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 #include <QTimer>
  48
  49 using namespace std;
  50 using namespace lyx::support;
  51
  52
  53
  54 namespace {
  55
  56 typedef pair<string, FileName> SnippetPair;
  57
  58 // A list of all snippets to be converted to previews
  59 typedef list<string> PendingSnippets;
  60
  61 // Each item in the vector is a pair<snippet, image file name>.
  62 typedef vector<SnippetPair> BitmapFile;
  63
  64
  65 FileName const unique_tex_filename(FileName const & bufferpath)
  66 {
  67         TempFile tempfile(bufferpath, "lyxpreviewXXXXXX.tex");
  68         tempfile.setAutoRemove(false);
  69         return tempfile.name();
  70 }
  71
  72
  73 lyx::Converter const * setConverter(string const & from)
  74 {
  75         typedef vector<string> FmtList;
  76         typedef lyx::graphics::Cache GCache;
  77         FmtList const & loadableFormats = GCache::get().loadableFormats();
  78         FmtList::const_iterator it = loadableFormats.begin();
  79         FmtList::const_iterator const end = loadableFormats.end();
  80
  81         for (; it != end; ++it) {
  82                 string const to = *it;
  83                 if (from == to)
  84                         continue;
  85
  86                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
  87                 if (ptr)
  88                         return ptr;
  89         }
  90
  91         // FIXME THREAD
  92         static bool first = true;
  93         if (first) {
  94                 first = false;
  95                 LYXERR0("PreviewLoader::startLoading()\n"
  96                         << "No converter from \"" << from << "\" format has been defined.");
  97         }
  98         return 0;
  99 }
 100
 101
 102 void setAscentFractions(vector<double> & ascent_fractions,
 103                         FileName const & metrics_file)
 104 {
 105         // If all else fails, then the images will have equal ascents and
 106         // descents.
 107         vector<double>::iterator it  = ascent_fractions.begin();
 108         vector<double>::iterator end = ascent_fractions.end();
 109         fill(it, end, 0.5);
 110
 111         ifstream in(metrics_file.toFilesystemEncoding().c_str());
 112         if (!in.good()) {
 113                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 114                         << "Unable to open file!");
 115                 return;
 116         }
 117
 118         bool error = false;
 119
 120         int snippet_counter = 1;
 121         while (!in.eof() && it != end) {
 122                 string snippet;
 123                 int id;
 124                 double ascent_fraction;
 125
 126                 in >> snippet >> id >> ascent_fraction;
 127
 128                 if (!in.good())
 129                         // eof after all
 130                         break;
 131
 132                 error = snippet != "Snippet";
 133                 if (error)
 134                         break;
 135
 136                 error = id != snippet_counter;
 137                 if (error)
 138                         break;
 139
 140                 *it = ascent_fraction;
 141
 142                 ++snippet_counter;
 143                 ++it;
 144         }
 145
 146         if (error) {
 147                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 148                         << "Error reading file!\n");
 149         }
 150 }
 151
 152
 153 class FindFirst
 154 {
 155 public:
 156         FindFirst(string const & comp) : comp_(comp) {}
 157         bool operator()(SnippetPair const & sp) const { return sp.first == comp_; }
 158 private:
 159         string const comp_;
 160 };
 161
 162
 163 /// Store info on a currently executing, forked process.
 164 class InProgress {
 165 public:
 166         ///
 167         InProgress() : pid(0) {}
 168         ///
 169         InProgress(string const & filename_base,
 170                    PendingSnippets const & pending,
 171                    string const & to_format);
 172         /// Remove any files left lying around and kill the forked process.
 173         void stop() const;
 174
 175         ///
 176         pid_t pid;
 177         ///
 178         string command;
 179         ///
 180         FileName metrics_file;
 181         ///
 182         BitmapFile snippets;
 183 };
 184
 185 typedef map<pid_t, InProgress>  InProgressProcesses;
 186
 187 typedef InProgressProcesses::value_type InProgressProcess;
 188
 189 } // namespace anon
 190
 191
 192
 193 namespace lyx {
 194 namespace graphics {
 195
 196 class PreviewLoader::Impl : public boost::signals::trackable {
 197 public:
 198         ///
 199         Impl(PreviewLoader & p, Buffer const & b);
 200         /// Stop any InProgress items still executing.
 201         ~Impl();
 202         ///
 203         PreviewImage const * preview(string const & latex_snippet) const;
 204         ///
 205         PreviewLoader::Status status(string const & latex_snippet) const;
 206         ///
 207         void add(string const & latex_snippet);
 208         ///
 209         void remove(string const & latex_snippet);
 210         /// \p wait whether to wait for the process to complete or, instead,
 211         /// to do it in the background.
 212         void startLoading(bool wait = false);
 213         ///
 214         void refreshPreviews();
 215
 216         /// Emit this signal when an image is ready for display.
 217         boost::signal<void(PreviewImage const &)> imageReady;
 218
 219         Buffer const & buffer() const { return buffer_; }
 220
 221 private:
 222         /// Called by the ForkedCall process that generated the bitmap files.
 223         void finishedGenerating(pid_t, int);
 224         ///
 225         void dumpPreamble(otexstream &, OutputParams::FLAVOR) const;
 226         ///
 227         void dumpData(odocstream &, BitmapFile const &) const;
 228
 229         /** cache_ allows easy retrieval of already-generated images
 230          *  using the LaTeX snippet as the identifier.
 231          */
 232         typedef shared_ptr<PreviewImage> PreviewImagePtr;
 233         ///
 234         typedef map<string, PreviewImagePtr> Cache;
 235         ///
 236         Cache cache_;
 237
 238         /** pending_ stores the LaTeX snippets in anticipation of them being
 239          *  sent to the converter.
 240          */
 241         PendingSnippets pending_;
 242
 243         /** in_progress_ stores all forked processes so that we can proceed
 244          *  thereafter.
 245             The map uses the conversion commands as its identifiers.
 246          */
 247         InProgressProcesses in_progress_;
 248
 249         ///
 250         PreviewLoader & parent_;
 251         ///
 252         Buffer const & buffer_;
 253         ///
 254         mutable int font_scaling_factor_;
 255         ///
 256         mutable int fg_color_;
 257         ///
 258         mutable int bg_color_;
 259         ///
 260         QTimer * delay_refresh_;
 261         ///
 262         bool finished_generating_;
 263
 264         /// We don't own this
 265         static lyx::Converter const * pconverter_;
 266 };
 267
 268
 269 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 270
 271
 272 //
 273 // The public interface, defined in PreviewLoader.h
 274 //
 275
 276 PreviewLoader::PreviewLoader(Buffer const & b)
 277         : pimpl_(new Impl(*this, b))
 278 {}
 279
 280
 281 PreviewLoader::~PreviewLoader()
 282 {
 283         delete pimpl_;
 284 }
 285
 286
 287 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 288 {
 289         return pimpl_->preview(latex_snippet);
 290 }
 291
 292
 293 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 294 {
 295         return pimpl_->status(latex_snippet);
 296 }
 297
 298
 299 void PreviewLoader::add(string const & latex_snippet) const
 300 {
 301         pimpl_->add(latex_snippet);
 302 }
 303
 304
 305 void PreviewLoader::remove(string const & latex_snippet) const
 306 {
 307         pimpl_->remove(latex_snippet);
 308 }
 309
 310
 311 void PreviewLoader::startLoading(bool wait) const
 312 {
 313         pimpl_->startLoading(wait);
 314 }
 315
 316
 317 void PreviewLoader::refreshPreviews()
 318 {
 319         pimpl_->refreshPreviews();
 320 }
 321
 322
 323 boost::signals::connection PreviewLoader::connect(slot_type const & slot) const
 324 {
 325         return pimpl_->imageReady.connect(slot);
 326 }
 327
 328
 329 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 330 {
 331         pimpl_->imageReady(pimage);
 332 }
 333
 334
 335 Buffer const & PreviewLoader::buffer() const
 336 {
 337         return pimpl_->buffer();
 338 }
 339
 340 } // namespace graphics
 341 } // namespace lyx
 342
 343
 344 // The details of the Impl
 345 // =======================
 346
 347 namespace {
 348
 349 class IncrementedFileName {
 350 public:
 351         IncrementedFileName(string const & to_format,
 352                             string const & filename_base)
 353                 : to_format_(to_format), base_(filename_base), counter_(1)
 354         {}
 355
 356         SnippetPair const operator()(string const & snippet)
 357         {
 358                 ostringstream os;
 359                 os << base_ << counter_++ << '.' << to_format_;
 360                 string const file = os.str();
 361
 362                 return make_pair(snippet, FileName(file));
 363         }
 364
 365 private:
 366         string const & to_format_;
 367         string const & base_;
 368         int counter_;
 369 };
 370
 371
 372 InProgress::InProgress(string const & filename_base,
 373                        PendingSnippets const & pending,
 374                        string const & to_format)
 375         : pid(0),
 376           metrics_file(filename_base + ".metrics"),
 377           snippets(pending.size())
 378 {
 379         PendingSnippets::const_iterator pit  = pending.begin();
 380         PendingSnippets::const_iterator pend = pending.end();
 381         BitmapFile::iterator sit = snippets.begin();
 382
 383         transform(pit, pend, sit,
 384                        IncrementedFileName(to_format, filename_base));
 385 }
 386
 387
 388 void InProgress::stop() const
 389 {
 390         if (pid)
 391                 ForkedCallsController::kill(pid, 0);
 392
 393         if (!metrics_file.empty())
 394                 metrics_file.removeFile();
 395
 396         BitmapFile::const_iterator vit  = snippets.begin();
 397         BitmapFile::const_iterator vend = snippets.end();
 398         for (; vit != vend; ++vit) {
 399                 if (!vit->second.empty())
 400                         vit->second.removeFile();
 401         }
 402 }
 403
 404 } // namespace anon
 405
 406
 407 namespace lyx {
 408 namespace graphics {
 409
 410 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 411         : parent_(p), buffer_(b), finished_generating_(true)
 412 {
 413         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 414         fg_color_ = strtol(theApp()->hexName(foregroundColor()).c_str(), 0, 16);
 415         bg_color_ = strtol(theApp()->hexName(backgroundColor()).c_str(), 0, 16);
 416         if (!pconverter_)
 417                 pconverter_ = setConverter("lyxpreview");
 418
 419         delay_refresh_ = new QTimer(&parent_);
 420         delay_refresh_->setSingleShot(true);
 421         QObject::connect(delay_refresh_, SIGNAL(timeout()),
 422                          &parent_, SLOT(refreshPreviews()));
 423 }
 424
 425
 426 PreviewLoader::Impl::~Impl()
 427 {
 428         delete delay_refresh_;
 429
 430         InProgressProcesses::iterator ipit  = in_progress_.begin();
 431         InProgressProcesses::iterator ipend = in_progress_.end();
 432
 433         for (; ipit != ipend; ++ipit)
 434                 ipit->second.stop();
 435 }
 436
 437
 438 PreviewImage const *
 439 PreviewLoader::Impl::preview(string const & latex_snippet) const
 440 {
 441         int fs = int(buffer_.fontScalingFactor());
 442         int fg = strtol(theApp()->hexName(foregroundColor()).c_str(), 0, 16);
 443         int bg = strtol(theApp()->hexName(backgroundColor()).c_str(), 0, 16);
 444         if (font_scaling_factor_ != fs || fg_color_ != fg || bg_color_ != bg) {
 445                 // Schedule refresh of all previews on zoom or color changes.
 446                 // The previews are regenerated only after the zoom factor
 447                 // has not been changed for about 1 second.
 448                 fg_color_ = fg;
 449                 bg_color_ = bg;
 450                 delay_refresh_->start(1000);
 451         }
 452         // Don't try to access the cache until we are done.
 453         if (delay_refresh_->isActive() || !finished_generating_)
 454                 return 0;
 455         Cache::const_iterator it = cache_.find(latex_snippet);
 456         return (it == cache_.end()) ? 0 : it->second.get();
 457 }
 458
 459
 460 void PreviewLoader::Impl::refreshPreviews()
 461 {
 462         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 463         // Reschedule refresh until the previous process completed.
 464         if (!finished_generating_) {
 465                 delay_refresh_->start(1000);
 466                 return;
 467         }
 468         Cache::const_iterator cit = cache_.begin();
 469         Cache::const_iterator cend = cache_.end();
 470         while (cit != cend)
 471                 parent_.remove((cit++)->first);
 472         finished_generating_ = false;
 473         buffer_.updatePreviews();
 474 }
 475
 476
 477 namespace {
 478
 479 class FindSnippet {
 480 public:
 481         FindSnippet(string const & s) : snippet_(s) {}
 482         bool operator()(InProgressProcess const & process) const
 483         {
 484                 BitmapFile const & snippets = process.second.snippets;
 485                 BitmapFile::const_iterator beg  = snippets.begin();
 486                 BitmapFile::const_iterator end = snippets.end();
 487                 return find_if(beg, end, FindFirst(snippet_)) != end;
 488         }
 489
 490 private:
 491         string const snippet_;
 492 };
 493
 494 } // namespace anon
 495
 496 PreviewLoader::Status
 497 PreviewLoader::Impl::status(string const & latex_snippet) const
 498 {
 499         Cache::const_iterator cit = cache_.find(latex_snippet);
 500         if (cit != cache_.end())
 501                 return Ready;
 502
 503         PendingSnippets::const_iterator pit  = pending_.begin();
 504         PendingSnippets::const_iterator pend = pending_.end();
 505
 506         pit = find(pit, pend, latex_snippet);
 507         if (pit != pend)
 508                 return InQueue;
 509
 510         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 511         InProgressProcesses::const_iterator ipend = in_progress_.end();
 512
 513         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 514         if (ipit != ipend)
 515                 return Processing;
 516
 517         return NotFound;
 518 }
 519
 520
 521 void PreviewLoader::Impl::add(string const & latex_snippet)
 522 {
 523         if (!pconverter_ || status(latex_snippet) != NotFound)
 524                 return;
 525
 526         string const snippet = trim(latex_snippet);
 527         if (snippet.empty())
 528                 return;
 529
 530         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
 531
 532         pending_.push_back(snippet);
 533 }
 534
 535
 536 namespace {
 537
 538 class EraseSnippet {
 539 public:
 540         EraseSnippet(string const & s) : snippet_(s) {}
 541         void operator()(InProgressProcess & process)
 542         {
 543                 BitmapFile & snippets = process.second.snippets;
 544                 BitmapFile::iterator it  = snippets.begin();
 545                 BitmapFile::iterator end = snippets.end();
 546
 547                 it = find_if(it, end, FindFirst(snippet_));
 548                 if (it != end)
 549                         snippets.erase(it, it+1);
 550         }
 551
 552 private:
 553         string const & snippet_;
 554 };
 555
 556 } // namespace anon
 557
 558
 559 void PreviewLoader::Impl::remove(string const & latex_snippet)
 560 {
 561         Cache::iterator cit = cache_.find(latex_snippet);
 562         if (cit != cache_.end())
 563                 cache_.erase(cit);
 564
 565         PendingSnippets::iterator pit  = pending_.begin();
 566         PendingSnippets::iterator pend = pending_.end();
 567
 568         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 569
 570         InProgressProcesses::iterator ipit  = in_progress_.begin();
 571         InProgressProcesses::iterator ipend = in_progress_.end();
 572
 573         for_each(ipit, ipend, EraseSnippet(latex_snippet));
 574
 575         while (ipit != ipend) {
 576                 InProgressProcesses::iterator curr = ipit++;
 577                 if (curr->second.snippets.empty())
 578                         in_progress_.erase(curr);
 579         }
 580 }
 581
 582
 583 void PreviewLoader::Impl::startLoading(bool wait)
 584 {
 585         if (pending_.empty() || !pconverter_)
 586                 return;
 587
 588         // Only start the process off after the buffer is loaded from file.
 589         if (!buffer_.isFullyLoaded())
 590                 return;
 591
 592         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 593
 594         // As used by the LaTeX file and by the resulting image files
 595         FileName const directory(buffer_.temppath());
 596
 597         FileName const latexfile = unique_tex_filename(directory);
 598         string const filename_base = removeExtension(latexfile.absFileName());
 599
 600         // Create an InProgress instance to place in the map of all
 601         // such processes if it starts correctly.
 602         InProgress inprogress(filename_base, pending_, pconverter_->to());
 603
 604         // clear pending_, so we're ready to start afresh.
 605         pending_.clear();
 606
 607         // Output the LaTeX file.
 608         // we use the encoding of the buffer
 609         Encoding const & enc = buffer_.params().encoding();
 610         ofdocstream of;
 611         try { of.reset(enc.iconvName()); }
 612         catch (iconv_codecvt_facet_exception const & e) {
 613                 LYXERR0("Caught iconv exception: " << e.what()
 614                         << "\nUnable to create LaTeX file: " << latexfile);
 615                 return;
 616         }
 617
 618         TexRow texrow;
 619         otexstream os(of, texrow);
 620         OutputParams runparams(&enc);
 621         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 622
 623         if (!openFileWrite(of, latexfile))
 624                 return;
 625
 626         if (!of) {
 627                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 628                                         << "Unable to create LaTeX file\n" << latexfile);
 629                 return;
 630         }
 631         of << "\\batchmode\n";
 632
 633         LYXERR(Debug::LATEX, "Format = " << buffer_.params().getDefaultOutputFormat());
 634         string latexparam = "";
 635         bool docformat = !buffer_.params().default_output_format.empty()
 636                         && buffer_.params().default_output_format != "default";
 637         // Use LATEX flavor if the document does not specify a specific
 638         // output format (see bug 9371).
 639         OutputParams::FLAVOR flavor = docformat
 640                                         ? buffer_.params().getOutputFlavor()
 641                                         : OutputParams::LATEX;
 642         if (buffer_.params().encoding().package() == Encoding::japanese) {
 643                 latexparam = " --latex=platex";
 644                 flavor = OutputParams::LATEX;
 645         }
 646         else if (buffer_.params().useNonTeXFonts) {
 647                 if (flavor == OutputParams::LUATEX)
 648                         latexparam = " --latex=lualatex";
 649                 else {
 650                         flavor = OutputParams::XETEX;
 651                         latexparam = " --latex=xelatex";
 652                 }
 653         }
 654         else {
 655                 switch (flavor) {
 656                         case OutputParams::PDFLATEX:
 657                                 latexparam = " --latex=pdflatex";
 658                                 break;
 659                         case OutputParams::XETEX:
 660                                 latexparam = " --latex=xelatex";
 661                                 break;
 662                         case OutputParams::LUATEX:
 663                                 latexparam = " --latex=lualatex";
 664                                 break;
 665                         case OutputParams::DVILUATEX:
 666                                 latexparam = " --latex=dvilualatex";
 667                                 break;
 668                         default:
 669                                 flavor = OutputParams::LATEX;
 670                 }
 671         }
 672         dumpPreamble(os, flavor);
 673         // handle inputenc etc.
 674         // I think, this is already hadled by dumpPreamble(): Kornel
 675         // buffer_.params().writeEncodingPreamble(os, features);
 676         of << "\n\\begin{document}\n";
 677         dumpData(of, inprogress.snippets);
 678         of << "\n\\end{document}\n";
 679         of.close();
 680         if (of.fail()) {
 681                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 682                                          << "File was not closed properly.");
 683                 return;
 684         }
 685
 686         // The conversion command.
 687         ostringstream cs;
 688         cs << pconverter_->command()
 689            << " " << quoteName(latexfile.toFilesystemEncoding())
 690            << " --dpi " << font_scaling_factor_;
 691
 692         // FIXME XHTML
 693         // The colors should be customizable.
 694         if (!buffer_.isExporting()) {
 695                 ColorCode const fg = PreviewLoader::foregroundColor();
 696                 ColorCode const bg = PreviewLoader::backgroundColor();
 697                 cs << " --fg " << theApp()->hexName(fg)
 698                    << " --bg " << theApp()->hexName(bg);
 699         }
 700
 701         cs << latexparam;
 702         if (buffer_.params().bibtex_command != "default")
 703                 cs << " --bibtex=" << quoteName(buffer_.params().bibtex_command);
 704         else if (buffer_.params().encoding().package() == Encoding::japanese)
 705                 cs << " --bibtex=" << quoteName(lyxrc.jbibtex_command);
 706         else
 707                 cs << " --bibtex=" << quoteName(lyxrc.bibtex_command);
 708         if (buffer_.params().bufferFormat() == "lilypond-book")
 709                 cs << " --lilypond";
 710
 711         string const command = cs.str();
 712
 713         if (wait) {
 714                 ForkedCall call(buffer_.filePath(), buffer_.layoutPos());
 715                 int ret = call.startScript(ForkedProcess::Wait, command);
 716                 // FIXME THREAD
 717                 static int fake = (2^20) + 1;
 718                 int pid = fake++;
 719                 inprogress.pid = pid;
 720                 inprogress.command = command;
 721                 in_progress_[pid] = inprogress;
 722                 finishedGenerating(pid, ret);
 723                 return;
 724         }
 725
 726         // Initiate the conversion from LaTeX to bitmap images files.
 727         ForkedCall::SignalTypePtr
 728                 convert_ptr(new ForkedCall::SignalType);
 729         convert_ptr->connect(bind(&Impl::finishedGenerating, this, _1, _2));
 730
 731         ForkedCall call(buffer_.filePath());
 732         int ret = call.startScript(command, convert_ptr);
 733
 734         if (ret != 0) {
 735                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 736                                         << "Unable to start process\n" << command);
 737                 return;
 738         }
 739
 740         // Store the generation process in a list of all such processes
 741         inprogress.pid = call.pid();
 742         inprogress.command = command;
 743         in_progress_[inprogress.pid] = inprogress;
 744 }
 745
 746
 747 double PreviewLoader::displayPixelRatio() const
 748 {
 749         return buffer().params().display_pixel_ratio;
 750 }
 751
 752 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 753 {
 754         // Paranoia check!
 755         InProgressProcesses::iterator git = in_progress_.find(pid);
 756         if (git == in_progress_.end()) {
 757                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 758                         "data for PID " << pid << endl;
 759                 finished_generating_ = true;
 760                 return;
 761         }
 762
 763         string const command = git->second.command;
 764         string const status = retval > 0 ? "failed" : "succeeded";
 765         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 766                                 << retval << "): processing " << status
 767                                 << " for " << command);
 768         if (retval > 0) {
 769                 in_progress_.erase(git);
 770                 finished_generating_ = true;
 771                 return;
 772         }
 773
 774         // Read the metrics file, if it exists
 775         vector<double> ascent_fractions(git->second.snippets.size());
 776         setAscentFractions(ascent_fractions, git->second.metrics_file);
 777
 778         // Add these newly generated bitmap files to the cache and
 779         // start loading them into LyX.
 780         BitmapFile::const_iterator it  = git->second.snippets.begin();
 781         BitmapFile::const_iterator end = git->second.snippets.end();
 782
 783         list<PreviewImagePtr> newimages;
 784
 785         int metrics_counter = 0;
 786         for (; it != end; ++it, ++metrics_counter) {
 787                 string const & snip = it->first;
 788                 FileName const & file = it->second;
 789                 double af = ascent_fractions[metrics_counter];
 790
 791                 // Add the image to the cache only if it's actually present
 792                 // and not empty (an empty image is signaled by af < 0)
 793                 if (af >= 0 && file.isReadableFile()) {
 794                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 795                         cache_[snip] = ptr;
 796
 797                         newimages.push_back(ptr);
 798                 }
 799
 800         }
 801
 802         // Remove the item from the list of still-executing processes.
 803         in_progress_.erase(git);
 804
 805         // Tell the outside world
 806         list<PreviewImagePtr>::const_reverse_iterator
 807                 nit  = newimages.rbegin();
 808         list<PreviewImagePtr>::const_reverse_iterator
 809                 nend = newimages.rend();
 810         for (; nit != nend; ++nit) {
 811                 imageReady(*nit->get());
 812         }
 813         finished_generating_ = true;
 814 }
 815
 816
 817 void PreviewLoader::Impl::dumpPreamble(otexstream & os, OutputParams::FLAVOR flavor) const
 818 {
 819         // Dump the preamble only.
 820         LYXERR(Debug::LATEX, "dumpPreamble, flavor == " << flavor);
 821         OutputParams runparams(&buffer_.params().encoding());
 822         runparams.flavor = flavor;
 823         runparams.nice = true;
 824         runparams.moving_arg = true;
 825         runparams.free_spacing = true;
 826         runparams.is_child = buffer_.parent();
 827         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 828
 829         // FIXME! This is a HACK! The proper fix is to control the 'true'
 830         // passed to WriteStream below:
 831         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 832         //                          OutputParams const & runparams) const
 833         // {
 834         //      WriteStream wi(os, runparams.moving_arg, true);
 835         //      par_->write(wi);
 836         //      return wi.line();
 837         // }
 838         os << "\n"
 839            << "\\def\\lyxlock{}\n"
 840            << "\n";
 841
 842         // All equation labels appear as "(#)" + preview.sty's rendering of
 843         // the label name
 844         if (lyxrc.preview_hashed_labels)
 845                 os << "\\renewcommand{\\theequation}{\\#}\n";
 846
 847         // Use the preview style file to ensure that each snippet appears on a
 848         // fresh page.
 849         // Also support PDF output (automatically generated e.g. when
 850         // \usepackage[pdftex]{hyperref} is used and XeTeX.
 851         os << "\n"
 852            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
 853            << "\n";
 854 }
 855
 856
 857 void PreviewLoader::Impl::dumpData(odocstream & os,
 858                                    BitmapFile const & vec) const
 859 {
 860         if (vec.empty())
 861                 return;
 862
 863         BitmapFile::const_iterator it  = vec.begin();
 864         BitmapFile::const_iterator end = vec.end();
 865
 866         for (; it != end; ++it) {
 867                 // FIXME UNICODE
 868                 os << "\\begin{preview}\n"
 869                    << from_utf8(it->first)
 870                    << "\n\\end{preview}\n\n";
 871         }
 872 }
 873
 874 } // namespace graphics
 875 } // namespace lyx
 876
 877 #include "moc_PreviewLoader.cpp"