--- /dev/null
+% \iffalse
+%% The preview style for extracting previews from LaTeX documents.
+%% Developed as part of AUCTeX <URL:http://www.gnu.org/software/auctex>.
+%
+% Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006,
+% 2010 Free Software Foundation
+%
+% 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 3 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., 51 Franklin St, Fifth Floor,
+% Boston, MA 02110-1301 USA
+% \fi
+% \CheckSum{1758}
+% \GetFileInfo{preview.sty}
+% \date{\filedate}
+% \author{David Kastrup\thanks{\texttt{dak@gnu.org}}}
+% \title{The \texttt{preview} Package for \LaTeX\\Version \fileversion}
+% \maketitle
+% \section{Introduction}
+% The main purpose of this package is the extraction of certain
+% environments (most notably displayed formulas) from \LaTeX\ sources
+% as graphics. This works with DVI files postprocessed by either
+% Dvips and Ghostscript or dvipng, but it also works when you are
+% using PDF\TeX\ for generating PDF files (usually also postprocessed
+% by Ghostscript).
+%
+% Current uses of the package include the \previewlatex\ package for
+% WYSIWYG functionality in the AUC\TeX\ editing environment,
+% generation of previews in LyX, as part of the operation of the
+% ps4pdf package, the tbook XML system and some other tools.
+%
+% Producing EPS files with Dvips and its derivatives using the
+% \texttt{-E} option is not a good alternative: People make do by
+% fiddling around with |\thispagestyle{empty}| and hoping for the best
+% (namely, that the specified contents will indeed fit on single
+% pages), and then trying to guess the baseline of the resulting code
+% and stuff, but this is at best dissatisfactory. The preview package
+% provides an easy way to ensure that exactly one page per request
+% gets shipped, with a well-defined baseline and no page decorations.
+% While you still can use the preview package with the `classic'
+% \begin{quote}
+% |dvips -E -i|
+% \end{quote}
+% invocation, there are better ways available that don't rely on Dvips
+% not getting confused by PostScript specials.
+%
+% For most applications, you'll want to make use of the |tightpage|
+% option. This will embed the page dimensions into the PostScript or
+% PDF code, obliterating the need to use the |-E -i| options to Dvips.
+% You can then produce all image files with a single run of
+% Ghostscript from a single PDF or PostScript (as opposed to EPS)
+% file.
+%
+% Various options exist that will pass \TeX\ dimensions and other
+% information about the respective shipped out material (including
+% descender size) into the log file, where external applications might
+% make use of it.
+%
+% The possibility for generating a whole set of graphics with a single
+% run of Ghostscript (whether from \LaTeX\ or PDF\LaTeX) increases
+% both speed and robustness of applications. It is also feasible to
+% use dvipng on a DVI file with the options
+% \begin{quote}
+% |-picky -noghostscript|
+% \end{quote}
+% to omit generating any image file that requires Ghostscript, then
+% let a script generate all missing files using Dvips/Ghostscript.
+% This will usually speed up the process significantly.
+%
+% \section{Package options}
+% The package is included with the customary
+% \begin{quote}
+% |\usepackage|\oarg{options}|{preview}|
+% \end{quote}
+% You should usually load this package as the last one, since it
+% redefines several things that other packages may also provide.
+%
+% The following options are available:
+% \begin{description}
+% \item[|active|] is the most essential option. If this option is not
+% specified, the |preview| package will be inactive and the document
+% will be typeset as if the |preview| package were not loaded,
+% except that all declarations and environments defined by the
+% package are still legal but have no effect. This allows defining
+% previewing characteristics in your document, and only activating
+% them by calling \LaTeX\ as
+% \begin{quote}
+% \raggedright
+% |latex '\PassOptionsToPackage{active}{preview}| |\input|\marg{filename}|'|
+% \end{quote}
+% \item[|noconfig|] Usually the file |prdefault.cfg| gets loaded
+% whenever the |preview| package gets activated. |prdefault.cfg| is
+% supposed to contain definitions that can cater for otherwise bad
+% results, for example, if a certain document class would otherwise
+% lead to trouble. It also can be used to override any settings
+% made in this package, since it is loaded at the very end of it.
+% In addition, there may be configuration files specific for certain
+% |preview| options like |auctex| which have more immediate needs.
+% The |noconfig| option suppresses loading of those option files,
+% too.
+% \item[|psfixbb|] Dvips determines the bounding boxes from the
+% material in the DVI file it understands. Lots of PostScript
+% specials are not part of that. Since the \TeX\ boxes do not make
+% it into the DVI file, but merely characters, rules and specials
+% do, Dvips might include far too small areas. The option |psfixbb|
+% will include |/dev/null| as a graphic file in the ultimate upper
+% left and lower right corner of the previewed box. This will make
+% Dvips generate an appropriate bounding box.
+% \item[|dvips|] If this option is specified as a class option or to
+% other packages, several packages pass things like page size
+% information to Dvips, or cause crop marks or draft messages
+% written on pages. This seriously hampers the usability of
+% previews. If this option is specified, the changes will be undone
+% if possible.
+% \item[|pdftex|] If this option is set, PDF\TeX\ is assumed as the
+% output driver. This mainly affects the |tightpage| option.
+% \item[|xetex|] If this option is set, Xe\TeX\ is assumed as the
+% output driver. This mainly affects the |tightpage| option.
+% \item[|displaymath|] will make all displayed math environments
+% subject to preview processing. This will typically be the most
+% desired option.
+% \item[|floats|] will make all float objects subject to preview
+% processing. If you want to be more selective about what floats to
+% pass through to a preview, you should instead use the
+% \cmd{\PreviewSnarfEnvironment} command on the floats you want to
+% have previewed.
+% \item[|textmath|] will make all text math subject to previews.
+% Since math mode is used throughly inside of \LaTeX\ even for other
+% purposes, this works by redefining \cmd\(, \cmd\)
+% and |$| and the |math| environment (apparently some people use
+% that). Only occurences of these text math delimiters in later
+% loaded packages and in the main document will thus be affected.
+% \item[|graphics|] will subject all \cmd{\includegraphics} commands
+% to a preview.
+% \item[|sections|] will subject all section headers to a preview.
+% \item[|delayed|] will delay all activations and redefinitions the
+% |preview| package makes until |\||begin{document}|. The purpose
+% of this is to cater for documents which should be subjected to the
+% |preview| package without having been prepared for it. You can
+% process such documents with
+% \begin{quote}
+% |latex '\RequirePackage[active,delayed,|\meta{options}|]{preview}|
+% |\input|\marg{filename}|'|
+% \end{quote}
+% This relaxes the requirement to be loading the |preview| package
+% as last package.
+% \item[\meta{driver}] loads a special driver file
+% |pr|\meta{driver}|.def|. The remaining options are implemented
+% through the use of driver files.
+% \item[|auctex|] This driver will produce fake error messages at the
+% start and end of every preview environment that enable the Emacs
+% package \previewlatex\ in connection with AUC\TeX\ to pinpoint
+% the exact source location where the previews have originated.
+% Unfortunately, there is no other reliable means of passing the
+% current \TeX\ input position \emph{in} a line to external
+% programs. In order to make the parsing more robust, this option
+% also switches off quite a few diagnostics that could be
+% misinterpreted.
+%
+% You should not specify this option manually, since it will only be
+% needed by automated runs that want to parse the pseudo error
+% messages. Those runs will then use \cmd{\PassOptionsToPackage} in
+% order to effect the desired behaviour. In addition,
+% |prauctex.cfg| will get loaded unless inhibited by the |noconfig|
+% option. This caters for the most frequently encountered
+% problematic commands.
+% \item[|showlabels|] During the editing process, some people like to
+% see the label names in their equations, figures and the like. Now
+% if you are using Emacs for editing, and in particular
+% \previewlatex, I'd strongly recommend that you check out the
+% Ref\TeX\ package which pretty much obliterates the need for this
+% kind of functionality. If you still want it, standard \LaTeX\
+% provides it with the |showkeys| package, and there is also the
+% less encompassing |showlabels| package. Unfortunately, since
+% those go to some pain not to change the page layout and spacing,
+% they also don't change |preview|'s idea of the \TeX\ dimensions of
+% the involved boxes. So if you are using |preview| for determing
+% bounding boxes, those packages are mostly useless. The option
+% |showlabels| offers a substitute for them.
+% \item[|tightpage|] It is not uncommon to want to use the results of
+% |preview| as graphic images for some other application. One
+% possibility is to generate a flurry of EPS files with
+% \begin{quote}
+% |dvips -E -i -Pwww -o| \meta{outputfile}|.000| \meta{inputfile}
+% \end{quote}
+% However, in case those are to be processed further into graphic
+% image files by Ghostscript, this process is inefficient since all
+% of those files need to be processed one by one. In addition, it
+% is necessary to extract the bounding box comments from the EPS
+% files and convert them into page dimension parameters for
+% Ghostscript in order to avoid full-page graphics. This is not
+% even possible if you wanted to use Ghostscript in a~\emph{single}
+% run for generating the files from a single PostScript file, since
+% Dvips will in that case leave no bounding box information
+% anywhere.
+%
+% The solution is to use the |tightpage| option. That way a single
+% command line like
+% \begin{quote}
+% \raggedright
+% \texttt{gs -sDEVICE=png16m -dTextAlphaBits=4 -r300
+% -dGraphicsAlphaBits=4 -dSAFER -q -dNOPAUSE
+% -sOutputFile=\meta{outputfile}\%d.png \meta{inputfile}.ps}
+% \end{quote}
+% will be able to produce tight graphics from a single PostScript
+% file generated with Dvips \emph{without} use of the options
+% |-E -i|, in a single run.
+%
+% The |tightpage| option actually also works when using the |pdftex|
+% option and generating PDF files with PDF\TeX. The resulting PDF
+% file has separate page dimensions for every page and can directly
+% be converted with one run of Ghostscript into image files.
+%
+% If neither |dvips| or |pdftex| have been specified, the
+% corresponding option will get autodetected and invoked.
+%
+% If you need this in a batch environment where you don't want to
+% use |preview|'s automatic extraction facilities, no problem: just
+% don't use any of the extraction options, and wrap everything to be
+% previewed into |preview| environments. This is how LyX does its
+% math previews.
+%
+% If the pages under the |tightpage| option are just too tight, you
+% can adjust by setting the length |\PreviewBorder| to a different
+% value by using \cmd{\setlength}. The default value is
+% |0.50001bp|, which is half of a usual PostScript point, rounded
+% up. If you go below this value, the resulting page size may drop
+% below |1bp|, and Ghostscript does not seem to like that. If you
+% need finer control, you can adjust the bounding box dimensions
+% individually by changing the macro |\PreviewBbAdjust| with the
+% help of |\renewcommand|. Its default value is
+% \begin{quote}
+% \raggedright
+% |\newcommand| |\PreviewBbAdjust|
+% |{-\PreviewBorder| |-\PreviewBorder|
+% |\PreviewBorder| |\PreviewBorder}|
+% \end{quote}
+% This adjusts the left, lower, right and upper borders by the given
+% amount. The macro must contain 4~\TeX\ dimensions after another,
+% and you may not omit the units if you specify them explicitly
+% instead of by register. PostScript points have the unit~|bp|.
+% \item[|lyx|] This option is for the sake of LyX developers. It will
+% output a few diagnostics relevant for the sake of LyX' preview
+% functionality (at the time of writing, mostly implemented for math
+% insets, in versions of LyX starting with 1.3.0).
+% \item[|counters|] This writes out diagnostics at the start and the
+% end of previews. Only the counters changed since the last output
+% get written, and if no counters changed, nothing gets written at
+% all. The list consists of counter name and value, both enclosed
+% in |{}| braces, followed by a space. The last such pair is
+% followed by a colon (|:|) if it is at the start of the preview
+% snippet, and by a period (|.|) if it is at the end. The order of
+% different diagnostics like this being issued depends on the order
+% of the specification of the options when calling the package.
+%
+% Systems like \previewlatex\ use this for keeping counters accurate
+% when single previews are regenerated.
+% \item[|footnotes|] This makes footnotes render as previews, and only
+% as their footnote symbol. A convenient editing feature inside of
+% Emacs.
+% \end{description}
+% The following options are just for debugging purposes of the package
+% and similar to the corresponding \TeX\ commands they allude to:
+% \begin{description}
+% \item[|tracingall|] causes lots of diagnostic output to appear in
+% the log file during the preview collecting phases of \TeX's
+% operation. In contrast to the similarly named \TeX\ command, it
+% will not switch to |\errorstopmode|, nor will it change the
+% setting of |\tracingonline|.
+% \item[|showbox|] This option will show the contents of the boxes
+% shipped out to the DVI files. It also sets |\showboxbreadth| and
+% |\showboxdepth| to their maximum values at the end of loading this
+% package, but you may reset them if you don't like that.
+% \end{description}
+% \section{Provided Commands}
+% \DescribeEnv{preview} The |preview| environment causes its contents
+% to be set as a single preview image. Insertions like figures and
+% footnotes (except those included in minipages) will typically lead
+% to error messages or be lost. In case the |preview| package has not
+% been activated, the contents of this environment will be typeset
+% normally.
+%
+% \DescribeEnv{nopreview} The |nopreview| environment will cause its
+% contents not to undergo any special treatment by the |preview|
+% package. When |preview| is active, the contents will be discarded
+% like all main text that does not trigger the |preview| hooks. When
+% |preview| is not active, the contents will be typeset just like the
+% main text.
+%
+% Note that both of these environments typeset things as usual when
+% preview is not active. If you need something typeset conditionally,
+% use the \cmd{\ifPreview} conditional for it.
+%
+% \DescribeMacro{\PreviewMacro} If you want to make a macro like
+% \cmd{\includegraphics} (actually, this is what is done by the
+% |graphics| option to |preview|) produce a preview image, you put a
+% declaration like
+% \begin{quote}
+% |\PreviewMacro[*[[!]{\includegraphics}|
+% \end{quote}
+% or, more readable,
+% \begin{quote}
+% |\PreviewMacro[{*[][]{}}]{\includegraphics}|
+% \end{quote}
+% into your preamble. The optional argument to \cmd{\PreviewMacro}
+% specifies the arguments \cmd{\includegraphics} accepts, since this
+% is necessary information for properly ending the preview box. Note
+% that if you are using the more readable form, you have to enclose
+% the argument in a |[{| and |}]| pair. The inner braces are
+% necessary to stop any included |[]| pairs from prematurely ending
+% the optional argument, and to make a single |{}|
+% denoting an optional argument not get stripped away by \TeX's
+% argument parsing.
+%
+% The letters simply mean
+% \begin{description}
+% \item[|*|] indicates an optional |*| modifier, as in
+% |\includegraphics*|.
+% \item[|[|]^^A]
+% indicates an optional argument in brackets. This syntax
+% is somewhat baroque, but brief.
+% \item[{|[]|}] also indicates an optional argument in brackets. Be
+% sure to have encluded the entire optional argument specification
+% in an additional pair of braces as described above.
+% \item[|!|] indicates a mandatory argument.
+% \item[|\char`{\char`}|] indicates the same. Again, be sure to have
+% that additional level of braces around the whole argument
+% specification.
+% \item[|?|\meta{delimiter}\marg{true case}\marg{false case}] is a
+% conditional. The next character is checked against being equal to
+% \meta{delimiter}. If it is, the specification \meta{true case} is
+% used for the further parsing, otherwise \meta{false case} will be
+% employed. In neither case is something consumed from the input,
+% so \marg{true case} will still have to deal with the upcoming
+% delimiter.
+% \item[|@|\marg{literal sequence}] will insert the given sequence
+% literally into the executed call of the command.
+% \item[|-|] will just drop the next token. It will probably be most
+% often used in the true branch of a |?| specification.
+% \item[|\#|\marg{argument}\marg{replacement}] is a transformation
+% rule that calls a macro with the given argument and replacement
+% text on the rest of the argument list. The replacement is used in
+% the executed call of the command. This can be used for parsing
+% arbitrary constructs. For example, the |[]| option could manually
+% be implemented with the option string |?[{#{[#1]}{[{#1}]}}{}|.
+% PStricks users might enjoy this sort of flexibility.
+% \item[|:|\marg{argument}\marg{replacement}] is again a
+% transformation rule. As opposed to |#|, however, the result of
+% the transformation is parsed again. You'll rarely need this.
+% \end{description}
+%
+% There is a second optional argument in brackets that can be used to
+% declare any default action to be taken instead. This is mostly for
+% the sake of macros that influence numbering: you would want to keep
+% their effects in that respect. The default action should use |#1|
+% for referring to the original (not the patched) command with the
+% parsed options appended. Not specifying a second optional argument
+% here is equivalent to specifying~|[#1]|.
+%
+% \DescribeMacro{\PreviewMacro*} A similar invocation
+% \cmd{\PreviewMacro*} simply throws the macro and all of its
+% arguments declared in the manner above away. This is mostly useful
+% for having things like \cmd{\footnote} not do their magic on their
+% arguments. More often than not, you don't want to declare any
+% arguments to scan to \cmd{\PreviewMacro*} since you would want the
+% remaining arguments to be treated as usual text and typeset in that
+% manner instead of being thrown away. An exception might be, say,
+% sort keys for \cmd{\cite}.
+%
+% A second optional argument in brackets can be used to declare any
+% default action to be taken instead. This is for the sake of macros
+% that influence numbering: you would want to keep their effects in
+% that respect. The default action might use |#1| for referring to
+% the original (not the patched) command with the parsed options
+% appended. Not specifying a second optional argument here is
+% equivalent to specifying~|[]| since the command usually gets thrown
+% away.
+%
+% As an example for using this argument, you might want to specify
+% \begin{quote}
+% |\PreviewMacro*\footnote[{[]}][#1{}]|
+% \end{quote}
+% This will replace a footnote by an empty footnote, but taking any
+% optional parameter into account, since an optional paramter changes
+% the numbering scheme. That way the real argument for the footnote
+% remains for processing by \previewlatex.
+%
+% \DescribeMacro{\PreviewEnvironment} The macro
+% \cmd{\PreviewEnvironment} works just as \cmd{\PreviewMacro} does,
+% only for environments. \DescribeMacro{\PreviewEnvironment*} And the
+% same goes for \cmd{\PreviewEnvironment*} as compared to
+% \cmd{\PreviewMacro*}.
+%
+% \DescribeMacro{\PreviewSnarfEnvironment} This macro does not typeset
+% the original environment inside of a preview box, but instead
+% typesets just the contents of the original environment inside of the
+% preview box, leaving nothing for the original environment. This has
+% to be used for figures, for example, since they would
+% \begin{enumerate}
+% \item produce insertion material that cannot be extracted to the
+% preview properly,
+% \item complain with an error message about not being in outer par
+% mode.
+% \end{enumerate}
+%
+% \DescribeMacro{\PreviewOpen}
+% \DescribeMacro{\PreviewClose}
+% Those Macros form a matched preview pair. This is for macros that
+% behave similar as \cmd{\begin} and \cmd{\end} of an environment. It
+% is essential for the operation of \cmd{\PreviewOpen} that the macro
+% treated with it will open an additional group even when the preview
+% falls inside of another preview or inside of a |nopreview|
+% environment. Similarly, the macro treated with \cmd{PreviewClose}
+% will close an environment even when inactive.
+%
+% \DescribeMacro{\ifPreview} In case you need to know whether
+% |preview| is active, you can use the conditional \cmd{\ifPreview}
+% together with |\else| and |\fi|.
+%
+% \StopEventually{}
+% \section{The Implementation}
+% Here we go: the start is somewhat obtuse since we figure out version
+% number and date from RCS strings. This should really be done at
+% docstrip time instead. Takers?
+% \begin{macro}{\pr@version}
+% \begin{macrocode}
+%<*style>
+%<*!active>
+\NeedsTeXFormat{LaTeX2e} \def\reserved@a #1#2$#3:
+#4${\xdef#1{\reserved@c #2#4 $}} \def\reserved@c #1 #2${#1}
+\begingroup \catcode`\_=12
+\reserved@a\pr@version $Name: release_11_86 $ \ifx\pr@version\@empty
+\reserved@a\pr@version CVS-$Revision: 1.126 $ \endgroup \else
+ \def\next release_{} \lccode`\_=`.
+ \edef\next{\lowercase{\endgroup
+ \def\noexpand\pr@version{\expandafter\next\pr@version}}} \next \fi
+\reserved@a\next $Date: 2010/02/14 16:19:00 $
+\edef\next{\noexpand\ProvidesPackage{preview}%
+ [\next\space \pr@version\space (AUCTeX/preview-latex)]}
+\next
+% \end{macrocode}
+% \end{macro}
+% Since many parts here will not be needed as long as the package is
+% inactive, we will include them enclosed with |<*active>| and
+% |</active>| guards. That way, we can append all of this stuff at a
+% place where it does not get loaded if not necessary.
+%
+%\begin{macro}{\ifPreview}
+% Setting the \cmd{\ifPreview} command should not be done by the
+% user, so we don't use \cmd{\newif} here. As a consequence, there
+% are no \cmd{\Previewtrue} and \cmd{\Previewfalse} commands.
+% \begin{macrocode}
+\let\ifPreview\iffalse
+%</!active>
+% \end{macrocode}
+%\end{macro}
+%\begin{macro}{\ifpr@outer}
+% We don't allow previews inside of previews. The macro
+% \cmd{\ifpr@outer} can be used for checking whether we are outside
+% of any preview code.
+% \begin{macrocode}
+%<*active>
+\newif\ifpr@outer
+\pr@outertrue
+%</active>
+% \end{macrocode}
+%\end{macro}
+%
+%\begin{macro}{\preview@delay}
+% The usual meaning of \cmd{\preview@delay} is to just echo its
+% argument in normal |preview| operation. If |preview| is inactive,
+% it swallows its argument. If the |delayed| option is active, the
+% contents will be passed to the \cmd{\AtBeginDocument} hook.
+%\begin{macro}{\pr@advise}
+% The core macro for modifying commands is \cmd{\pr@advise}. You
+% pass it the original command name as first argument and what should
+% be executed before the saved original command as second argument.
+%\begin{macro}{\pr@advise@ship}
+% The most often used macro for modifying commands is
+% \cmd{\pr@advise@ship}. It receives three arguments. The first is
+% the macro to modify, the second specifies some actions to be done
+% inside of a box to be created before the original macro gets
+% executed, the third one specifies actions after the original macro
+% got executed.
+%\begin{macro}{\pr@loadcfg}
+% The macro \cmd{\pr@loadcfg} is used for loading in configuration
+% files, unless disabled by the |noconfig| option.
+% \begin{macrocode}
+%<*!active>
+\let\preview@delay=\@gobble
+\let\pr@advise=\@gobbletwo
+\long\def\pr@advise@ship#1#2#3{}
+\def\pr@loadcfg#1{\InputIfFileExists{#1.cfg}{}{}}
+\DeclareOption{noconfig}{\let\pr@loadcfg=\@gobble}
+% \end{macrocode}
+%\begin{macro}{\pr@addto@front}
+% This adds code globally to the front of a macro.
+% \begin{macrocode}
+\long\def\pr@addto@front#1#2{%
+ \toks@{#2}\toks@\expandafter{\the\expandafter\toks@#1}%
+ \xdef#1{\the\toks@}}
+% \end{macrocode}
+% \end{macro}
+% These commands get more interesting when |preview| is active:
+% \begin{macrocode}
+\DeclareOption{active}{%
+ \let\ifPreview\iftrue
+ \def\pr@advise#1{%
+ \expandafter\pr@adviseii\csname pr@\string#1\endcsname#1}%
+ \long\def\pr@advise@ship#1#2#3{\pr@advise#1{\pr@protect@ship{#2}{#3}}}%
+ \let\preview@delay\@firstofone}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\pr@adviseii}
+% Now \cmd{\pr@advise} needs its helper macro. In order to avoid
+% recursive definitions, we advise only macros that are not yet
+% advised. Or, more exactly, we throw away the old advice and only
+% take the new one. We use e\TeX's \cmd{\protected} where available
+% for some extra robustness.
+% \begin{macrocode}
+\long\def\pr@adviseii#1#2#3{\preview@delay{%
+ \ifx#1\relax \let#1#2\fi
+ \toks@{#3#1}%
+ \ifx\@undefined\protected \else \protected\fi
+ \long\edef#2{\the\toks@}}}
+% \end{macrocode}
+%\end{macro}
+%
+% The |delayed| option is easy to implement: this is \emph{not} done
+% with \cmd{\let} since at the course of document processing, \LaTeX\
+% redefines \cmd{\AtBeginDocument} and we want to follow that
+% redefinition.
+% \begin{macrocode}
+\DeclareOption{delayed}{%
+ \ifPreview \def\preview@delay{\AtBeginDocument}\fi
+}
+% \end{macrocode}
+%
+%\begin{macro}{\ifpr@fixbb}
+% Another conditional. \cmd{\ifpr@fixbb} tells us whether we want to
+% surround the typeset materials with invisible rules so that Dvips
+% gets the bounding boxes right for, say, pure PostScript inclusions.
+%
+% If you are installing this on an operating system different from
+% the one |preview| has been developed on, you might want to redefine
+% |\pr@markerbox| in your |prdefault.cfg| file to use a file known to
+% be empty, like |/dev/null| is under Unix. Make this redefinition
+% depend on \cmd{\ifpr@fixbb} since only then |\pr@markerbox| will be
+% defined.
+% \begin{macrocode}
+\newif\ifpr@fixbb
+\pr@fixbbfalse
+\DeclareOption{psfixbb}{\ifPreview%
+ \pr@fixbbtrue
+ \newbox\pr@markerbox
+ \setbox\pr@markerbox\hbox{\special{psfile=/dev/null}}\fi
+}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@graphicstype}
+% The |dvips| option redefines the |bop-hook| to reset the page
+% size.
+% \begin{macrocode}
+\let\pr@graphicstype=\z@
+\DeclareOption{dvips}{%
+ \let\pr@graphicstype\@ne
+ \preview@delay{\AtBeginDvi{%
+ \special{!/preview@version(\pr@version)def}
+ \special{!userdict begin/preview-bop-level 0 def%
+ /bop-hook{/preview-bop-level dup load dup 0 le{/isls false def%
+ /vsize 792 def/hsize 612 def}if 1 add store}bind def%
+ /eop-hook{/preview-bop-level dup load dup 0 gt{1 sub}if
+ store}bind def end}}}}
+% \end{macrocode}
+% The |pdftex| option just sets \cmd{\pr@graphicstype}.
+% \begin{macrocode}
+\DeclareOption{pdftex}{%
+ \let\pr@graphicstype\tw@}
+% \end{macrocode}
+% And so does the |xetex| option.
+% \begin{macrocode}
+\DeclareOption{xetex}{%
+ \let\pr@graphicstype\thr@@}
+%</!active>
+% \end{macrocode}
+% \end{macro}
+% \subsection{The internals}
+%
+% Those are only needed if |preview| is active.
+% \begin{macrocode}
+%<*active>
+% \end{macrocode}
+% \begin{macro}{\pr@snippet}
+% \cmd{\pr@snippet} is the current snippet number. We need a
+% separate counter to \cmd{\c@page} since several other commands
+% might fiddle with the page number.
+% \begin{macrocode}
+\newcount\pr@snippet
+\global\pr@snippet=1
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@protect}
+% This macro gets one argument which is unpacked and executed in
+% typesetting situations where we are not yet inside of a preview.
+% \begin{macrocode}
+\def\pr@protect{\ifx\protect\@typeset@protect
+ \ifpr@outer \expandafter\expandafter\expandafter
+ \@secondoftwo\fi\fi\@gobble}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@protect@ship}
+% Now for the above mentioned \cmd{\pr@protect@ship}. This gets
+% three arguments. The first is what to do at the beginning of the
+% preview, the second what to do at the end, the third is the macro
+% where we stored the original definition.
+%
+% In case we are not in a typesetting situation,
+% \cmd{\pr@protect@ship} leaves the stored macro to fend for its
+% own. No better or worse protection than the original. And we
+% only do anything different when \cmd{\ifpr@outer} turns out to be
+% true.
+% \begin{macrocode}
+\def\pr@protect@ship{\pr@protect{\@firstoftwo\pr@startbox}%
+ \@gobbletwo}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@insert}
+% \begin{macro}{\pr@mark}
+% \begin{macro}{\pr@marks}
+% We don't want insertions to end up on our lists. So we disable
+% them right now by replacing them with the following:
+% \begin{macrocode}
+\def\pr@insert{\begingroup\afterassignment\pr@insertii\count@}
+\def\pr@insertii{\endgroup\setbox\pr@box\vbox}
+% \end{macrocode}
+% Similar things hold for marks.
+% \begin{macrocode}
+\def\pr@mark{{\afterassignment}\toks@}
+\def\pr@marks{{\aftergroup\pr@mark\afterassignment}\count@}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\pr@box}
+% \begin{macro}{\pr@startbox}
+% Previews will be stored in \cmd{\box}\cmd{\pr@box}.
+% \cmd{\pr@startbox} gets two arguments: code to execute immediately
+% before the following stuff, code to execute afterwards. You have
+% to cater for \cmd{\pr@endbox} being called at the right time
+% yourself. We will use a \cmd{\vsplit} on the box later in order
+% to remove any leading glues, penalties and similar stuff. For
+% this reason we start off the box with an optimal break point.
+% \begin{macrocode}
+\newbox\pr@box
+\long\def\pr@startbox#1#2{%
+ \ifpr@outer
+ \toks@{#2}%
+ \edef\pr@cleanup{\the\toks@}%
+ \setbox\pr@box\vbox\bgroup
+ \break
+ \pr@outerfalse\@arrayparboxrestore
+ \let\insert\pr@insert
+ \let\mark\pr@mark
+ \let\marks\pr@marks
+ \expandafter\expandafter\expandafter
+ \pr@ship@start
+ \expandafter\@firstofone
+ \else
+ \expandafter \@gobble
+ \fi{#1}}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\pr@endbox}
+% Cleaning up also is straightforward. If we have to watch the
+% bounding \TeX\ box, we want to remove spurious skips. We also
+% want to unwrap a possible single line paragraph, so that the box
+% is not full line length. We use \cmd{\vsplit} to clean up leading
+% glue and stuff, and we make some attempt of removing trailing
+% ones. After that, we wrap up the box including possible material
+% from \cmd{\AtBeginDvi}. If the |psfixbb| option is active, we
+% adorn the upper left and lower right corners with copies of
+% \cmd{\pr@markerbox}. The first few lines cater for \LaTeX\ hiding
+% things like like the code for \cmd{\paragraph} in \cmd{\everypar}.
+% \begin{macrocode}
+\def\pr@endbox{%
+ \let\reserved@a\relax
+ \ifvmode \edef\reserved@a{\the\everypar}%
+ \ifx\reserved@a\@empty\else
+ \dimen@\prevdepth
+ \noindent\par
+ \setbox\z@\lastbox\unskip\unpenalty
+ \prevdepth\dimen@
+ \setbox\z@\hbox\bgroup\penalty-\maxdimen\unhbox\z@
+ \ifnum\lastpenalty=-\maxdimen\egroup
+ \else\egroup\box\z@ \fi\fi\fi
+ \ifhmode \par\unskip\setbox\z@\lastbox
+ \nointerlineskip\hbox{\unhbox\z@\/}%
+ \else \unskip\unpenalty\unskip \fi
+ \egroup
+ \setbox\pr@box\vbox{%
+ \baselineskip\z@skip \lineskip\z@skip \lineskiplimit\z@
+ \@begindvi
+ \nointerlineskip
+ \splittopskip\z@skip\setbox\z@\vsplit\pr@box to\z@
+ \unvbox\z@
+ \nointerlineskip
+ %\color@setgroup
+ \box\pr@box
+ %\color@endgroup
+ }%
+% \end{macrocode}
+% \begin{macro}{\pr@ship@end}
+% \label{sec:prshipend}At this point, \cmd{\pr@ship@end} gets
+% called. You must not under any circumstances change |\box\pr@box|
+% in any way that would add typeset material at the front of it,
+% except for PostScript header specials, since the front of
+% |\box\pr@box| may contain stuff from \cmd{\AtBeginDvi}.
+% \cmd{\pr@ship@end} contains two types of code additions: stuff
+% that adds to |\box\pr@box|, like the |labels| option does, and
+% stuff that measures out things or otherwise takes a look at the
+% finished |\box\pr@box|, like the |auctex| or |showbox| option do.
+% The former should use \cmd{pr@addto@front} for adding to this
+% hook, the latter use \cmd{g@addto@macro} for adding at the end of
+% this hook.
+%
+% Note that we shift the output box up by its height via
+% \cmd{\voffset}. This has three reasons: first we make sure that
+% no package-inflicted non-zero value of \cmd{\voffset} or
+% \cmd{\hoffset} will have any influence on the positioning of our
+% box. Second we shift the box such that its basepoint will exactly
+% be at the (1in,1in)~mark defined by \TeX. That way we can
+% properly take ascenders into account. And the third reason is
+% that \TeX\ treats a \cmd{\hbox} and a \cmd{\vbox} differently with
+% regard to the treating of its depth. Shifting \cmd{\voffset} and
+% \cmd{\hoffset} can be inhibited by setting |\pr@offset@override|.
+% \begin{macrocode}
+ \pr@ship@end
+ {\let\protect\noexpand
+ \ifx\pr@offset@override\@undefined
+ \voffset=-\ht\pr@box
+ \hoffset=\z@
+ \fi
+ \c@page=\pr@snippet
+ \pr@shipout
+ \ifpr@fixbb\hbox{%
+ \dimen@\wd\pr@box
+ \@tempdima\ht\pr@box
+ \@tempdimb\dp\pr@box
+ \box\pr@box
+ \llap{\raise\@tempdima\copy\pr@markerbox\kern\dimen@}%
+ \lower\@tempdimb\copy\pr@markerbox}%
+ \else \box\pr@box \fi}%
+ \global\advance\pr@snippet\@ne
+ \pr@cleanup
+}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% Oh, and we kill off the usual meaning of \cmd{\shipout} in case
+% somebody makes a special output routine. The following test is
+% pretty much the same as in |everyshi.sty|. One of its implications
+% is that if someone does a \cmd{\shipout} of a \emph{void} box,
+% things will go horribly wrong.
+% \begin{macro}{\shipout}
+% \begin{macrocode}
+\let\pr@shipout=\shipout
+\def\shipout{\deadcycles\z@\bgroup\setbox\z@\box\voidb@x
+ \afterassignment\pr@shipoutegroup\setbox\z@}
+\def\pr@shipoutegroup{\ifvoid\z@ \expandafter\aftergroup\fi \egroup}
+% \end{macrocode}
+% \end{macro}
+% \subsection{Parsing commands}
+% \begin{macro}{\pr@parseit}
+% \begin{macro}{\pr@endparse}
+% \begin{macro}{\pr@callafter}
+% The following stuff is for parsing the arguments of commands we
+% want to somehow surround with stuff. Usage is
+% \begin{quote}
+% \cmd{\pr@callafter}\meta{aftertoken}\meta{parsestring}\cmd{\pr@endparse}\\
+% \qquad\meta{macro}\meta{parameters}
+% \end{quote}
+% \meta{aftertoken} is stored away and gets executed once parsing
+% completes, with its first argument being the parsed material.
+% \meta{parsestring} would be, for example for the
+% \cmd{\includegraphics} macro, |*[[!|, an optional |*| argument
+% followed by two optional arguments enclosed in |[]|, followed by
+% one mandatory argument.
+%
+% For the sake of a somewhat more intuitive syntax, we now support
+% also the syntax |{*[]{}}| in the optional argument. Since \TeX\
+% strips redundant braces, we have to write |[{{}}]| in this syntax
+% for a single mandatory argument. Hard to avoid. We use an
+% unusual character for ending the parsing. The implementation is
+% rather trivial.
+% \begin{macrocode}
+\def\pr@parseit#1{\csname pr@parse#1\endcsname}
+\let\pr@endparse=\@percentchar
+\def\next#1{%
+\def\pr@callafter{%
+ \afterassignment\pr@parseit
+ \let#1= }}
+\expandafter\next\csname pr@parse\pr@endparse\endcsname
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\pr@parse*}
+% Straightforward, same mechanism \LaTeX\ itself employs. We take
+% some care not to pass potential |#| tokens unprotected through
+% macros.
+% \begin{macrocode}
+\long\expandafter\def\csname pr@parse*\endcsname#1\pr@endparse#2{%
+ \begingroup\toks@{#1\pr@endparse{#2}}%
+ \edef\next##1{\endgroup##1\the\toks@}%
+ \@ifstar{\next{\pr@parse@*}}{\next\pr@parseit}}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@parse[}
+% \begin{macro}{\pr@brace}
+% Copies optional parameters in brackets if present. The additional
+% level of braces is necessary to ensure that braces the user might
+% have put to hide a~|]| bracket in an optional argument don't get
+% lost. There will be no harm if such braces were not there at the
+% start.
+% \begin{macrocode}
+\long\expandafter\def\csname pr@parse[\endcsname#1\pr@endparse#2{%
+ \begingroup\toks@{#1\pr@endparse{#2}}%
+ \edef\next##1{\endgroup##1\the\toks@}%
+ \@ifnextchar[{\next\pr@bracket}{\next\pr@parseit}}
+\long\def\pr@bracket#1\pr@endparse#2[#3]{%
+ \pr@parseit#1\pr@endparse{#2[{#3}]}}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\pr@parse]}
+% This is basically a do-nothing, so that we may use the syntax
+% |{*[][]!}| in the optional argument instead of the more concise
+% but ugly |*[[!| which confuses the brace matchers of editors.
+% \begin{macrocode}
+\expandafter\let\csname pr@parse]\endcsname=\pr@parseit
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@parse}
+% \begin{macro}{\pr@parse!}
+% Mandatory arguments are perhaps easiest to parse.
+% \begin{macrocode}
+\long\def\pr@parse#1\pr@endparse#2#3{%
+ \pr@parseit#1\pr@endparse{#2{#3}}}
+\expandafter\let\csname pr@parse!\endcsname=\pr@parse
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\pr@parse?}
+% \begin{macro}{\pr@parsecond}
+% This does an explicit call of |\@ifnextchar| and forks into the
+% given two alternatives as a result.
+% \begin{macrocode}
+\long\expandafter\def\csname pr@parse?\endcsname#1#2\pr@endparse#3{%
+ \begingroup\toks@{#2\pr@endparse{#3}}%
+ \@ifnextchar#1{\pr@parsecond\@firstoftwo}%
+ {\pr@parsecond\@secondoftwo}}
+\def\pr@parsecond#1{\expandafter\endgroup
+ \expandafter\expandafter\expandafter\pr@parseit
+ \expandafter#1\the\toks@}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\pr@parse@}
+% This makes it possible to insert literal material into the
+% argument list.
+% \begin{macrocode}
+ \long\def\pr@parse@#1#2\pr@endparse#3{%
+ \pr@parseit #2\pr@endparse{#3#1}}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@parse-}
+% This will just drop the next token.
+% \begin{macrocode}
+\long\expandafter\def\csname pr@parse-\endcsname
+ #1\pr@endparse#2{\begingroup
+ \toks@{\endgroup\pr@parseit #1\pr@endparse{#2}}%
+ {\aftergroup\the\aftergroup\toks@ \afterassignment}%
+ \let\next= }
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@parse:}
+% The following is a transform rule. A macro is being defined with
+% the given argument list and replacement, and the transformed
+% version replaces the original. The result of the transform is
+% still subject to being parsed.
+% \begin{macrocode}
+\long\expandafter\def\csname pr@parse:\endcsname
+ #1#2#3\pr@endparse#4{\begingroup
+ \toks@{\endgroup \pr@parseit#3\pr@endparse{#4}}%
+ \long\def\next#1{#2}%
+ \the\expandafter\toks@\next}
+% \end{macrocode}
+% \end{macro}
+% \edef\next{\noexpand\begin{macro}{\noexpand
+% \pr@parse\string#}}
+% \next
+% Another transform rule, but this passes the transformed material
+% into the token list.
+% \begin{macrocode}
+\long\expandafter\def\csname pr@parse#\endcsname
+ #1#2#3\pr@endparse#4{\begingroup
+ \toks@{#4}%
+ \long\edef\next##1{\toks@{\the\toks@##1}}%
+ \toks@{\endgroup \pr@parseit#3\pr@endparse}%
+ \long\def\reserved@a#1{{#2}}%
+ \the\expandafter\next\reserved@a}
+%</active>
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Selection options}
+% The |displaymath| option. The |equation| environments in AMS\LaTeX\
+% already do too much before our hook gets to interfere, so we hook
+% earlier. Some juggling is involved to ensure we get the original
+% |\everydisplay| tokens only once and where appropriate.
+%
+% The incredible hack with |\dt@ptrue| is necessary for working around
+% bug `amslatex/3425'.
+% \begin{macrocode}
+%<*!active>
+\begingroup
+\catcode`\*=11
+\@firstofone{\endgroup
+\DeclareOption{displaymath}{%
+ \preview@delay{\toks@{%
+ \pr@startbox{\noindent$$%
+ \aftergroup\pr@endbox\@gobbletwo}{$$}\@firstofone}%
+ \everydisplay\expandafter{\the\expandafter\toks@
+ \expandafter{\the\everydisplay}}}%
+ \pr@advise@ship\equation{\begingroup\aftergroup\pr@endbox
+ \def\dt@ptrue{\m@ne=\m@ne}\noindent}%
+ {\endgroup}%
+ \pr@advise@ship\equation*{\begingroup\aftergroup\pr@endbox
+ \def\dt@ptrue{\m@ne=\m@ne}\noindent}%
+ {\endgroup}%
+ \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
+ \edef\next{\catcode`@=\the\catcode`@\relax}%
+ \makeatother\expandafter\xyreuncatcodes\next\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. Two optional parameters might occur in
+% |memoir.cls|.
+% \begin{macrocode}
+\DeclareOption{sections}{%
+ \PreviewMacro[!!!!!!*[[!]{\@startsection}%]]
+ \PreviewMacro[*[[!]{\chapter}%]]
+}
+% \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}
+% We use the normal output routine, but hijack it a bit for our
+% purposes to preserve \cmd{\AtBeginDvi} hooks and not get previews
+% while in output: that could become rather ugly.
+%
+% The main work of disabling normal output relies on a \cmd{\shipout}
+% redefinition.
+% \begin{macro}{\pr@output}
+% \begin{macrocode}
+\newtoks\pr@output
+\pr@output\output
+\output{%
+ \pr@outerfalse
+ \let\@begindvi\@empty
+ \the\pr@output}
+\let\output\pr@output
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@typeinfos}
+% Then we have some document info that style files might want to
+% output.
+% \begin{macrocode}
+\def\pr@typeinfos{\typeout{Preview: Fontsize \f@size pt}%
+ \ifnum\mag=\@m\else\typeout{Preview: Magnification \number\mag}\fi
+ \ifx\pdfoutput\@undefined
+ \ifx\XeTeXversion\@undefined \else
+ % FIXME: The message should not be emitted if XeTeX does not produce
+ % PDF. There does not seem to be a primitive for that, though.
+ \typeout{Preview: PDFoutput 1}%
+ \fi
+ \else
+ \ifx\pdfoutput\relax \else
+ \ifnum\pdfoutput>\z@
+ \typeout{Preview: PDFoutput 1}%
+ \fi
+ \fi
+ \fi
+}
+\AtBeginDocument{\pr@typeinfos}
+% \end{macrocode}
+% \end{macro}
+% And at the end we load the default configuration file, so that it
+% may override settings from this package:
+% \begin{macrocode}
+\pr@loadcfg{prdefault}
+%</active>
+%</style>
+% \end{macrocode}
+%
+% \section{The option files}
+% \subsection{The \texttt{auctex} option}
+% The AUC\TeX\ option will cause error messages to spew. We want them
+% on the terminal, but we don't want \LaTeX\ to stop its automated
+% run. We delay \cmd{\nonstopmode} in case the user has any
+% pseudo-interactive folderol like reading in of file names in his
+% preamble. Because we are so good-hearted, we will not break this as
+% long as the document has not started, but after that we need the
+% error message mechanism operative.
+%
+% The |\nofiles| command here tries to avoid clobbering input files
+% used for references and similar. It will come too late if you call
+% the package with \cmd{\AtBeginDocument}, so you'll need to issue
+% |\nofiles| yourself in that case. Previously, this was done
+% unconditionally in the main style file, but since we don't know what
+% the package may be used for, this was inappropriate.
+%
+% So here is the contents of the |prauctex.def| file:
+% \begin{macrocode}
+%<auctex>\ifPreview\else\expandafter\endinput\fi
+%<auctex>\nofiles
+%<auctex>\preview@delay{\nonstopmode}
+% \end{macrocode}
+% Ok, here comes creative error message formatting. It turns out a
+% sizable portion of the runtime is spent in I/O. Making the error
+% messages short is an advantage. It is not possible to convince
+% \TeX\ to make shorter error messages than this: \TeX\ always wants
+% to include context. This is about the shortest \ae sthetic one we
+% can muster.
+% \begin{macrocode}
+%<auctex>\begingroup
+%<auctex>\lccode`\~=`\-
+%<auctex>\lccode`\{=`\<
+%<auctex>\lccode`\}=`\>
+%<auctex>\lowercase{\endgroup
+%<auctex> \def\pr@msgi{{~}}}
+%<auctex>\def\pr@msgii{Preview:
+%<auctex> Snippet \number\pr@snippet\space}
+%<auctex>\begingroup
+%<auctex>\catcode`\-=13
+%<auctex>\catcode`\<=13
+%<auctex>\@firstofone{\endgroup
+%<auctex>\def\pr@msg#1{{%
+%<auctex> \let<\pr@msgi
+%<auctex> \def-{\pr@msgii#1}%
+%<auctex> \errhelp{Not a real error.}%
+%<auctex> \errmessage<}}}
+%<auctex>\g@addto@macro\pr@ship@start{\pr@msg{started}}
+%<auctex>\g@addto@macro\pr@ship@end{\pr@msg{ended.%
+%<auctex> (\number\ht\pr@box+\number\dp\pr@box x\number\wd\pr@box)}}
+% \end{macrocode}
+% This looks pretty baffling, but it produces something short and
+% semi-graphical, namely |<-><->|. That is a macro |<| that expands
+% into |<->|, where |<| and |>| are the braces around an
+% \cmd{\errmessage} argument and |-| is a macro expanding to the full
+% text of the error message. Cough cough. You did not really want to
+% know, did you?
+%
+% Since over/underfull boxes are about the messiest things to parse,
+% we disable them by setting the appropriate badness limits and making
+% the variables point to junk. We also disable other stuff. While we
+% set \cmd{\showboxbreadth} and \cmd{\showboxdepth} to indicate as
+% little diagnostic output as possible, we keep them operative, so
+% that the user retains the option of debugging using this stuff. The
+% other variables concerning the generation of warnings and
+% daignostics, however, are more often set by commonly employed
+% packages and macros such as \cmd{\sloppy}. So we kill them off for
+% good.
+% \begin{macrocode}
+%<auctex>\hbadness=\maxdimen
+%<auctex>\newcount\hbadness
+%<auctex>\vbadness=\maxdimen
+%<auctex>\let\vbadness=\hbadness
+%<auctex>\hfuzz=\maxdimen
+%<auctex>\newdimen\hfuzz
+%<auctex>\vfuzz=\maxdimen
+%<auctex>\let\vfuzz=\hfuzz
+%<auctex>\showboxdepth=-1
+%<auctex>\showboxbreadth=-1
+% \end{macrocode}
+% Ok, now we load a possible configuration file.
+% \begin{macrocode}
+%<auctex>\pr@loadcfg{prauctex}
+% \end{macrocode}
+% And here we cater for several frequently used commands in
+% |prauctex.cfg|:
+% \begin{macrocode}
+%<auccfg>\PreviewMacro*[[][#1{}]\footnote
+%<auccfg>\PreviewMacro*[?[{@{[]}}{}][#1]\item
+%<auccfg>\PreviewMacro*\emph
+%<auccfg>\PreviewMacro*\textrm
+%<auccfg>\PreviewMacro*\textit
+%<auccfg>\PreviewMacro*\textsc
+%<auccfg>\PreviewMacro*\textsf
+%<auccfg>\PreviewMacro*\textsl
+%<auccfg>\PreviewMacro*\texttt
+%<auccfg>\PreviewMacro*\textcolor
+%<auccfg>\PreviewMacro*\mbox
+%<auccfg>\PreviewMacro*[][#1{}]\author
+%<auccfg>\PreviewMacro*[][#1{}]\title
+%<auccfg>\PreviewMacro*\and
+%<auccfg>\PreviewMacro*\thanks
+%<auccfg>\PreviewMacro*[][#1{}]\caption
+%<auccfg>\preview@delay{\@ifundefined{pr@\string\@startsection}{%
+%<auccfg> \PreviewMacro*[!!!!!!*][#1{}]\@startsection}{}}
+%<auccfg>\preview@delay{\@ifundefined{pr@\string\chapter}{%
+%<auccfg> \PreviewMacro*[*][#1{}]\chapter}{}}
+%<auccfg>\PreviewMacro*\index
+% \end{macrocode}
+%
+% \subsection{The \texttt{lyx} option}
+% The following is the option providing LyX with info for its preview
+% implementation.
+% \begin{macrocode}
+%<lyx>\ifPreview\else\expandafter\endinput\fi
+%<lyx>\pr@loadcfg{prlyx}
+%<lyx>\g@addto@macro\pr@ship@end{\typeout{Preview:
+%<lyx> Snippet \number\pr@snippet\space
+%<lyx> \number\ht\pr@box\space \number\dp\pr@box \space\number\wd\pr@box}}
+% \end{macrocode}
+%
+% \subsection{The \texttt{counters} option}
+% This outputs a checkpoint. We do this by saving all counter
+% registers in backup macros starting with |\pr@c@| in their name. A
+% checkpoint first writes out all changed counters (previously
+% unchecked counters are not written out unless different from zero),
+% then saves all involved counter values. \LaTeX\ tracks its counters
+% in the global variable \cmd{\cl@ckpt}.
+% \begin{macrocode}
+%<counters>\ifPreview\else\expandafter\endinput\fi
+%<counters>\def\pr@eltprint#1{\expandafter\@gobble\ifnum\value{#1}=0%
+%<counters> \csname pr@c@#1\endcsname\else\relax
+%<counters> \space{#1}{\arabic{#1}}\fi}
+%<counters>\def\pr@eltdef#1{\expandafter\xdef
+%<counters> \csname pr@c@#1\endcsname{\arabic{#1}}}
+%<counters>\def\pr@ckpt#1{{\let\@elt\pr@eltprint\edef\next{\cl@@ckpt}%
+%<counters> \ifx\next\@empty\else\typeout{Preview: Counters\next#1}%
+%<counters> \let\@elt\pr@eltdef\cl@@ckpt\fi}}
+%<counters>\pr@addto@front\pr@ship@start{\pr@ckpt:}
+%<counters>\pr@addto@front\pr@ship@end{\pr@ckpt.}
+% \end{macrocode}
+%
+% \subsection{Debugging options}
+% Those are for debugging the operation of |preview|, and thus are
+% mostly of interest for people that want to use |preview| for their
+% own purposes. Since debugging output is potentially confusing to
+% the error message parsing from AUC\TeX, you should not turn on
+% |\tracingonline| or switch from |\nonstopmode| unless you are
+% certain your package will never be used with \previewlatex.
+%
+% \paragraph{The \texttt{showbox} option} will generate diagnostic
+% output for every produced box. It does not delay the resetting of
+% the |\showboxbreadth| and |\showboxdepth| parameters so that you can
+% still change them after the loading of the package. It does,
+% however, move them to the end of the package loading, so that they
+% will not be affected by the |auctex| option.
+% \begin{macrocode}
+%<showbox>\ifPreview\else\expandafter\endinput\fi
+%<showbox>\AtEndOfPackage{%
+%<showbox> \showboxbreadth\maxdimen
+%<showbox> \showboxdepth\maxdimen}
+%<showbox>\g@addto@macro\pr@ship@end{\showbox\pr@box}
+% \end{macrocode}
+%
+% \paragraph{The \texttt{tracingall} option} is for the really heavy
+% diagnostic stuff. For the reasons mentioned above, we do not want
+% to change the setting of the interaction mode, nor of the
+% |tracingonline| flag. If the user wants them different, he should
+% set them outside of the preview boxes.
+% \begin{macrocode}
+%<tracingall>\ifPreview\else\expandafter\endinput\fi
+%<tracingall>\pr@addto@front\pr@ship@start{\let\tracingonline\count@
+%<tracingall> \let\errorstopmode\@empty\tracingall}
+% \end{macrocode}
+%
+% \subsection{Supporting conversions}
+% It is not uncommon to want to use the results of |preview| as
+% images. One possibility is to generate a flurry of EPS files with
+% \begin{quote}
+% |dvips -E -i -Ppdf -o| \meta{outputfile}|.000| \meta{inputfile}
+% \end{quote}
+% However, in case those are to be processed further into graphic
+% image files by Ghostscript, this process is inefficient. One cannot
+% use Ghostscript in a single run for generating the files, however,
+% since one needs to set the page size (or full size pages will be
+% produced). The |tightpage| option will set the page dimensions at
+% the start of each PostScript page so that the output will be sized
+% appropriately. That way, a single pass of Dvips followed by a
+% single pass of Ghostscript will be sufficient for generating all
+% images.
+%
+% You will have to specify the output driver to be used, either
+% |dvips| or |pdftex|.
+%
+% \begin{macro}{\PreviewBorder}
+% \begin{macro}{\PreviewBbAdjust}
+% We start this off with the user tunable parameters which get
+% defined even in the case of an inactive package, so that
+% redefinitions and assignments to them will always work:
+% \begin{macrocode}
+%<tightpage>\ifx\PreviewBorder\@undefined
+%<tightpage> \newdimen\PreviewBorder
+%<tightpage> \PreviewBorder=0.50001bp
+%<tightpage>\fi
+%<tightpage>\ifx\PreviewBbAdjust\@undefined
+%<tightpage> \def\PreviewBbAdjust{-\PreviewBorder -\PreviewBorder
+%<tightpage> \PreviewBorder \PreviewBorder}
+%<tightpage>\fi
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% Here is stuff used for parsing this:
+% \begin{macrocode}
+%<tightpage>\ifPreview\else\expandafter\endinput\fi
+%<tightpage>\def\pr@nextbb{\edef\next{\next\space\number\dimen@}%
+%<tightpage> \expandafter\xdef\csname pr@bb@%
+%<tightpage> \romannumeral\count@\endcsname{\the\dimen@}%
+%<tightpage> \advance\count@\@ne\ifnum\count@<5
+%<tightpage> \afterassignment\pr@nextbb\dimen@=\fi}
+% \end{macrocode}
+% And here is the stuff that we fudge into our hook. Of course, we
+% have to do it in a box, and we start this box off with our special.
+% There is one small consideration here: it might come before any
+% |\AtBeginDvi| stuff containing header specials. It turns out Dvips
+% rearranges this amicably: header code specials get transferred to
+% the appropriate header section, anyhow, so this ensures that we come
+% right after the bop section. We insert the 7~numbers here: the
+% 4~bounding box adjustments, and the 3~\TeX\ box dimensions. In case
+% the box adjustments have changed since the last time, we write them
+% out to the console.
+% \begin{macrocode}
+%<tightpage>\ifnum\pr@graphicstype=\z@
+%<tightpage> \ifcase
+%<tightpage> \ifx\XeTeXversion\@undefined
+%<tightpage> \ifx\pdfoutput\@undefined \@ne\fi
+%<tightpage> \ifx\pdfoutput\relax \@ne\fi
+%<tightpage> \ifnum\pdfoutput>\z@ \tw@\fi \@ne
+%<tightpage> \else \thr@@\fi
+%<tightpage> \or \ExecuteOptions{dvips}\relax
+%<tightpage> \or \ExecuteOptions{pdftex}\relax
+%<tightpage> \or \ExecuteOptions{xetex}\relax\fi\fi
+%<tightpage>\global\let\pr@bbadjust\@empty
+%<tightpage>\pr@addto@front\pr@ship@end{\begingroup
+%<tightpage> \let\next\@gobble
+%<tightpage> \count@\@ne\afterassignment\pr@nextbb
+%<tightpage> \dimen@\PreviewBbAdjust
+%<tightpage> \ifx\pr@bbadjust\next
+%<tightpage> \else \global\let\pr@bbadjust\next
+%<tightpage> \typeout{Preview: Tightpage \pr@bbadjust}%
+%<tightpage> \fi\endgroup}
+%<tightpage>\ifcase\pr@graphicstype
+%<tightpage>\or
+%<tightpage> \g@addto@macro\pr@ship@end{\setbox\pr@box\hbox{%
+%<tightpage> \special{ps::\pr@bbadjust\space
+%<tightpage> \number\ifdim\ht\pr@box>\z@ \ht\pr@box
+%<tightpage> \else \z@
+%<tightpage> \fi \space
+%<tightpage> \number\ifdim\dp\pr@box>\z@ \dp\pr@box
+%<tightpage> \else \z@
+%<tightpage> \fi \space
+%<tightpage> \number\ifdim\wd\pr@box>\z@ \wd\pr@box
+%<tightpage> \else \z@
+%<tightpage> \fi}\box\pr@box}}
+%<tightpage>\or
+%<tightpage> \g@addto@macro\pr@ship@end{{\dimen@\ht\pr@box
+%<tightpage> \ifdim\dimen@<\z@ \dimen@\z@\fi
+%<tightpage> \advance\dimen@\pr@bb@iv
+%<tightpage> \dimen@ii=\dimen@
+%<tightpage> \global\pdfvorigin\dimen@
+%<tightpage> \dimen@\dp\pr@box
+%<tightpage> \ifdim\dimen@<\z@ \dimen@\z@\fi
+%<tightpage> \advance\dimen@-\pr@bb@ii
+%<tightpage> \advance\dimen@\dimen@ii
+%<tightpage> \global\pdfpageheight\dimen@
+%<tightpage> \dimen@\wd\pr@box
+%<tightpage> \ifdim\dimen@<\z@ \dimen@=\z@\fi
+%<tightpage> \advance\dimen@-\pr@bb@i
+%<tightpage> \advance\dimen@\pr@bb@iii
+%<tightpage> \global\pdfpagewidth\dimen@
+%<tightpage> \global\pdfhorigin-\pr@bb@i}}
+%<tightpage>\or
+%<tightpage> \g@addto@macro\pr@ship@end{\dimen@\ht\pr@box
+%<tightpage> \ifdim\dimen@<\z@ \dimen@\z@\fi
+%<tightpage> \advance\dimen@\pr@bb@iv
+%<tightpage> \dimen@ii=\dimen@
+%<tightpage> \voffset=-1in
+%<tightpage> \advance\voffset\dimen@
+%<tightpage> \advance\voffset-\ht\pr@box
+%<tightpage> \dimen@\dp\pr@box
+%<tightpage> \ifdim\dimen@<\z@ \dimen@\z@\fi
+%<tightpage> \advance\dimen@-\pr@bb@ii
+%<tightpage> \advance\dimen@\dimen@ii
+%<tightpage> \global\pdfpageheight\dimen@
+%<tightpage> \global\paperheight\dimen@
+%<tightpage> \dimen@\wd\pr@box
+%<tightpage> \ifdim\dimen@<\z@ \dimen@=\z@\fi
+%<tightpage> \advance\dimen@-\pr@bb@i
+%<tightpage> \advance\dimen@\pr@bb@iii
+%<tightpage> \global\pdfpagewidth\dimen@
+%<tightpage> \hoffset=-1in
+%<tightpage> \advance\hoffset-\pr@bb@i
+%<tightpage> \let\pr@offset@override\@empty}
+%<tightpage>\fi
+% \end{macrocode}
+% Ok, here comes the beef. First we fish the 7~numbers from the file
+% with |token| and convert them from \TeX~|sp| to PostScript points.
+% \begin{macrocode}
+%<tightpage>\ifnum\pr@graphicstype=\@ne
+%<tightpage>\preview@delay{\AtBeginDvi{%
+% \end{macrocode}
+% Backwards-compatibility. Once we are certain that dvipng-1.6 or
+% later is widely used, the three following specials can be exchanged
+% for the simple |\special{!/preview@tightpage true def}|
+% \begin{macrocode}
+%<tightpage> \special{!/preview@tightpage true def (%
+%<tightpage> compatibility PostScript comment for dvipng<=1.5 }
+%<tightpage> \special{!userdict begin/bop-hook{%
+%<tightpage> 7{currentfile token not{stop}if
+%<tightpage> 65781.76 div DVImag mul}repeat
+%<tightpage> 72 add 72 2 copy gt{exch}if 4 2 roll
+%<tightpage> neg 2 copy lt{exch}if dup 0 gt{pop 0 exch}%
+%<tightpage> {exch dup 0 lt{pop 0}if}ifelse 720 add exch 720 add
+%<tightpage> 3 1 roll
+%<tightpage> 4{5 -1 roll add 4 1 roll}repeat
+%<tightpage> <</PageSize[5 -1 roll 6 index sub 5 -1 roll 5 index sub]%
+%<tightpage> /PageOffset[7 -2 roll [1 1 dtransform exch]%
+%<tightpage> {0 ge{neg}if exch}forall]>>setpagedevice%
+%<tightpage> //bop-hook exec}bind def end}
+%<tightpage> \special{!userdict (some extra code to avoid
+%<tightpage> dvipng>=1.6 unknown special:
+%<tightpage> 7{currentfile token not{stop}if 65781.76 div })) pop}
+% \end{macrocode}
+% The ``userdict'' at the start of the last special is also there to
+% avoid an unknown special in dvipng<=1.6. This is the end of the
+% backwards-compatibility code.
+% \begin{macrocode}
+%<tightpage> \special{!userdict begin/bop-hook{%
+%<tightpage> preview-bop-level 0 le{%
+%<tightpage> 7{currentfile token not{stop}if
+%<tightpage> 65781.76 div DVImag mul}repeat
+% \end{macrocode}
+% Next we produce the horizontal part of the bounding box as
+% \[ (1\mathrm{in},1\mathrm{in}) +
+% \bigl(\min(|\wd\pr@box|,0),\max(|\wd\pr@box|,0)\bigr) \]
+% and roll it to the bottom of the stack:
+% \begin{macrocode}
+%<tightpage> 72 add 72 2 copy gt{exch}if 4 2 roll
+% \end{macrocode}
+% Next is the vertical part of the bounding box. Depth counts in
+% negatively, and we again take $\min$ and $\max$ of possible extents
+% in the vertical direction, limited by 0. 720 corresponds to
+% $10\,\mathrm{in}$ and is the famous $1\,\mathrm{in}$ distance away
+% from the edge of letterpaper.
+% \begin{macrocode}
+%<tightpage> neg 2 copy lt{exch}if dup 0 gt{pop 0 exch}%
+%<tightpage> {exch dup 0 lt{pop 0}if}ifelse 720 add exch 720 add
+%<tightpage> 3 1 roll
+% \end{macrocode}
+% Ok, we now have the bounding box on the stack in the proper order
+% llx, lly, urx, ury. We add the adjustments:
+% \begin{macrocode}
+%<tightpage> 4{5 -1 roll add 4 1 roll}repeat
+% \end{macrocode}
+% The page size is calculated as the appropriate differences, the page
+% offset consists of the coordinates of the lower left corner, with
+% those coordinates negated that would be reckoned positive in the
+% device coordinate system.
+% \begin{macrocode}
+%<tightpage> <</PageSize[5 -1 roll 6 index sub 5 -1 roll 5 index sub]%
+%<tightpage> /PageOffset[7 -2 roll [1 1 dtransform exch]%
+%<tightpage> {0 ge{neg}if exch}forall]>>setpagedevice}if%
+% \end{macrocode}
+% So we now bind the old definition of |bop-hook| into our new
+% definition and finish it.
+% \begin{macrocode}
+%<tightpage> //bop-hook exec}bind def end}}}
+%<tightpage>\fi
+% \end{macrocode}
+%
+% \subsection{The \texttt{showlabels} option}
+% During the editing process, some people like to see the label names
+% in their equations, figures and the like. Now if you are using
+% Emacs for editing, and in particular \previewlatex, I'd strongly
+% recommend that you check out the Ref\TeX\ package which pretty much
+% obliterates the need for this kind of functionality. If you still
+% want it, standard \LaTeX\ provides it with the |showkeys| package,
+% and there is also the less encompassing |showlabels| package.
+% Unfortunately, since those go to some pain not to change the page
+% layout and spacing, they also don't change |preview|'s idea of the
+% \TeX\ dimensions of the involved boxes.
+%
+% So those packages are mostly useless. So we present here an
+% alternative hack that will get the labels through.
+% \begin{macro}{\pr@labelbox}
+% This works by collecting them into a separate box which we then
+% tack to the right of the previews.
+% \begin{macrocode}
+%<showlabels>\ifPreview\else\expandafter\endinput\fi
+%<showlabels>\newbox\pr@labelbox
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@label}
+% We follow up with our own definition of the \cmd{\label} macro
+% which will be active only in previews. The original definition is
+% stored in |\pr@@label|. |\pr@lastlabel| contains the last typeset
+% label in order to avoid duplication in certain environments, and
+% we keep the stuff in |\pr@labelbox|.
+% \begin{macrocode}
+%<showlabels>\def\pr@label#1{\pr@@label{#1}%
+% \end{macrocode}
+% Ok, now we generate the box, by placing the label below any existing
+% stuff.
+% \begin{macrocode}
+%<showlabels> \ifpr@setbox\z@{#1}%
+%<showlabels> \global\setbox\pr@labelbox\vbox{\unvbox\pr@labelbox
+%<showlabels> \box\z@}\egroup\fi}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\ifpr@setbox}
+% |\ifpr@setbox| receives two arguments, |#1| is the box into which
+% to set a label, |#2| is the label text itself. If a label needs
+% to be set (if it is not a duplicate in the current box, and is
+% nonempty, and we are in the course of typesetting and so on), we
+% are left in a true conditional and an open group with the preset
+% box. If nothing should be set, no group is opened, and we get
+% into skipping to the closing of the conditional. Since
+% |\ifpr@setbox| is a macro, you should not place the call to it
+% into conditional text, since it will not pair up with |\fi| until
+% being expanded.
+%
+% We have some trickery involved here. |\romannumeral\z@| expands
+% to empty, and will also remove everything between the two of them
+% that also expands to empty, like a chain of |\fi|.
+% \begin{macrocode}
+%<showlabels>\def\ifpr@setbox#1#2{%
+%<showlabels> \romannumeral%
+%<showlabels> \ifx\protect\@typeset@protect\ifpr@outer\else
+% \end{macrocode}
+% Ignore empty labels\dots
+% \begin{macrocode}
+%<showlabels> \z@\bgroup
+%<showlabels> \protected@edef\next{#2}\@onelevel@sanitize\next
+%<showlabels> \ifx\next\@empty\egroup\romannumeral\else
+% \end{macrocode}
+% and labels equal to the last one.
+% \begin{macrocode}
+%<showlabels> \ifx\next\pr@lastlabel\egroup\romannumeral\else
+%<showlabels> \global\let\pr@lastlabel\next
+%<showlabels> \setbox#1\pr@boxlabel\pr@lastlabel
+%<showlabels> \expandafter\expandafter\romannumeral\fi\fi\fi\fi
+%<showlabels> \z@\iffalse\iftrue\fi}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@boxlabel}
+% Now the actual typesetting of a label box is done. We use a small
+% typewriter font inside of a framed box (the default frame/box
+% separating distance is a bit large).
+% \begin{macrocode}
+%<showlabels>\def\pr@boxlabel#1{\hbox{\normalfont
+%<showlabels> \footnotesize\ttfamily\fboxsep0.4ex\relax\fbox{#1}}}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@maketag}
+% And here is a version for |amsmath| equations. They look better
+% when the label is right beside the tag, so we place it there, but
+% augment |\box\pr@labelbox| with an appropriate placeholder.
+% \begin{macrocode}
+%<showlabels>\def\pr@maketag#1{\pr@@maketag{#1}%
+%<showlabels> \ifpr@setbox\z@{\df@label}%
+%<showlabels> \global\setbox\pr@labelbox\vbox{%
+%<showlabels> \hrule\@width\wd\z@\@height\z@
+%<showlabels> \unvbox\pr@labelbox}%
+% \end{macrocode}
+% Set the width of the box to empty so that the label placement gets
+% not disturbed, then append it.
+% \begin{macrocode}
+%<showlabels> \wd\z@\z@\box\z@ \egroup\fi}
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pr@lastlabel}
+% Ok, here is how we activate this: we clear out box and label info
+% \begin{macrocode}
+%<showlabels>\g@addto@macro\pr@ship@start{%
+%<showlabels> \global\setbox\pr@labelbox\box\voidb@x
+%<showlabels> \xdef\pr@lastlabel{}%
+% \end{macrocode}
+% The definitions above are global because we might be in any amount
+% of nesting. We then reassign the appropriate labelling macros:
+% \begin{macrocode}
+%<showlabels> \global\let\pr@@label\label \let\label\pr@label
+%<showlabels> \global\let\pr@@maketag\maketag@@@
+%<showlabels> \let\maketag@@@\pr@maketag
+%<showlabels>}
+% \end{macrocode}
+% \end{macro}
+% Now all we have to do is to add the stuff to the box in question.
+% The stuff at the front works around a bug in |ntheorem.sty|.
+% \begin{macrocode}
+%<showlabels>\pr@addto@front\pr@ship@end{%
+%<showlabels> \ifx \label\pr@label \global\let\label\pr@@label \fi
+%<showlabels> \ifx \maketag@@@\pr@maketag
+%<showlabels> \global\let\maketag@@@\pr@@maketag \fi
+%<showlabels> \ifvoid\pr@labelbox
+%<showlabels> \else \setbox\pr@box\hbox{%
+%<showlabels> \box\pr@box\,\box\pr@labelbox}%
+%<showlabels> \fi}
+% \end{macrocode}
+% \subsection{The \texttt{footnotes} option}
+% This is rather simplistic right now. It overrides the default
+% footnote action (which is to disable footnotes altogether for better
+% visibility).
+% \begin{macrocode}
+%<footnotes>\PreviewMacro[[!]\footnote %]
+% \end{macrocode}
+%
+% \section{Various driver files}
+% The installer, in case it is missing. If it is to be used via
+% |make|, we don't specify an installation path, since
+% \begin{quote}
+% |make install|
+% \end{quote}
+% is supposed to cater for the installation itself.
+% \begin{macrocode}
+%<installer> \input docstrip
+%<installer&make> \askforoverwritefalse
+%<installer> \generate{
+%<installer> \file{preview.drv}{\from{preview.dtx}{driver}}
+%<installer&!make> \usedir{tex/latex/preview}
+%<installer> \file{preview.sty}{\from{preview.dtx}{style}
+%<installer> \from{preview.dtx}{style,active}}
+%<installer> \file{prauctex.def}{\from{preview.dtx}{auctex}}
+%<installer> \file{prauctex.cfg}{\from{preview.dtx}{auccfg}}
+%<installer> \file{prshowbox.def}{\from{preview.dtx}{showbox}}
+%<installer> \file{prshowlabels.def}{\from{preview.dtx}{showlabels}}
+%<installer> \file{prtracingall.def}{\from{preview.dtx}{tracingall}}
+%<installer> \file{prtightpage.def}{\from{preview.dtx}{tightpage}}
+%<installer> \file{prlyx.def}{\from{preview.dtx}{lyx}}
+%<installer> \file{prcounters.def}{\from{preview.dtx}{counters}}
+%<installer> \file{prfootnotes.def}{\from{preview.dtx}{footnotes}}
+%<installer> }
+%<installer> \endbatchfile
+% \end{macrocode}
+% And here comes the documentation driver.
+% \begin{macrocode}
+%<driver> \documentclass{ltxdoc}
+%<driver> \usepackage{preview}
+%<driver> \let\ifPreview\relax
+%<driver> \newcommand\previewlatex{\texttt{preview-latex}}
+%<driver> \begin{document}
+%<driver> \DocInput{preview.dtx}
+%<driver> \end{document}
+% \end{macrocode}
+% \Finale{}
+% \iffalse
+% Local Variables:
+% mode: doctex
+% TeX-master: "preview.drv"
+% End:
+% \fi
projects / coq-hetmet.git / commitdiff