Counting section for each chapter

Question

I am newbie with latex and I try to create a section with movable section number tabs as shown below:

In the following code, I used both tikz and titlesec packages to format the required sections

\documentclass{report}
\usepackage{totcount}
\usepackage{tikz}
\usepackage{blindtext}
    \usetikzlibrary{calc,shapes,arrows,positioning,patterns,fit,decorations.pathmorphing}
    \usetikzlibrary{decorations.text}
\usepackage[explicit,calcwidth,compact]{titlesec}
\regtotcounter{section}
\newcommand{\secnum}{\arabic{section}}
\titleformat{\section}{\Large\bfseries}{}{0mm}{\tikz[]{
\node [rectangle,,inner sep=0cm,text width=\textwidth] (A) {#1};
\pgfmathsetmacro\ABC{(\secnum-1)/(\totvalue{section}-1)}
\node [yshift=0.4cm] (B) at ($([xshift=1cm]A.north west)!{\ABC}!([xshift=-1cm]A.north east)$) {\thesection};
\draw [rounded corners] ([yshift=0.2cm]A.north west) -| (B.north west) -- (B.north east) |- ([yshift=0.2cm]A.north east);
\draw ([yshift=-0.2cm]A.south west) -- ([yshift=-0.2cm]A.south east);
}}

\begin{document}
\chapter{First Chapter}
\section{First section}
A short paragraph for first section
\section{Second section}
The second paragraph
\section{Third section}
The third paragraph
\section{Last section}
The last paragraph

\chapter{Second Chapter}
\section{First section}
A short paragraph for first section
\section{Last section}
The Last paragraph

\end{document}

The problem is If I use totcount with section counter, then It counts only the sections for the last chapter only (It counts 2 for my code). Is there any macro that counts the sections for each chapter? sorry for my simple English.

Answer 1

This might not be the easiest way, but basically, you may use a new auxiliary file which stores this per chapter. Please note that this requires two compilation runs to work (and the \flushchapter before \end{document).

\documentclass{report}
\usepackage{tikz}
\usepackage{blindtext}
    \usetikzlibrary{calc,shapes,arrows,positioning,patterns,fit,decorations.pathmorphing}
    \usetikzlibrary{decorations.text}
\usepackage[explicit,calcwidth,compact]{titlesec}

\usepackage{etoolbox}
\makeatletter
\IfFileExists{\jobname.chap}{\input{\jobname.chap}}{}

\newwrite\chapfile
\immediate\openout\chapfile=\jobname.chap

\let\origchapter\chapter
\def\flushchapter{\protected@write\chapfile{}{\string\expandafter\string\def\string\csname\space chapter\the\c@chapter\string\endcsname{\the\c@section}}}
\renewcommand\chapter{\flushchapter\origchapter}

\titleformat{\section}{\Large\bfseries}{}{0mm}{\tikz[]{
\node [rectangle,,inner sep=0cm,text width=\textwidth] (A) {#1};
\ifcsdef{chapter\the\c@chapter}{%
    \pgfmathsetmacro\ABC{(\the\c@section-1)/(\csname chapter\the\c@chapter\endcsname - 1)}%
}{%
    \pgfmathsetmacro\ABC{1}%
}
\node [yshift=0.4cm] (B) at ($([xshift=1cm]A.north west)!{\ABC}!([xshift=-1cm]A.north east)$) {\thesection};
\draw [rounded corners] ([yshift=0.2cm]A.north west) -| (B.north west) -- (B.north east) |- ([yshift=0.2cm]A.north east);
\draw ([yshift=-0.2cm]A.south west) -- ([yshift=-0.2cm]A.south east);
}}
\makeatother

\begin{document}
\chapter{First Chapter}
\section{First section}
A short paragraph for first section
\section{Second section}
The second paragraph
\section{Third section}
The third paragraph
\section{Last section}
The last paragraph

\chapter{Second Chapter}
\section{First section}
A short paragraph for first section
\section{Last section}
The Last paragraph

\flushchapter
\end{document}