LaTeX: To use priview package ('tightpage' option) with dvipdfmx

prdvipdfmx.def

%
% prdvipdfmx.def
%
%% Avoids duplicate loading.
\csname bxpw@prdvipdfmx@loaded\endcsname
\def\bxpw@prdvipdfmx@loaded{\endinput}
%% If the engine is XeTeX or pdfTeX/LuaTeX then quits.
\@tempswatrue
\ifx\XeTeXversion\@undefined\else \@tempswafalse \fi
\ifx\pdfoutput\@undefined\else
  \ifnum\pdfoutput>\z@  \@tempswafalse \fi
\fi
\if@tempswa\else \expandafter\endinput\fi\relax
%% If prtightpage.def is already loaded, it's too late.
\ifx\pr@bbadjust\@undefined\else
  \PackageError{preview}%
   {'dvipdfmx' must be specified earlier}\@ehc
\expandafter\endinput\fi\relax
%% Sets \pr@graphicstype.
\let\pr@graphicstype\m@ne
%% Interrupts the process of 'tightpage' option.
\let\bxpw@default@ds\default@ds
\def\default@ds{%
  \ifnum\pr@graphicstype=\m@ne
    \def\bxpw@tightpage{tightpage}%
  \fi
  \ifx\CurrentOption\bxpw@tightpage
    \bxpw@dispatch
  \else \bxpw@default@ds
  \fi}
%% \bxpw@dispatch
% Dispatched when 'tightpage' option is found.
\def\bxpw@dispatch{%
%
  \typeout{Preview: (dvipdfmx)}%
%% Same as in prtightpage.def
\ifx\PreviewBorder\@undefined
  \newdimen\PreviewBorder
  \PreviewBorder=0.50001bp
\fi
\ifx\PreviewBbAdjust\@undefined
  \def\PreviewBbAdjust{-\PreviewBorder -\PreviewBorder
    \PreviewBorder \PreviewBorder}
\fi
%% if active
\ifPreview\bxpw@dispatch@active \fi
%
}
\def\bxpw@dispatch@active{%
%
%% Same as in prtightpage.def
\def\pr@nextbb{\edef\next{\next\space\number\dimen@}%
  \expandafter\xdef\csname pr@bb@%
    \romannumeral\count@\endcsname{\the\dimen@}%
  \advance\count@\@ne\ifnum\count@<5
  \afterassignment\pr@nextbb\dimen@=\fi}%
\global\let\pr@bbadjust\@empty
\pr@addto@front\pr@ship@end{\begingroup
  \let\next\@gobble
  \count@\@ne\afterassignment\pr@nextbb
  \dimen@\PreviewBbAdjust
  \ifx\pr@bbadjust\next
  \else \global\let\pr@bbadjust\next
  \typeout{Preview: Tightpage \pr@bbadjust}%
  \fi\endgroup}%
%% post-shipout process for dvipdfmx
  \g@addto@macro\pr@ship@end{\dimen@\ht\pr@box
    \ifdim\dimen@<\z@ \dimen@\z@\fi
    \advance\dimen@\pr@bb@iv
    \dimen@ii=\dimen@
    \voffset=-1in
    \advance\voffset\dimen@
    \advance\voffset-\ht\pr@box
    \dimen@\dp\pr@box
    \ifdim\dimen@<\z@ \dimen@\z@\fi
    \advance\dimen@-\pr@bb@ii
    \advance\dimen@\dimen@ii
    \paperheight\dimen@
    \dimen@\wd\pr@box
    \ifdim\dimen@<\z@ \dimen@=\z@\fi
    \advance\dimen@-\pr@bb@i
    \advance\dimen@\pr@bb@iii
    \paperwidth\dimen@
    \setbox\pr@box\hbox{%
      \special{papersize=\the\paperwidth,\the\paperheight}%
      \box\pr@box}%
    \hoffset=-1in
    \advance\hoffset-\pr@bb@i
    \let\pr@offset@override\@empty}%
%
}
%% all done
\endinput

test-preview.tex

\documentclass[a4paper]{article}
\usepackage[active,dvipdfmx,tightpage]{preview} % add 'dvipdfmx'
\begin{document}
\begin{preview}
Happy {\TeX}ing!!
\end{preview}
\end{document}