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 "LaTeXFeatures.h"
  23 #include "LyXRC.h"
  24 #include "output.h"
  25 #include "OutputParams.h"
  26 #include "TexRow.h"
  27 #include "texstream.h"
  28
  29 #include "frontends/Application.h" // hexName
  30
  31 #include "support/convert.h"
  32 #include "support/debug.h"
  33 #include "support/FileName.h"
  34 #include "support/filetools.h"
  35 #include "support/ForkedCalls.h"
  36 #include "support/lstrings.h"
  37
  38 #include "support/TempFile.h"
  39
  40 #include <atomic>
  41 #include <fstream>
  42 #include <iomanip>
  43 #include <memory>
  44 #include <mutex>
  45 #include <sstream>
  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 void setAscentFractions(vector<double> & ascent_fractions,
  74                         FileName const & metrics_file)
  75 {
  76         // If all else fails, then the images will have equal ascents and
  77         // descents.
  78         vector<double>::iterator it  = ascent_fractions.begin();
  79         vector<double>::iterator end = ascent_fractions.end();
  80         fill(it, end, 0.5);
  81
  82         ifstream in(metrics_file.toFilesystemEncoding().c_str());
  83         if (!in.good()) {
  84                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
  85                         << "Unable to open file!");
  86                 return;
  87         }
  88
  89         bool error = false;
  90
  91         int snippet_counter = 1;
  92         while (!in.eof() && it != end) {
  93                 string snippet;
  94                 int id;
  95                 double ascent_fraction;
  96
  97                 in >> snippet >> id >> ascent_fraction;
  98
  99                 if (!in.good())
 100                         // eof after all
 101                         break;
 102
 103                 error = snippet != "Snippet";
 104                 if (error)
 105                         break;
 106
 107                 error = id != snippet_counter;
 108                 if (error)
 109                         break;
 110
 111                 *it = ascent_fraction;
 112
 113                 ++snippet_counter;
 114                 ++it;
 115         }
 116
 117         if (error) {
 118                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 119                         << "Error reading file!\n");
 120         }
 121 }
 122
 123
 124 std::function <bool (SnippetPair const &)> FindFirst(string const & comp)
 125 {
 126         return [&comp](SnippetPair const & sp) { return sp.first == comp; };
 127 }
 128
 129
 130 /// Store info on a currently executing, forked process.
 131 class InProgress {
 132 public:
 133         ///
 134         InProgress() : pid(0) {}
 135         ///
 136         InProgress(string const & filename_base,
 137                    PendingSnippets const & pending,
 138                    string const & to_format);
 139         /// Remove any files left lying around and kill the forked process.
 140         void stop() const;
 141
 142         ///
 143         string command;
 144         ///
 145         FileName metrics_file;
 146         ///
 147         BitmapFile snippets;
 148         ///
 149         pid_t pid;
 150 };
 151
 152 typedef map<pid_t, InProgress>  InProgressProcesses;
 153
 154 typedef InProgressProcesses::value_type InProgressProcess;
 155
 156 } // namespace
 157
 158
 159 namespace lyx {
 160 namespace graphics {
 161
 162 class PreviewLoader::Impl {
 163 public:
 164         ///
 165         Impl(PreviewLoader & p, Buffer const & b);
 166         /// Stop any InProgress items still executing.
 167         ~Impl();
 168         ///
 169         PreviewImage const * preview(string const & latex_snippet) const;
 170         ///
 171         PreviewLoader::Status status(string const & latex_snippet) const;
 172         ///
 173         void add(string const & latex_snippet);
 174         ///
 175         void remove(string const & latex_snippet);
 176         /// \p wait whether to wait for the process to complete or, instead,
 177         /// to do it in the background.
 178         void startLoading(bool wait = false);
 179         ///
 180         void refreshPreviews();
 181
 182         /// Emit this signal when an image is ready for display.
 183         signals2::signal<void(PreviewImage const &)> imageReady;
 184
 185         Buffer const & buffer() const { return buffer_; }
 186
 187         lyx::Converter const * setConverter(string const & from);
 188
 189 private:
 190         /// Called by the ForkedCall process that generated the bitmap files.
 191         void finishedGenerating(pid_t, int);
 192         ///
 193         void dumpPreamble(otexstream &, OutputParams::FLAVOR) const;
 194         ///
 195         void dumpData(odocstream &, BitmapFile const &) const;
 196
 197         /** cache_ allows easy retrieval of already-generated images
 198          *  using the LaTeX snippet as the identifier.
 199          */
 200         typedef std::shared_ptr<PreviewImage> PreviewImagePtr;
 201         ///
 202         typedef map<string, PreviewImagePtr> Cache;
 203         ///
 204         Cache cache_;
 205
 206         /** pending_ stores the LaTeX snippets in anticipation of them being
 207          *  sent to the converter.
 208          */
 209         PendingSnippets pending_;
 210
 211         /** in_progress_ stores all forked processes so that we can proceed
 212          *  thereafter.
 213          */
 214         InProgressProcesses in_progress_;
 215
 216         ///
 217         PreviewLoader & parent_;
 218         ///
 219         Buffer const & buffer_;
 220         ///
 221         mutable int font_scaling_factor_;
 222         ///
 223         mutable int fg_color_;
 224         ///
 225         mutable int bg_color_;
 226         ///
 227         QTimer * delay_refresh_;
 228         ///
 229         Trackable trackable_;
 230         ///
 231         bool finished_generating_;
 232
 233         /// We don't own this
 234         static lyx::Converter const * pconverter_;
 235
 236 };
 237
 238
 239 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 240
 241
 242 //
 243 // The public interface, defined in PreviewLoader.h
 244 //
 245
 246 PreviewLoader::PreviewLoader(Buffer const & b)
 247         : pimpl_(new Impl(*this, b))
 248 {}
 249
 250
 251 PreviewLoader::~PreviewLoader()
 252 {
 253         delete pimpl_;
 254 }
 255
 256
 257 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 258 {
 259         return pimpl_->preview(latex_snippet);
 260 }
 261
 262
 263 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 264 {
 265         return pimpl_->status(latex_snippet);
 266 }
 267
 268
 269 void PreviewLoader::add(string const & latex_snippet) const
 270 {
 271         pimpl_->add(latex_snippet);
 272 }
 273
 274
 275 void PreviewLoader::remove(string const & latex_snippet) const
 276 {
 277         pimpl_->remove(latex_snippet);
 278 }
 279
 280
 281 void PreviewLoader::startLoading(bool wait) const
 282 {
 283         pimpl_->startLoading(wait);
 284 }
 285
 286
 287 void PreviewLoader::refreshPreviews()
 288 {
 289         pimpl_->refreshPreviews();
 290 }
 291
 292
 293 signals2::connection PreviewLoader::connect(slot const & slot) const
 294 {
 295         return pimpl_->imageReady.connect(slot);
 296 }
 297
 298
 299 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 300 {
 301         pimpl_->imageReady(pimage);
 302 }
 303
 304
 305 Buffer const & PreviewLoader::buffer() const
 306 {
 307         return pimpl_->buffer();
 308 }
 309
 310 } // namespace graphics
 311 } // namespace lyx
 312
 313
 314 // The details of the Impl
 315 // =======================
 316
 317 namespace {
 318
 319 class IncrementedFileName {
 320 public:
 321         IncrementedFileName(string const & to_format,
 322                             string const & filename_base)
 323                 : to_format_(to_format), base_(filename_base), counter_(1)
 324         {}
 325
 326         SnippetPair const operator()(string const & snippet)
 327         {
 328                 ostringstream os;
 329                 os << base_ << counter_++ << '.' << to_format_;
 330                 string const file_name = os.str();
 331                 return make_pair(snippet, FileName(file_name));
 332         }
 333
 334 private:
 335         string const & to_format_;
 336         string const & base_;
 337         int counter_;
 338 };
 339
 340
 341 InProgress::InProgress(string const & filename_base,
 342                        PendingSnippets const & pending,
 343                        string const & to_format)
 344         : metrics_file(filename_base + ".metrics"),
 345           snippets(pending.size()), pid(0)
 346 {
 347         PendingSnippets::const_iterator pit  = pending.begin();
 348         PendingSnippets::const_iterator pend = pending.end();
 349         BitmapFile::iterator sit = snippets.begin();
 350
 351         transform(pit, pend, sit,
 352                        IncrementedFileName(to_format, filename_base));
 353 }
 354
 355
 356 void InProgress::stop() const
 357 {
 358         if (pid)
 359                 ForkedCallsController::kill(pid, 0);
 360
 361         if (!metrics_file.empty())
 362                 metrics_file.removeFile();
 363
 364         BitmapFile::const_iterator vit  = snippets.begin();
 365         BitmapFile::const_iterator vend = snippets.end();
 366         for (; vit != vend; ++vit) {
 367                 if (!vit->second.empty())
 368                         vit->second.removeFile();
 369         }
 370 }
 371
 372 } // namespace
 373
 374
 375 namespace lyx {
 376 namespace graphics {
 377
 378 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 379         : parent_(p), buffer_(b), finished_generating_(true)
 380 {
 381         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 382         if (theApp()) {
 383                 fg_color_ = convert(theApp()->hexName(foregroundColor()).c_str(), 16);
 384                 bg_color_ = convert(theApp()->hexName(backgroundColor()).c_str(), 16);
 385         } else {
 386                 fg_color_ = 0x0;
 387                 bg_color_ = 0xffffff;
 388         }
 389         if (!pconverter_)
 390                 pconverter_ = setConverter("lyxpreview");
 391
 392         delay_refresh_ = new QTimer(&parent_);
 393         delay_refresh_->setSingleShot(true);
 394         QObject::connect(delay_refresh_, SIGNAL(timeout()),
 395                          &parent_, SLOT(refreshPreviews()));
 396 }
 397
 398
 399 lyx::Converter const * PreviewLoader::Impl::setConverter(string const & from)
 400 {
 401         typedef vector<string> FmtList;
 402         FmtList const & loadableFormats = graphics::Cache::get().loadableFormats();
 403         FmtList::const_iterator it = loadableFormats.begin();
 404         FmtList::const_iterator const end = loadableFormats.end();
 405
 406         for (; it != end; ++it) {
 407                 string const to = *it;
 408                 if (from == to)
 409                         continue;
 410
 411                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
 412                 if (ptr)
 413                         return ptr;
 414         }
 415
 416         // Show the error only once. This is thread-safe.
 417         static nullptr_t no_conv = [&]{
 418                 LYXERR0("PreviewLoader::startLoading()\n"
 419                         << "No converter from \"" << from
 420                         << "\" format has been defined.");
 421                 return nullptr;
 422         } ();
 423
 424         return no_conv;
 425 }
 426
 427
 428 PreviewLoader::Impl::~Impl()
 429 {
 430         delete delay_refresh_;
 431
 432         InProgressProcesses::iterator ipit  = in_progress_.begin();
 433         InProgressProcesses::iterator ipend = in_progress_.end();
 434
 435         for (; ipit != ipend; ++ipit)
 436                 ipit->second.stop();
 437 }
 438
 439
 440 PreviewImage const *
 441 PreviewLoader::Impl::preview(string const & latex_snippet) const
 442 {
 443         int fs = int(buffer_.fontScalingFactor());
 444         int fg = 0x0;
 445         int bg = 0xffffff;
 446         if (theApp()) {
 447                 fg = convert(theApp()->hexName(foregroundColor()).c_str(), 16);
 448                 bg = convert(theApp()->hexName(backgroundColor()).c_str(), 16);
 449         }
 450         if (font_scaling_factor_ != fs || fg_color_ != fg || bg_color_ != bg) {
 451                 // Schedule refresh of all previews on zoom or color changes.
 452                 // The previews are regenerated only after the zoom factor
 453                 // has not been changed for about 1 second.
 454                 fg_color_ = fg;
 455                 bg_color_ = bg;
 456                 delay_refresh_->start(1000);
 457         }
 458         // Don't try to access the cache until we are done.
 459         if (delay_refresh_->isActive() || !finished_generating_)
 460                 return nullptr;
 461
 462         Cache::const_iterator it = cache_.find(latex_snippet);
 463         return (it == cache_.end()) ? nullptr : it->second.get();
 464 }
 465
 466
 467 void PreviewLoader::Impl::refreshPreviews()
 468 {
 469         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 470         // Reschedule refresh until the previous process completed.
 471         if (!finished_generating_) {
 472                 delay_refresh_->start(1000);
 473                 return;
 474         }
 475         Cache::const_iterator cit = cache_.begin();
 476         Cache::const_iterator cend = cache_.end();
 477         while (cit != cend)
 478                 parent_.remove((cit++)->first);
 479         finished_generating_ = false;
 480         buffer_.updatePreviews();
 481 }
 482
 483
 484 namespace {
 485
 486 std::function<bool (InProgressProcess const &)> FindSnippet(string const & s)
 487 {
 488         return [&s](InProgressProcess const & process) {
 489                 BitmapFile const & snippets = process.second.snippets;
 490                 BitmapFile::const_iterator beg  = snippets.begin();
 491                 BitmapFile::const_iterator end = snippets.end();
 492                 return find_if(beg, end, FindFirst(s)) != end;
 493         };
 494 }
 495
 496 } // namespace
 497
 498 PreviewLoader::Status
 499 PreviewLoader::Impl::status(string const & latex_snippet) const
 500 {
 501         Cache::const_iterator cit = cache_.find(latex_snippet);
 502         if (cit != cache_.end())
 503                 return Ready;
 504
 505         PendingSnippets::const_iterator pit  = pending_.begin();
 506         PendingSnippets::const_iterator pend = pending_.end();
 507
 508         pit = find(pit, pend, latex_snippet);
 509         if (pit != pend)
 510                 return InQueue;
 511
 512         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 513         InProgressProcesses::const_iterator ipend = in_progress_.end();
 514
 515         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 516         if (ipit != ipend)
 517                 return Processing;
 518
 519         return NotFound;
 520 }
 521
 522
 523 void PreviewLoader::Impl::add(string const & latex_snippet)
 524 {
 525         if (!pconverter_ || status(latex_snippet) != NotFound)
 526                 return;
 527
 528         string const snippet = trim(latex_snippet);
 529         if (snippet.empty())
 530                 return;
 531
 532         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
 533
 534         pending_.push_back(snippet);
 535 }
 536
 537
 538 namespace {
 539
 540 std::function<void (InProgressProcess &)> EraseSnippet(string const & s)
 541 {
 542         return [&s](InProgressProcess & process) {
 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(s));
 548                 if (it != end)
 549                         snippets.erase(it, it+1);
 550         };
 551 }
 552
 553 } // namespace
 554
 555
 556 void PreviewLoader::Impl::remove(string const & latex_snippet)
 557 {
 558         Cache::iterator cit = cache_.find(latex_snippet);
 559         if (cit != cache_.end())
 560                 cache_.erase(cit);
 561
 562         PendingSnippets::iterator pit  = pending_.begin();
 563         PendingSnippets::iterator pend = pending_.end();
 564
 565         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 566
 567         InProgressProcesses::iterator ipit  = in_progress_.begin();
 568         InProgressProcesses::iterator ipend = in_progress_.end();
 569
 570         for_each(ipit, ipend, EraseSnippet(latex_snippet));
 571
 572         while (ipit != ipend) {
 573                 InProgressProcesses::iterator curr = ipit++;
 574                 if (curr->second.snippets.empty())
 575                         in_progress_.erase(curr);
 576         }
 577 }
 578
 579
 580 void PreviewLoader::Impl::startLoading(bool wait)
 581 {
 582         if (pending_.empty() || !pconverter_)
 583                 return;
 584
 585         // Only start the process off after the buffer is loaded from file.
 586         if (!buffer_.isFullyLoaded())
 587                 return;
 588
 589         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 590
 591         // As used by the LaTeX file and by the resulting image files
 592         FileName const directory(buffer_.temppath());
 593
 594         FileName const latexfile = unique_tex_filename(directory);
 595         string const filename_base = removeExtension(latexfile.absFileName());
 596
 597         // Create an InProgress instance to place in the map of all
 598         // such processes if it starts correctly.
 599         InProgress inprogress(filename_base, pending_, pconverter_->to());
 600
 601         // clear pending_, so we're ready to start afresh.
 602         pending_.clear();
 603
 604         // Output the LaTeX file.
 605         // we use the encoding of the buffer
 606         Encoding const & enc = buffer_.params().encoding();
 607         ofdocstream of;
 608         try { of.reset(enc.iconvName()); }
 609         catch (iconv_codecvt_facet_exception const & e) {
 610                 LYXERR0("Caught iconv exception: " << e.what()
 611                         << "\nUnable to create LaTeX file: " << latexfile);
 612                 return;
 613         }
 614
 615         otexstream os(of);
 616         OutputParams runparams(&enc);
 617         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 618
 619         if (!openFileWrite(of, latexfile))
 620                 return;
 621
 622         if (!of) {
 623                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 624                                         << "Unable to create LaTeX file\n" << latexfile);
 625                 return;
 626         }
 627         of << "\\batchmode\n";
 628
 629         // Set \jobname of previews to the document name (see bug 9627)
 630         of << "\\def\\jobname{"
 631            << from_utf8(changeExtension(buffer_.latexName(), ""))
 632            << "}\n";
 633
 634         LYXERR(Debug::LATEX, "Format = " << buffer_.params().getDefaultOutputFormat());
 635         string latexparam = "";
 636         bool docformat = !buffer_.params().default_output_format.empty()
 637                         && buffer_.params().default_output_format != "default";
 638         // Use LATEX flavor if the document does not specify a specific
 639         // output format (see bug 9371).
 640         OutputParams::FLAVOR flavor = docformat
 641                                         ? buffer_.params().getOutputFlavor()
 642                                         : OutputParams::LATEX;
 643         if (buffer_.params().encoding().package() == Encoding::japanese) {
 644                 latexparam = " --latex=platex";
 645                 flavor = OutputParams::LATEX;
 646         }
 647         else if (buffer_.params().useNonTeXFonts) {
 648                 if (flavor == OutputParams::LUATEX)
 649                         latexparam = " --latex=lualatex";
 650                 else {
 651                         flavor = OutputParams::XETEX;
 652                         latexparam = " --latex=xelatex";
 653                 }
 654         }
 655         else {
 656                 switch (flavor) {
 657                         case OutputParams::PDFLATEX:
 658                                 latexparam = " --latex=pdflatex";
 659                                 break;
 660                         case OutputParams::XETEX:
 661                                 latexparam = " --latex=xelatex";
 662                                 break;
 663                         case OutputParams::LUATEX:
 664                                 latexparam = " --latex=lualatex";
 665                                 break;
 666                         case OutputParams::DVILUATEX:
 667                                 latexparam = " --latex=dvilualatex";
 668                                 break;
 669                         default:
 670                                 flavor = OutputParams::LATEX;
 671                 }
 672         }
 673         dumpPreamble(os, flavor);
 674         // handle inputenc etc.
 675         // I think this is already handled by dumpPreamble(): Kornel
 676         // buffer_.params().writeEncodingPreamble(os, features);
 677         of << "\n\\begin{document}\n";
 678         dumpData(of, inprogress.snippets);
 679         of << "\n\\end{document}\n";
 680         of.close();
 681         if (of.fail()) {
 682                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 683                                          << "File was not closed properly.");
 684                 return;
 685         }
 686
 687         // The conversion command.
 688         ostringstream cs;
 689         cs << pconverter_->command()
 690            << " " << quoteName(latexfile.toFilesystemEncoding())
 691            << " --dpi " << font_scaling_factor_;
 692
 693         // FIXME XHTML
 694         // The colors should be customizable.
 695         if (!buffer_.isExporting()) {
 696                 ColorCode const fg = PreviewLoader::foregroundColor();
 697                 ColorCode const bg = PreviewLoader::backgroundColor();
 698                 cs << " --fg " << theApp()->hexName(fg)
 699                    << " --bg " << theApp()->hexName(bg);
 700         }
 701
 702         cs << latexparam;
 703         cs << " --bibtex=" << quoteName(buffer_.params().bibtexCommand());
 704         if (buffer_.params().bufferFormat() == "lilypond-book")
 705                 cs << " --lilypond";
 706
 707         string const command = cs.str();
 708
 709         if (wait) {
 710                 ForkedCall call(buffer_.filePath(), buffer_.layoutPos());
 711                 int ret = call.startScript(ForkedProcess::Wait, command);
 712                 // PID_MAX_LIMIT is 2^22 so we start one after that
 713                 static atomic_int fake((1 << 22) + 1);
 714                 int pid = fake++;
 715                 inprogress.pid = pid;
 716                 inprogress.command = command;
 717                 in_progress_[pid] = inprogress;
 718                 finishedGenerating(pid, ret);
 719                 return;
 720         }
 721
 722         // Initiate the conversion from LaTeX to bitmap images files.
 723         ForkedCall::sigPtr convert_ptr = make_shared<ForkedCall::sig>();
 724         convert_ptr->connect(ForkedProcess::slot([this](pid_t pid, int retval){
 725                                 finishedGenerating(pid, retval);
 726                         }).track_foreign(trackable_.p()));
 727
 728         ForkedCall call(buffer_.filePath());
 729         int ret = call.startScript(command, convert_ptr);
 730
 731         if (ret != 0) {
 732                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 733                                         << "Unable to start process\n" << command);
 734                 return;
 735         }
 736
 737         // Store the generation process in a list of all such processes
 738         inprogress.pid = call.pid();
 739         inprogress.command = command;
 740         in_progress_[inprogress.pid] = inprogress;
 741 }
 742
 743
 744 double PreviewLoader::displayPixelRatio() const
 745 {
 746         return buffer().params().display_pixel_ratio;
 747 }
 748
 749 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 750 {
 751         // Paranoia check!
 752         InProgressProcesses::iterator git = in_progress_.find(pid);
 753         if (git == in_progress_.end()) {
 754                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 755                         "data for PID " << pid << endl;
 756                 finished_generating_ = true;
 757                 return;
 758         }
 759
 760         string const command = git->second.command;
 761         string const status = retval > 0 ? "failed" : "succeeded";
 762         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 763                                 << retval << "): processing " << status
 764                                 << " for " << command);
 765         if (retval > 0) {
 766                 in_progress_.erase(git);
 767                 finished_generating_ = true;
 768                 return;
 769         }
 770
 771         // Read the metrics file, if it exists
 772         vector<double> ascent_fractions(git->second.snippets.size());
 773         setAscentFractions(ascent_fractions, git->second.metrics_file);
 774
 775         // Add these newly generated bitmap files to the cache and
 776         // start loading them into LyX.
 777         BitmapFile::const_iterator it  = git->second.snippets.begin();
 778         BitmapFile::const_iterator end = git->second.snippets.end();
 779
 780         list<PreviewImagePtr> newimages;
 781
 782         size_t metrics_counter = 0;
 783         for (; it != end; ++it, ++metrics_counter) {
 784                 string const & snip = it->first;
 785                 FileName const & file = it->second;
 786                 double af = ascent_fractions[metrics_counter];
 787
 788                 // Add the image to the cache only if it's actually present
 789                 // and not empty (an empty image is signaled by af < 0)
 790                 if (af >= 0 && file.isReadableFile()) {
 791                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 792                         cache_[snip] = ptr;
 793
 794                         newimages.push_back(ptr);
 795                 }
 796
 797         }
 798
 799         // Remove the item from the list of still-executing processes.
 800         in_progress_.erase(git);
 801
 802         // Tell the outside world
 803         list<PreviewImagePtr>::const_reverse_iterator
 804                 nit  = newimages.rbegin();
 805         list<PreviewImagePtr>::const_reverse_iterator
 806                 nend = newimages.rend();
 807         for (; nit != nend; ++nit) {
 808                 imageReady(*nit->get());
 809         }
 810         finished_generating_ = true;
 811 }
 812
 813
 814 void PreviewLoader::Impl::dumpPreamble(otexstream & os, OutputParams::FLAVOR flavor) const
 815 {
 816         // Dump the preamble only.
 817         LYXERR(Debug::LATEX, "dumpPreamble, flavor == " << flavor);
 818         OutputParams runparams(&buffer_.params().encoding());
 819         runparams.flavor = flavor;
 820         runparams.nice = true;
 821         runparams.moving_arg = true;
 822         runparams.free_spacing = true;
 823         runparams.is_child = buffer_.parent();
 824         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 825
 826         // FIXME! This is a HACK! The proper fix is to control the 'true'
 827         // passed to WriteStream below:
 828         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 829         //                          OutputParams const & runparams) const
 830         // {
 831         //      WriteStream wi(os, runparams.moving_arg, true);
 832         //      par_->write(wi);
 833         //      return wi.line();
 834         // }
 835         os << "\n"
 836            << "\\def\\lyxlock{}\n"
 837            << "\n";
 838
 839         // All equation labels appear as "(#)" + preview.sty's rendering of
 840         // the label name
 841         if (lyxrc.preview_hashed_labels)
 842                 os << "\\renewcommand{\\theequation}{\\#}\n";
 843
 844         // Use the preview style file to ensure that each snippet appears on a
 845         // fresh page.
 846         // Also support PDF output (automatically generated e.g. when
 847         // \usepackage[pdftex]{hyperref} is used and XeTeX.
 848         os << "\n"
 849            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
 850            << "\n";
 851 }
 852
 853
 854 void PreviewLoader::Impl::dumpData(odocstream & os,
 855                                    BitmapFile const & vec) const
 856 {
 857         if (vec.empty())
 858                 return;
 859
 860         BitmapFile::const_iterator it  = vec.begin();
 861         BitmapFile::const_iterator end = vec.end();
 862
 863         for (; it != end; ++it) {
 864                 // FIXME UNICODE
 865                 os << "\\begin{preview}\n"
 866                    << from_utf8(it->first)
 867                    << "\n\\end{preview}\n\n";
 868         }
 869 }
 870
 871 } // namespace graphics
 872 } // namespace lyx
 873
 874 #include "moc_PreviewLoader.cpp"