Memoir, how to make \makechapterstyle aware if chapter title is in frontmatter?

Question

for my book i define own chapter style which i like to use only in body of document (after \mainmatter). in front matter i like to preserve default memoir chapter style.

background:

my chapter style gives the following result:

in the front matter i increase text width to the right border of chapter title (see mwe below). consequently chapter title is pushed out of page (in this case title of table of content, i.e.: "Content").

to make it visible, i looking for how to make my chapter style aware, where is used. for star i like to have in front matter memoir default style.

mwe:

\documentclass{memoir}
\usepackage{lmodern}
\usepackage{tikz}
\usetikzlibrary{positioning, shadows}
%---------------------------------------------------------------%
    \newlength{\marginwidth}
    \setlength{\marginwidth}{\dimexpr\marginparsep+\marginparwidth\relax}
    \newsavebox{\bookbox}
    \newcommand{\zfcbookname}[1]{\sbox{\bookbox}{\textsc{#1}}}
    \zfcbookname{<book title>}
%---------------------------------------------------------------%
\makechapterstyle{zfcBook}{%
\setlength\beforechapskip{9\baselineskip}
\setlength\afterchapskip{7\baselineskip}
\setlength\midchapskip{1\baselineskip}
    \renewcommand*{\chaptitlefont}{\normalfont\Huge\bfseries}
    \renewcommand*{\chapnamefont}{\chaptitlefont}
    \renewcommand*{\chapnumfont}{\bfseries\fontsize{77}{84}\selectfont}
        \renewcommand*{\printchaptername}{}
    \renewcommand*{\chapternamenum}{}
    \renewcommand*{\printchapternum}{%
        \begin{adjustwidth}{\marginwidth}{-\marginwidth}
    \begin{tikzpicture}
%-------
\node[name=chapter,
      rectangle,fill=white,minimum width=\textwidth,minimum height=22mm,
      copy shadow={shadow xshift=6pt,shadow yshift=-2pt,fill=black}] {~};
\node[above left] at (chapter.south east) {
            \ifanappendix\chaptitlefont\@chapapp\fi
            \chapnumfont\thechapter};
\node[below right=1mm and 0mm] at (chapter.south west) {\usebox{\bookbox}};
%-------
    \end{tikzpicture}
        \end{adjustwidth}
                                   }%end od print chapter num
    \renewcommand*{\printchaptertitle}[1]{
        \begin{adjustwidth}{\marginwidth}{-\marginwidth}
    \raggedleft{\chaptitlefont ##1}\par\nobreak%
        \end{adjustwidth}
                                        }% end of print chapter title
                            }%end of zfcBook
%---------------------------------------------------------------%
\usepackage{lipsum}

\begin{document}
    \chapterstyle{zfcBook}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\frontmatter
\changetext{0pt}{\marginwidth}{-\marginwidth}{0pt}{0pt}
\tableofcontents                                % kazalo
\changetext{0pt}{-\marginwidth}{\marginwidth}{0pt}{0pt}
\mainmatter

\chapter{ena}
\lipsum[11]
    \section{ena ena}
    \section{ena dva}
    \section{ena tri}
\chapter{dva}
    \section{dva ena}
    \section{dva dva}
    \section{dva tri}
\end{document}

question:

how to change my \makechapterstyle that it will be aware of \frontmatter and there use or default memoir style or new defined style (very different from one used in \mainmatter)?

Answer 1

Does \if@mainmatter...\else ...\fi inside \makechapterstyle help?

\frontmatter sets \@mainmatterfalse.

\documentclass{memoir}
\usepackage{lmodern}
\usepackage{tikz}
\usetikzlibrary{positioning, shadows}
%---------------------------------------------------------------%
    \newlength{\marginwidth}
    \setlength{\marginwidth}{\dimexpr\marginparsep+\marginparwidth\relax}
    \newsavebox{\bookbox}
    \newcommand{\zfcbookname}[1]{\sbox{\bookbox}{\textsc{#1}}}
    \zfcbookname{<book title>}
%---------------------------------------------------------------%

\makeatletter
\makechapterstyle{zfcBook}{%
  \if@mainmatter
  \setlength\beforechapskip{9\baselineskip}
  \setlength\afterchapskip{7\baselineskip}
  \setlength\midchapskip{1\baselineskip}
  \renewcommand*{\chaptitlefont}{\normalfont\Huge\bfseries}
  \renewcommand*{\chapnamefont}{\chaptitlefont}
  \renewcommand*{\chapnumfont}{\bfseries\fontsize{77}{84}\selectfont}
  \renewcommand*{\printchaptername}{}
  \renewcommand*{\chapternamenum}{}
  \renewcommand*{\printchapternum}{%
    \begin{adjustwidth}{\marginwidth}{-\marginwidth}
      \begin{tikzpicture}
%-------
        \node[name=chapter,
        rectangle,fill=white,minimum width=\textwidth,minimum height=22mm,
        copy shadow={shadow xshift=6pt,shadow yshift=-2pt,fill=black}] {~};
        \node[above left] at (chapter.south east) {
          \ifanappendix\chaptitlefont\@chapapp\fi
          \chapnumfont\thechapter};
        \node[below right=1mm and 0mm] at (chapter.south west) {\usebox{\bookbox}};
        % -------
      \end{tikzpicture}
    \end{adjustwidth}
  }%end od print chapter num
  \renewcommand*{\printchaptertitle}[1]{
    \begin{adjustwidth}{\marginwidth}{-\marginwidth}
      \raggedleft{\chaptitlefont ##1}\par\nobreak%
    \end{adjustwidth}
  }% end of print chapter title
  \else
  \chapterstyle{default}% Is done anyway...
  \fi
}%end of zfcBook
\makeatother
%---------------------------------------------------------------%
\usepackage{lipsum}

\begin{document}
    \chapterstyle{zfcBook}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\frontmatter
\changetext{0pt}{\marginwidth}{-\marginwidth}{0pt}{0pt}
\tableofcontents                                % kazalo
\changetext{0pt}{-\marginwidth}{\marginwidth}{0pt}{0pt}
\mainmatter

\chapter{ena}
\lipsum[11]
    \section{ena ena}
    \section{ena dva}
    \section{ena tri}
\chapter{dva}
    \section{dva ena}
    \section{dva dva}
    \section{dva tri}
\end{document}