% \iffalse meta-comment
%
% This program is free software; you can redistribute it and/or
% modify it under the terms of the GNU General Public License
% as published by the Free Software Foundation; either version 2
% of the License, or (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software
% Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
%
% \fi
%
% \DoNotIndex{\#,\$,\%,\&,\@,\\,\{,\},\^,\_,\~,\ }
% \DoNotIndex{\def,\long,\edef,\xdef,\gdef,\let,\global}
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% \CheckSum{417}
%
% \MakeShortVerb\|
%
% \iffalse
% \begin{macrocode}
%<*driver>
\documentclass{ltxdoc}
\RequirePackage{hyperref}
\EnableCrossrefs
%\DisableCrossrefs % Say \DisableCrossrefs if index is ready
\CodelineIndex
\RecordChanges
\setcounter{IndexColumns}{2} % make a twocolumn index
\setlength{\columnseprule}{0pt} % no rules between columns ...
\setlength{\columnsep}{2em} % ... but more spacing instead.
\setcounter{unbalance}{4}
\setlength{\IndexMin}{100pt}
\OnlyDescription
\setlength\hfuzz{3pt}
%\hbadness=7000
\frenchspacing
\begin{document}
\DocInput{mparhack.dtx}
\raggedright
\end{document}
%</driver>
% \end{macrocode}
% ^^A See CTAN:tools/filehdr/filehdr.dvi for an explanation for the following stuff
%
% ===================================================================
% @LaTeX-package-file{
% version = "1.5",
% date = "2021-05-02",
% filename = "mparhack.sty",
% author-1 = "Tom Sgouros",
% email-1 = "tomfool@top.gso.uri.edu",
% author-2 = "Stefan Ulrich",
% email-2 = "stefanulrich@users.sourceforge.net",
% codetable = "ISO/ASCII",
% keywords = "marginpar, marginpars, marginal notes, wrong margin"
% supported = "yes",
% docstring = "User manual and documented source code and for the
% LaTeX package mparhack.sty"
% }
% ===================================================================
% \fi
% \newcommand*\Com[1]{\texttt{\char`\\#1}}
% \newcommand*\File[1]{\texttt{#1}}
% \newcommand*\Explanation[1]{\noindent
% \rule[.5ex]{.4\linewidth}{.6pt}\kern1em
% ^^A$\bullet\bullet\bullet$
% {\itshape\small #1}^^A
% }^^A\kern1em\rule[.5ex]{6em}{.6pt}}
% \newenvironment{Addition}{\par\noindent\Explanation{begin addition}\par\noindent\ignorespaces}^^A
% {\Explanation{end addition}}
% \newenvironment{Replacement}{\par\noindent\Explanation{begin replacement:}\par\noindent\ignorespaces}^^A
% {\Explanation{end replacement}}
% \newcommand*\ReplacedBy{\par\noindent\Explanation{by:}\par\noindent\ignorespaces}
% \newcommand*\PackageNameNoExt{mparhack}
% \newcommand*\PackageName{\texttt{\PackageNameNoExt.sty}}
% \def\AfterElseFi#1\else#2\fi{\else#2\fi#1}
% \GetFileInfo{mparhack.sty}
% \title{\PackageName}
% \author{Tom Sgouros\\ {\small\texttt{tomfool@top.gso.uri.edu}} \and
% Stefan Ulrich\\ {\small\href{mailto:stefanulrich@users.sourceforge.net}{\texttt{stefanulrich@users.sourceforge.net}}}}
% \date{v1.5 2021-05-02\\[1ex] {\footnotesize CTAN:
% \href{https://ctan.org/pkg/mparhack}
% {\texttt{https://ctan.org/pkg/mparhack}}}
% \\[1ex]
% {\footnotesize Github:
% \href{https://github.com/u-fischer/mparhack}
% {\texttt{https://github.com/u-fischer/mparhack}}}
% }
% \maketitle
%
% \begin{abstract}
% This package implements a workaround for the \LaTeX\ bug
% that marginpars sometimes show up on the wrong margin.
% \end{abstract}
%
% \changes{v1.0}{1999/03/02}{Created}
% \changes{v1.1}{1999/09/23}{Rewrite to use only one label per page, and to implement
% `twocolumn' document option.}
% \changes{v1.2}{2000/02/29}{Small documentation changes}
% \changes{v1.2a}{2000/03/14}{Fixed the \Com{NeedsTeXFormat} to use 1997/04/14}
% \changes{v1.2c}{2001/02/07}{Small documentation changes}
% \changes{v1.3}{2001/02/07}{Use \Com{mph@tempa} instead of \Com{@tempa} to avoid
% possible clashes with other classes (e.g. scrpage2)}
% \changes{v1.4}{2005/04/17}{Fix a bug with eso-pic.sty (latex/3775)}
%
%
% {\parskip 0pt \tableofcontents }
%
% ^^A --------------------------------------------------
% \section{Introduction}
% ^^A --------------------------------------------------
%
% A persistent problem with the |\marginpar| command is that the
% marginalia produced often show up on the wrong margin. This has
% been noted in the \LaTeX\ bugs database.^^A
% \footnote{See \url{https://www.latex-project.org/cgi-bin/ltxbugs2html}:
% \href{https://www.latex-project.org/cgi-bin/ltxbugs2html?pr=latex/2361}{latex/2361},
% \href{https://www.latex-project.org/cgi-bin/ltxbugs2html?pr=latex/2484}{latex/2484},
% \href{https://www.latex-project.org/cgi-bin/ltxbugs2html?pr=latex/2617}{latex/2617}.}
%
%
% The problem occurs most likely when a marginpar appears near
% the top of a page. The problem is exacerbated when
% the page break penalties are adjusted so that the page look is
% quite ragged. In cases like this, if there is a deal of white
% space on a page, the marginpars on the next page will be on the
% wrong side for the same length of the page.
% The reason for this is that the \LaTeX\ output routine is not
% in complete synchronization with the \TeX\ page breaker, so that
% sometimes
% material might still move to a later page \emph{after} \LaTeX's
% marginpar algorithm has determined a page number for the marginpar.
%
% The fix suggested in the bugs database is to insert |\pagebreak|
% commands at the places where the page breaks naturally fall;
% then the marginpars will appear on the correct side. However, this is
% awkward and unpleasant work for a document that changes
% regularly, and seems to fly against the spirit of \LaTeX.
%
% A different approach was suggested by D. E. Knuth in his
% \emph{Macros for Jill}\footnote{Originally published in TUGboat
% \textbf{8}, pp.~309--314, reprinted in his \emph{Digital
% Typography} pp.~185--193.}: make two |.dvi| files, one with all
% notes in the left margin, the other one with all notes in the
% right margin. Then print the odd pages from one file, and the
% even pages from the other file; merge them by hand.
%
% However, Knuth also mentions the possibility to use an auxiliar
% file to save the page information for each marginpar and use this
% information to position it correctly in a second \TeX\ run; and
% this is the strategy adopted by \PackageName.
% Each marginpar is assigned a unique number; the output routine
% writes the number of the last marginpar of each page\slash column
% to the |.aux| file, and this information is used in
% |\@addmarginpar| to position the current marginpar on the correct
% margin.
%
%
% ^^A --------------------------------------------------
% \section{Usage}
% ^^A --------------------------------------------------
% Just insert |\usepackage{mparhack}| into your document preamble.
% After the first run, you'll probably get the warning message
% `\texttt{Marginpars may have changed. Rerun to get them right}'.
% This is similar to \LaTeX's warning `\texttt{Label(s) may have
% changed}'; it indicates that the |.aux| file doesn't contain the
% information needed to position the marginpars correctly, due to
% some changes in the document since the last run. The warning
% should go away after running \LaTeX\ again (eventually several
% times if there's also a table of contents etc.).
%
% \DescribeMacro{debug}^^A
% If you think something is going wrong, the package also has a
% \texttt{debug} option; this will output a lot of tracing
% information and will add numbers to the marginpars in the |.dvi|
% file for reference.
%
%
% ^^A --------------------------------------------------
% \section{Bugs\slash Restrictions}
% ^^A --------------------------------------------------
% \begin{itemize}
% \item
% The package works with the |twocolumn| document option, but not
% with the |multicol| package (you can't use marginpars inside
% the |multicols| environment).
% \item
% The package uses one command sequence per page, and the total number
% of command sequences available is limited on most \TeX\ systems.
% Note however that most current \TeX\ implementations
% can allocate more than several thousand command names, and some can
% be configured to allocate more than the default during run-time,
% so this shouldn't be a problem for moderately sized documents.
% \item
% The package has to hook into three commands of the \LaTeX2e\ output
% routine (by redefining some command), so it requires at least
% \LaTeX\ version 1997/04/14 and might break with future \LaTeX\
% versions that change these commands.
% We try to detect this by requiring a version newer than 1997/04/14
% and using some heuristics to check if the redefinitions have worked.
% You should watch out for this warning message:\par
% {\ttfamily\footnotesize\begin{tabular}{@{}l@{}l@{}}
%LaTeX Warning:&\ You have requested release `1997/04/14' of LaTeX,\\
% &\ but only release `...' is available.
% \end{tabular}}\par\noindent
% It might be that the package also works with older versions of \LaTeX,
% but this hasn't been tested. If one of the heuristics detects an incompatible
% change, it will raise an error:\par
% {\ttfamily\footnotesize\begin{tabular}{@{}l@{}}
%Package mparhack Error: Couldn't hook into command `xyz'.
% \end{tabular}}\par\noindent
% \vskip-\lastskip\noindent
% It might also happen that the heuristics don't detect a change
% properly. If the package simply seems to fail, this could be a reason.
% In both cases, please send a bug report to
% \href{mailto:stefanulrich@users.sourceforge.net}{\texttt{stefanulrich@users.sourceforge.net}}
% (if neccessary including the
% |.log| file of your \LaTeX\ run with the \texttt{debug}
% package option enabled). Suggestions/improvements are also welcome,
% of course.
% \end{itemize}
%
% ^^A --------------------------------------------------
% \section{Acknowledgements}
% ^^A --------------------------------------------------
% Thanks to Donald Arseneau and Robin Fairbairns for providing
% detailed hints\footnote{in \texttt{<23AUG199920123097@erich.triumf.ca>} and
% \texttt{<7prb8s\$dpr\$1@pegasus.csx.cam.ac.uk>}, respectively.}
% on how to implement the page referencing mechanism using only one
% label per page (instead of one label each marginpar, as in a
% previous version).
%
% \AlsoImplementation
% \StopEventually{\relax}
% ^^A --------------------------------------------------
% \section{Implementation}
% ^^A --------------------------------------------------
%
% ^^A --------------------------------------------------
% \subsection{Overview}\label{implementation}
% ^^A --------------------------------------------------
% Here's the algorithm for recording the positioning information for
% marginpars in more detail: Every marginpar has a unique number $n$ and
% writes to the |.aux| file a string like\par\medskip
% ^^A
% \begin{tabular}{@{}l}
% |\def\mph@nr{|$n$|}|.
% \end{tabular}\par\medskip
%
% The commands shipping out the columns and pages write to the
% |.aux| file strings like:\par\medskip
% ^^A
% \begin{tabular}{@{}l}
% |\mph@setcol{|$x{\texttt{:}}$|\thepage}{\mph@nr}|,
% \end{tabular}\par\medskip\noindent
% ^^A
% with $x = \mbox{i}$ for the first column and $x = \mbox{ii}$
% otherwise. Then when reading the |.aux|
% file at the begin of the \LaTeX\ run, |\mph@nr| will be substitued
% by the number of the last marginpar (the value of the |\mph@nr| command
% read before that),
% and |\mph@setcol| will assign that number to the command sequence |\csname|
% |mph@last@|$x{\texttt{:}}$|\thepage\endcsname|; so this will contain
% the number of the last marginpar on column\slash page $x{\texttt{:}}$|\thepage|.
%
% Later on, in the document itself, |\@addmarginpar| will be able to check the value of
% |\csname| |mph@last@|$x{\texttt{:}}$\Com{thepage}\Com{end\-csname},
% using the current values for $x$ and |\thepage|. Then there are two
% cases:
%
% (a) |\csname| |mph@last@|$x{\texttt{:}}$|\thepage\endcsname| is
% undefined, which means that there has been no |.aux| file
% previously, or that there are more pages\slash marginpars than in
% the previous run; in this case, |\@addmarginpar| will fall back to using
% the value of |\c@page| to determine the current page number (yielding the
% same result as without this package), or
%
% (b) |\csname| |mph@last@|$x{\texttt{:}}$|\thepage\endcsname| is defined as
% an integer $z$, the number of the last marginpar on |\thepage|.
% Then $z \leq n$, the number of the current marginpar.^^A
% \footnote{$z$ cannot be greater than $n$: this would
% mean that \TeX\ had shifted some material (including a marginpar)
% from later pages to earlier pages, which AFAIK cannot happen.}
% While $z < n$, the page counter will be incremented (inside a group)
% until |\csname| |mph@last@|$x{\texttt{:}}$|\thepage\endcsname| for
% that new page is $\geq n$, or until
% we end up in case (a). The incremented value for the page counter
% now represents the actual page number of the current marginpar,
% and it will be used instead of the original page counter in the
% check for even-\slash oddness.
%
% ^^A --------------------------------------------------
% \subsection{Code}
% ^^A --------------------------------------------------
%
% We need at least \LaTeX\ version 1997/04/14 which introduced
% |\normalsfcodes| into |\@outputdblcol|.
% \begin{macrocode}
%<*sty>
\NeedsTeXFormat{LaTeX2e}[1997/04/14]
\ProvidesPackage{mparhack}
[2021-05-02 v1.5 (T. Sgouros and S. Ulrich)]
% \end{macrocode}
% ^^A --------------------------------------------------
% \subsubsection{Booleans, Options, etc.}
% ^^A --------------------------------------------------
% Some boolean switches which we will be using:
% |\if@mph@firstcol@| indicates that the current column is the
% first column, |\if@mph@warning@| toggles the warning message
% about changed marginpars, and |\if@debug@| toggles printing (lots
% of) debugging messages.
% \begin{macrocode}
\newif\if@mph@firstcol@
\newif\if@mph@warning@
\newif\if@debug@
% \end{macrocode}
% \begin{macro}{\mph@debug}
% This command will print the debugging messages if |@debug@| is |true|:
% \begin{macrocode}
\newcommand*\mph@debug[2][]{%
\if@debug@
\typeout{DBG: #2}%
\else
\ifx#1\@empty\else
\typeout{DBG (#1): #2}%
\fi
\fi
}
% \end{macrocode}
% \end{macro}
% The |debug| package option sets |@debug@| to true and adds
% numbers to each marginpar by redefining \Com{@xmpar} and
% \Com{@ympar}. The numbers are put into boxes of dimension
% zero so that they don't alter the spacing.
% \begin{macrocode}
\DeclareOption{debug}{%
\newcommand\mph@info{%
\@tempcnta=\mph@cnt
\advance\@tempcnta1
\raisebox{0pt}[0pt][0pt]{\makebox[0pt][r]{\tiny\the\@tempcnta}}%
}%
\long\def\@xmpar[#1]#2{%
\@savemarbox\@marbox{\mph@info#1}%
\@savemarbox\@currbox{\mph@info#2}%
\@xympar
}%
\long\def\@ympar#1{%
\@savemarbox\@marbox{\mph@info#1}%
\global\setbox\@currbox\copy\@marbox
\@xympar
}%
\global\@debug@true
}%
\ProcessOptions*
% \end{macrocode}
% ^^A --------------------------------------------------
% \subsubsection{Commands}
% ^^A --------------------------------------------------
% \begin{macro}{\mph@nr}
% A command sequence containing the current marginpar number (which
% will be written to the |.aux| file).
% \begin{macrocode}
\newcommand*\mph@nr{0}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\mph@pg@new}
% A command sequence for saving the newly determined value of |\thepage| for later use.
% \begin{macrocode}
\newcommand*\mph@pg@new{0}
\newcommand*\mph@lastpage{0}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\mph@cnt}
% Emulate a counter with a command name to save one count
% register. Oh well~\dots \texttt{;-)}
% \begin{macrocode}
\newcommand*\mph@cnt{0}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\mph@step@cnt}
% Use this instead of |\stepcounter| to increment the `counter'
% passed as the argument.
% \begin{macrocode}
\newcommand*\mph@step@cnt[1]{%
\begingroup
\@tempcnta#1
\advance\@tempcnta\@ne
\protected@xdef#1{\the\@tempcnta}%
\endgroup
}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\mph@setcol}
% The command sequence written to the |.aux| file that will save
% the column number\slash page number of the last marginpar on the
% column\slash page.^^A The additional |ignore@warn#1| macro is used
% ^^A in the |\mph@check| macro.
% \begin{macrocode}
\newcommand*\mph@setcol[2]{%
% \@ifundefined{mph@last@#1}{%
% \relax
% }{%
% \expandafter\xdef\csname ignore@warn#1\endcsname{x}%
% }%
\expandafter\xdef\csname mph@last@#1\endcsname{#2}%
}
% \end{macrocode}
% \end{macro}
% \begin{macro}{\mph@check}
% Similar to \LaTeX's |\@testdef| for labels, this will be called
% at the end of the \LaTeX\ run to check if the meaning of |#2| is
% still equal to |mph@last@#1| or if it has changed since the last
% run.
% \begin{macrocode}
\newcommand*\mph@tempa{}
\newcommand*\mph@check[2]{%
\protected@edef\mph@tempa{#2}%
\expandafter\ifx\csname mph@last@#1\endcsname\mph@tempa
\mph@debug{\csname mph@last@#1\endcsname\space == \mph@tempa}%
\else
\mph@debug{\csname mph@last@#1\endcsname\space != \mph@tempa!}%
\global\@mph@warning@true
\fi
}
\newcommand*\mph@do@warn{%
\if@mph@warning@
\PackageWarningNoLine{mparhack}{Marginpars may have
changed.\MessageBreak Rerun to get them right%
}%
\fi
}
% \end{macrocode}
% \end{macro}
% To avoid warnings about undefined commands when someone stops using
% this package, we |\providecommand| the |\mph@setcol| command that
% we're going to write to the |.aux| file.
% \begin{macrocode}
\AtBeginDocument{%
\protected@write\@auxout{}{%
\string\providecommand\string\mph@setcol[2]{}%
}%
% \end{macrocode}
% Fix for latex/3775\footnote{^^A
% \url{https://www.latex-project.org/cgi-bin/ltxbugs2html?pr=latex/3775}^^A
% }: eso-pic uses \Com{@picture} inside the output routine,
% which causes problems with our redefinition of \Com{hb@xt@} in \Com{@outputdblcol}.
% So, as suggested by M. H\o gholm in his reply to the above bug report, we patch
% \Com{@picture} to revert to the original definition of \Com{hb@xt@}.
% \begin{macrocode}
\@ifpackageloaded{eso-pic}{%
\let\mph@orig@picture\@picture
\renewcommand\@picture{\let\hb@xt@\mph@orig@hb@xt@\mph@orig@picture}%
}{%
\relax
}%
}
% \end{macrocode}
% Add the needed checks to |\@enddocumenthook|. Again, use
% |\csname| ... |\endcsname| to avoid warnings about undefined
% commands.
% \changes{v1.2}{2000/02/29}{%
% Use \Com{csname...} when writing commands to \texttt{.aux} file
% }%
% \begin{macrocode}
\AtEndDocument{%
\let\mph@setcol\mph@check
\clearpage
\immediate\write\@auxout{%
\string\gdef\string\mph@lastpage{\the\c@page}^^J%
\string\csname\space mph@do@warn\string\endcsname
}%
}
% \end{macrocode}
%
% \begin{macro}{\mph@ifundef@or@smaller}
% A helper macro that checks if the command sequence in |#1| is
% undefined or if its value is smaller than |\mph@cnt| (it assumes
% that |#1| is never empty). If one of these conditions is true,
% the second argument is evaluated, else the third argument is
% evaluated (similar to \LaTeX's |\@ifundefined|). This macro
% will be used to shorten the body of the next macro definition.
% \changes{v1.2}{2000/02/29}{%
% Renamed this command, and updated the documentation
% }%
% \begin{macrocode}
\newcommand*\mph@ifundef@or@smaller[1]{%
\expandafter\ifx#1\relax
\let\mph@tempa\@firstoftwo
\else
\ifnum#1<\mph@cnt\relax
\let\mph@tempa\@firstoftwo
\else
\let\mph@tempa\@secondoftwo
\fi
\fi
\mph@tempa
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\mph@pg@orig}
% \changes{v1.2}{2000/02/29}{%
% Added the \Com{mph@pg@orig} macro
% }%
% The macro |\mph@pg@orig| is used to
% save the original value of |\c@page| which is used in case the |.aux|
% file information is not up-to date and we can't determine the
% correct value; this should give the same results as if \PackageName\
% hadn't been used.
% \begin{macrocode}
\newcommand*\mph@pg@orig{}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\mph@get@margin}
% This macro does most of the work described in
% section~\ref{implementation}.
% \changes{v1.2}{2000/02/29}{%
% Use \Com{c@page} instead of \Com{thepage} as value in \Com{mph@pg@new}
% }%
% \begin{macrocode}
\newcommand*\mph@get@margin{%
\begingroup
\edef\mph@pg@orig{\the\c@page}
\loop
% \end{macrocode}
% This loop will be controlled by |\@tempswa|; all changes to that
% and to |\thepage| will be local to the current group.
% \begin{macrocode}
\@tempswafalse
\mph@debug{--- checking marginpar \mph@cnt}%
\if@twocolumn
% \end{macrocode}
% When we are in twocolumn mode, first check if the current
% marginpar number is greater than the last marginpar in the first
% column. If it isn't, we're in the first column. If it is, do the
% check for the last marginpar of the entire page. If this returns
% false, we're in the second column. Else, advance the page number
% and try again.
% \begin{macrocode}
\mph@debug{last on page \thepage:
\csname mph@last@i:\thepage\endcsname(i)
\csname mph@last@ii:\thepage\endcsname(ii),
}%
\mph@ifundef@or@smaller{%
\csname mph@last@i:\thepage\endcsname
}{%
\mph@ifundef@or@smaller{%
\csname mph@last@ii:\thepage\endcsname
}{%
\global\@mph@firstcol@true
\@tempswatrue
\advance\c@page by 1
\mph@debug{\mph@cnt\space >
\csname mph@last@ii:\thepage\endcsname,
incrementing \thepage, set col to i
}%
}{%
\global\@mph@firstcol@false
\@tempswafalse
\mph@debug{\mph@cnt\space <=
\csname mph@last@ii:\thepage\endcsname,
exiting loop
}%
}%
}{%
\@tempswafalse
\global\@mph@firstcol@true
\mph@debug{exiting loop}%
}%
\else
% \end{macrocode}
% Not in twocolumn mode, we need only check for |mph@last@ii|:
% \begin{macrocode}
\mph@debug{last on page \thepage\space is
\csname mph@last@ii:\thepage\endcsname
}%
\mph@ifundef@or@smaller{%
\csname mph@last@ii:\thepage\endcsname
}{%
\@tempswatrue
\advance\c@page by 1
\mph@debug{\mph@cnt\space >
\csname mph@last@ii:\thepage\endcsname,
incrementing page number
}%
}{%
\@tempswafalse
\mph@debug{\mph@cnt\space <=
\csname mph@last@ii:\thepage\endcsname,
exiting loop
}%
}%
\fi
% \end{macrocode}
% Now we have either found the correct page, or reached the end of the document
% without finding the appropriate page (e.\,g., if the |.aux| file hasn't existed
% before, or if the document has grown a lot since the last run).
% In this case we reset |\c@page| and |\if@mph@firstcol@| to their original values
% and jump out of the loop.
% \changes{v1.2}{2000/02/29}{%
% Use original values for page and column number by default%
% }%
% \begin{macrocode}
\ifnum\mph@lastpage>\c@page
\else
\@tempswafalse
\mph@debug{\c@page >= \mph@lastpage!}%
\c@page=\mph@pg@orig
\if@firstcolumn
\global\@mph@firstcol@true
\else
\global\@mph@firstcol@false
\fi
\mph@debug{using original value: \c@page for
\string\c@page and exiting loop.
}%
\fi
\if@tempswa
\mph@debug{iterating ...}%
\repeat
% \end{macrocode}
% After having finished the loop, we save the current (eventually modified)
% value of |\c@page| to |\mph@pg@new|:
% \begin{macrocode}
\mph@debug{=== marginpar \mph@cnt\space is on page \thepage%
\if@twocolumn, col \if@mph@firstcol@ 1 \else 2 \fi\fi
}%
\protected@xdef\mph@pg@new{\the\c@page}%
\endgroup
}
% \end{macrocode}
% \end{macro}
%
% ^^A --------------------------------------------------
% \subsubsection{Patching the output routine}
% ^^A --------------------------------------------------
% We have to hook into 3 commands that are part of \LaTeX's output routine:
% |\@addmarginpar|, |\@outputdblcol| and |\@outputpage|. For the latter, we can use the default
% \LaTeX\ mechanism |\g@addto@macro|. For the others, this is more difficult,
% since the changes need to go somewhere `in between'.
%
% One could use hard redefinitions (plus
% \Com{CheckCommand*} to verify that the correct version of
% the command was being defined); but this soon gets too bothersome
% with new \LaTeX2e\ versions introducing minor changes that don't
% affect the stuff which we are concerned, but that nevertheless
% would require multiplying the redefinitions for the various versions.
%
% So instead, we locally redefine some
% commands to hook into the existing definitions. As a heuristic of
% detecting whether we change the appropriate commands, we check
% the values of some special counters \Com{mph@chk@xyz} that get
% incremented by some of the `hooks'.
%
% \changes{v1.3a}{2003/05/22}{%
% Use \Com{g@addto@macro} for \Com{@outputpage} to
% improve compatibility with e.g. the memoir class
% }%
% \changes{v1.2}{2000/02/29}{%
% Added \Com{CheckCommand*} for \Com{@addmarginpar}, \Com{@outputpage}
% and \Com{@outputdblcol}
% }%
% \changes{v1.2b}{2000/09/01}{%
% Replaced \Com{CheckCommand*} and the full redefinitions of
% \Com{@addmarginpar}, \Com{@outputpage} and \Com{@outputdblcol}
% by hooking into certain commands inside them
% }%
%
% \begin{macro}{\mph@error}
% Error message if something suspicious happened with the redefintions:
% \begin{macrocode}
\newcommand\mph@error[1]{%
\PackageError{mparhack}{%
Couldn't hook into command `#1'
}{%
This means that a LaTeX version incompatible with
mparhack.sty^^J%
has been used. See also the section on `Bugs/Restrictions'^^J%
in mparhack.dvi. Please send an email about this bug to^^J%
<stefanulrich@users.sourceforge.net>, along with the file `\jobname.log'.
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@addmarginpar}
% This command adds the marginpar box to the current page.
% We change the \Com{c@page} counter and the \Com{if@firstcolumn} switch
% to the values that have been set correctly by the \Com{mph@get@margin}
% command. There's no further error checking done here.
%
% \begin{macrocode}
\newcommand\mph@orig@c@page{}
\newcommand\mph@orig@addmarginpar{}
\let\mph@orig@addmarginpar\@addmarginpar
\renewcommand\@addmarginpar{%
\mph@step@cnt\mph@cnt
\protected@write\@auxout{}%
{\string\def\string\mph@nr{\mph@cnt}}%
\mph@get@margin
\def\mph@orig@c@page{\c@page}
\c@page=\mph@pg@new
\if@mph@firstcol@
\@firstcolumntrue
\else
\@firstcolumnfalse
\fi
\mph@orig@addmarginpar
\c@page=\mph@orig@c@page
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@outputpage}
% Add the |\mph@outputpage@hook| hook to |\@outputpage|.
% We need to decrement |\c@page|, since |\@outputpage| will
% have incremented it after dumping the page contents.
% The group in |\mph@outputpage@hook| is to keep this change local.
% \begin{macrocode}
\newcommand*\mph@outputpage@hook{%
\bgroup
\advance\c@page\m@ne
\immediate\write\@auxout{%
\string\mph@setcol{ii:\thepage}{\string\mph@nr}%
}%
\egroup
}
\g@addto@macro{\@outputpage}{\mph@outputpage@hook}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@outputdblcol}
% In case an entire twocolumn page is finished, this command calls
% \Com{hb@xt@} with the boxes for the two columns inside, and each
% one needs to set a marker with the current column number. So
% we hook into \Com{hb@xt@} and check if its first argument equals
% \Com{columnwidth} (\Com{hb@xt@} is also called for the entire page,
% but in this case the first argument is \Com{textwidth}).
%
% The current column number is represented by \Com{mph@chk@dcl}, and at
% the end we check if this number equals 0 (in which case the
% page hadn't been fininshed yet, and we didn't need to do anything)
% or 2 (the `interesting' case); else we signal an error.
% \changes{v1.5}{2021-04-02}{%
% Changed definition of \Com{@outputdblcol} to allow
% \Com{hb@xt@} to correctly expands in shipout hooks. See
% \url{https://tex.stackexchange.com/q/595272/2388}
% }%
% \begin{macrocode}
\newcommand\mph@orig@hb@xt@{}
\newcommand\mph@orig@outputdblcol{}
\newcommand\mph@chk@dcl{0}%
\let\mph@orig@hb@xt@\hb@xt@
\let\mph@orig@outputdblcol\@outputdblcol
\renewcommand\@outputdblcol{%
\def\mph@chk@dcl{0}%
\def\hb@xt@##1##2{%
\ifx##1\columnwidth
\mph@step@cnt\mph@chk@dcl
\protected@edef\mph@tempa{%
\noexpand\write\noexpand\@auxout{%
\noexpand\string\noexpand\mph@setcol{%
\romannumeral\mph@chk@dcl:\noexpand\thepage%
}{%
\noexpand\string\noexpand\mph@nr%
}%
}%
}%
\mph@orig@hb@xt@##1{##2\mph@tempa}%
\else
\mph@orig@hb@xt@##1{##2}%
\fi
}%
\mph@orig@outputdblcol
\def\hb@xt@{\mph@orig@hb@xt@}%
\ifnum\mph@chk@dcl=0\relax
\else
\ifnum\mph@chk@dcl=2\relax
\else
\mph@error{\string\@outputdblcol}%
\fi
\fi
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\mph@orig@picture}
% \begin{macrocode}
\newcommand\mph@orig@picture{}
% \end{macrocode}
% \end{macro}
%
% \begin{macrocode}
%</sty>
% \end{macrocode}
% ^^A\typeout{End of package documentation.}
% ^^A makeindex -s gind.ist \PackageNameNoExt^^J}
% \PrintIndex
% \PrintChanges
% \Finale