setting width of parallel column to the length of a blockquote

Can I change the width of the parallel paragraphs created with reledpar package?

I want to be equal to the width of a blockquote.

\documentclass{scrartcl}
\usepackage[english]{babel}
\usepackage[style=authoryear]{biblatex}
\usepackage{lmodern,csquotes,lipsum}

\usepackage{reledmac,reledpar}

\begin{document}

\begin{pairs}
\begin{Leftside}
\beginnumbering
\pstart
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
\pend
\endnumbering
\end{Leftside}
%
\begin{Rightside}
\beginnumbering
\pstart
But I must explain to you how all this mistaken idea of denouncing pleasure and praising pain was born and I will give you a complete account of the system, and expound the actual teachings of the great explorer of the truth, the master-builder of human happiness. No one rejects, dislikes, or avoids pleasure itself, because it is pleasure, but because those who do not know how to pursue pleasure rationally encounter consequences that are extremely painful.
\pend
\endnumbering
\end{Rightside}
\end{pairs}
\Columns

\blockquote{\lipsum*[1]...}

\lipsum*[1]
\end{document}

• I have changed your title a to more explicit. Please, next time be directly explicit. I am looking for this problem (there is a solution, I know) – Maïeul Dec 10 '16 at 21:13

reledpar allows you to define the width of columns, and the space between them.

The most complex operation is to find the width of a \blockquote. As \blockquote calls quote environment, we can have to determine the witdh of quote.

The file scrartcl.cls defines it unexplicitly:

\newenvironment{quote}{%
\list{}{\rightmargin\leftmargin}%
\item\relax
}{%
\endlist
}


That tells us that the left and the right margin of a quote is set to \rightmargin+\leftmargin.

So the width of a quote is equal to \textwidth-2\leftmargin-2\rightmargin.

We can define a new length to store this value:

\newlength{\widthofquote}
\setlength{\widthofquote}{\dimexpr\textwidth-2\leftmargin-2\rightmargin\relax}


Now, we can define the length of left and right reledpar column, to 0.45 of the width of a quote. As explained in the handbook, that is by setting \Lcolwidth and \Rcolwidth values:

\setlength{\Lcolwidth}{0.45\widthofquote}
\setlength{\Rcolwidth}{0.45\widthofquote}


There is a still a problem, by default reledpar, the column are aligned at right margin. You can tel to center it, using, as explained in the hanbdbook.

\columnsposition{C}


But that is problematic, because of the space between the column, which is not automatically set to a good value. So you can change it to set it equal to 0.1 width of a quotation.

With that the width for left column + the width of the space between columns + the widht of the space for right columns will be equal to 0.45 width of quote + 0.1 widht of quote + 0.45 width of quote = width of quote.

So we define, as explained in the handbook, the space between columns

\setlength{\beforecolumnseparator}{0.05\widthofquote}
\setlength{\aftercolumnseparator}{0.05\widthofquote}


For the code readibility, it is better to set all these setting in the preamble. However, \textwidth could be change at the begin of the document environment. So the better is to set set them in the preamble, in a \AtBeginDocument command:

\AtBeginDocument{
% Determine the length of a quote environment
\newlength{\widthofquote}
\setlength{\widthofquote}{\dimexpr\textwidth-2\leftmargin-2\rightmargin\relax}

% Fixe the length of columns
\setlength{\Lcolwidth}{0.45\widthofquote}
\setlength{\Rcolwidth}{0.45\widthofquote}

% Centering correctly
\columnsposition{C}
\setlength{\beforecolumnseparator}{0.05\widthofquote}
\setlength{\aftercolumnseparator}{0.05\widthofquote}
}


Last but not least, we tell to LaTeX to allow more flexible space between words inside columns, because the columns width is small, and we want to prevent overfull hboxes:

\AtBeginPairs{\sloppy}


So, the final example (I have deleted biblatex calling, as not required for this example):

\documentclass{scrartcl}
\usepackage[english]{babel}
\usepackage{lmodern,csquotes,lipsum}

\usepackage{reledmac,reledpar}
\AtBeginDocument{
% Determine the length of a quote environment
\newlength{\widthofquote}
\setlength{\widthofquote}{\dimexpr\textwidth-2\leftmargin-2\rightmargin\relax}

% Fixe the length of columns
\setlength{\Lcolwidth}{0.45\widthofquote}
\setlength{\Rcolwidth}{0.45\widthofquote}

% Centering correctly
\columnsposition{C}
\setlength{\beforecolumnseparator}{0.05\widthofquote}
\setlength{\aftercolumnseparator}{0.05\widthofquote}
}
\AtBeginPairs{\sloppy}
\begin{document}
\begin{pairs}
\begin{Leftside}
\beginnumbering
\pstart
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
\pend
\endnumbering
\end{Leftside}
%
\begin{Rightside}
\beginnumbering
\pstart
But I must explain to you how all this mistaken idea of denouncing pleasure and praising pain was born and I will give you a complete account of the system, and expound the actual teachings of the great explorer of the truth, the master-builder of human happiness. No one rejects, dislikes, or avoids pleasure itself, because it is pleasure, but because those who do not know how to pursue pleasure rationally encounter consequences that are extremely painful.
\pend
\endnumbering
\end{Rightside}
\end{pairs}
\Columns

\noindent\hfill\rule[0.5ex]{\widthofquote}{0.1mm}\hfill\null
\blockquote{\lipsum*[1]…}

\lipsum*[1]
\end{document}


I can help with at least with one problem.

First if all, the biblatex stuff is not necessary for your problem as far as I can tell, so I removed that bit of code.

You can tell csquotes a threshold for when to indent a quote. I changed it to 1000 lines. This means basically that it is not indented anymore.

\documentclass{scrartcl}
\usepackage[english]{babel}
\usepackage{lmodern,lipsum}
\usepackage[
threshold = 1000,
thresholdtype = lines,
]{csquotes}

\usepackage{reledmac,reledpar}

\begin{document}

\begin{pairs}
\begin{Leftside}
\beginnumbering
\pstart
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
\pend
\endnumbering
\end{Leftside}
%
\begin{Rightside}
\beginnumbering
\pstart
But I must explain to you how all this mistaken idea of denouncing pleasure and praising pain was born and I will give you a complete account of the system, and expound the actual teachings of the great explorer of the truth, the master-builder of human happiness. No one rejects, dislikes, or avoids pleasure itself, because it is pleasure, but because those who do not know how to pursue pleasure rationally encounter consequences that are extremely painful.
\pend
\endnumbering
\end{Rightside}
\end{pairs}
\Columns

\blockquote{\lipsum*[1]...}

\lipsum*[1]
\end{document}


• that is, I think, not a solution, because that only change the moment indentation start, and I think ReRunner wanted to change the size of the columns… – Maïeul Dec 10 '16 at 20:55
• Well, I did my best :) – Dr. Manuel Kuehner Dec 10 '16 at 21:11