summaryrefslogtreecommitdiff
path: root/macros/latex/contrib/threadcol/threadcol.dtx
blob: 7b257d368b7243e0ef23a3b98c8364ed5ce3a8cf (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
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
% \iffalse meta-comment
%
% Copyright (C) 2013 by Scott Pakin <scott+thrcl@pakin.org>
% -------------------------------------------------------
%
% This file may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3c
% of this license or (at your option) any later version.
% The latest version of this license is in:
%
%    http://www.latex-project.org/lppl.txt
%
% and version 1.3c or later is part of all distributions of LaTeX
% version 2008/05/04 or later.
%
% \fi
%
% \iffalse
%<*driver>
\ProvidesFile{threadcol.dtx}
%</driver>
%<package>\NeedsTeXFormat{LaTeX2e}[1999/12/01]
%<package>\ProvidesPackage{threadcol}
%<*package>
    [2013/01/06 v1.0 Convert columns to PDF article threads]
%</package>
%
%<*driver>
\documentclass{ltxdoc}
\usepackage{threadcol}
\usepackage{graphicx}
\usepackage{hyperref}
\EnableCrossrefs
\CodelineIndex
\RecordChanges
\setthreadname{User documentation}
\begin{document}
  \sloppy
  \DocInput{threadcol.dtx}
  \setthreadname{Developer documentation}
%  \PrintChanges
  \setthreadname{}
  \makeatletter
  \let\orig@index@prologue=\index@prologue
  \def\index@prologue{%
    \phantomsection\addcontentsline{toc}{section}{Index}
    \orig@index@prologue
  }%
  \makeatother
  \PrintIndex
\end{document}
%</driver>
% \fi
%
% \CheckSum{119}
%
% \CharacterTable
%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%   Digits        \0\1\2\3\4\5\6\7\8\9
%   Exclamation   \!     Double quote  \"     Hash (number) \#
%   Dollar        \$     Percent       \%     Ampersand     \&
%   Acute accent  \'     Left paren    \(     Right paren   \)
%   Asterisk      \*     Plus          \+     Comma         \,
%   Minus         \-     Point         \.     Solidus       \/
%   Colon         \:     Semicolon     \;     Less than     \<
%   Equals        \=     Greater than  \>     Question mark \?
%   Commercial at \@     Left bracket  \[     Backslash     \\
%   Right bracket \]     Circumflex    \^     Underscore    \_
%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%   Right brace   \}     Tilde         \~}
%
%
% \changes{v1.0}{2013/01/06}{Initial version}
%
% \GetFileInfo{threadcol.dtx}
%
% \DoNotIndex{\@empty,\box,\copy,\def,\else,\fi,\gdef,\global}
% \DoNotIndex{\hss,\ifx,\let}
% \DoNotIndex{\MessageBreak,\newcommand,\protect}
% \DoNotIndex{\setbox,\space,\vbox}
%
% ^^A  Define a few helper commands.
% \DeclareRobustCommand{\pkgname}[1]{\mbox{\textsf{#1}}\SortIndex{#1}{\textsf{#1}}}
% \DeclareRobustCommand{\acro}[1]{\textsc{\MakeLowercase{#1}}}
% \DeclareRobustCommand{\menu}[1]{\textit{#1}~$\to$ }
% \DeclareRobustCommand{\menuentry}[1]{\textit{#1}}
% \makeatletter
% \DeclareRobustCommand{\panel}[1]{\textit{#1}}
% \DeclareRobustCommand{\kbd}[1]{\textit{#1}}
% \DeclareRobustCommand{\AAR}{Adobe Acrobat\slash Reader}
%
% ^^A  Specify this document's metadata.
% \title{The \textsf{threadcol} package\thanks{This document
%   corresponds to \textsf{threadcol}~\fileversion, dated \filedate.}}
% \author{Scott Pakin \\ \texttt{scott+thrcl@pakin.org}}
% \hypersetup{^^A
%   pdftitle={The threadcol package},
%   pdfauthor={Scott Pakin},
%   pdfsubject={Organize document columns into PDF "article threads"},
%   pdfkeywords={LaTeX, PDF, article threads, beads, automatic column scrolling}
% }
%
% \maketitle
%
% \section{Introduction}
% \label{sec:introduction}
%
% Consider the following situation: You have a two-column \acro{PDF}
% file that you want to read on your computer (or tablet or whatever).
% Because you have a relatively small screen---and/or less-than-perfect
% eyesight---you zoom in to more easily read the text.  You read the
% first column of the first page, then scroll back to the top of the
% page and over to the right to read the second column, then scroll left
% to read the first column of the second page, then scroll up and over
% to read the second column, and so forth.  With all this distracting
% scrolling, it's easy to lose track of where you were or what you were
% reading.
%
% The \pkgname{threadcol} package helps you avoid this situation for the
% \LaTeX\ documents you create.  It puts every column into a \acro{PDF}
% ``article thread''.  A user can then opt to have his \acro{PDF} reader
% automatically scroll through the document in proper reading order.  In
% \AAR\ this is accomplished simply by clicking any place in the
% document window where the mouse pointer is shown as a hand with an
% arrow in it.  The user can scroll forward by clicking in the document
% window or pressing \kbd{Enter} and backward by shift-clicking or
% pressing \kbd{Shift}+\kbd{Enter}.  See the \AAR\ \menuentry{Help}
% documents for more information.
%
% \AAR\ provide an \Acrobatmenu{ArticleThreads}{Articles navigation
%   panel} that lists all of the document's article threads and lets the
% user jump to a specified thread.  Figure~\ref{fig:articles-ar9} shows
% what the \panel{Articles} panel looks like in Adobe Reader~9 on Linux.
% The panel may have to be displayed explicitly by the user.  This can
% be done by right-clicking on the navigation-panel button list and
% selecting \menuentry{Articles}.  Alternatively, in \AAR~9, one can
% also follow the \menu{View}\menu{Navigation
%   Panels}\menuentry{Articles} menu path or in \AAR~X and~XI the
% \menu{View}\menu{Show/Hide}\menu{Navigation
%   Panels}\menuentry{Articles} menu path.  If \panel{Articles} appears
% as a pop-up, it can be docked simply by dragging the tab to the
% navigation panel.
%
% \begin{figure}[htbp]
%   \centering
%   \includegraphics[width=\linewidth]{articles-ar9}
%   \caption{The \panel{Articles} button and navigation panel in Adobe Reader~9}
%   \label{fig:articles-ar9}
% \end{figure}
%
% I don't know if any \acro{PDF} readers other than Adobe's provide
% special viewing of threads.
%
% \bigskip
%
% Although \pkgname{threadcol} is most beneficial to two-column
% documents, it nevertheless also works with single-column
% documents---and even documents that switch between the two using
% |\onecolumn| and |\twocolumn|.  In fact, although it is typeset in a
% single column, this document is itself threaded using
% \pkgname{threadcol}.  Section~\ref{sec:implementation}, which presents
% the commented \pkgname{threadcol} source code, lies in a thread
% entitled, ``Developer documentation''.
% Sections~\ref{sec:introduction}--\ref{sec:limitations}
% and~\ref{sec:future-work} lie in a thread entitled, ``User
% documentation''.  What this structure implies is that you can
% double-click ``User documentation'' in the
% \Acrobatmenu{ArticleThreads}{Articles navigation panel} then
% repeatedly click (or press \kbd{Enter}) on the document's text to read
% all of the user documentation while automatically skipping the
% developer documentation.  Likewise, double-clicking on ``Developer
% documentation'' takes you right to that, bypassing all of the user
% documentation.
%
% Indexes are not normally read from start to finish so this document's
% index is omitted from both the ``User documentation'' and ``Developer
% documentation'' threads.
%
%
% \section{Usage}
% \label{sec:usage}
%
% One of the \pkgname{threadcol} package's goals is simplicity.  All you
% have to do is include a
% \begin{verbatim}
    \usepackage{threadcol}
% \end{verbatim}
% \unskip\noindent
% in your document's preamble for \pkgname{threadcol} to do its work.
%
% \bigskip
%
% \DescribeMacro{\setthreadname}
% One bit of customization that \pkgname{threadcol} does provide,
% however, is control over the name of the article thread.  By default,
% this is ``Entire document''.  However, if you prefer a different name,
% you can write |\setthreadname{|\meta{name}|}| to change the name of
% the article thread to \meta{name}.  It is in fact permissible to
% invoke |\setthreadname| multiple times and with different names.  In
% this case, \pkgname{threadcol} produces one thread per unique name.
% For example, the document shown in Figure~\ref{fig:articles-ar9} used
% two threads in the following manner:
%
% \bigskip
% \begingroup
%   \obeylines
%   |\setthreadname{Some thread}|
%   \meta{Text for the first thread}
%   |\setthreadname{Another thread}|
%   \meta{Text for the second thread}
%   |\setthreadname{Some thread}|
%   \meta{More text for the first thread}
% \endgroup
% \bigskip
%
% \noindent
% When the user clicks on the ``Some thread'' thread, navigation
% automatically bypasses all text in the ``Another thread'' thread and
% vice versa.  One caveat is that in the current version of
% \pkgname{threadcol}, |\setthreadname| issues a |\clearpage| command to
% ensure that text is assigned to the correct thread.  Hence,
% \pkgname{threadcol} cannot currently be used for sophisticated
% magazine- or newspaper-style documents with intertwined threads
% weaving through the pages.  Still, it may be useful for coarsely
% divided units of text.
%
% As a special case, specifying an empty thread name
% (i.e.,~|\setthreadname{}|) stops adding text to threads.  This can be
% useful for a document's front matter and back matter, which may not
% belong in any thread's normal reading order.
%
%
% \section{Limitations}
% \label{sec:limitations}
%
% \pkgname{threadcol} is a fairly simple package.  As such, it has a
% number of limitations, including the following:
%
% \begin{enumerate}
%   \item \pkgname{threadcol} requires pdf\LaTeX\ or Lua\LaTeX; it does
%     nothing when used with ordinary \LaTeX\ or
%     X\lower0.5ex\hbox{\kern-.15em\reflectbox{E}}\kern-0.1667em\LaTeX\@.
%     The package also relies on \pkgname{etoolbox}, which requires
%     \mbox{$\varepsilon$-\TeX} support, but this is provided by all
%     modern \TeX\ distributions.
%
%   \item \pkgname{threadcol} is incompatible with the
%     \pkgname{fixltx2e} and \pkgname{cuted} packages.  These packages
%     redefine \LaTeX's text-output routines in a manner that confuses
%     \pkgname{threadcol}.
%
%   \item Marginal notes (|\marginpar|) are not included in threads.
%     The same is true for text that sticks out into the margin
%     (e.g.,~using |\llap| or |\rlap|), such as the macro names in
%     Section~\ref{sec:implementation}.
%
%   \item As mentioned in Section~\ref{sec:usage}, threads currently
%     must begin on their own page.  Hence, |\setthreadname| forces a
%     page break, which is often undesirable.
%
%   \item \pkgname{threadcol} does not recognize columns created using
%     the |multicols| environment from the \pkgname{multicol} package.
%     These appear to \pkgname{threadcol} as a single column.
%
%   \item No attempt is made to preserve proper reading order beyond
%     page and column order.  For example, if a page ends with the first
%     part of a sentence and the next page begins with a top float, the
%     thread will present the text in that same order: the first part of
%     the sentence, then the float, then the second part of the
%     sentence.  Even worse, \pkgname{threadcol} is oblivious to
%     footnotes that span columns; it will show the first column of
%     text, including the first part of a long footnote, then the second
%     column of text, which ends with the second part of the long
%     footnote.
%
%   \item The package has not been tested thoroughly.  Consequently,
%     there are probably many more limitations than those listed above.
% \end{enumerate}
%
%
% \StopEventually{^^A
%
% \setthreadname{User documentation}
%
% \section{Future work}
% \label{sec:future-work}
%
% A future version of \pkgname{threadcol} may address some of the
% limitations described in Section~\ref{sec:limitations}.  In addition,
% it would great if the package could integrate seamlessly with the
% \pkgname{flowfram} package, where \acro{PDF} article threads would
% make a lot of sense.
%
% One far more difficult change to implement would be to make
% \pkgname{threadcol} cognizant of the ``true'' reading order, perhaps
% with help from the author.  For example, the author could specify the
% point at which the thread should jump to a floating figure before
% jumping back to the corresponding text.
%
% In practice, \LaTeXe's output routines can be quite arcane, especially
% with regards to the handling of inserts (e.g.,~floats and footnotes).
% Getting \pkgname{threadcol} to do more than what it currently does is
% likely beyond my current level of \LaTeX\ expertise.
%
% }
%
% \setthreadname{Developer documentation}
%
% \section{Implementation}
% \label{sec:implementation}
%
% This section is intended for developers and advanced users to learn
% how \pkgname{threadcol} is implemented.  Most readers can ignore this
% section.
%
% \bigskip
%
% We begin by loading a few helper packages upon which we rely:
% \pkgname{ifpdf} to ensure that we have access to |\pdfstartthread| and
% |\pdfendthread| and \pkgname{etoolbox} for the |\patchcmd| macro.
%    \begin{macrocode}
\RequirePackage{ifpdf}
\RequirePackage{etoolbox}
%    \end{macrocode}
%
% \begin{macro}{\thrcl@thread@name}
% Define the name of the current thread.  This is what shows up in the
% \Acrobatmenu{ArticleThreads}{\panel{Articles} navigation panel} in
% Adobe Acrobat and Adobe Reader.
%    \begin{macrocode}
\def\thrcl@thread@name{Entire document}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\setthreadname}
% Let the author change the name of the current thread
% (i.e.,~|\thrcl@thread@name|).  The starred version suppresses the
% |\clearpage|.
%    \begin{macrocode}
\newcommand*{\setthreadname}{%
  \@ifstar{\gdef\thrcl@thread@name}{\clearpage\gdef\thrcl@thread@name}%
}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\thrcl@threaded@box}
% This is a copy of the column box but surrounded by |\pdfstartthread|
% and |\pdfendthread|.
%    \begin{macrocode}
\newbox\thrcl@threaded@box
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\thrcl@box}
% Mimic \TeX's |\box| primitive but wrap the given box within a
% |\pdfstartthread| and |\pdfendthread|.  If |\thrcl@thread@name| is
% empty, however, invoke |\box| directly.
%    \begin{macrocode}
\def\thrcl@box#1{%
  \ifx\thrcl@thread@name\@empty
    \box#1
  \else
    \setbox\thrcl@threaded@box=\vbox{%
      \pdfstartthread name {\thrcl@thread@name}%
      \copy#1
      \pdfendthread
    }%
    \box\thrcl@threaded@box
  \fi
}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\thrcl@orig@outputpage}
% We want |\thrcl@outputdblcol| to use the original |\@outputpage| but
% all other invocations to use our modified |\@outputpage|.
%    \begin{macrocode}
\let\thrcl@orig@outputpage=\@outputpage
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\thrcl@patchcmd}
% Wrap \pkgname{etoolbox}'s 5-argument |\patchcmd| with a 3-argument
% version that uses hard-wired success and failure operations.  The
% whole command is executed only if all of the previous
% |\thrcl@patchcmd| commands succeeded.
%    \begin{macrocode}
\def\thrcl@patchcmd#1#2#3{%
  \ifx\thrcl@patches@succeeded Y
    \patchcmd{#1}{#2}{#3}{}{\let\thrcl@patches@succeeded=N}%
  \fi
}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\thrcl@outputdblcol}
% \begin{macro}{\thrcl@outputpage}
% \begin{macro}{\thrcl@comdblflelt}
% \begin{macro}{\thrcl@patches@succeeded}
% Replace |\box| with |\thrcl@box| in \LaTeXe's |\@outputdblcol| and
% |\@outputpage| macros, which are used to output a column in,
% respectively, a two-column document or a one-column document.  To
% avoid nesting of |\pdfstartthread|\dots\linebreak[0]|\pdfendthread|,
% we replace calls to |\@outputpage| with calls to
% |\thrcl@orig@outputpage| in |\@outputdblcol|.
%
% Because there we need to apply multiple patches, we attempt to patch
% copies of |\@outputdblcol|, |\@outputpage|, and |\@comdblflelt| and
% replace the originals only if all changes are successful.  We store
% ``|Y|'' in |\thrcl@patches@succeeded| if this is the case,
% otherwise~``|N|''.
%    \begin{macrocode}
\let\thrcl@outputdblcol=\@outputdblcol
\let\thrcl@outputpage=\@outputpage
\let\thrcl@comdblflelt=\@comdblflelt
\let\thrcl@patches@succeeded=Y
\ifpdf
%    \end{macrocode}
% We're in \acro{PDF}-generating mode.  Apply all of our patches.
%    \begin{macrocode}
  \thrcl@patchcmd
    {\thrcl@outputdblcol}%
    {\box\@leftcolumn\hss}%
    {\thrcl@box\@leftcolumn\hss}%
  \thrcl@patchcmd
    {\thrcl@outputdblcol}%
    {\box\@outputbox\hss}%
    {\thrcl@box\@outputbox\hss}%
  \thrcl@patchcmd
    {\thrcl@outputdblcol}%
    {\@outputpage}%
    {\thrcl@orig@outputpage}%
  \thrcl@patchcmd
    {\thrcl@outputdblcol}%
    {\@outputpage}%
    {\thrcl@orig@outputpage}%
  \thrcl@patchcmd
    {\thrcl@outputpage}%
    {\box\@outputbox}%
    {\thrcl@box\@outputbox}%
  \thrcl@patchcmd
    {\thrcl@comdblflelt}%
    {\box}%
    {\thrcl@box}%
  \ifx\thrcl@patches@succeeded Y
%    \end{macrocode}
% All of our patches succeeded.  We can finally redefine
% |\@outputdblcol|, |\@outputpage|, and |\@comdblflelt| for real.
%    \begin{macrocode}
    \global\let\@outputdblcol=\thrcl@outputdblcol
    \global\let\@outputpage=\thrcl@outputpage
    \global\let\@comdblflelt=\thrcl@comdblflelt
  \else
%    \end{macrocode}
% Issue a warning message if any patch failed.  This should happen only
% if a class or package redefines |\@outputdblcol|, |\@outputpage|, or
% |\@comdblflelt| in a manner incompatible with \LaTeXe's default
% definition.
%    \begin{macrocode}
    \PackageError{threadcol}{Failed to patch the output routine}{%
      The threadcol package needs to modify LaTeX's
      \protect\@outputdblcol\space macro to\MessageBreak
      incorporate support for PDF article threads.  These
      modifications failed,\MessageBreak
      presumably due to a class or package that redefined
      \protect\@outputdblcol\space in a\MessageBreak
      form incompatible with what threadcol expects.%
    }%
  \fi
\else
%    \end{macrocode}
% We're not in \acro{PDF}-generating mode.  Warn the author that
% the package will do nothing.
%    \begin{macrocode}
  \PackageWarningNoLine{threadcol}{%
    This package has an effect only when running\MessageBreak
    pdfLaTeX or LuaLaTeX and only when in\MessageBreak
    PDF-generating mode%
  }%
\fi
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \Finale
\endinput