Annotating text with comments with margins (no margin notes and footnotes)

Question

This is an Italian edition of "Il Milione" by Marco Polo. Within this edition I have the main codex (main text), the “optimum”, and other codices from other documentary sources (Comment 1 and Comment 2) that enrich the choosen codex with other details that are missing from the original text.

I would like to replicate a similar pattern in LaTeX using something similar with this code:

% Main Text
Non hanno ferro per fare aguti;
%  Comment 1
\begin{UnknownEnvironment}
 \textit{Cas.} [ma fano cavechie de legno e con quele conficano le soe nave;]
\end{UnknownEnvironment}
% Please note that at this point, the main text continues
% below right the word “aguti”
ed è grande pericolo a navicare \dots Egli è vero che vi viene un vento$^2$ talvolta la sate,
% Comment 2
\begin{UnknownEnvironment}
 \textit{Pad.} [de verso uno destro de sabione ch'é atorno de quel punto]
\end{UnknownEnvironment}
% Even in this case, the main text continues below right “aguti”
di verso lo sabbion, con tanto caldo che \dots 

More clearly, I want that all the comments and all the main text stays in the main part of the page, and that the notes are both reentrant, and both allow the main text to continue from the same point where it was break.

Is there a package that does both an indentent comment inside an environment and that, after such comment, the main text continues below right the next word? Thanks in advance!

Answer 1

Here is a solution using the linegoal-package. It does have a big flaw, in that it only works with \raggedright-text. I am sure there is a smart solution to get around this, though.

The indentation of the created environment is created with changepage-package, with the adjustwidth-environment. There are of course other alternatives.

Output

Code

\documentclass{article}
\usepackage{linegoal}
\usepackage{changepage}

\newlength{\previousLine}
\newenvironment{UnknownEnvironment}
  {%
    \setlength{\previousLine}{\linewidth}%
    \addtolength{\previousLine}{-\linegoal}
    \par\bigskip%
    \bfseries%
    \begin{adjustwidth}{3cm}{0cm}%
  }
  {%
  \end{adjustwidth}
  \par\bigskip%
  \hspace*{\previousLine}%
  }
\raggedright
\begin{document}

 Main Text
Non hanno ferro per fare aguti;
%  Comment 1
\begin{UnknownEnvironment}
 \textit{Cas.} [ma fano cavechie de legno e con quele conficano le soe nave;]
\end{UnknownEnvironment}%
% Please note that at this point, the main text continues
% below right the word �aguti�
ed è grande pericolo a navicare \dots Egli è vero che vi viene un vento$^2$ talvolta la sate,
% Comment 2
\begin{UnknownEnvironment}
 \textit{Pad.} [de verso uno destro de sabione ch'é atorno de quel punto]
\end{UnknownEnvironment}%
% Even in this case, the main text continues below right �aguti�
di verso lo sabbion, con tanto caldo che \dots

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur imperdiet ante a turpis pulvinar, quis pharetra lorem finibus. Sed iaculis ritus sed molestie elementum. Duis porta maximus velit quis imperdiet. Sed nec lacis vitae nisl rutrum accumsan. Nam molestie purus hendrerit ex tempus volutpat. Donec luctus,
\begin{UnknownEnvironment}
  Some example text
\end{UnknownEnvironment}%
nulla nec molestie eleifend, lectus sapien rhoncus nisl, id maximus diam ex sed metus. Present volutpat eu mi in vehicula. In lobortis vitae magna at finibus. Phasellus tempor urna eros, consequat blandit sem rhoncus a. Aliquam erat volutpat. Aliquam venenatis maximus felis, vel feugiat mauris tincidunt mattis. Maecenas accumsan metus nec tortor tempor maximus.%
\end{document}

Answer 2

If you want justified text you can use the zref-savepos package to store the location where you end the text before a comment. Be aware that it needs some compilations until all the references are resolved:

\documentclass{article}
\usepackage[italian]{babel}
\usepackage{zref-savepos}
\usepackage{changepage}
\newcounter{mycomment}

\newenvironment{UnknownEnvironment}
 {\unskip\stepcounter{mycomment}\zsavepos{endpar\the\value{mycomment}}%
    \par\bigskip%
    \bfseries%
    \begin{adjustwidth}{3cm}{0cm}}
 {\end{adjustwidth}
  \par\bigskip
  \noindent\hspace*{\dimexpr\zposx{endpar\the\value{mycomment}}sp-\oddsidemargin-1in}\ignorespaces}
\begin{document}

 Main Text
Non hanno ferro per fare aguti;
%  Comment 1
\begin{UnknownEnvironment}
 \textit{Cas.} [ma fano cavechie de legno e con quele conficano le soe nave;]
\end{UnknownEnvironment}
ed è grande pericolo a navicare \dots Egli è vero che vi viene un vento$^2$ talvolta la sate,
% Comment 2
\begin{UnknownEnvironment}
 \textit{Pad.} [de verso uno destro de sabione ch'é atorno de quel punto]
\end{UnknownEnvironment}
% Even in this case, the main text continues below right �aguti�
di verso lo sabbion, con tanto caldo che \dots

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur imperdiet ante a turpis pulvinar, quis pharetra lorem finibus. Sed iaculis ritus sed molestie elementum. Duis porta maximus velit quis imperdiet. Sed nec lacis vitae nisl rutrum accumsan. Nam molestie purus hendrerit ex tempus volutpat. Donec luctus,
\begin{UnknownEnvironment}
  Some example text
\end{UnknownEnvironment}
nulla nec molestie eleifend, lectus sapien rhoncus nisl, id maximus diam ex sed metus. Present volutpat eu mi in vehicula. In lobortis vitae magna at finibus. Phasellus tempor urna eros, consequat blandit sem rhoncus a. Aliquam erat volutpat. Aliquam venenatis maximus felis, vel feugiat mauris tincidunt mattis. Maecenas accumsan metus nec tortor tempor maximus.%
\end{document}