%% This is file `stocksize.sty',
%%
%% Copyright (C) 2024 by João M. Lourenço <joao.lourenco@fct.unl.pt>
%%
%% This file may be distributed and/or modified under the conditions of
%% the LaTeX Project Public License, either version 1.3c of this license
%% or (at your option) any later version. The latest version of this
%% license is in:
%%
%%    http://www.latex-project.org/lppl.txt
%%
%% and version 1.3c or later is part of all distributions of LaTeX
%% version 2006/05/20 or later.
%%
\def\fileversion{1.0.2}
\def\filedate   {2024/11/13}
\edef\filename  {\@currname}

\ProvidesPackage{stocksize}[%
  \filedate\  v\fileversion (João M. Lourenço) User defined PDF paper (stock) size.]

% Load geometry if it was was not loaded by the user
\AddToHook{begindocument/before}{
  \@ifpackageloaded{geometry}{}{
    \RequirePackage[reset]{geometry}
  }
}

% Change the physical paper (stock) size
% Works with pdfLaTeX, XeLaTeX and LuaLaTeX
\newcommand*{\@ss@setpdfpagesize}[2]{%
  \@ifundefined{pdfpageheight}{}{\pdfpageheight=#1}%
  \@ifundefined{pdfpagewidth}{}{\pdfpagewidth=#2}%
  \@ifundefined{pageheight}{}{\pageheight=#1}%
  \@ifundefined{pagewidth}{}{\pagewidth=#2}%
  \paperheight=#1\stockheight=#1%
  \paperwidth=#2\stockwidth=#2%
}

\newcounter{@ss@cnt}
\newcommand*{\pdfsavegeometry}[1]{%
  \expandafter\edef\csname @sspw@\arabic{@ss@cnt}\endcsname%
                {\the\dimexpr\Gm@lmargin+\Gm@width+\Gm@rmargin\relax}%
  \expandafter\edef\csname @ssph@\arabic{@ss@cnt}\endcsname%
                {\the\dimexpr\Gm@tmargin+\Gm@height+\Gm@bmargin\relax}%
  \stepcounter{@ss@cnt}%
  \savegeometry{@ss@cnt@\arabic{@ss@cnt}}%
  \newdimen\@tempdimd%
  \@tempdima=\Gm@lmargin\@tempdimb=\Gm@rmargin%
  \@tempdimc=\Gm@tmargin\@tempdimd=\Gm@bmargin%
  \define@key{Gm}{keepmargins}[true]{\setkeys{Gm}{lmargin=\the\@tempdima,
          rmargin=\the\@tempdimb, tmargin=\the\@tempdimc, bmargin=\the\@tempdimd
  }}%
  \restoregeometry%
  \newgeometry{#1}%
  \edef\@sspw{\the\dimexpr\Gm@lmargin+\Gm@width+\Gm@rmargin\relax}%
  \edef\@ssph{\the\dimexpr\Gm@tmargin+\Gm@height+\Gm@bmargin\relax}%
  \@ss@setpdfpagesize{\@ssph}{\@sspw}%
}

\newcommand*{\pdfrestoregeometry}{%
  \loadgeometry{@ss@cnt@\arabic{@ss@cnt}}%
  \addtocounter{@ss@cnt}{-1}%
  \@ss@setpdfpagesize{\csname @ssph@\arabic{@ss@cnt}\endcsname}%
                     {\csname @sspw@\arabic{@ss@cnt}\endcsname}%
}

\newcommand*{\newstocksize}{\pdfsavegeometry}
\newcommand*{\restorestocksize}{\pdfrestoregeometry}