Kdtyjb

I will try to describe my question as clear as possible. First a working example.

documentclass[french,11pt]{article}



usepackage[french]{babel}



usepackage[utf8]{inputenc}

usepackage[T1]{fontenc}

 usepackage{kpfonts}

 usepackage{geometry}

 geometry{ a4paper, total={170mm,257mm}, left=20mm, top=20mm}

 usepackage{blindtext}



setlength{parskip}{1.2ex} setlength{parindent}{0em} clubpenalty = 10000 widowpenalty = 10000



 usepackage{graphicx,bm,url, amsfonts, latexsym, verbatim, xspace, setspace,mathrsfs,marvosym,wasysym,amsmath, amssymb}

 usepackage{caption}

 usepackage[caption=false]{subfig}

 usepackage{epstopdf}



usepackage[colorlinks=true, linkcolor=red, urlcolor=blue, pdftitle={article}, pdfauthor={DSA}]{hyperref} 



usepackage{authblk}



begin{document}



title{BlaBlaBla} author[,1]{Dimitriosthanks{texttt{url{dimitrios.@X.fr}}}} %



date{}



clearpagemaketitle thispagestyle{empty}



begin{itemize}

item blindtext 



See reference ref{foo3}.

item blindtext



See reference ref{foo1}.



item blindtext 



See reference ref{foo2}. 

end{itemize}



newpage



blindtext



begin{enumerate}

itemlabel{foo1} textbf{The foo1 reference}

itemlabel{foo2} blindtext 



textbf{The foo2 reference}



itemlabel{foo3} textbf{The foo3 reference}.

end{enumerate}





end{document} 

When I click to the link, I move to the associated reference. What I want to achieve is by clicking to an small triangle or a vertical-point-upwards arrow next to the reference to move backwards to the text that the link is. That is, like the forth-and-back effect that wikipedia articles have (see Figure below).

Here is an etoolbox-based implementation of a backref-able ref.

Use backrefref{<label>} to create a reference to a <label> that can will be linked back to. Use backreflabel{<label>} to set a label and output the backref marks. Note that backreflabel should be called directly where the <label> anchor attaches. Otherwise you may end up with incorrect link targets.

The solution works by writing info to the .aux file, so it may will need at least two LaTeX runs.

documentclass[french,11pt]{article}

usepackage{babel}

usepackage[utf8]{inputenc}

usepackage[T1]{fontenc}



usepackage{blindtext}



usepackage{etoolbox}



usepackage[colorlinks]{hyperref}



newcommand*{backrefmarker}{$uparrow$}

newcommand*{backrefmultformat}{textsuperscript}



makeatletter

newcommand*{br@currlabels}{}

newcommand*{br@linklabels}{}



newcommand*{backrefref}[1]{%

  listgadd{br@currlabels}{#1}%

  ifltxcounter{br@curr@#1}

    {}

    {newcounter{br@curr@#1}

     csgdef{thebr@curr@#1}{alph{br@curr@#1}}}%

  {refstepcounter{br@curr@#1}%

   label{br@#1@thevalue{br@curr@#1}}}%

  ref{#1}}





newcommand*{backreflabel}[1]{%

  label{#1}%

  backreflabel@display{#1}}



newcommand*{backreflabel@display}[1]{%

  ifltxcounter{br@link@#1}

    {ifnumequal{value{br@link@#1}}{1}

       {hyperref[br@#1@1]{backrefmarker}}

       {ifnumgreater{value{br@link@#1}}{1}

          {backrefmarker

           backrefmultformat{backreflabel@display@loop{#1}}}

          {textbf{??}}}}

    {textbf{??}}}



newcounter{br@label@loop}



newcommand*{backreflabel@display@loop}[1]{%

  setcounter{br@label@loop}{0}%

  whileboolexpr{test {ifnumless{value{br@label@loop}}{value{br@link@#1}}}}

    {stepcounter{br@label@loop}%

     ref{br@#1@thevalue{br@label@loop}}}}





newcommand*{br@aux@readlabel}[2]{%

  ifinlist{#1}{br@linklabels}

    {}

    {listgadd{br@linklabels}{#1}}%

  ifltxcounter{br@link@#1}

    {}

    {newcounter{br@link@#1}}%

  setcounter{br@link@#1}{#2}}



newcommand*{br@writelabel}[1]{%

  ifltxcounter{br@link@#1}

    {ifnumequal{value{br@curr@#1}}{value{br@link@#1}}

       {}

       {@latex@warning@no@line{%

          Label(s) may have changed.

          Rerun to get cross-references right}}}

    {@latex@warning@no@line{%

       Label(s) may have changed.

       Rerun to get cross-references right}}%

  immediatewrite@mainaux{stringbr@aux@readlabel{#1}{thevalue{br@curr@#1}}}}



AtEndDocument{%

  forlistloop{br@writelabel}{br@currlabels}}

makeatother



begin{document}



begin{itemize}

item blindtext



See reference backrefref{foo3}.

item blindtext



See reference backrefref{foo1}.



item blindtext



See reference backrefref{foo2}.

end{itemize}



clearpage



blindtext



begin{enumerate}

itembackreflabel{foo1} textbf{The foo1 reference}

itembackreflabel{foo2} blindtext



textbf{The foo2 reference}



itembackreflabel{foo3} textbf{The foo3 reference}.

end{enumerate}



clearpage



See reference backrefref{foo1}.

See reference backrefref{foo2}.



clearpage



See reference backrefref{foo2}.

end{document}

This is more an extended comment than a real answer.

I agree with previous comments for the easy way to do that with backref package or more precisely the backref option passed to hyperref at load time. But it could be interesting to extend it to label and not only to cite. In my answer to question Back link all headings with respective TOC entry
I have provided a solution that could be used as a starting point.

But this raises a problem of ambiguity : the reference to a label is unique, but the reverse direction is not, as you could reference a single label several times.

Furthermore, the future references are not known at creation of the label, and even if you decide to fix the ambiguity by choosing to back link to last (or first) reference, you will have to write it to .aux file and read it back at the next compilation, which becomes much more involved.

If you really need that, and left me a delay of a few days, I could extend the above quoted solution to labels.

By the way the requested feature is implemented out of the box in several popular pdf viewers, as they can keep a trace of browsing history, thus lifting the ambiguity problem.