Are you aware of tentatives to customize the table of contents with TikZ in LaTeX?
I'm thinking of fancy graphical objects (coloured ovals, squares, rectangles, etc) coming with the usual terms "chapter" or with the numbering. That could use the titletoc package for instance.
Edit 1: below is a try. Maybe the pfgpicture environment is more relevant for the toc. Also, I'm far to be knowledgeable in tikz-pgf but I could not move the tikzpicture into the toc margins.
\documentclass{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{kpfonts}
\usepackage{tikz}
\usepackage{titletoc}
\contentsmargin{0cm}
\titlecontents{chapter}[0pc]
{\addvspace{30pt}%
\begin{tikzpicture}%
\draw[help lines,step=.4cm,color=red] (0,0) grid (3.2,1.2);%
\pgftext[left,x=.1cm,y=.6cm]{\Large\sc chapter};%
\fill[fill=white,draw=red] (2.7,.6) circle (0.35cm);%
\pgftext[x=2.7cm,y=.6cm]{\thecontentslabel};%
\end{tikzpicture}\\\color{red}\large\sc\bfseries}%
{}
{}
{\;\titlerule\;\large\bfseries \thecontentspage}%
\titlecontents{section}[2.4pc]
{\addvspace{1pt}}
{\contentslabel[\thecontentslabel]{2.4pc}}
{}
{\hfill\small \thecontentspage}
[]
\titlecontents*{subsection}[4pc]
{\addvspace{-1pt}\small}
{}
{}
{\ --- \small\thecontentspage}
[ \textbullet\ ][]
\begin{document}
\tableofcontents
\chapter{(title chapter 1)}
\section{(title section 1)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\section{(title section 2)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\chapter{(title chapter 2)}
\section{(title section 1)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\section{(title section 2)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\end{document}
EDIT 2: second try (that I like) but I do not know how to access the title of a chapter with titletoc, do you ?
\documentclass{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{kpfonts}
\usepackage[tmargin=2cm,rmargin=3.8cm,lmargin=3.8cm,bmargin=2cm]{geometry}
\usepackage{tikz}
\definecolor{doc}{RGB}{0,60,110}
\usepackage{titletoc}
\contentsmargin{0cm}
\titlecontents{chapter}[0pc]
{\addvspace{30pt}%
\begin{tikzpicture}[remember picture, overlay]%
\draw[fill=doc!30,draw=doc!30] (-4,-.1) rectangle (-1,.5);%
\pgftext[left,x=-3.7cm,y=0.2cm]{\color{white}\Large\sc\bfseries chapter\ \thecontentslabel};%
\end{tikzpicture}\color{doc!40}\large\sc\bfseries}%
{}
{}
{\;\titlerule\;\large\sc\bfseries Page \thecontentspage
\begin{tikzpicture}[remember picture, overlay]
\draw[fill=doc!25,draw=doc!20] (2pt,0) rectangle (6,0.1pt);
\end{tikzpicture}}%
\titlecontents{section}[2.4pc]
{\addvspace{1pt}}
{\contentslabel[\thecontentslabel]{2.4pc}}
{}
{\hfill\small \thecontentspage}
[]
\titlecontents*{subsection}[4pc]
{\addvspace{-1pt}\small}
{}
{}
{\ --- \small\thecontentspage}
[ \textbullet\ ][]
\makeatletter
\renewcommand{\tableofcontents}{%
\chapter*{%
\vspace*{-20\p@}%
\begin{tikzpicture}[remember picture, overlay]%
\pgftext[right,x=15cm,y=0.2cm]{\color{doc!30}\Huge\sc\bfseries \contentsname};%
\draw[fill=doc!30,draw=doc!30] (13,-.75) rectangle (20,1);%
\clip (13,-.75) rectangle (20,1);
\pgftext[right,x=15cm,y=0.2cm]{\color{white}\Huge\sc\bfseries \contentsname};%
\end{tikzpicture}}%
\@starttoc{toc}}
\makeatother
\begin{document}
\tableofcontents
\chapter{Questions of Design}
\section{(title section 1)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\section{(title section 2)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\chapter{Questions of Drawing}
\section{(title section 1)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\section{(title section 2)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\chapter{Questions of Technique}
\section{(title section 1)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\section{(title section 2)}
\subsection{(title sub-section 1)}
\subsection{(title sub-section 2)}
\end{document}
