             = 4,
            tabsize            = 2,
            numbers            = left,
            language           = [LaTeX]TeX,
            % linewidth          = 0.5\linewidth
    }%
}
\newcount\LaTeXdemo@count
\newcommand*\LaTeXdemo@input{%
  \catcode`\^^M = 10\relax
  \input{\jobname-\number\[email protected]}%
}
\LaTeXdemo@new{code and example}{%
  \setbox\LaTeXdemo@box=\hbox\bgroup
    \global\advance\LaTeXdemo@count by 1 %
    \lst@BeginAlsoWriteFile{\jobname-\number\[email protected]}%
    \LaTeXdemo@common
}{%
    \lst@EndWriteFile
  \egroup
  \begin{center}
    \ifdim\wd\LaTeXdemo@box > 0.48\linewidth
      \begin{minipage}{\linewidth}
        \usebox\LaTeXdemo@box
      \end{minipage}%
      \par
      \begin{minipage}{\linewidth}
        \LaTeXdemo@input
      \end{minipage}
    \else
      \begin{minipage}{0.48\linewidth}
        \LaTeXdemo@input
      \end{minipage}%
      \hfil
      \begin{minipage}{0.48\linewidth}
        \usebox\LaTeXdemo@box
      \end{minipage}%
    \fi
  \end{center}
}
\LaTeXdemo@new{code and float}{%
  \global\advance\LaTeXdemo@count by 1 %
  \lst@BeginAlsoWriteFile{\jobname-\number\[email protected]}%
  \LaTeXdemo@common
}{%
  \lst@EndWriteFile
  \LaTeXdemo@input
}
\LaTeXdemo@new{code only}{\LaTeXdemo@common}{}
\makeatother

\begin{document}
    \begin{LaTeXdemo}
        \begin{enumerate}
            \item 1
            \item 2
            \item 3
            \item 4
            \item 5
        \end{enumerate}
    \end{LaTeXdemo}
\end{document}

问题

MWE 效果很好。但当我想给代码部分上色时，我发现它太长了： 在此处输入图片描述

于是我用 来linewidth调整它。然后我想：为什么不自己计算宽度呢？然后我想像往常一样使用 LaTeX3 来计算宽度。

但是！问题是： lstnewenvironment就像newenvironment：代码不包含该BODY部分environ，所以我无法测量宽度。

那么有什么方法可以获取 的主体吗lstnewenvironment？然后我可以将其存储到框中并获取其宽度。

问题摘要

感谢@user202729 提醒我\LaTeXdemo@box包含内容，我确实测量了宽度，但是我无法设置宽度，似乎内容已经固定了，虽然我得到了它的宽度，但 lstset 根本没有影响它。

相关内容