preview.dtx.svn-base

moses开源的机器翻译系统

  \PreviewOpen[][\def\dt@ptrue{\m@ne=\m@ne}\noindent#1]\[%
  \PreviewClose\]%
  \PreviewEnvironment[][\noindent#1]{eqnarray}%
  \PreviewEnvironment[][\noindent#1]{eqnarray*}%
  \PreviewEnvironment{displaymath}%
}}
%    \end{macrocode}
%
% The |textmath| option.  Some folderol in order to define the active
% |$|
% math mode delimiter.  \cmd\pr@textmathcheck is used for checking
% whether we have a single |$| or double |$$|.
% In the latter case, we enter display math (this sort of display math
% is not allowed inside of \LaTeX\ because of inconsistent spacing,
% but surprisingly many people use it nevertheless).  Strictly
% speaking, this is incorrect, since not every
% |$$| actually means display math.  For example, |\hbox{$$}| will
% because of restricted horizontal mode rather yield an empty text
% math formula.  Since our implementation moved the sequence inside of
% a |\vbox|, the interpretation will change.  People should just not
% enter rubbish like that.
%    \begin{macrocode}
\begingroup
\def\next#1#2{%
  \endgroup
  \DeclareOption{textmath}{%
    \PreviewEnvironment{math}%
    \preview@delay{\ifx#1\@undefined \let#1=$%$
      \fi\catcode`\$=\active
      \ifx\xyreuncatcodes\@undefined\else
        \makeatother\xyreuncatcodes\makeatletter\fi}%
    \pr@advise@ship\(\pr@endaftergroup{}% \)
    \pr@advise@ship#1{\@firstoftwo{\let#1=#2%
        \futurelet\reserved@a\pr@textmathcheck}}{}}%
  \def\pr@textmathcheck{\expandafter\pr@endaftergroup
    \ifx\reserved@a#1{#2#2}\expandafter\@gobbletwo\fi#2}}
\lccode`\~=`\$
\lowercase{\expandafter\next\expandafter~}%
  \csname pr@\string$%$
  \endcsname
%</!active>
%    \end{macrocode}
% \begin{macro}{\pr@endaftergroup}
%   This justs ends the box after the group opened by |#1| is closed
%   again.
%    \begin{macrocode}
%<*active>
\def\pr@endaftergroup#1{#1\aftergroup\pr@endbox}
%</active>
%    \end{macrocode}
% \end{macro}
%
% The |graphics| option.
%    \begin{macrocode}
%<*!active>
\DeclareOption{graphics}{%
  \PreviewMacro[*[[!]{\includegraphics}%]]
}
%    \end{macrocode}
% The |floats| option.  The complications here are merely to spare us
% bug reports about broken document classes that use |\let| on
% |\endfigure| and similar.  Notable culprits that have not been
% changed in years in spite of reports are |elsart.cls| and
% |IEEEtran.cls|.  Complain when you are concerned.
%    \begin{macrocode}
\def\pr@floatfix#1#2{\ifx#1#2%
  \ifx#1\@undefined\else
  \PackageWarningNoLine{preview}{%
Your document class has a bad definition^^J
of \string#1, most likely^^J
\string\let\string#1=\string#2^^J
which has now been changed to^^J
\string\def\string#1{\string#2}^^J
because otherwise subsequent changes to \string#2^^J
(like done by several packages changing float behaviour)^^J
can't take effect on \string#1.^^J
Please complain to your document class author}%
  \def#1{#2}\fi\fi}
\begingroup
\def\next#1#2{\endgroup
  \DeclareOption{floats}{%
    \pr@floatfix\endfigure\end@float
    \pr@floatfix\endtable\end@float
    \pr@floatfix#1\end@dblfloat
    \pr@floatfix#2\end@dblfloat
    \PreviewSnarfEnvironment[![]{@float}%]
    \PreviewSnarfEnvironment[![]{@dblfloat}%]
  }}
\expandafter\next\csname endfigure*\expandafter\endcsname
  \csname endtable*\endcsname
%    \end{macrocode}
%  The |sections| option.
%    \begin{macrocode}
\DeclareOption{sections}{%
  \PreviewMacro[!!!!!!*[!]{\@startsection}%]
}
%    \end{macrocode}
% We now interpret any further options as driver files we load.  Note
% that these driver files are loaded even when |preview| is not
% active.  The reason is that they might define commands (like
% \cmd{\PreviewCommand}) that should be available even in case of an
% inactive package.  Large parts of the |preview| package will not
% have been loaded in this case: you have to cater for that.
%    \begin{macrocode}
\DeclareOption*
   {\InputIfFileExists{pr\CurrentOption.def}{}{\OptionNotUsed}}
%    \end{macrocode}
%
% \subsection{Preview attaching commands}
% \begin{macro}{\PreviewMacro}
%   As explained above. Detect possible |*| and call appropriate
%   macro.
%    \begin{macrocode}
\def\PreviewMacro{\@ifstar\pr@starmacro\pr@macro}
%    \end{macrocode}
% The version without |*| is now rather straightforward.
% \begin{macro}{\pr@macro}
% \begin{macro}{\pr@domacro}
% \begin{macro}{\pr@macroii}
% \begin{macro}{\pr@endmacro}
%    \begin{macrocode}
\long\def\pr@domacro#1#2{%
   \long\def\next##1{#2}%
   \pr@callafter\next#1]\pr@endparse}
\newcommand\pr@macro[1][]{%
   \toks@{\pr@domacro{#1}}%
   \long\edef\next[##1]##2{%
    \noexpand\pr@advise@ship{##2}{\the\toks@{##1\noexpand\pr@endbox}}{}}%
   \@ifnextchar[\next\pr@macroii}
\def\pr@macroii{\next[##1]}
\long\def\pr@endmacro#1{#1\pr@endbox}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{macro}{PreviewMacro*}
% \begin{macro}{\pr@protect@domacro}
% \begin{macro}{\pr@starmacro}
%   The version with |*| has to parse the arguments, then throw them
%   away.  Some internal macros first, then the interface call.
%    \begin{macrocode}
\long\def\pr@protect@domacro#1#2{\pr@protect{%
    \long\def\next##1{#2}%
    \pr@callafter\next#1]\pr@endparse}}
\newcommand\pr@starmacro[1][]{\toks@{\pr@protect@domacro{#1}}%
    \long\edef\next[##1]##2{%
      \noexpand\pr@advise##2{\the\toks@{##1}}}%
    \@ifnextchar[\next{\next[]}}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{macro}{\PreviewOpen}
%   As explained above. Detect possible |*| and call appropriate macro.
%    \begin{macrocode}
\def\PreviewOpen{\@ifstar\pr@starmacro\pr@open}
%    \end{macrocode}
% The version without |*| is now rather straightforward.
% \begin{macro}{\pr@open}
%    \begin{macrocode}
\newcommand\pr@open[1][]{%
   \toks@{\pr@domacro{#1}}%
   \long\edef\next[##1]##2{%
     \noexpand\pr@advise##2{\begingroup
     \noexpand\pr@protect@ship
        {\the\toks@{\begingroup\aftergroup\noexpand\pr@endbox##1}}%
        {\endgroup}}}%
   \@ifnextchar[\next\pr@macroii}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \begin{macro}{\PreviewClose}
%   As explained above. Detect possible |*| and call appropriate
%   macro.
%    \begin{macrocode}
\def\PreviewClose{\@ifstar\pr@starmacro\pr@close}
%    \end{macrocode}
% The version without |*| is now rather straightforward.
% \begin{macro}{\pr@close}
%    \begin{macrocode}
\newcommand\pr@close[1][]{%
  \toks@{\pr@domacro{#1}}%
  \long\edef\next[##1]##2{%
   \noexpand\pr@advise{##2}{\the\toks@{##1\endgroup}}}%
   \@ifnextchar[\next\pr@macroii}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \begin{macro}{\PreviewEnvironment}
%   Actually, this ignores any syntax argument.  But don't tell
%   anybody.  Except for the |*|~variant, it respects (actually
%   ignores) any argument!  Of course, we'll need to deactivate
%   |\end{|\meta{environment}|}| as well.
%    \begin{macrocode}
\def\PreviewEnvironment{\@ifstar\pr@starenv\pr@env}
\newcommand\pr@starenv[1][]{\toks@{\pr@starmacro[{#1}]}%
  \long\edef\next##1##2{%
    \the\toks@[{##2}]##1}%
  \begingroup\pr@starenvii}
\newcommand\pr@starenvii[2][]{\endgroup
  \expandafter\next\csname#2\endcsname{#1}%
  \expandafter\pr@starmacro\csname end#2\endcsname}
\newcommand\pr@env[1][]{%
   \toks@{\pr@domacro{#1}}%
   \long\edef\next[##1]##2{%
   \noexpand\expandafter\noexpand\pr@advise@ship
     \noexpand\csname##2\noexpand\endcsname{\the\toks@
      {\begingroup\aftergroup\noexpand\pr@endbox##1}}{\endgroup}}%
   \@ifnextchar[\next\pr@macroii %]
 }
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\PreviewSnarfEnvironment}
%   This is a nuisance since we have to advise \emph{both} the
%   environment and its end.
%    \begin{macrocode}
\newcommand{\PreviewSnarfEnvironment}[2][]{%
  \expandafter\pr@advise
   \csname #2\endcsname{\pr@snarfafter{#1}}%
 \expandafter\pr@advise
   \csname end#2\endcsname{\pr@endsnarf}}
%</!active>
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\pr@snarfafter}
% \begin{macro}{\pr@startsnarf}
% \begin{macro}{\pr@endsnarf}
%   Ok, this looks complicated, but we have to start a group in order
%   to be able to hook \cmd{\pr@endbox} into the game only when
%   \cmd{\ifpr@outer} has triggered the start.  And we need to get our
%   start messages out before parsing the arguments.
%    \begin{macrocode}
%<*active>
\let\pr@endsnarf\relax
\long\def\pr@snarfafter#1{\ifpr@outer
     \pr@ship@start
     \let\pr@ship@start\relax
     \let\pr@endsnarf\endgroup
   \else
     \let\pr@endsnarf\relax
   \fi
  \pr@protect{\pr@callafter\pr@startsnarf#1]\pr@endparse}}
\def\pr@startsnarf#1{#1\begingroup
   \pr@startbox{\begingroup\aftergroup\pr@endbox}{\endgroup}%
   \ignorespaces}
%</active>
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \begin{macro}{\pr@ship@start}
% \begin{macro}{\pr@ship@end}
%   The hooks \cmd{\pr@ship@start} and \cmd{\pr@ship@end} can be added
%   to by option files by the help of the \cmd{\g@addto@macro} command
%   from \LaTeX, and by the \cmd{\pr@addto@front} command from
%   |preview.sty| itself.  They are called just before starting to
%   process some preview, and just after it.  Here is the policy for
%   adding to them: \cmd{\pr@ship@start} is called inside of the vbox
%   |\pr@box| before typeset material gets produced.  It is, however,
%   preceded by a break command that is intended for usage in
%   \cmd{\vsplit}, so that any following glue might disappear.  In
%   case you want to add any material on the list, you have to precede
%   it with \cmd{\unpenalty} and have to follow it with \cmd{\break}.
%   You have make sure that under no circumstances any other legal
%   breakpoints appear before that, and your material should
%   contribute no nonzero dimensions to the page.  For the policies of
%   the \cmd{\pr@ship@end} hook, see the description on
%   page~\pageref{sec:prshipend}.
%    \begin{macrocode}
%<*!active>
\let\pr@ship@start\@empty
\let\pr@ship@end\@empty
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \begin{environment}{preview}
% \begin{environment}{nopreview}
%   First we write the definitions of these environments when
%   |preview| is inactive.  We will redefine them if |preview| gets
%   activated.
%    \begin{macrocode}
\newenvironment{preview}{\ignorespaces}{\ifhmode\unskip\fi}
\newenvironment{nopreview}{\ignorespaces}{\ifhmode\unskip\fi}
%    \end{macrocode}
% \end{environment}
% \end{environment}
%
% We now process the options and finish in case we are not active.
%    \begin{macrocode}
\ProcessOptions\relax
\ifPreview\else\expandafter\endinput\fi
%</!active>
%    \end{macrocode}
% Now for the redefinition of the |preview| and |endpreview|
% environments:
%    \begin{macrocode}
%<*active>
\renewenvironment{preview}{\begingroup
   \pr@startbox{\begingroup\aftergroup\pr@endbox}%
               {\endgroup}%
   \ignorespaces}%
   {\ifhmode\unskip\fi\endgroup}
\renewenvironment{nopreview}{\pr@outerfalse\ignorespaces}%
  {\ifhmode\unskip\fi}
%    \end{macrocode}
% Let the output routine throw everything gathered regularly away.
% Start with all float boxes, continue with output box, pack
% everything afloat from \cmd{\@currlist} back into \cmd{\@freelist}.
%    \begin{macrocode}
\output{\def\@elt#1{\global\setbox#1=\box\voidb@x}%