toc.tex

\usepackage{xcolor}
\usepackage{framed}
\usepackage{titletoc}
\usepackage{etoolbox}

% definition of some personal colors
\definecolor{myred}{RGB}{127,0,0}
\definecolor{myyellow}{RGB}{169,121,69}

% command for the circle for the number of part entries
\newcommand\Circle[1]{\tikz[overlay,remember picture]
    \node[draw,circle, text width=18pt,line width=1pt] {#1};}

% patching of \tableofcontents to use sans serif font for the tile
\patchcmd{\tableofcontents}{\contentsname}{\contentsname}{}{}
% patching of \@part to typeset the part number inside a framed box in its own line
% and to add color
\makeatletter
\patchcmd{\@part}
{\addcontentsline{toc}{part}{\thepart\hspace{1em}#1}}
{\addtocontents{toc}{\protect\addvspace{20pt}}
    \addcontentsline{toc}{part}{\huge{\protect\color{myyellow}%
        \setlength\fboxrule{2pt}\protect\Circle{%
            \hfil\thepart\hfil%
        }%
    }\\[2ex]\color{myred}#1}}{}{}

%\patchcmd{\@part}
%  {\addcontentsline{toc}{part}{\thepart\hspace{1em}#1}}
%  {\addtocontents{toc}{\protect\addvspace{20pt}}
%    \addcontentsline{toc}{part}{\huge{\protect\color{myyellow}%
%      \setlength\fboxrule{2pt}\protect\fbox{\protect\parbox[c][1em][c]{1.5em}{%
%        \hfil\thepart\hfil%
%      }}%
%    }\\[2ex]\color{myred}#1}}{}{}
\makeatother

% this is the environment used to typeset the chapter entries in the ToC
% it is a modification of the leftbar environment of the framed package
\renewenvironment{leftbar}
{\def\FrameCommand{\hspace{6em}%
{\color{myyellow}\vrule width 2pt depth 6pt}\hspace{1em}}%
    \MakeFramed{\parshape 1 0cm \dimexpr\textwidth-6em\relax\FrameRestore}\vskip2pt%
}
{\endMakeFramed}

% using titletoc we redefine the ToC entries for parts, chapters, sections, and subsections
\titlecontents{part}
[0em]{\centering}
{\contentslabel}
{}{}
\titlecontents{chapter}
[0em]{\vspace*{2\baselineskip}}
{\parbox{4.5em}{%
    \hfill\Huge\bfseries\color{myred}\thecontentspage}%
    \vspace*{-2.3\baselineskip}\leftbar\textsc{\small\chaptername~\thecontentslabel}\\}
{}{\endleftbar}
\titlecontents{section}
[8.4em]
{\contentslabel{3em}}{}{}
{\hspace{0.5em}\nobreak\itshape\color{myred}\contentspage}
\titlecontents{subsection}
[8.4em]
{\contentslabel{3em}}{}{}
{\hspace{0.5em}\nobreak\itshape\color{myred}\contentspage}

\setcounter{tocdepth}{3}