How to define reference label and caption name in 'duplicated' environment?

Question

I want to define a new environment that is very similar to the longtable environment, therefore I tried the following:

\documentclass{report}
\usepackage{caption}
\usepackage{longtable}
\usepackage{hyperref}
\usepackage{xcolor}
\usepackage{colortbl}


%% Defining the examplebox environment
\definecolor{examplebox}{gray}{0.95} %define the examplebox color
\newcounter{examplebox}
\newcommand*{\exampleboxautorefname}{Example box}
\newenvironment{examplebox}{
    \refstepcounter{examplebox}
    \addtocounter{table}{-1}
    \renewcommand*\tablename{Example box}‌\longtable
}{\endlongtable}

\begin{document}
\autoref{box:test} is the label of this examplebox.\\

The current counter for examplebox is \theexamplebox.

\begin{examplebox}{|c|} \hline
    \rowcolor{examplebox} Hello there.\\ \hline
    \caption{Caption of this example box.}
    \label{box:test}
\end{examplebox}

The current counter for examplebox is now \theexamplebox.

\begin{table}[h]
    \begin{center}
        \begin{tabular}{| c c c |}
            \hline
        1&2&3\\ \hline
        4&5&6\\ \hline
    \end{tabular}
    \caption{Random table caption}
    \end{center}
\end{table}

The current counter for examplebox is still \theexamplebox.

\end{document}

This gives the caption 'Examplebox 0: Caption of this example box.'. After the examplebox, the counter has increased to 1, so the counter of examplebox seems to work. However, the environment folows the Table counter, and using \autoref gives 'Table 0' instead of 'Example box 0'.

How can I get examplebox to use the defined counter and to include this in the autoref command? Can anyone help me out please?

Thanks in advance!

Tim

Answer 1

In your example it looks as though examplebox is just a box with coloured background in which case dedicated box packages like tcolorbox, mdframed or framed might be a better choice than a self-made longtable environment.

Anyway, ltcaption's \LTcaptype looked promising. To be able to use it I we can define a new float type with help of the newfloat package. \DeclareFloatingEnvironment{examplebox} already defines a new counter and the environment, so that we only need to redefine it for longtable.

\documentclass{report}
\usepackage{caption}
\usepackage{longtable}
\usepackage[table]{xcolor}
\usepackage{newfloat}
\usepackage{hyperref}

\definecolor{examplebox}{gray}{0.95}
\DeclareFloatingEnvironment{examplebox}[Example box][List of example boxes]
\newcommand*{\exampleboxautorefname}{Example box}
\renewenvironment{examplebox}{%
   \renewcommand\LTcaptype{examplebox}%
   \longtable}
  {\endlongtable}

\begin{document}
\autoref{box:test} is the label of this examplebox.

The current counter for examplebox is \theexamplebox.

\begin{examplebox}{|c|} \hline
    \rowcolor{examplebox} Hello there.\\ \hline
    \caption{Caption of this example box.}
    \label{box:test}
\end{examplebox}

The current counter for examplebox is now \theexamplebox.

\begin{table}[h]
    \begin{center}
        \begin{tabular}{| c c c |}
            \hline
        1&2&3\\ \hline
        4&5&6\\ \hline
    \end{tabular}
    \caption{Random table caption}
    \end{center}
\end{table}

The current counter for examplebox is still \theexamplebox.
\end{document}

Answer 2

Be aware that longtable

• makes use of the table-counter.
• causes the \caption-command to write entries for the list of tables (the .lot-file) and to make use of the table-counter.

These aspects are "hard-wired" both into the longtable environment and into the patch for the longtable-environment provided by the hyperref package.

In other words:
Unfortunately there is no \usecounter and no \uselistof for longtable-environments.

With your example-boxes you might wish

• to use another counter than the table-counter
• not to have entries for example-boxes merged into the list of tables but to have a separate list of example boxes.

As things are somewhat "hardwired" in the longtable-package, if you want to be accurate, you need to derive your own style-file/your own package, containing your own variant of the longtable-environment where each occurrence of the usage of the table-counter is replaced by usage of the examplebox-counter, and where each attempt at writing to the .lot-file is replaced by attempts at writing to the list-of-exampleboxes-file (.loEB-file in the example below).
That package should also take into account patches as provided by the hyperref-package.

If you don't wish to be accurate, you can within the examplebox-environment

• redirect using the infrastructure of the table-counter to using the infrastructure of the examplebox-counter. Be aware that macros like \hyper@makecurrent, which use the counter-name directly for deriving names of anchors for hyperlinks, need to be patched so that they crank out the usage of the name of the table-counter and replace it by usage of the name of the examplebox-counter.
• redirect writing to the .lot-file to writing to another file, e.g., to a .loEB-file. In order to achieve this, the macro \addcontentsline can be patched to crank out cases where entries shall go to the .lot-file / the \ext@table-file.

Spontaneously I see two important reasons why this redirection-approach is not accurate:

1. This redirection-approach breaks nesting inside your examplebox-environment things other than examplebox-environments that also use the table-counter and/or that also write entries for the list of tables/for the .lot-file.

2. This redirection-approach might break \autoreferencing tables and other things where the table-counter was used for creating the corresponding referencing-label for cases where the auto-reference is to occur/to take place "inside" the examplebox-environment.

Thus a rule of thumb: With the code below don't nest tables and other things that make use of the table-counter or that do write to the list of tables inside the examplebox-environment.

In case you can live with this, here is some code:

\documentclass{report}
\usepackage{caption}
\usepackage{longtable}
\usepackage{hyperref}
\usepackage{xcolor}
\usepackage{colortbl}

\makeatletter
%% Use examplebox-stuff instead of table-stuff:
%%
%% Inside the examplebox-environment
%%
%% - \hyper@makecurrent needs to redirect using the table-counter 
%%   to using the examplebox-counter. The following things are needed
%%   for patching \hyper@makecurrent inside the examplebox environment:
\newcommand\MySavedhyper@makecurrent{}%
\AtBeginDocument{\let\MySavedhyper@makecurrent=\hyper@makecurrent}%
\newcommand\Mytablestring{table}%
\newcommand\MyPatchedhyper@makecurrent[1]{%
  \begingroup
  \long\def\@tempa{#1}%
  \expandafter\endgroup
  \ifx\@tempa\Mytablestring
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi
  {\MySavedhyper@makecurrent{examplebox}}%
  {\MySavedhyper@makecurrent{#1}}%
}%
%% - \addcontentsline needs to redirect writing to the lot-file
%%   to writing to the loEB-file (list of Example Boxes).
%%   The following things are needed for patching \addcontentsline
%%   inside the examplebox environment:
\newcommand\MySavedAddcontentsline{}%
\AtBeginDocument{\let\MySavedAddcontentsline=\addcontentsline}%
\newcommand\Mylotstring{lot}%
\newcommand\Mylotstringb{\csname ext@table\endcsname}%
\newcommand\MyPatchedAddcontentsline[1]{%
  \begingroup
  \long\def\@tempa{#1}%
  \ifx\@tempa\Mylotstring
    \expandafter\@secondoftwo
  \else
    \expandafter\@firstofone
  \fi
  {%
    \ifx\@tempa\Mylotstringb
      \expandafter\@secondoftwo
    \else
      \expandafter\@firstoftwo
    \fi
    {\endgroup\MySavedAddcontentsline{#1}}%
  }%
  {\endgroup\MySavedAddcontentsline{loEB}}%
}%
%%
%% \ExampleboxStuffInsteadOfTableStuff performs redirecting and patching.
%% 
\newcommand\ExampleboxStuffInsteadOfTableStuff{%
  % Redirect LaTeX 2e-kernel-counter-infrastructure-stuff of 
  % the table counter to the examplebox counter
  \let\c@table=\c@examplebox
  \let\thetable=\theexamplebox
  \let\p@table=\p@examplebox
  \let\cl@table=\cl@examplebox
  % Redirect hyperref-counter-infrastructure-stuff and \autoref-stuff
  % of the table counter to the examplebox counter:
  \let\theHtable=\theHexamplebox
  % \let\tableautorefname=\exampleboxautorefname
  \let\tablename=\exampleboxname %<- in case \tableautorefname is undefined, 
                                 %   this will break \autoref-erencing tables
                                 %   inside the examplebox-environment!
  % patch for hyperref's longtable patch =
  % patch \hyper@makecurrent to crank out usage of the table-counter:
  \let\hyper@makecurrent=\MyPatchedhyper@makecurrent
  % patch \addcontentsline to crank out usage of lot:
  \let\addcontentsline=\MyPatchedAddcontentsline
}%

%% examplebox environment
%%
\definecolor{examplebox}{gray}{0.95} %define the examplebox color
\newcounter{examplebox}
\newcommand*{\exampleboxautorefname}{Example box}
\newcommand*{\exampleboxname}{Example box}
\newcommand*\listexampleboxname{List of example boxes}%
\newenvironment{examplebox}{%
   \ExampleboxStuffInsteadOfTableStuff
   \longtable
}{\endlongtable}

%% \listofexampleboxes
%%
\newcommand\listofexampleboxes{%
  \if@twocolumn
    \@restonecoltrue
    \onecolumn
  \else 
    \@restonecolfalse 
  \fi 
  \chapter*{\listexampleboxname}%
  \@mkboth{\MakeUppercase\listexampleboxname}%
          {\MakeUppercase\listexampleboxname}%
  \@starttoc{loEB}%
  \if@restonecol\twocolumn\fi
}%

\makeatother

\begin{document}

\listoftables\newpage

\listofexampleboxes\newpage

\autoref{box:test} is the label of this examplebox.\\

The current counter for examplebox is \theexamplebox.

% A column of type p{<width>} from the array package is 
% used to make enumerate and itemize work.
\begin{examplebox}{|p{5cm}|} \hline
    \rowcolor{examplebox}%
    \label{box:test}%
    \begin{itemize}
    \item A
    \item B
    \item C
    \end{itemize}
    \begin{enumerate}
    \item A
    \item B
    \item C
    \end{enumerate}
     Hello there.\\ \hline
    \caption{Caption of this example box.}
\end{examplebox}

The current counter for examplebox is now \theexamplebox.

\begin{table}[h]
    \begin{center}
        \begin{tabular}{| c c c |}
            \hline
        1&2&3\\ \hline
        4&5&6\\ \hline
    \end{tabular}
    \caption{Random table caption}
    \end{center}
\end{table}

The current counter for examplebox is still \theexamplebox.

\end{document}