LaTeX: to make 'pagebox' option key of \includegraphics available with dvipdfmx/xetex drivers

tcpagebox.sty

% tcpagebox.sty
%
%% Prologue
\ifx\tcizIntr\undefined \let\tcizISkip\relax
\else \long\def\tcizISkip#1\tcizISkip{}
\fi \tcizISkip
% When loaded with \usepackage, start from here.

%% package declaration
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{tcpagebox}[2015/07/19 v0.2]

%% preparations
\def\tciz@pkgname{tcpagebox}
\def\tciz@error{\PackageError\tciz@pkgname}
\def\tciz@warn{\PackageWarning\tciz@pkgname}
\providecommand\bxDebug[1]{}

%% prerequisite packages
\RequirePackage{etoolbox}
\RequirePackage{pdftexcmds}

%--------------------------------------- settings

%% \tciz@temp@base
% The base-name of the temporary MetaPost source file.
\edef\tciz@temp@base{\jobname-bb}

%% \tciz@cmd@mpost
% The name of MetaPost command.
\def\tciz@cmd@mpost{mpost}

%% \tciz@cmd@pdftex
\def\tciz@cmd@pdftex{pdftex}

%% \iftciz@clean
% Is clean-up needed?
\newbool{tciz@clean}

%% options
\DeclareOption{clean}{%
  \tciz@cleantrue
}
\DeclareOption{noclean}{%
  \tciz@cleanfalse
}
\ExecuteOptions{clean}
\ProcessOptions*\relax

%--------------------------------------- environment check

% e-TeX cehck
\ifx\patchcmd\@undefined
\expandafter\endinput\fi\relax

%% \tciz@driver
\let\tciz@driver\relax

%% detect graphics driver
\@ifpackageloaded{graphicx}{%
  \ifnum\pdf@strcmp{\Gin@driver}{dvipdfmx.def}=\z@
    \def\tciz@driver{dvipdfmx}%
  \else\ifnum\pdf@strcmp{\Gin@driver}{xetex.def}=\z@
    \def\tciz@driver{xetex}%
  \else
    \tciz@warn{Unsupported graphics driver '\Gin@driver' is used,\MessageBreak
      package loading aborted}%
  \fi\fi
}{%else
  \tciz@error{Package 'graphicx' is not yet loaded}{%
    The '\tciz@pkgname' package must be loaded after 'graphicx'
    package.\MessageBreak\@ehc}%
}

%% check if pagebox is seemingly already supported
\ifnum 0\ifdefined\Gin@pagebox 1\fi
        \ifdefined\Gin@XeTeX@pagebox 1\fi
        \ifdefined\GTP@pagebox 1\fi >\z@
  \let\Gin@driver\relax
\fi

%% aobrt if wrong
\ifx\tciz@driver\relax
\expandafter\endinput\fi\relax

%--------------------------------------- helpers

%% variables
\newbool{tciz@ok}
\csuse{newwrite}\tciz@out
\newbool{tciz@cmd@ok}

%% unique tokens
\def\tciz@end{\tciz@end@}
\def\tciz@mt{\tciz@mt@}
\let\tciz@stop\relax

%% \tciz@PC: the string '%'
%% \tciz@BS: the string '\'
\begingroup \escapechar\m@ne
  \xdef\tciz@PC{\string\%}
  \xdef\tciz@BS{\string\\}
\endgroup

%% \if\tciz@eq{<str1>}{<str2>}...\fi
\def\tciz@eq#1#2{%
  \ifnum\pdf@strcmp{#1}{#2}=\z@ T\else F\fi T%
}

%% tciz@avail@shell
% shell escape availablity
\let\tciz@avail@shell\m@ne
\ifdefined\pdf@shellescape
  \chardef\tciz@avail@shell=\pdf@shellescape\relax
\fi
\begingroup
\ifnum\tciz@avail@shell=\z@
  \if\tciz@eq{\tciz@driver}{dvipdfmx}%
    \tciz@error{Shell escape is entirely disabled}%
      {Package loading is aborted.\MessageBreak\@ehc}%
      \aftergroup\endinput
  \fi
\fi
\endgroup

%% \tciz@drop@dot
% (fully-expandable)
\def\tciz@drop@dot#1{%
  \expandafter\tciz@drop@dot@a#1\tciz@end#1%
}
\def\tciz@drop@dot@a#1#2\tciz@end#3{\def#3{#2}}

%% \tciz@write@to@file{<filename>}{<content>}
\def\tciz@write@to@file#1#2{%
  \begingroup
    \catcode10=12 \newlinechar=10
    \let\%\tciz@PC \let\\\tciz@BS
    \def\n{^^J}\let\ \@space
    \immediate\openout\tciz@out=#1\relax
    \immediate\write\tciz@out{#2}%
    \immediate\closeout\tciz@out
  \endgroup
}

%% \tciz@empty@mark : empty-file marker
\edef\tciz@empty@mark{\string\empty}

%% \tciz@if@file@empty{<filename>}{<true>}{<false>}
\def\tciz@if@file@empty#1{%
  \openin\@inputcheck#1\relax
  \ifeof\@inputcheck
    \global\let\@gtempa\@firstoftwo
  \else
    \begingroup \endlinechar\m@ne
      \readline\@inputcheck to\tciz@tmpa
      \if\tciz@eq{\tciz@tmpa}{\tciz@empty@mark}%
        \global\let\@gtempa\@firstoftwo
      \else
        \global\let\@gtempa\@secondoftwo
      \fi
    \endgroup
  \fi
  \@gtempa
}

%% \tciz@clobber@file{<filename>}
\def\tciz@clobber@file#1{%
  \tciz@write@to@file{#1}{\tciz@empty@mark}%
}

%--------------------------------------- graphics parameters

%% \tciz@base
\let\tciz@base\relax
%% \tciz@ext
\let\tciz@ext\relax
%% \tciz@page
\let\tciz@page\@empty
%% \tciz@pagebox
\let\tciz@pagebox\@empty

%% \tciz@set@imgfile{<file>}
% Sets \tciz@base and \tciz@ext.
\def\tciz@set@imgfile#1{%
  \edef\tciz@tmpa{#1}%
  \IfFileExists\tciz@tmpa{%
    \filename@parse\tciz@tmpa
    \edef\tciz@base{\filename@area\filename@base}%
    \edef\tciz@ext{\filename@ext}%
  }{%else
    \tciz@error{File '\tciz@tmpa' not found}\@ehc
    \tciz@okfalse
  }%
}

%% \tciz@set@imgfileext{<base>}{.<ext>}
% Sets \tciz@base and \tciz@exr.
\def\tciz@set@imgfileext#1#2{%
  \IfFileExists{#1#2}{%
    \edef\tciz@base{#1}%
    \edef\tciz@ext{#2}\tciz@drop@dot\tciz@ext%
  }{%else
    \tciz@error{File '#1#2' not found}\@ehc
    \tciz@okfalse
  }%
}

%% \tciz@set@page{<page>}
% Sets \tciz@page.
\def\tciz@set@page#1{%
  \unless\if\tciz@eq{#1}{}%
    \afterassignment\tciz@set@page@a\count@=#1\tciz@stop{#1}%
  \fi
}
\def\tciz@set@page@a#1\tciz@stop#2{%
  \ifx\tciz@mt#1\tciz@mt
    \edef\tciz@page{\the\count@}%
  \else
    \tciz@error{Invalid number format (#2)}\@ehc
  \fi
}

%% \tciz@set@pagebox{<box-spec>}
% Sets to \tciz@pagebox.
\def\tciz@set@pagebox#1{%
  \unless\if\tciz@eq{#1}{}%
    \ifcsundef{tciz@box/#1}{%
      \tciz@error{Invalid pagebox value (#1)}\@ehc
    }{%else
      \edef\tciz@pagebox{#1}%
    }%
  \fi
}
\@for\tciz@x:={media,crop,bleed,trim,art}\do{%
  \csedef{tciz@box/\tciz@x box}{\tciz@x}%
}

%--------------------------------------- oatch to graphics driver
\if\tciz@eq{\tciz@driver}{dvipdfmx}%

%% \tciz@bbox : the result
\let\tciz@bbox\relax
%% tciz@g@clean
\chardef\tciz@g@clean=0

%% add Gin parameters
\AtBeginDocument{%
  \tciz@oktrue
  % 'page' may or may not exist
  \unless\ifdefined\KV@Gin@page
    \define@key{Gin}{page}{}%
  \fi
    %NB. \patchcmd fails to do with '#1' in replacement...
  \let\tciz@KV@page\KV@Gin@page
  \def\KV@Gin@page#1{%
    \tciz@set@page{#1}% added
    \tciz@KV@page{#1}}%
  % 'pagebox' must not exist
  \ifdefined\KV@Gin@pagebox
    \Gin@ok@false
  \else
    \define@key{Gin}{pagebox}{%
      \tciz@set@pagebox{#1}}%
  \fi
  \unless\iftciz@ok
    \PackageError{Patch to graphics driver has failed}\@ehc
  \fi
}

%% rewrite \Gread@pdf
\let\tciz@Gread@pdf\Gread@pdf
\def\Gread@pdf#1{%
  \if\tciz@eq{\tciz@pagebox}{}%
    \tciz@Gread@pdf{#1}% do original
  \else
    \begingroup
      \edef\tciz@base{\Gin@base}%
      \edef\tciz@ext{\Gin@ext}%
      \let\tciz@bbox\relax
      \tciz@measure@pagebox
      \ifx\tciz@bbox\relax
        \tciz@error{Cannot determine size of image (no BoundingBox)}%
        \@ehc
        \gdef\@gtempa{0 0 72 72 }%
      \else
        \xdef\@gtempa{\tciz@bbox\space}%
      \fi
    \endgroup
    \expandafter\Gread@parse@bb\@gtempa\\%
  \fi
}

%% \tcizIntrResult{<text>}
% The result handler.
\def\tcizIntrResult#1{%
  \def\tciz@bbox{#1}%
}

%% \tciz@measure@pagebox@mpost
\def\tciz@measure@pagebox@mpost{%
  \tciz@write@to@file{\tciz@temp@base.tex}{%
    \% \tciz@temp@base.mp\n
    verbatimtex\n
    \%&pdftex -translate-file=natural\n
    \\let\\tcizIntr=t \\input \tciz@pkgname.sty\\relax\n
    \\tcizIntrMPProcess{\tciz@base\tciz@ext}%
      {\tciz@page}{\tciz@pagebox}{\tciz@temp@base.aux}\n
    etex\n
    label(btex \\relax etex, (0, 0));\n
    bye}%
  \tciz@exec@sub{\tciz@cmd@mpost}{2}%
}

%% \tciz@measure@pagebox@pdftex
\def\tciz@measure@pagebox@pdftex{%
  \tciz@write@to@file{\tciz@temp@base.tex}{%
    \% \tciz@temp@base.tex\n
    \\let\\tcizIntr=t \\input \tciz@pkgname.sty\\relax\n
    \\tcizIntrProcess{\tciz@base\tciz@ext}%
      {\tciz@page}{\tciz@pagebox}{\tciz@temp@base.aux}\n
    \\bye}%
  \tciz@exec@sub{\tciz@cmd@pdftex}{1}%
}

%% \tciz@exec@sub{<command>}{<clear>}
\def\tciz@exec@sub#1#2{%
  \tciz@clobber@file{\tciz@temp@base.log}%
  \tciz@clobber@file{\tciz@temp@base.aux}%
  \pdf@system{#1 \tciz@temp@base.tex}%
  \tciz@if@file@empty{\tciz@temp@base.log}{% not executed
    \tciz@cmd@okfalse
  }{%else
    \tciz@cmd@oktrue
    \global\chardef\tciz@g@clean=#2\relax
    \input{\tciz@temp@base.aux}%
  }%
}

%% \tciz@measure@pagebox@disabled
\def\tciz@measure@pagebox@disabled{%
  \tciz@warn{Process feiled, perhaps because shell is\MessageBreak
    disabled}%
}

%% \tciz@measure@pagebox@trial
\def\tciz@measure@pagebox@trial{%
  \tciz@measure@pagebox@pdftex
  \iftciz@cmd@ok
    \tciz@resolve@proc\tciz@measure@pagebox@pdftex
  \else
    \tciz@measure@pagebox@mpost
    \iftciz@cmd@ok
      \tciz@resolve@proc\tciz@measure@pagebox@mpost
    \else
      \tciz@measure@pagebox@disabled
      \tciz@resolve@proc\tciz@measure@pagebox@disabled
    \fi
  \fi
}

%% \tciz@resolve@proc
\def\tciz@resolve@proc#1{%
  \global\let\tciz@measure@pagebox=#1\relax
  \global\undef\tciz@measure@pagebox@disabled
  \global\undef\tciz@measure@pagebox@pdftex
  \global\undef\tciz@measure@pagebox@mpost
  \global\undef\tciz@measure@pagebox@trial
  \global\undef\tciz@resolve@proc
}
\ifcase\tciz@avail@shell
  \tciz@resolve@proc\tciz@measure@pagebox@disabled
\or \tciz@resolve@proc\tciz@measure@pagebox@pdftex
\or \tciz@resolve@proc\tciz@measure@pagebox@mpost
\else \let\tciz@measure@pagebox\tciz@measure@pagebox@trial
\fi

%% clean-up
\iftciz@clean
  \AtEndDocument{%
    \ifcase\tciz@g@clean
      \relax % nothing to do
    \or % 'pdftex' is done
      \tciz@write@to@file{\tciz@temp@base.lua}{%
        os.remove([=[\tciz@temp@base.tex]=])\n
        os.remove([=[\tciz@temp@base.aux]=])\n
        os.remove([=[\tciz@temp@base.log]=])\n
        os.remove([=[\tciz@temp@base.pdf]=])\n
        os.remove([=[\tciz@temp@base.lua]=])\n
      }%
      \pdf@system{texlua \tciz@temp@base.lua}%
    \or % 'mpost' is done
      % shell is restricted, so files cannot be removed
      \tciz@clobber@file{\tciz@temp@base.tex}%
      \tciz@clobber@file{\tciz@temp@base.aux}%
      \tciz@clobber@file{\tciz@temp@base.log}%
      \tciz@clobber@file{\tciz@temp@base.mpx}%
    \fi
  }
\fi

\fi
%--------------------------------------- oatch to graphics driver (Xetex)
\if\tciz@eq{\tciz@driver}{xetex}%

%% add Gin parameters
\AtBeginDocument{%
  \tciz@oktrue
  % 'page' must exist
  \ifdefined\KV@Gin@page
    \let\tciz@KV@page\KV@Gin@page
    \def\KV@Gin@page#1{%
      \tciz@set@page{#1}% added
      \tciz@KV@page{#1}}%
  \else
    \tciz@okfalse
  \fi
  % 'pagebox' must not exist
  \ifdefined\KV@Gin@pagebox
    \Gin@ok@false
  \else
    \define@key{Gin}{pagebox}{%
      \tciz@set@pagebox{#1}}%
  \fi
  % \Ginclude@ for pdf
  \@gobble\if \@gobble\if
  \patchcmd{\Ginclude@QTm}{%
    { page\Gin@XeTeX@page}\fi
  }{%
    { page\Gin@XeTeX@page}\fi
    \tciz@pagebox@info
  }{}{\tciz@okfalse}%
  % \Gread@ for pdf
  \@gobble\if \@gobble\if
  \patchcmd{\G@measure@QTm}{%
    { page\Gin@XeTeX@page}\fi
  }{%
    { page\Gin@XeTeX@page}\fi
    \tciz@pagebox@info
  }{}{\tciz@okfalse}%
  % check
  \unless\iftciz@ok
    \PackageError{Patch to graphics driver has failed}\@ehc
    \let\tciz@pagebox@info\relax
  \fi
}

%% \tciz@pagebox@info
\def\tciz@pagebox@info{%
  \unless\ifx\tciz@pagebox\@empty
    \edef\picpage{\picpage\space
      \@nameuse{tciz@box/\tciz@pagebox}}%
  \fi
}

\fi
%--------------------------------------- done
\endinput
\tcizISkip
%=======================================
% The code below is employed on plain pdfTeX spawned
% inside the run of MetaPost.
%--------------------------------------- intra-MetaPost procedures

%% code guards
\edef\tcizIRestore{%
  \catcode64=\the\catcode64%<@>
\relax}
\catcode64=11 %\makeatletter

%% variables
\newwrite\tciz@out

%%<+> \tcizIntrMPProcess{<file>}{<page>}{<page_box>}{<out_file>}
\def\tcizIntrMPProcess#1#2#3#4{%
  \begingroup
    \edef\tciz@imgfile{#1}%
    \edef\tciz@outfile{#4}%
    \edef\tciz@page{#2}%
    \edef\tciz@pagebox{#3}%
    \tciz@get@bbox
    \tciz@write@out
    \tciz@write@dvi
  \endgroup
}

%%<+> \tcizIntrProcess{<file>}{<page>}{<page_box>}{<out_file>}
\def\tcizIntrProcess#1#2#3#4{%
  \begingroup
    \edef\tciz@imgfile{#1}%
    \edef\tciz@outfile{#4}%
    \edef\tciz@page{#2}%
    \edef\tciz@pagebox{#3}%
    \tciz@get@bbox
    \tciz@write@out
  \endgroup
}

%% \tciz@get@bbox
% Obtains the bbox of the target image.
\def\tciz@get@bbox{%
  \edef\tciz@tmpa{%
    \ifx\tciz@page\empty\else page \tciz@page\space\fi
    \tciz@pagebox}%
  \pdfximage\tciz@tmpa{\tciz@imgfile}%
  \edef\tciz@bbox{%
    \pdfximagebbox\pdflastximage 1 \space
    \pdfximagebbox\pdflastximage 2 \space
    \pdfximagebbox\pdflastximage 3 \space
    \pdfximagebbox\pdflastximage 4}%
}

%% \tciz@write@out
% Writes the result file.
\def\tciz@write@out{%
  \begingroup
    \immediate\openout\tciz@out=\tciz@outfile\relax
    \immediate\write\tciz@out{%
      \string\tcizIntrResult{\tciz@bbox}}%
    \immediate\closeout\tciz@out
  \endgroup
}

%% \tciz@dummy@dvi
% The desired procedure requires features that are available
% only in PDF-mode. MetaPost that spawned pdfTeX, however,
% expects that there will be a DVI file output as result.
% Thus I prepare a dummy DVI file to fake "output".
% Here is the hex-dump of the file.
\edef\tciz@dummy@dvi{\pdfunescapehex{%
F702018392C01C3B0000000003E8008B%
00000001000000000000000000000000%
00000000000000000000000000000000%
0000000000000000FFFFFFFF8D840000%
0001000000018E8CF80000000F018392%
C01C3B0000000003E800000000000000%
0100010001F90000004802DFDFDFDFDF%
}}

%% \tciz@write@dvi
% Writes the dummy DVI file.
\def\tciz@write@dvi{%
  \immediate\openout\tciz@out=\jobname.dvi\relax
  \immediate\write\tciz@out{\tciz@dummy@dvi}%
  \immediate\closeout\tciz@out
}

%--------------------------------------- done
\tcizIRestore
\endinput
%% EOF

test.tex

% LaTeX document
\documentclass[a4paper,dvipdfmx]{article}% dvipdfmx!
\usepackage{graphicx}
% Load it after graphicx.
\usepackage{tcpagebox}
%\includegraphics[width=2cm]{testimg.pdf}
\begin{document}

% 'pagebox' is respected. (.xbb file is not used.)
\includegraphics[width=2cm,pagebox=mediabox]{image.pdf}
\includegraphics[width=2cm,page=2,pagebox=artbox]{image.pdf}

% When 'pagebox' is absent, the command will work exactly
% the same when tcpagebox is not loaded.
% Note that 'page' key is not (fully) supported in some old
% version of the dvipdfmx driver.
\includegraphics[width=2cm]{image.pdf}
\includegraphics[width=2cm,page=2]{image.pdf}

\end{document}