[Tex/LaTex] How to format sections/subsections/etc. like nested lists

listssectioningsections-paragraphs

I would like to format sections/subsections/etc. so that the entire body text of subsections is indented relative to the body text of the parent section as it is for nested lists, i.e.

1. Section heading.  Lorem ipsum dolor sit amet, consectetur adipisicing elit,
   sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

   a. Subsection heading.  Duis aute irure dolor in reprehenderit in voluptate
      velit esse cillum dolore eu fugiat nulla pariatur.

I am currently using the titlesec package to achieve the run-in section heading with the following macros:

\titleformat{\section}[runin]{\normalfont\bfseries}{\thesection.}{.5em}{}[\quad]

\titleformat{\subsection}[runin]{\normalfont\bfseries}{\thesubsection.}{.5em}{}[\quad]
\titlespacing{\subsection}{\parindent}{*2}{\wordsep}

The resulting output looks like this:

1. Section heading.  Lorem ipsum dolor sit amet, consectetur adipisicing elit,
sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

   a. Subsection heading.  Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur.

I've tried using the hanging package and the underlying \hangindent and \hangafter commands in the \titleformat definitions, but nothing I've tried has produced the desired results.

Best Answer

Not really. In theory, the \section command could be rewritten to adjust the page layout, but that would not be fun. Also, it could be ambiguous, sometimes, where sections end. I recommend instead something like the following, where you redefine the section headings into environments and then change the margins with the changepage package. .

\documentclass[twoside]{article}
\usepackage{changepage,lipsum}
\newenvironment{h1}[2][]{\section[#1]{#2}}{}
\newenvironment{h2}[2][]{%
  \begin{adjustwidth}{2em}{}
    \subsection[#1]{#2}%
}{%
  \end{adjustwidth}
}
\newenvironment{h3}[2][]{%
  \begin{adjustwidth}{2em}{}
    \subsubsection[#1]{#2}%
}{%
  \end{adjustwidth}
}
\begin{document}
\begin{h1}{first}
  \lipsum[1]
  \begin{h2}{second}
    \lipsum[2]
  \end{h2}
  \begin{h2}{third}
    \lipsum[3]
    \begin{h3}{fourth}
      \lipsum[4]
    \end{h3}
  \end{h2}
\end{h1}
\end{document}

Changing the formatting of the section headings can be done, as you mention, with titlesec.

Related Solutions

[Tex/LaTex] Numbering sections, subsections etc manually

I'm not sure why you'd want to do this. Even more, I believe you shouldn't discharge the usual commands: if you don't like the appearance of section headings there's the package titlesec that allows for changing them.

Here I propose a \DIV macro that can be called with an optional argument and a mandatory argument for the subdivision level; the optional argument is the number to use (if not specified, just step the normal counter).

\usepackage{xparse}
\NewDocumentCommand{\DIV}{om}{%
  \IfValueT{#1}{\setcounter{#2}{\numexpr#1-1\relax}}%
  \csname #2\endcsname
}

Now you can call

\DIV[42]{section}{The answer to the fundamental question}

and the section will be numbered 42. If the next section is called with

\DIV{section}{Don't panic!}

it will be numbered 43.

Should you want to remove this manual numbering, just comment the \IfValueT line.

[Tex/LaTex] Have “enumerate” continue the numbering of Sections, Subsections, Subsubsections, etc

If you also want text within sections indented as if these were items of an enumeration environment, you may want to consider also using replacing the sectioning commands by enumerations.

I'm setting up an enumeration environment called ryuenum below that allows you to use \Item{<title>} instead of \item to produce items with a heading that is formatted like a section heading of the appropriate depth. It also inserts an entry in the TOC.

\documentclass{article}

\usepackage{enumitem}
\newlist{ryuenum}{enumerate}{5}                             %% <- max depth = 5
\setlist[ryuenum]{align=left,labelindent=0pt,               %% <- label placement
                  listparindent=\parindent,parsep=\parskip} %% <- set parindent/parskip

\setlist[ryuenum,1]{label=\Roman*.,ref=\Roman*,
  before={\ryuenumsetup[\ryutoctop]{section}{.5em}{.5em}{\Large\bfseries}}}
\setlist[ryuenum,2]{label=\Alph*.,ref=\Alph*,
  before={\ryuenumsetup{subsection}{.5em}{.5em}{\large\bfseries}}}
\setlist[ryuenum,3]{label=\arabic*.,ref=\arabic*,
  before={\ryuenumsetup{subsubsection}{.5em}{.5em}{\normalsize\bfseries}}}
\setlist[ryuenum,4]{label=\roman*.,ref=\roman*}
\setlist[ryuenum,5]{label=\alph*.,ref=\alph*}

%% Sets parameters that determine appearance of headings/toc entries:
\newlength\ryuspacebefore \newlength\ryuspaceafter
\newcommand\ryuenumsetup[5][\ryutocnormal]{%
  \let\ryutocformat#1%
  \def\ryusecdp{#2}%
  \setlength{\ryuspacebefore}{#3}%
  \setlength{\ryuspaceafter}{#4}%
  \def\ryusecformat{#5}%
}

%% Toc entry styles:
\newcommand*\ryutocnormal[2]{\protect\numberline{#1.}#2}
\newcommand*\ryutoctop[2]{Article #1: #2}

%% The \Item command
\makeatletter %% <- make @ usable in command sequences
\newcommand*\Item[1]{%
  \begingroup                                  %% <- limit scope of font change
    \normalfont\ryusecformat                   %% <- set font
    \par\vspace{\ryuspacebefore}%              %% <- space above
    \item                                      %% <- item
    \interlinepenalty\@M                       %% <- inhibit page breaks
    #1\par%                                    %% <- heading, paragraph break
    \vspace{\ryuspaceafter}                    %% <- space below
    \csname\ryusecdp mark\endcsname{#1}%       %% <- \sectionmark etc.
    \ifx\ryusecdp\empty\else                   %% <- if ryusecdp is non-empty
      \addcontentsline{toc}{\ryusecdp}         %% <- ...create toc entry at right depth
        {\ryutocformat{\@currentlabel}{#1}}%   %% <- ... with the right number/name
    \fi
  \endgroup
  \@afterheading                               %% <- prohibit indentation and enum topsep
  \ignorespaces                                %% <- does what it says
}
\makeatother  %% <- revert @

\usepackage{hyperref} %% <- not necessary, but compatible

\begin{document}

\tableofcontents

\vspace{1cm}\noindent\rule{\linewidth}{1pt}\par\vspace{1cm}

\begin{ryuenum}
    \Item{Preamble}
    \begin{ryuenum}
        \Item{Name}
        We shall be called The Government.
        \Item{Purpose}
        \begin{ryuenum}
        \item To represent the people.
            \begin{ryuenum}
            \item subclause!
            \end{ryuenum}
        \item To preserve democracy.
        \end{ryuenum}
        \Item{Senate}
        Who are the members?
        \begin{ryuenum}
            \Item{Voting Members}
            These people can vote.
        \end{ryuenum}
    \end{ryuenum}
\Item{Final item}
Lorem ipsum dolor sit.
\end{ryuenum}

\end{document}

I'm using the enumitem package (which I see you're also using) to set up a custom list environment and I'm setting this environment up with

before={\ryuenumsetup[<toc style>]{<section type>}{<space above>}{<space below>}{<font>}}`.

The \ryuenumsetup command sets up the variables that determine what a heading created with \Item will look like. You can tweak these values if you like to make this match your needs.

Remarks

Instead of defining a new enumeration environment you could also modify enumerate with \renewlist{enumerate}{enumerate}{5} and \setlist[enumerate,<n>]{…}.
Currently, the section headings are indented exactly as much as the content below it. This may not work for large numbers at the top level because roman numerals can be quite wide.
You may wish to also tweak the appearance of the toc a bit. It is by default set up so that the distance between the start of the section numbers and the titles increases with depth because section titles usually stack. From what I hear the tocloft package is good for doing this sort of thing, but I have very little experience with it.
You can leave the first mandatory parameter of \ryuenumsetup empty, in which case headings at this level won't show up in the table of contents.
Most of the definition of \Item was taken from the default sectioning commands, but some parts are left out. \Item will thus not behave exactly as a sectioning command. (It most notably won't increment the \<sub*>section counter.)

Best Answer

Related Solutions

[Tex/LaTex] Numbering sections, subsections etc manually

[Tex/LaTex] Have “enumerate” continue the numbering of Sections, Subsections, Subsubsections, etc

Remarks

Related Question