# Place chapter title between two lines

I want to place a chapter title between two lines. The lines shall be on the left and the right side of the centered title like in this screenshot:

Note that the lines are slightly overhanging the text below. It would be nice if I could do the same. Obviously the length of the chapter titles is varies, so the solution needs to automatically adapt to the length.

By now I have the following:

\documentclass{memoir}
\usepackage{graphics}
\usepackage{fontspec}

\makeatletter
\def\thickhrulefill{\leavevmode \leaders \hrule height 1pt \hfill \kern \z@}
\vspace*{60\p@}%
{\parindent \z@ \centering \reset@font
\scshape \large \@chapapp{} \thechapter
}
\par\nobreak
\interlinepenalty\@M
\Huge \itshape #1\par\nobreak
\thickhrulefill
\par\nobreak
\vskip 40\p@
}}
\usepackage{lipsum}
\setcounter{chapter}{12}
\begin{document}

\chapter{Implementation}
\lipsum
\end{document}

which gives me this:

Here is an idea:

\documentclass{memoir}% http://ctan.org/pkg/memoir

\makeatletter
\def\thickhrulefill{\leavevmode \leaders \hrule height 1pt \hfill \kern \z@}
\vspace*{60\p@}%
{\parindent \z@ \centering \reset@font
{
\scshape \large \@chapapp{} \thechapter
}
\par\bigskip\nobreak
\interlinepenalty\@M
\makebox[\linewidth]{%
\makebox[\dimexpr\linewidth+4em]{\Huge \itshape \thickhrulefill~\raisebox{-.5ex}{#1}~\thickhrulefill}}\par\nobreak
\par\nobreak
\vskip 40\p@
}}
\usepackage{lipsum}
\setcounter{chapter}{12}
\begin{document}

\chapter{Implementation}
\lipsum
\end{document}

I've placed the header (only the chapter title) inside a box of with \linewidth, which ensure no overfull \hboxes. Then, inside that box, I place two \thickhrulefills beside the actual title, inside another box of width \linewidth+4em. Since these boxes centre their content by default, it allows for a 2em overhang on either side.

A slight raise of -1ex (or a drop) centres the heading with respect to the rules.

• Seems to do the job but be careful if your chapter title is too long, it won't break the line... – Ludovic C. Sep 15 '13 at 16:33
• @LudovicC.: Yes, and if that's a problem, a fix is possible. – Werner Sep 15 '13 at 16:34

Here's another approach using the interface offered by memoir to design a new chapter style; I also make some additional adjustments: the titles were always be placed inside a centered box which has a maximum width of 0.7\textwidth.

This approach allows to define the behaviour for both numbered and unnumbered chapters, without redefining internal commands:

\documentclass{memoir}
\usepackage{lipsum}
\usepackage{varwidth}

\makeatletter
\makechapterstyle{mystyle}{%
\chapterstyle{default}
\renewcommand*{\chapnamefont}{\normalfont\scshape}
\renewcommand*{\chapnumfont}{\normalfont\scshape}
\renewcommand*{\printchaptername}{%
\chapnamefont\centering\@chapapp}
\renewcommand*{\printchapternum}{\chapnumfont\thechapter}
\renewcommand*{\chaptitlefont}{\normalfont\Huge\itshape}
\renewcommand*{\printchaptertitle}[1]{%
\makebox[\linewidth][c]{\makebox[\dimexpr\textwidth+4em\relax][c]{%
\hrulefill\hspace{1em}\raisebox{-.65ex}{\begin{varwidth}{\dimexpr0.7\textwidth-2em\relax}\centering\chaptitlefont##1\end{varwidth}}\hspace*{1em}\hrulefill}}}
\renewcommand*{\afterchaptertitle}{\vskip\afterchapskip}
\renewcommand*{\printchapternonum}{%
\vphantom{\chapnumfont \textit{9}}\afterchapternum}
}
\makeatother

\chapterstyle{mystyle}

\begin{document}

\chapter{Implementation}
\lipsum[4]
\chapter{A long title spanning more than one line}
\lipsum[4]
\chapter*{A title for an unnumbered chapter}
\lipsum[4]

\end{document}

An image for a numbered chapter with a short title:

An image for a numbered chapter with a longer title:

An image for an unnumbered chapter: