summaryrefslogtreecommitdiff
path: root/macros/latex/contrib/varwidth/varwidth.sty
blob: 5809254a4937567a55088efd44c8df13ad892dbc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
% varwidth.sty  v 0.92  Mar 2009  Donald Arseneau asnd@triumf.ca
%
% Copyright 2003-2004,2009 by Donald Arseneau (asnd@triumf.ca).
% This software is released under the terms of the LaTeX Project Public 
% License  (ftp://ctan.tug.org/tex-archive/macros/latex/base/lppl.txt).
% (Essentially: Free to use, copy, distribute (sell) and change, but, if
% changed, that fact must be clearly displayed to the user.)
%
% The varwidth environment is based on minipage, and takes the same
% parameters, but the specified width is just a maximum value -- the
% environment will be typeset with a narrower "natural" width if
% possible.
%
% In a varwidth environment, paragraph line-breaks are chosen
% according to the specified width, but each line is reset to 
% match a narrower natural width, if there is one.
%
% The \narrowragged command works like \raggedright, but produces 
% generally narrower lines in paragraphs, with more text in the last 
% line (the lines have more-equal lengths).
%
% This version works fine, but there are still many questions about
% how it would work best.  Should there be a version that avoids the
% usual minipage formatting style?
%
% Numbered equations are not handled well, especially with leqno.
% AMSmath environments have not been tried, and undoubtedly fail.
%
% To do:  Extend v-list wrappers to handle all e-TeX primitives.
%         (pdfTeX too?)
%         Capture marks and floats, propagating them out of the box
%         Support numbered equations, including ams math.
% 

\ProvidesPackage{varwidth}[2009/03/30 ver 0.92; \space 
    Variable-width minipages]

\newcommand\narrowragged{\rightskip \z@ plus .25\hsize 
  \@rightskip\rightskip \parfillskip\z@ plus .15\hsize
  \sloppy }

\newbox\@vwid@box

% The varwidth environment is based on minipage, and takes the same
% parameters, but the specified width is only a limit -- a narrower
% natural width may be used.  \varwidth uses \minipage.

\def\varwidth{\let\@minipagerestore\@vwid@setup \minipage}

% Many things may appear on vertical lists that can't be re-processed,
% so they have to be modified. 

\def\@vwid@setup{%
  % several things can't appear in vertical mode, so they may get 
  % a \vbox wrapped around them.
  \let\@bsphack\@vwid@bsphack % \label and others
  \let\mark\@gobble % Marks disappear in minipages anyway
  \let\special\@vwid@special % \color and others
  \let\pdfliteral\@vwid@pdfliteral % \color and others
  \let\addtocontents\@vwid@addtocontents % \addcontentsline
  % Shifted boxes (\parshape,\hangindent) will have their shifts
  % indicated in a separate box.
  \let\@hangfrom\@vwid@hangfrom % hanging indents
  \let\list\@vwid@list
  \let\endtrivlist\@vwid@endtrivlist
  \postdisplaypenalty\@vwid@posteqp
  \predisplaypenalty\@vwid@preeqp
  \def\@eqnnum{\aftergroup\@vwid@afterva\@@vwid@eqnnum}%
  \global\@vwid@roff\z@  \global\@vwid@loff\z@
  % Begin an inner minipage-like vertical box (in \@tempboxa)
  \let\@minipagerestore\@@vwid@minipagerestore \@minipagerestore
  \setbox\@tempboxa\vbox\bgroup\begingroup
  % Flag the top of the list
  \penalty\@vwid@toppen
}

\let\@@vwid@minipagerestore\@minipagerestore

%  At end of varwidth environment.
\def\endvarwidth{\par\@@par
   \unskip
   % Handle minipage-style notes.
   \ifvoid\@mpfootins\else
     \vskip\skip\@mpfootins
     \normalcolor
     \@vwid@wrap\footnoterule
     \unvbox\@mpfootins
   \fi
   \unskip
   \@minipagefalse
   \endgroup\egroup % got my \@tempboxa
   %{\showoutput\showbox\@tempboxa}%
   % in a discarded box, sift through list measuring max width.
   \begingroup\setbox\z@\vbox\bgroup
%\message{-------------------------------------------------------------}%
%\message{First pass; hsize=\the\hsize...  }%{\tracingall\showlists}%%
     \unvcopy\@tempboxa
     \@tempdima-\maxdimen
     \let\@vwid@resetb\@vwid@measure
     \let\@vwid@append\relax
     \sift@deathcycles\z@
     \@vwid@sift
     \xdef\@vwid@{\the\@tempdima}%
   \egroup\endgroup
   % Done measuring.  Now empty \@tempboxa onto current vertical list
   % which is the contents of a minipage environment
%\message{Got natural width \@vwid@ (compare \the\hsize) }%
   \unvbox\@tempboxa
   % Choose the natural width or the declared width, whichever is smaller.
   \ifdim\@vwid@<\hsize
     \hsize\@vwid@
   \fi
   % Go through the vertical list reboxing and moving everything into
   % \@vwid@box; then spill \@vwid@box.  If the natural width is narrower,
   \setbox\@vwid@box\vbox{}%
   \sift@deathcycles\z@
%\message{----------------------------------------------------------------}%
%\message{Second pass; hsize=\the\hsize...  }%{\tracingall\showlists}%
   \@vwid@sift
%\message{After sifting:}%
%{\showoutput\showbox\@vwid@box}%
   \unvbox\@vwid@box
   % end the minipage environment
   \endminipage}

%
% Here are definitions for sifting through the vertical list, either
% measuring things or reboxing them.  
%
% Penalties used as signals to the vertical-list processor:

\mathchardef\@vwid@posteqp  17321 % Penalty below equations
\mathchardef\@vwid@preeqp   17322 % Penalty above equations
\mathchardef\@vwid@postnump 17323 % Penalty below numbered equations
\mathchardef\@vwid@toppen   17324 % Penalty marking top of vertical list
\mathchardef\@vwid@offsets  17325 % Penalty below special h-offsets box
\mathchardef\@vwid@postw    17326 % Penalty below a \vbox-wrapped object

\newcount\sift@deathcycles

\def\@vwid@sift{%
  \skip@\lastskip\unskip
  \dimen@\lastkern\unkern
  \count@\lastpenalty\unpenalty
  \setbox\z@\lastbox
%{\showoutput\showbox\z@}%
  \ifvoid\z@ \advance\sift@deathcycles\@ne \else \sift@deathcycles\z@ \fi
  \ifnum\sift@deathcycles>33 
    \let\@vwid@sift\relax
    \PackageWarning{varwidth}{Failed to reprocess entire contents}%
  \fi
%\message{\the\sift@deathcycles: skip \the\skip@; kern \the\dimen@; penalty \the\count@. }%
%\ifhbox\z@\setbox99\hbox to0pt{\unhcopy\z@}\fi  % = message
  \ifnum\count@=\@vwid@preeqp \@vwid@eqmodefalse\fi
%\ifnum\count@=\@vwid@preeqp \message{End equation mode. }\fi
  \ifnum\count@=\@vwid@posteqp \@vwid@eqmodetrue\fi
%\ifnum\count@=\@vwid@posteqp\message{Begin equation mode. }\fi
%\if@vwid@eqmode {\showoutput\showbox\z@}\fi
  \ifnum\count@=\@vwid@toppen % finished
    \let\@vwid@sift\relax
  \else\ifnum\count@=\@vwid@offsets
    \@vwid@setoffsets
  \else
    \ifnum\count@=\@vwid@postw
    \else
      \@vwid@resetb % reset box \z@ or measure it
    \fi
    \@vwid@append
  \fi\fi
  \@vwid@sift}

\def\@vwid@setoffsets{%
 \setbox\z@=\hbox{\unhbox\z@
  \global\@vwid@roff\lastkern\unkern
  \global\@vwid@loff\lastkern\unkern}%
%\message{Set offsets to \the\@vwid@loff,  \the\@vwid@roff. }%
}

\def\@vwid@append{% Append contents of box \z@ and glue to \@vwid@box
  \setbox\@vwid@box\vbox{%
    \unvbox\z@
    \ifdim\dimen@=\z@\else \kern\dimen@ \fi
    \vskip\skip@
    \unvbox\@vwid@box
  }%{\tracingall\showbox\@vwid@box}%
}

%  reset box \z@ to \hsize, applying shifts, and wrap in vbox
%  Don't worry about numbered equations because we won't get
%  here if there are any.
\def\@vwid@resetb{%
  \setbox\z@\vbox\bgroup
    \ifvoid\z@
    \else
       \ifvbox\z@
         \box\z@
       \else % \hbox
         \@tempdima\hsize
         \advance\@tempdima-\@vwid@roff
         \advance\@tempdima-\@vwid@loff
         \advance\@tempdima-\p@
%\message{Test if \the\wd\z@ > \the\@tempdima, }%
         \ifdim\wd\z@>\@tempdima % full-width line; rebox it
%\message{An ordinary line or alignment. (\the\wd\z@ > \the\@tempdima) }%
            \hbox to\hsize
              {\kern\@vwid@loff \unhbox\z@ \kern\@vwid@roff}%
         \else % an equation or direct \hbox
           \if@vwid@eqmode % re-center unnumbered equations
%\message{A centered equation hsize=\the\hsize. }%
              \hbox to\hsize
                {\hskip\@vwid@loff\@plus1fil
                 \unhbox\z@ \hskip\@vwid@roff\@plus1fil}%
           \else % plain narrow \hbox; leave it as-is
%\message{Plain narrow box}%
              \box\z@
    \fi\fi\fi\fi
  \egroup}


% Measure a line (in box \z@) and keep a running tally of the
% widest natural width in \@tempdima

\def\@vwid@measure{%
  \ifvoid\z@
  \else
    % numbered equations not part of alignments can't be reset,
    % so force retention of full width.
    \ifnum\count@=\@vwid@postnump \ifdim\wd\z@<\linewidth
      \ifdim\@tempdima<\linewidth \@tempdima\linewidth \fi
    \fi\fi
    \ifhbox\z@
      \setbox\z@=\hbox
        {\kern\@vwid@loff \unhbox\z@ \kern\@vwid@roff}%
    \fi
    \ifdim\wd\z@>\@tempdima \@tempdima\wd\z@ \fi
  \fi}

\newdimen\@vwid@loff
\newdimen\@vwid@roff

\let\@@bsphack\@bsphack
\let\@@esphack\@esphack
\let\@@Esphack\@Esphack

\def\@vwid@bsphack{\@@bsphack
  \ifx\@vwid@wrap\@firstofone
    \bgroup
  \else
    \ifvmode
      \setbox\@vwid@box \vbox\bgroup \vbox\bgroup
      \let\@vwid@wrap\@firstofone
      \def\@esphack{\@vwid@esphack\@@esphack}%
      \def\@Esphack{\@vwid@esphack\@@Esphack}%
    \fi
  \fi}

\def\@vwid@esphack{\egroup
  \ifx\@vwid@wrap\@firstofone\else
    \egroup % end outer box
    \unvbox\@vwid@box % put inner box on list without lineskip
    \penalty\@vwid@postw
  \fi}

% \vbox Wrapper for misc vlist items
\long\def\@vwid@wrap{\relax
  \ifvmode\expandafter\@vwid@dowrap \else \expandafter\@firstofone \fi}
\long\def\@vwid@dowrap#1{%
  \setbox\@vwid@box \vbox{\vbox{\let\@vwid@wrap\@firstofone
    #1}\penalty\@vwid@postw
  }\unvbox\@vwid@box }

\let\@@vwid@special\special
\let\@@vwid@pdfliteral\pdfliteral
\let\@@vwid@addtocontents\addtocontents
\let\@@vwid@list\list
\let\@@vwid@endtrivlist\endtrivlist
\let\@@vwid@eqnnum\@eqnnum

\long\def\@vwid@special#1{\@vwid@wrap{\@@vwid@special{#1}}}
\long\def\@vwid@pdfliteral#1{\@vwid@wrap{\@@vwid@pdfliteral{#1}}}
\long\def\@vwid@addtocontents#1#2{\@vwid@wrap{\@@vwid@addtocontents{#1}{#2}}}

\long\def\@vwid@hangfrom#1{\par
  \setbox\@tempboxa\hbox{{#1}}%
  \setbox\@vwid@box \vbox{\hbox{\kern\z@ \kern\z@
   }\penalty\@vwid@offsets}\unvbox\@vwid@box
  \def\par{\relax\ifhmode\unskip\fi
    \vadjust{\hbox{\kern\hangindent\kern\z@}\penalty\@vwid@offsets}%
    \@restorepar\par}%
  \hangindent \wd\@tempboxa\noindent\box\@tempboxa}

\def\@vwid@list{\@vwid@setlist\@@vwid@list}
\def\@vwid@endtrivlist{\@vwid@setlist\@@vwid@endtrivlist}

\def\@vwid@setlist{\relax\ifhmode \unskip\expandafter\vadjust\fi
  {\setbox\@vwid@box \vbox{\hbox{%
    \advance\hsize-\linewidth \advance\hsize-\@totalleftmargin
    \kern\@totalleftmargin  \kern\hsize}%
    \penalty\@vwid@offsets}%
   \unvbox\@vwid@box}}

\newif\if@vwid@eqmode

\def\@vwid@afterva{\vadjust{\penalty\@vwid@postnump}}

%  Should I do this? ...

\@ifundefined{newcolumntype}{}{%
 \@ifundefined{NC@rewrite@V}{
 \newcolumntype{V}[1]{%
   >{\begin{varwidth}[t]{#1}\narrowragged\let\\\tabularnewline}%
   l%
   <{\@finalstrut\@arstrutbox\end{varwidth}}}
 }{}
}

% V 0.91  Always restack contents, even if width didn't change.
% V 0.92  fix \special, \pdfliteral