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[features.git] / src / graphics / PreviewLoader.cpp
1 /**
2  * \file PreviewLoader.cpp
3  * This file is part of LyX, the document processor.
4  * Licence details can be found in the file COPYING.
5  *
6  * \author Angus Leeming
7  *
8  * Full author contact details are available in file CREDITS.
9  */
10
11 #include <config.h>
12
13 #include "PreviewLoader.h"
14 #include "PreviewImage.h"
15 #include "GraphicsCache.h"
16
17 #include "Buffer.h"
18 #include "BufferParams.h"
19 #include "Converter.h"
20 #include "Encoding.h"
21 #include "Format.h"
22 #include "InsetIterator.h"
23 #include "LaTeXFeatures.h"
24 #include "LyXRC.h"
25 #include "output.h"
26 #include "OutputParams.h"
27 #include "TexRow.h"
28
29 #include "frontends/Application.h" // hexName
30
31 #include "insets/Inset.h"
32
33 #include "support/convert.h"
34 #include "support/debug.h"
35 #include "support/FileName.h"
36 #include "support/filetools.h"
37 #include "support/ForkedCalls.h"
38 #include "support/lstrings.h"
39
40 #include "support/bind.h"
41 #include "support/TempFile.h"
42
43 #include <sstream>
44 #include <fstream>
45 #include <iomanip>
46
47 using namespace std;
48 using namespace lyx::support;
49
50
51
52 namespace {
53
54 typedef pair<string, FileName> SnippetPair;
55
56 // A list of all snippets to be converted to previews
57 typedef list<string> PendingSnippets;
58
59 // Each item in the vector is a pair<snippet, image file name>.
60 typedef vector<SnippetPair> BitmapFile;
61
62
63 FileName const unique_tex_filename(FileName const & bufferpath)
64 {
65         TempFile tempfile(bufferpath, "lyxpreviewXXXXXX.tex");
66         tempfile.setAutoRemove(false);
67         return tempfile.name();
68 }
69
70
71 lyx::Converter const * setConverter(string const & from)
72 {
73         typedef vector<string> FmtList;
74         typedef lyx::graphics::Cache GCache;
75         FmtList const & loadableFormats = GCache::get().loadableFormats();
76         FmtList::const_iterator it = loadableFormats.begin();
77         FmtList::const_iterator const end = loadableFormats.end();
78
79         for (; it != end; ++it) {
80                 string const to = *it;
81                 if (from == to)
82                         continue;
83
84                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
85                 if (ptr)
86                         return ptr;
87         }
88
89         // FIXME THREAD
90         static bool first = true;
91         if (first) {
92                 first = false;
93                 LYXERR0("PreviewLoader::startLoading()\n"
94                         << "No converter from \"" << from << "\" format has been defined.");
95         }
96         return 0;
97 }
98
99
100 void setAscentFractions(vector<double> & ascent_fractions,
101                         FileName const & metrics_file)
102 {
103         // If all else fails, then the images will have equal ascents and
104         // descents.
105         vector<double>::iterator it  = ascent_fractions.begin();
106         vector<double>::iterator end = ascent_fractions.end();
107         fill(it, end, 0.5);
108
109         ifstream in(metrics_file.toFilesystemEncoding().c_str());
110         if (!in.good()) {
111                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
112                         << "Unable to open file!");
113                 return;
114         }
115
116         bool error = false;
117
118         int snippet_counter = 1;
119         while (!in.eof() && it != end) {
120                 string snippet;
121                 int id;
122                 double ascent_fraction;
123
124                 in >> snippet >> id >> ascent_fraction;
125
126                 if (!in.good())
127                         // eof after all
128                         break;
129
130                 error = snippet != "Snippet";
131                 if (error)
132                         break;
133
134                 error = id != snippet_counter;
135                 if (error)
136                         break;
137
138                 *it = ascent_fraction;
139
140                 ++snippet_counter;
141                 ++it;
142         }
143
144         if (error) {
145                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
146                         << "Error reading file!\n");
147         }
148 }
149
150
151 class FindFirst
152 {
153 public:
154         FindFirst(string const & comp) : comp_(comp) {}
155         bool operator()(SnippetPair const & sp) const { return sp.first == comp_; }
156 private:
157         string const comp_;
158 };
159
160
161 /// Store info on a currently executing, forked process.
162 class InProgress {
163 public:
164         ///
165         InProgress() : pid(0) {}
166         ///
167         InProgress(string const & filename_base,
168                    PendingSnippets const & pending,
169                    string const & to_format);
170         /// Remove any files left lying around and kill the forked process.
171         void stop() const;
172
173         ///
174         pid_t pid;
175         ///
176         string command;
177         ///
178         FileName metrics_file;
179         ///
180         BitmapFile snippets;
181 };
182
183 typedef map<pid_t, InProgress>  InProgressProcesses;
184
185 typedef InProgressProcesses::value_type InProgressProcess;
186
187 } // namespace anon
188
189
190
191 namespace lyx {
192 namespace graphics {
193
194 class PreviewLoader::Impl : public boost::signals::trackable {
195 public:
196         ///
197         Impl(PreviewLoader & p, Buffer const & b);
198         /// Stop any InProgress items still executing.
199         ~Impl();
200         ///
201         PreviewImage const * preview(string const & latex_snippet) const;
202         ///
203         PreviewLoader::Status status(string const & latex_snippet) const;
204         ///
205         void add(string const & latex_snippet);
206         ///
207         void remove(string const & latex_snippet);
208         /// \p wait whether to wait for the process to complete or, instead,
209         /// to do it in the background.
210         void startLoading(bool wait = false);
211
212         /// Emit this signal when an image is ready for display.
213         boost::signal<void(PreviewImage const &)> imageReady;
214
215         Buffer const & buffer() const { return buffer_; }
216
217 private:
218         /// Called by the ForkedCall process that generated the bitmap files.
219         void finishedGenerating(pid_t, int);
220         ///
221         void dumpPreamble(otexstream &, OutputParams::FLAVOR) const;
222         ///
223         void dumpData(odocstream &, BitmapFile const &) const;
224
225         /** cache_ allows easy retrieval of already-generated images
226          *  using the LaTeX snippet as the identifier.
227          */
228         typedef shared_ptr<PreviewImage> PreviewImagePtr;
229         ///
230         typedef map<string, PreviewImagePtr> Cache;
231         ///
232         Cache cache_;
233
234         /** pending_ stores the LaTeX snippets in anticipation of them being
235          *  sent to the converter.
236          */
237         PendingSnippets pending_;
238
239         /** in_progress_ stores all forked processes so that we can proceed
240          *  thereafter.
241             The map uses the conversion commands as its identifiers.
242          */
243         InProgressProcesses in_progress_;
244
245         ///
246         PreviewLoader & parent_;
247         ///
248         Buffer const & buffer_;
249         ///
250         mutable int font_scaling_factor_;
251
252         /// We don't own this
253         static lyx::Converter const * pconverter_;
254 };
255
256
257 lyx::Converter const * PreviewLoader::Impl::pconverter_;
258
259
260 //
261 // The public interface, defined in PreviewLoader.h
262 //
263
264 PreviewLoader::PreviewLoader(Buffer const & b)
265         : pimpl_(new Impl(*this, b))
266 {}
267
268
269 PreviewLoader::~PreviewLoader()
270 {
271         delete pimpl_;
272 }
273
274
275 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
276 {
277         return pimpl_->preview(latex_snippet);
278 }
279
280
281 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
282 {
283         return pimpl_->status(latex_snippet);
284 }
285
286
287 void PreviewLoader::add(string const & latex_snippet) const
288 {
289         pimpl_->add(latex_snippet);
290 }
291
292
293 void PreviewLoader::remove(string const & latex_snippet) const
294 {
295         pimpl_->remove(latex_snippet);
296 }
297
298
299 void PreviewLoader::startLoading(bool wait) const
300 {
301         pimpl_->startLoading(wait);
302 }
303
304
305 boost::signals::connection PreviewLoader::connect(slot_type const & slot) const
306 {
307         return pimpl_->imageReady.connect(slot);
308 }
309
310
311 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
312 {
313         pimpl_->imageReady(pimage);
314 }
315
316
317 Buffer const & PreviewLoader::buffer() const
318 {
319         return pimpl_->buffer();
320 }
321
322 } // namespace graphics
323 } // namespace lyx
324
325
326 // The details of the Impl
327 // =======================
328
329 namespace {
330
331 class IncrementedFileName {
332 public:
333         IncrementedFileName(string const & to_format,
334                             string const & filename_base)
335                 : to_format_(to_format), base_(filename_base), counter_(1)
336         {}
337
338         SnippetPair const operator()(string const & snippet)
339         {
340                 ostringstream os;
341                 os << base_ << counter_++ << '.' << to_format_;
342                 string const file = os.str();
343
344                 return make_pair(snippet, FileName(file));
345         }
346
347 private:
348         string const & to_format_;
349         string const & base_;
350         int counter_;
351 };
352
353
354 InProgress::InProgress(string const & filename_base,
355                        PendingSnippets const & pending,
356                        string const & to_format)
357         : pid(0),
358           metrics_file(filename_base + ".metrics"),
359           snippets(pending.size())
360 {
361         PendingSnippets::const_iterator pit  = pending.begin();
362         PendingSnippets::const_iterator pend = pending.end();
363         BitmapFile::iterator sit = snippets.begin();
364
365         transform(pit, pend, sit,
366                        IncrementedFileName(to_format, filename_base));
367 }
368
369
370 void InProgress::stop() const
371 {
372         if (pid)
373                 ForkedCallsController::kill(pid, 0);
374
375         if (!metrics_file.empty())
376                 metrics_file.removeFile();
377
378         BitmapFile::const_iterator vit  = snippets.begin();
379         BitmapFile::const_iterator vend = snippets.end();
380         for (; vit != vend; ++vit) {
381                 if (!vit->second.empty())
382                         vit->second.removeFile();
383         }
384 }
385
386 } // namespace anon
387
388
389 namespace lyx {
390 namespace graphics {
391
392 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
393         : parent_(p), buffer_(b)
394 {
395         font_scaling_factor_ = int(buffer_.fontScalingFactor());
396         if (!pconverter_)
397                 pconverter_ = setConverter("lyxpreview");
398 }
399
400
401 PreviewLoader::Impl::~Impl()
402 {
403         InProgressProcesses::iterator ipit  = in_progress_.begin();
404         InProgressProcesses::iterator ipend = in_progress_.end();
405
406         for (; ipit != ipend; ++ipit)
407                 ipit->second.stop();
408 }
409
410
411 PreviewImage const *
412 PreviewLoader::Impl::preview(string const & latex_snippet) const
413 {
414         int fs = int(buffer_.fontScalingFactor());
415         if (font_scaling_factor_ != fs) {
416                 // Refresh all previews on zoom changes
417                 font_scaling_factor_ = fs;
418                 Cache::const_iterator cit = cache_.begin();
419                 Cache::const_iterator cend = cache_.end();
420                 while (cit != cend) {
421                         string const snippet = (cit++)->first;
422                         parent_.remove(snippet);
423                         parent_.add(snippet);
424                 }
425                 parent_.startLoading(false);
426         }
427         Cache::const_iterator it = cache_.find(latex_snippet);
428         return (it == cache_.end()) ? 0 : it->second.get();
429 }
430
431
432 namespace {
433
434 class FindSnippet {
435 public:
436         FindSnippet(string const & s) : snippet_(s) {}
437         bool operator()(InProgressProcess const & process) const
438         {
439                 BitmapFile const & snippets = process.second.snippets;
440                 BitmapFile::const_iterator beg  = snippets.begin();
441                 BitmapFile::const_iterator end = snippets.end();
442                 return find_if(beg, end, FindFirst(snippet_)) != end;
443         }
444
445 private:
446         string const snippet_;
447 };
448
449 } // namespace anon
450
451 PreviewLoader::Status
452 PreviewLoader::Impl::status(string const & latex_snippet) const
453 {
454         Cache::const_iterator cit = cache_.find(latex_snippet);
455         if (cit != cache_.end())
456                 return Ready;
457
458         PendingSnippets::const_iterator pit  = pending_.begin();
459         PendingSnippets::const_iterator pend = pending_.end();
460
461         pit = find(pit, pend, latex_snippet);
462         if (pit != pend)
463                 return InQueue;
464
465         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
466         InProgressProcesses::const_iterator ipend = in_progress_.end();
467
468         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
469         if (ipit != ipend)
470                 return Processing;
471
472         return NotFound;
473 }
474
475
476 void PreviewLoader::Impl::add(string const & latex_snippet)
477 {
478         if (!pconverter_ || status(latex_snippet) != NotFound)
479                 return;
480
481         string const snippet = trim(latex_snippet);
482         if (snippet.empty())
483                 return;
484
485         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
486
487         pending_.push_back(snippet);
488 }
489
490
491 namespace {
492
493 class EraseSnippet {
494 public:
495         EraseSnippet(string const & s) : snippet_(s) {}
496         void operator()(InProgressProcess & process)
497         {
498                 BitmapFile & snippets = process.second.snippets;
499                 BitmapFile::iterator it  = snippets.begin();
500                 BitmapFile::iterator end = snippets.end();
501
502                 it = find_if(it, end, FindFirst(snippet_));
503                 if (it != end)
504                         snippets.erase(it, it+1);
505         }
506
507 private:
508         string const & snippet_;
509 };
510
511 } // namespace anon
512
513
514 void PreviewLoader::Impl::remove(string const & latex_snippet)
515 {
516         Cache::iterator cit = cache_.find(latex_snippet);
517         if (cit != cache_.end())
518                 cache_.erase(cit);
519
520         PendingSnippets::iterator pit  = pending_.begin();
521         PendingSnippets::iterator pend = pending_.end();
522
523         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
524
525         InProgressProcesses::iterator ipit  = in_progress_.begin();
526         InProgressProcesses::iterator ipend = in_progress_.end();
527
528         for_each(ipit, ipend, EraseSnippet(latex_snippet));
529
530         while (ipit != ipend) {
531                 InProgressProcesses::iterator curr = ipit++;
532                 if (curr->second.snippets.empty())
533                         in_progress_.erase(curr);
534         }
535 }
536
537
538 void PreviewLoader::Impl::startLoading(bool wait)
539 {
540         if (pending_.empty() || !pconverter_)
541                 return;
542
543         // Only start the process off after the buffer is loaded from file.
544         if (!buffer_.isFullyLoaded())
545                 return;
546
547         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
548
549         // As used by the LaTeX file and by the resulting image files
550         FileName const directory(buffer_.temppath());
551
552         FileName const latexfile = unique_tex_filename(directory);
553         string const filename_base = removeExtension(latexfile.absFileName());
554
555         // Create an InProgress instance to place in the map of all
556         // such processes if it starts correctly.
557         InProgress inprogress(filename_base, pending_, pconverter_->to());
558
559         // clear pending_, so we're ready to start afresh.
560         pending_.clear();
561
562         // Output the LaTeX file.
563         // we use the encoding of the buffer
564         Encoding const & enc = buffer_.params().encoding();
565         ofdocstream of;
566         try { of.reset(enc.iconvName()); }
567         catch (iconv_codecvt_facet_exception const & e) {
568                 LYXERR0("Caught iconv exception: " << e.what()
569                         << "\nUnable to create LaTeX file: " << latexfile);
570                 return;
571         }
572
573         TexRow texrow;
574         otexstream os(of, texrow);
575         OutputParams runparams(&enc);
576         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
577
578         if (!openFileWrite(of, latexfile))
579                 return;
580
581         if (!of) {
582                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
583                                         << "Unable to create LaTeX file\n" << latexfile);
584                 return;
585         }
586         of << "\\batchmode\n";
587
588         LYXERR(Debug::LATEX, "Format = " << buffer_.params().getDefaultOutputFormat());
589         string latexparam = "";
590         OutputParams::FLAVOR flavor = buffer_.params().getOutputFlavor();
591         if (buffer_.params().encoding().package() == Encoding::japanese) {
592                 latexparam = " --latex=platex";
593                 flavor = OutputParams::LATEX;
594         }
595         else if (buffer_.params().useNonTeXFonts) {
596                 if (flavor == OutputParams::LUATEX)
597                         latexparam = " --latex=lualatex";
598                 else {
599                         flavor = OutputParams::XETEX;
600                         latexparam = " --latex=xelatex";
601                 }
602         }
603         else {
604                 switch (flavor) {
605                         case OutputParams::PDFLATEX:
606                                 latexparam = " --latex=pdflatex";
607                                 break;
608                         case OutputParams::XETEX:
609                                 latexparam = " --latex=xelatex";
610                                 break;
611                         case OutputParams::LUATEX:
612                                 latexparam = " --latex=lualatex";
613                                 break;
614                         case OutputParams::DVILUATEX:
615                                 latexparam = " --latex=dvilualatex";
616                                 break;
617                         default:
618                                 flavor = OutputParams::LATEX;
619                 }
620         }
621         dumpPreamble(os, flavor);
622         // handle inputenc etc.
623         // I think, this is already hadled by dumpPreamble(): Kornel
624         // buffer_.params().writeEncodingPreamble(os, features);
625         of << "\n\\begin{document}\n";
626         dumpData(of, inprogress.snippets);
627         of << "\n\\end{document}\n";
628         of.close();
629         if (of.fail()) {
630                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
631                                          << "File was not closed properly.");
632                 return;
633         }
634
635         // The conversion command.
636         ostringstream cs;
637         cs << pconverter_->command()
638            << " " << quoteName(latexfile.toFilesystemEncoding())
639            << " --dpi " << font_scaling_factor_;
640
641         // FIXME XHTML 
642         // The colors should be customizable.
643         if (!buffer_.isExporting()) {
644                 ColorCode const fg = PreviewLoader::foregroundColor();
645                 ColorCode const bg = PreviewLoader::backgroundColor();
646                 cs << " --fg " << theApp()->hexName(fg) 
647                    << " --bg " << theApp()->hexName(bg);
648         }
649
650         cs << latexparam;
651         if (buffer_.params().bibtex_command != "default")
652                 cs << " --bibtex=" << quoteName(buffer_.params().bibtex_command);
653         else if (buffer_.params().encoding().package() == Encoding::japanese)
654                 cs << " --bibtex=" << quoteName(lyxrc.jbibtex_command);
655         else
656                 cs << " --bibtex=" << quoteName(lyxrc.bibtex_command);
657         if (buffer_.params().bufferFormat() == "lilypond-book")
658                 cs << " --lilypond";
659
660         string const command = cs.str();
661
662         if (wait) {
663                 ForkedCall call(buffer_.filePath());
664                 int ret = call.startScript(ForkedProcess::Wait, command);
665                 // FIXME THREAD
666                 static int fake = (2^20) + 1;
667                 int pid = fake++;
668                 inprogress.pid = pid;
669                 inprogress.command = command;
670                 in_progress_[pid] = inprogress;
671                 finishedGenerating(pid, ret);
672                 return;
673         }
674
675         // Initiate the conversion from LaTeX to bitmap images files.
676         ForkedCall::SignalTypePtr
677                 convert_ptr(new ForkedCall::SignalType);
678         convert_ptr->connect(bind(&Impl::finishedGenerating, this, _1, _2));
679
680         ForkedCall call(buffer_.filePath());
681         int ret = call.startScript(command, convert_ptr);
682
683         if (ret != 0) {
684                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
685                                         << "Unable to start process\n" << command);
686                 return;
687         }
688
689         // Store the generation process in a list of all such processes
690         inprogress.pid = call.pid();
691         inprogress.command = command;
692         in_progress_[inprogress.pid] = inprogress;
693 }
694
695
696 double PreviewLoader::displayPixelRatio() const
697 {
698         return buffer().params().display_pixel_ratio;
699 }
700
701 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
702 {
703         // Paranoia check!
704         InProgressProcesses::iterator git = in_progress_.find(pid);
705         if (git == in_progress_.end()) {
706                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
707                         "data for PID " << pid << endl;
708                 return;
709         }
710
711         string const command = git->second.command;
712         string const status = retval > 0 ? "failed" : "succeeded";
713         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
714                                 << retval << "): processing " << status
715                                 << " for " << command);
716         if (retval > 0)
717                 return;
718
719         // Read the metrics file, if it exists
720         vector<double> ascent_fractions(git->second.snippets.size());
721         setAscentFractions(ascent_fractions, git->second.metrics_file);
722
723         // Add these newly generated bitmap files to the cache and
724         // start loading them into LyX.
725         BitmapFile::const_iterator it  = git->second.snippets.begin();
726         BitmapFile::const_iterator end = git->second.snippets.end();
727
728         list<PreviewImagePtr> newimages;
729
730         int metrics_counter = 0;
731         for (; it != end; ++it, ++metrics_counter) {
732                 string const & snip = it->first;
733                 FileName const & file = it->second;
734                 double af = ascent_fractions[metrics_counter];
735
736                 // Add the image to the cache only if it's actually present
737                 // and not empty (an empty image is signaled by af < 0)
738                 if (af >= 0 && file.isReadableFile()) {
739                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
740                         cache_[snip] = ptr;
741
742                         newimages.push_back(ptr);
743                 }
744
745         }
746
747         // Remove the item from the list of still-executing processes.
748         in_progress_.erase(git);
749
750         // Tell the outside world
751         list<PreviewImagePtr>::const_reverse_iterator
752                 nit  = newimages.rbegin();
753         list<PreviewImagePtr>::const_reverse_iterator
754                 nend = newimages.rend();
755         for (; nit != nend; ++nit) {
756                 imageReady(*nit->get());
757         }
758 }
759
760
761 void PreviewLoader::Impl::dumpPreamble(otexstream & os, OutputParams::FLAVOR flavor) const
762 {
763         // Dump the preamble only.
764         LYXERR(Debug::LATEX, "dumpPreamble, flavor == " << flavor);
765         OutputParams runparams(&buffer_.params().encoding());
766         runparams.flavor = flavor;
767         runparams.nice = true;
768         runparams.moving_arg = true;
769         runparams.free_spacing = true;
770         runparams.is_child = buffer_.parent();
771         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
772
773         // FIXME! This is a HACK! The proper fix is to control the 'true'
774         // passed to WriteStream below:
775         // int InsetMathNest::latex(Buffer const &, odocstream & os,
776         //                          OutputParams const & runparams) const
777         // {
778         //      WriteStream wi(os, runparams.moving_arg, true);
779         //      par_->write(wi);
780         //      return wi.line();
781         // }
782         os << "\n"
783            << "\\def\\lyxlock{}\n"
784            << "\n";
785
786         // All equation labels appear as "(#)" + preview.sty's rendering of
787         // the label name
788         if (lyxrc.preview_hashed_labels)
789                 os << "\\renewcommand{\\theequation}{\\#}\n";
790
791         // Use the preview style file to ensure that each snippet appears on a
792         // fresh page.
793         // Also support PDF output (automatically generated e.g. when
794         // \usepackage[pdftex]{hyperref} is used and XeTeX.
795         os << "\n"
796            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
797            << "\n";
798 }
799
800
801 void PreviewLoader::Impl::dumpData(odocstream & os,
802                                    BitmapFile const & vec) const
803 {
804         if (vec.empty())
805                 return;
806
807         BitmapFile::const_iterator it  = vec.begin();
808         BitmapFile::const_iterator end = vec.end();
809
810         for (; it != end; ++it) {
811                 // FIXME UNICODE
812                 os << "\\begin{preview}\n"
813                    << from_utf8(it->first)
814                    << "\n\\end{preview}\n\n";
815         }
816 }
817
818 } // namespace graphics
819 } // namespace lyx