Customizing toc in book class (appendix and coloring sections depending on current chapter)

Question

I'm trying to customize my TOC as in this post (second example) and I'm having two issues.

The first one is documented but I can't figure out what I'm doing wrong : I want to write "Appendix" instead of "Chapter". If I don't customize \titlecontents{chapter} then everything works fine, but if I do, I get a "Chapter" instead of "Appendix". I've tried all sorts of configs (I think it's due to the book class), with/without \begin{appendices}, loading (or not) the appendix package with the titletoc options... Any help would be very appreciated !

The second "problem" I'm having is I'm trying to customize the look of the subsections in the TOC according to the chapter they're in. Each chapter has its own color and I would like the sections to have the same color as the chapter they're in.

Here is my MWE and the result.

\documentclass[11pt]{book}
\usepackage[table]{xcolor}
\usepackage{ifthen}
\usepackage{tikz,pgf}

\definecolor{chapa}{HTML}{15CA7F}
\definecolor{chapb}{HTML}{CA16BD}
\definecolor{chapc}{HTML}{DE1841}

\makeatletter
\newcommand{\ch@p}{chapa}
\newcommand{\ch@ngeCouleurs}[1]
{
    \ifthenelse{\equal{#1}{1}}{\renewcommand{\ch@p}{chapa}}{}
    \ifthenelse{\equal{#1}{2}}{\renewcommand{\ch@p}{chapb}}{}
    \ifthenelse{\equal{#1}{3}}{\renewcommand{\ch@p}{chapc}}{}
}


\usepackage[titletoc]{appendix}
\usepackage{titletoc}
\usepackage{titlesec}

\contentsmargin{-1.5cm}
\titlecontents{chapter}[4pc]
    {\addvspace{30pt}%
    \ch@ngeCouleurs{\thecontentslabel}%
    \begin{tikzpicture}[remember picture, overlay]%
        \draw[\ch@p,fill=\ch@p] (-4.2,-.1) rectangle (-.8,.5);%
        \pgftext[left,x=-3.7cm,y=0.2cm]{\color{white}\large\bfseries\sc\@chapapp\ \thecontentslabel};%
    \end{tikzpicture}%
    \large\bfseries\color{\ch@p!80!black}}%
    {}
    {}
    {\titlerule\, Page \thecontentspage
    \begin{tikzpicture}[remember picture, overlay]
       \draw[\ch@p] (2pt,0) rectangle (6,0.1pt);
    \end{tikzpicture}%
    }
    [\addvspace{.2cm}]%

\titlecontents{section}[0pc]
    {\addvspace{5pt}}
    {
        \color{\ch@p}\contentslabel[\thecontentslabel]{2pc}\color{black}}
    {}
    {\hfill\small\color{black}\thecontentspage}
    [\addvspace{3pt}]
\makeatother

\begin{document}
\tableofcontents
\chapter{One chapter}
\section{First section}
\section{First subsection}
\chapter{Another chapter}
\section{Foo}
\section{Bar}
\begin{appendices}
    \chapter{First appendix}
\end{appendices}
\end{document}

The result (2.1 and 2.2 should be in purple, and "Chapter A" should be "Appendix A").

I think I know how to work around the coloring problem of the appendix (comes from the fact that the chapter counter has been reset which can be avoided using packages totcount and assoccnt).

But I don't understand why my \ch@ngeCouleurs macro has no effect on the \titlecontents{section}. If I could access the chapter number in the \titlecontents{section}, that would solve my problem.

Thank you for reading my (long) post ! And thanks to anyone who can provide help !

Answer 1

The \renewcommand{\ch@p} does not survive the typesetting phase of the chapter title in the ToC and as such, section ToC entries use the wrong color setting.

\renewcommand is not global (unless being specified directly in the preamble or in the document body outside of nested groups. If the colour settings should be persistent, use \gdef\ch@p instead.

Now the Appendix issue:

At the time of writing the ToC lines, \@chapapp defaults to Chapter, so even with an appendix environment, this would come too early in the ToC to change to \appendixname (i.e. 'Appendix'). This can be cured by explicitly writting the redefinition to theToC`.

It won't have an effect for later \@chapapp usages in the body, since \tableofcontents uses \@starttoc, which in turn loads the .toc file in a group.

\documentclass[11pt]{book}
\usepackage[table]{xcolor}
\usepackage{ifthen}
\usepackage{tikz,pgf}

\definecolor{chapa}{HTML}{15CA7F}
\definecolor{chapb}{HTML}{CA16BD}
\definecolor{chapc}{HTML}{DE1841}

\usepackage{titletoc}
\usepackage{titlesec}

\usepackage[titletoc]{appendix}

\makeatletter
\newcommand{\ch@p}{chapa}
\newcommand{\ch@ngeCouleurs}[1]
{%
  \ifthenelse{\equal{#1}{1}}{\gdef\ch@p{chapa}}{}
  \ifthenelse{\equal{#1}{2}}{\gdef\ch@p{chapb}}{}
  \ifthenelse{\equal{#1}{3}}{\gdef\ch@p{chapc}}{}
}


\usepackage{etoolbox}
\AtBeginEnvironment{appendices}{%
  \makeatletter
  \addtocontents{toc}{\protect\renewcommand{\protect\@chapapp}{\protect\appendixname}}
  \makeatother
}


\contentsmargin{-1.5cm}
\titlecontents{chapter}[4pc]
    {\addvspace{30pt}%
      \ch@ngeCouleurs{\thecontentslabel}%
      \begin{tikzpicture}[remember picture, overlay]%
        \draw[\ch@p,fill=\ch@p] (-4.2,-.1) rectangle (-.8,.5);%
        \pgftext[left,x=-3.7cm,y=0.2cm]{\color{white}\large\bfseries\sc\@chapapp\ \thecontentslabel};%
      \end{tikzpicture}%
      \large\bfseries\color{\ch@p!80!black}}%
    {}
    {}
    {\titlerule\, Page \thecontentspage
    \begin{tikzpicture}[remember picture, overlay]
       \draw[\ch@p] (2pt,0) rectangle (6,0.1pt);
    \end{tikzpicture}%
    }
    [\addvspace{.2cm}]%

\titlecontents{section}[0pc]
    {\addvspace{5pt}}
    {
      \color{\ch@p}\contentslabel[\thecontentslabel]{2pc}}%
    {}
    {\hfill\small\color{black}\thecontentspage}
    [\addvspace{3pt}]
\makeatother

\begin{document}
\tableofcontents
\chapter{One chapter}
\section{First section}
\section{First subsection}
\chapter{Another chapter}
\section{Foo}
\section{Bar}
\begin{appendices}
  \chapter{First appendix}
\end{appendices}
\end{document}