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 #include "support/os.h"
  38
  39 #include "support/TempFile.h"
  40
  41 #include <atomic>
  42 #include <fstream>
  43 #include <iomanip>
  44 #include <memory>
  45 #include <mutex>
  46 #include <sstream>
  47
  48 #include <QTimer>
  49
  50 using namespace std;
  51 using namespace lyx::support;
  52
  53
  54
  55 namespace {
  56
  57 typedef pair<string, FileName> SnippetPair;
  58
  59 // A list of all snippets to be converted to previews
  60 typedef list<string> PendingSnippets;
  61
  62 // Each item in the vector is a pair<snippet, image file name>.
  63 typedef vector<SnippetPair> BitmapFile;
  64
  65
  66 FileName const unique_tex_filename(FileName const & bufferpath)
  67 {
  68         TempFile tempfile(bufferpath, "lyxpreviewXXXXXX.tex");
  69         tempfile.setAutoRemove(false);
  70         return tempfile.name();
  71 }
  72
  73
  74 void setAscentFractions(vector<double> & ascent_fractions,
  75                         FileName const & metrics_file)
  76 {
  77         // If all else fails, then the images will have equal ascents and
  78         // descents.
  79         vector<double>::iterator it  = ascent_fractions.begin();
  80         vector<double>::iterator end = ascent_fractions.end();
  81         fill(it, end, 0.5);
  82
  83         ifstream in(metrics_file.toFilesystemEncoding().c_str());
  84         if (!in.good()) {
  85                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
  86                         << "Unable to open file!");
  87                 return;
  88         }
  89
  90         bool error = false;
  91
  92         int snippet_counter = 1;
  93         while (!in.eof() && it != end) {
  94                 string snippet;
  95                 int id;
  96                 double ascent_fraction;
  97
  98                 in >> snippet >> id >> ascent_fraction;
  99
 100                 if (!in.good())
 101                         // eof after all
 102                         break;
 103
 104                 error = snippet != "Snippet";
 105                 if (error)
 106                         break;
 107
 108                 error = id != snippet_counter;
 109                 if (error)
 110                         break;
 111
 112                 *it = ascent_fraction;
 113
 114                 ++snippet_counter;
 115                 ++it;
 116         }
 117
 118         if (error) {
 119                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 120                         << "Error reading file!\n");
 121         }
 122 }
 123
 124
 125 std::function <bool (SnippetPair const &)> FindFirst(string const & comp)
 126 {
 127         return [&comp](SnippetPair const & sp) { return sp.first == comp; };
 128 }
 129
 130
 131 /// Store info on a currently executing, forked process.
 132 class InProgress {
 133 public:
 134         ///
 135         InProgress() : pid(0) {}
 136         ///
 137         InProgress(string const & filename_base,
 138                    PendingSnippets const & pending,
 139                    string const & to_format);
 140         /// Remove any files left lying around and kill the forked process.
 141         void stop() const;
 142
 143         ///
 144         string command;
 145         ///
 146         FileName metrics_file;
 147         ///
 148         BitmapFile snippets;
 149         ///
 150         pid_t pid;
 151 };
 152
 153 typedef map<pid_t, InProgress>  InProgressProcesses;
 154
 155 typedef InProgressProcesses::value_type InProgressProcess;
 156
 157 } // namespace
 158
 159
 160 namespace lyx {
 161 namespace graphics {
 162
 163 class PreviewLoader::Impl {
 164 public:
 165         ///
 166         Impl(PreviewLoader & p, Buffer const & b);
 167         /// Stop any InProgress items still executing.
 168         ~Impl();
 169         ///
 170         PreviewImage const * preview(string const & latex_snippet) const;
 171         ///
 172         PreviewLoader::Status status(string const & latex_snippet) const;
 173         ///
 174         void add(string const & latex_snippet);
 175         ///
 176         void remove(string const & latex_snippet);
 177         /// \p wait whether to wait for the process to complete or, instead,
 178         /// to do it in the background.
 179         void startLoading(bool wait = false);
 180         ///
 181         void refreshPreviews();
 182
 183         /// Emit this signal when an image is ready for display.
 184         signal<void(PreviewImage const &)> imageReady;
 185
 186         Buffer const & buffer() const { return buffer_; }
 187
 188         lyx::Converter const * setConverter(string const & from);
 189
 190 private:
 191         /// Called by the ForkedCall process that generated the bitmap files.
 192         void finishedGenerating(pid_t, int);
 193         ///
 194         void dumpPreamble(otexstream &, Flavor) const;
 195         ///
 196         void dumpData(odocstream &, BitmapFile const &) const;
 197
 198         /** cache_ allows easy retrieval of already-generated images
 199          *  using the LaTeX snippet as the identifier.
 200          */
 201         typedef std::shared_ptr<PreviewImage> PreviewImagePtr;
 202         ///
 203         typedef map<string, PreviewImagePtr> Cache;
 204         ///
 205         Cache cache_;
 206
 207         /** pending_ stores the LaTeX snippets in anticipation of them being
 208          *  sent to the converter.
 209          */
 210         PendingSnippets pending_;
 211
 212         /** in_progress_ stores all forked processes so that we can proceed
 213          *  thereafter.
 214          */
 215         InProgressProcesses in_progress_;
 216
 217         ///
 218         PreviewLoader & parent_;
 219         ///
 220         Buffer const & buffer_;
 221         ///
 222         mutable int font_scaling_factor_;
 223         ///
 224         mutable int fg_color_;
 225         ///
 226         mutable int bg_color_;
 227         ///
 228         QTimer * delay_refresh_;
 229         ///
 230         bool finished_generating_;
 231
 232         /// We don't own this
 233         static lyx::Converter const * pconverter_;
 234
 235 };
 236
 237
 238 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 239
 240
 241 //
 242 // The public interface, defined in PreviewLoader.h
 243 //
 244
 245 PreviewLoader::PreviewLoader(Buffer const & b)
 246         : pimpl_(make_shared<Impl>(*this, b))
 247 {}
 248
 249
 250 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 251 {
 252         return pimpl_->preview(latex_snippet);
 253 }
 254
 255
 256 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 257 {
 258         return pimpl_->status(latex_snippet);
 259 }
 260
 261
 262 void PreviewLoader::add(string const & latex_snippet) const
 263 {
 264         pimpl_->add(latex_snippet);
 265 }
 266
 267
 268 void PreviewLoader::remove(string const & latex_snippet) const
 269 {
 270         pimpl_->remove(latex_snippet);
 271 }
 272
 273
 274 void PreviewLoader::startLoading(bool wait) const
 275 {
 276         pimpl_->startLoading(wait);
 277 }
 278
 279
 280 void PreviewLoader::refreshPreviews()
 281 {
 282         pimpl_->refreshPreviews();
 283 }
 284
 285
 286 connection PreviewLoader::connect(slot const & slot) const
 287 {
 288         return pimpl_->imageReady.connect(slot);
 289 }
 290
 291
 292 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 293 {
 294         pimpl_->imageReady(pimage);
 295 }
 296
 297
 298 Buffer const & PreviewLoader::buffer() const
 299 {
 300         return pimpl_->buffer();
 301 }
 302
 303 } // namespace graphics
 304 } // namespace lyx
 305
 306
 307 // The details of the Impl
 308 // =======================
 309
 310 namespace {
 311
 312 class IncrementedFileName {
 313 public:
 314         IncrementedFileName(string const & to_format,
 315                             string const & filename_base)
 316                 : to_format_(to_format), base_(filename_base), counter_(1)
 317         {}
 318
 319         SnippetPair const operator()(string const & snippet)
 320         {
 321                 ostringstream os;
 322                 os << base_ << counter_++ << '.' << to_format_;
 323                 string const file_name = os.str();
 324                 return make_pair(snippet, FileName(file_name));
 325         }
 326
 327 private:
 328         string const & to_format_;
 329         string const & base_;
 330         int counter_;
 331 };
 332
 333
 334 InProgress::InProgress(string const & filename_base,
 335                        PendingSnippets const & pending,
 336                        string const & to_format)
 337         : metrics_file(filename_base + ".metrics"),
 338           snippets(pending.size()), pid(0)
 339 {
 340         PendingSnippets::const_iterator pit  = pending.begin();
 341         PendingSnippets::const_iterator pend = pending.end();
 342         BitmapFile::iterator sit = snippets.begin();
 343
 344         transform(pit, pend, sit,
 345                        IncrementedFileName(to_format, filename_base));
 346 }
 347
 348
 349 void InProgress::stop() const
 350 {
 351         if (pid)
 352                 ForkedCallsController::kill(pid, 0);
 353
 354         if (!metrics_file.empty())
 355                 metrics_file.removeFile();
 356
 357         BitmapFile::const_iterator vit  = snippets.begin();
 358         BitmapFile::const_iterator vend = snippets.end();
 359         for (; vit != vend; ++vit) {
 360                 if (!vit->second.empty())
 361                         vit->second.removeFile();
 362         }
 363 }
 364
 365 } // namespace
 366
 367
 368 namespace lyx {
 369 namespace graphics {
 370
 371 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 372         : parent_(p), buffer_(b), finished_generating_(true)
 373 {
 374         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 375         if (theApp()) {
 376                 fg_color_ = convert(theApp()->hexName(foregroundColor()), 16);
 377                 bg_color_ = convert(theApp()->hexName(backgroundColor()), 16);
 378         } else {
 379                 fg_color_ = 0x0;
 380                 bg_color_ = 0xffffff;
 381         }
 382         if (!pconverter_)
 383                 pconverter_ = setConverter("lyxpreview");
 384
 385         delay_refresh_ = new QTimer(&parent_);
 386         delay_refresh_->setSingleShot(true);
 387         QObject::connect(delay_refresh_, SIGNAL(timeout()),
 388                          &parent_, SLOT(refreshPreviews()));
 389 }
 390
 391
 392 lyx::Converter const * PreviewLoader::Impl::setConverter(string const & from)
 393 {
 394         typedef vector<string> FmtList;
 395         FmtList const & loadableFormats = graphics::Cache::get().loadableFormats();
 396         FmtList::const_iterator it = loadableFormats.begin();
 397         FmtList::const_iterator const end = loadableFormats.end();
 398
 399         for (; it != end; ++it) {
 400                 string const to = *it;
 401                 if (from == to)
 402                         continue;
 403
 404                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
 405                 if (ptr)
 406                         return ptr;
 407         }
 408
 409         // Show the error only once. This is thread-safe.
 410         static nullptr_t no_conv = [&]{
 411                 LYXERR0("PreviewLoader::startLoading()\n"
 412                         << "No converter from \"" << from
 413                         << "\" format has been defined.");
 414                 return nullptr;
 415         } ();
 416
 417         return no_conv;
 418 }
 419
 420
 421 PreviewLoader::Impl::~Impl()
 422 {
 423         delete delay_refresh_;
 424
 425         InProgressProcesses::iterator ipit  = in_progress_.begin();
 426         InProgressProcesses::iterator ipend = in_progress_.end();
 427
 428         for (; ipit != ipend; ++ipit)
 429                 ipit->second.stop();
 430 }
 431
 432
 433 PreviewImage const *
 434 PreviewLoader::Impl::preview(string const & latex_snippet) const
 435 {
 436         int fs = int(buffer_.fontScalingFactor());
 437         int fg = 0x0;
 438         int bg = 0xffffff;
 439         if (theApp()) {
 440                 fg = convert(theApp()->hexName(foregroundColor()), 16);
 441                 bg = convert(theApp()->hexName(backgroundColor()), 16);
 442         }
 443         if (font_scaling_factor_ != fs || fg_color_ != fg || bg_color_ != bg) {
 444                 // Schedule refresh of all previews on zoom or color changes.
 445                 // The previews are regenerated only after the zoom factor
 446                 // has not been changed for about 1 second.
 447                 fg_color_ = fg;
 448                 bg_color_ = bg;
 449                 delay_refresh_->start(1000);
 450         }
 451         // Don't try to access the cache until we are done.
 452         if (delay_refresh_->isActive() || !finished_generating_)
 453                 return nullptr;
 454
 455         Cache::const_iterator it = cache_.find(latex_snippet);
 456         return (it == cache_.end()) ? nullptr : 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 std::function<bool (InProgressProcess const &)> FindSnippet(string const & s)
 480 {
 481         return [&s](InProgressProcess const & process) {
 482                 BitmapFile const & snippets = process.second.snippets;
 483                 BitmapFile::const_iterator beg  = snippets.begin();
 484                 BitmapFile::const_iterator end = snippets.end();
 485                 return find_if(beg, end, FindFirst(s)) != end;
 486         };
 487 }
 488
 489 } // namespace
 490
 491 PreviewLoader::Status
 492 PreviewLoader::Impl::status(string const & latex_snippet) const
 493 {
 494         Cache::const_iterator cit = cache_.find(latex_snippet);
 495         if (cit != cache_.end())
 496                 return Ready;
 497
 498         PendingSnippets::const_iterator pit  = pending_.begin();
 499         PendingSnippets::const_iterator pend = pending_.end();
 500
 501         pit = find(pit, pend, latex_snippet);
 502         if (pit != pend)
 503                 return InQueue;
 504
 505         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 506         InProgressProcesses::const_iterator ipend = in_progress_.end();
 507
 508         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 509         if (ipit != ipend)
 510                 return Processing;
 511
 512         return NotFound;
 513 }
 514
 515
 516 void PreviewLoader::Impl::add(string const & latex_snippet)
 517 {
 518         if (!pconverter_ || status(latex_snippet) != NotFound)
 519                 return;
 520
 521         string const snippet = trim(latex_snippet);
 522         if (snippet.empty())
 523                 return;
 524
 525         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
 526
 527         pending_.push_back(snippet);
 528 }
 529
 530
 531 namespace {
 532
 533 std::function<void (InProgressProcess &)> EraseSnippet(string const & s)
 534 {
 535         return [&s](InProgressProcess & process) {
 536                 BitmapFile & snippets = process.second.snippets;
 537                 BitmapFile::iterator it  = snippets.begin();
 538                 BitmapFile::iterator end = snippets.end();
 539
 540                 it = find_if(it, end, FindFirst(s));
 541                 if (it != end)
 542                         snippets.erase(it, it+1);
 543         };
 544 }
 545
 546 } // namespace
 547
 548
 549 void PreviewLoader::Impl::remove(string const & latex_snippet)
 550 {
 551         Cache::iterator cit = cache_.find(latex_snippet);
 552         if (cit != cache_.end())
 553                 cache_.erase(cit);
 554
 555         PendingSnippets::iterator pit  = pending_.begin();
 556         PendingSnippets::iterator pend = pending_.end();
 557
 558         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 559
 560         InProgressProcesses::iterator ipit  = in_progress_.begin();
 561         InProgressProcesses::iterator ipend = in_progress_.end();
 562
 563         for_each(ipit, ipend, EraseSnippet(latex_snippet));
 564
 565         while (ipit != ipend) {
 566                 InProgressProcesses::iterator curr = ipit++;
 567                 if (curr->second.snippets.empty())
 568                         in_progress_.erase(curr);
 569         }
 570 }
 571
 572
 573 void PreviewLoader::Impl::startLoading(bool wait)
 574 {
 575         if (pending_.empty() || !pconverter_)
 576                 return;
 577
 578         // Only start the process off after the buffer is loaded from file.
 579         if (!buffer_.isFullyLoaded())
 580                 return;
 581
 582         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 583
 584         // As used by the LaTeX file and by the resulting image files
 585         FileName const directory(buffer_.temppath());
 586
 587         FileName const latexfile = unique_tex_filename(directory);
 588         string const filename_base = removeExtension(latexfile.absFileName());
 589
 590         // Create an InProgress instance to place in the map of all
 591         // such processes if it starts correctly.
 592         InProgress inprogress(filename_base, pending_, pconverter_->to());
 593
 594         // clear pending_, so we're ready to start afresh.
 595         pending_.clear();
 596
 597         // Output the LaTeX file.
 598         // we use the encoding of the buffer
 599         Encoding const & enc = buffer_.params().encoding();
 600         ofdocstream of;
 601         try { of.reset(enc.iconvName()); }
 602         catch (iconv_codecvt_facet_exception const & e) {
 603                 LYXERR0("Caught iconv exception: " << e.what()
 604                         << "\nUnable to create LaTeX file: " << latexfile);
 605                 return;
 606         }
 607
 608         otexstream os(of);
 609         OutputParams runparams(&enc);
 610         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 611
 612         if (!openFileWrite(of, latexfile))
 613                 return;
 614
 615         if (!of) {
 616                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 617                                         << "Unable to create LaTeX file\n" << latexfile);
 618                 return;
 619         }
 620         of << "\\batchmode\n";
 621
 622         LYXERR(Debug::OUTFILE, "Format = " << buffer_.params().getDefaultOutputFormat());
 623         string latexparam = "";
 624         bool docformat = !buffer_.params().default_output_format.empty()
 625                         && buffer_.params().default_output_format != "default";
 626         // Use LATEX flavor if the document does not specify a specific
 627         // output format (see bug 9371).
 628         Flavor flavor = docformat
 629                                         ? buffer_.params().getOutputFlavor()
 630                                         : Flavor::LaTeX;
 631         if (buffer_.params().encoding().package() == Encoding::japanese) {
 632                 latexparam = " --latex=platex";
 633                 flavor = Flavor::LaTeX;
 634         }
 635         else if (buffer_.params().useNonTeXFonts) {
 636                 if (flavor == Flavor::LuaTeX)
 637                         latexparam = " --latex=lualatex";
 638                 else {
 639                         flavor = Flavor::XeTeX;
 640                         latexparam = " --latex=xelatex";
 641                 }
 642         }
 643         else {
 644                 switch (flavor) {
 645                         case Flavor::PdfLaTeX:
 646                                 latexparam = " --latex=pdflatex";
 647                                 break;
 648                         case Flavor::XeTeX:
 649                                 latexparam = " --latex=xelatex";
 650                                 break;
 651                         case Flavor::LuaTeX:
 652                                 latexparam = " --latex=lualatex";
 653                                 break;
 654                         case Flavor::DviLuaTeX:
 655                                 latexparam = " --latex=dvilualatex";
 656                                 break;
 657                         default:
 658                                 flavor = Flavor::LaTeX;
 659                 }
 660         }
 661         dumpPreamble(os, flavor);
 662         // handle inputenc etc.
 663         // I think this is already handled by dumpPreamble(): Kornel
 664         // buffer_.params().writeEncodingPreamble(os, features);
 665         of << "\n\\begin{document}\n";
 666         dumpData(of, inprogress.snippets);
 667         of << "\n\\end{document}\n";
 668         of.close();
 669         if (of.fail()) {
 670                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 671                                          << "File was not closed properly.");
 672                 return;
 673         }
 674
 675         // The conversion command.
 676         ostringstream cs;
 677         cs << subst(pconverter_->command(), "$${python}", os::python())
 678            << " " << quoteName(latexfile.toFilesystemEncoding())
 679            << " --dpi " << font_scaling_factor_;
 680
 681         // FIXME XHTML
 682         // The colors should be customizable.
 683         if (!buffer_.isExporting()) {
 684                 ColorCode const fg = PreviewLoader::foregroundColor();
 685                 ColorCode const bg = PreviewLoader::backgroundColor();
 686                 cs << " --fg " << theApp()->hexName(fg)
 687                    << " --bg " << theApp()->hexName(bg);
 688         }
 689
 690         cs << latexparam;
 691         cs << " --bibtex=" << quoteName(buffer_.params().bibtexCommand());
 692         if (buffer_.params().bufferFormat() == "lilypond-book")
 693                 cs << " --lilypond";
 694
 695         string const command = cs.str();
 696
 697         if (wait) {
 698                 ForkedCall call(buffer_.filePath(), buffer_.layoutPos());
 699                 int ret = call.startScript(ForkedProcess::Wait, command);
 700                 // PID_MAX_LIMIT is 2^22 so we start one after that
 701                 static atomic_int fake((1 << 22) + 1);
 702                 int pid = fake++;
 703                 inprogress.pid = pid;
 704                 inprogress.command = command;
 705                 in_progress_[pid] = inprogress;
 706                 finishedGenerating(pid, ret);
 707                 return;
 708         }
 709
 710         // Initiate the conversion from LaTeX to bitmap images files.
 711         ForkedCall::sigPtr convert_ptr = make_shared<ForkedCall::sig>();
 712         weak_ptr<PreviewLoader::Impl> this_ = parent_.pimpl_;
 713         convert_ptr->connect([this_](pid_t pid, int retval){
 714                         if (auto p = this_.lock()) {
 715                                 p->finishedGenerating(pid, retval);
 716                         }
 717                 });
 718
 719         ForkedCall call(buffer_.filePath());
 720         int ret = call.startScript(command, convert_ptr);
 721
 722         if (ret != 0) {
 723                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 724                                         << "Unable to start process\n" << command);
 725                 return;
 726         }
 727
 728         // Store the generation process in a list of all such processes
 729         inprogress.pid = call.pid();
 730         inprogress.command = command;
 731         in_progress_[inprogress.pid] = inprogress;
 732 }
 733
 734
 735 double PreviewLoader::displayPixelRatio() const
 736 {
 737         return buffer().params().display_pixel_ratio;
 738 }
 739
 740 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 741 {
 742         // Paranoia check!
 743         InProgressProcesses::iterator git = in_progress_.find(pid);
 744         if (git == in_progress_.end()) {
 745                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 746                         "data for PID " << pid << endl;
 747                 finished_generating_ = true;
 748                 return;
 749         }
 750
 751         string const command = git->second.command;
 752         string const status = retval > 0 ? "failed" : "succeeded";
 753         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 754                                 << retval << "): processing " << status
 755                                 << " for " << command);
 756         if (retval > 0) {
 757                 in_progress_.erase(git);
 758                 finished_generating_ = true;
 759                 return;
 760         }
 761
 762         // Read the metrics file, if it exists
 763         vector<double> ascent_fractions(git->second.snippets.size());
 764         setAscentFractions(ascent_fractions, git->second.metrics_file);
 765
 766         // Add these newly generated bitmap files to the cache and
 767         // start loading them into LyX.
 768         BitmapFile::const_iterator it  = git->second.snippets.begin();
 769         BitmapFile::const_iterator end = git->second.snippets.end();
 770
 771         list<PreviewImagePtr> newimages;
 772
 773         size_t metrics_counter = 0;
 774         for (; it != end; ++it, ++metrics_counter) {
 775                 string const & snip = it->first;
 776                 FileName const & file = it->second;
 777                 double af = ascent_fractions[metrics_counter];
 778
 779                 // Add the image to the cache only if it's actually present
 780                 // and not empty (an empty image is signaled by af < 0)
 781                 if (af >= 0 && file.isReadableFile()) {
 782                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 783                         cache_[snip] = ptr;
 784
 785                         newimages.push_back(ptr);
 786                 }
 787
 788         }
 789
 790         // Remove the item from the list of still-executing processes.
 791         in_progress_.erase(git);
 792
 793         // Tell the outside world
 794         list<PreviewImagePtr>::const_reverse_iterator
 795                 nit  = newimages.rbegin();
 796         list<PreviewImagePtr>::const_reverse_iterator
 797                 nend = newimages.rend();
 798         for (; nit != nend; ++nit) {
 799                 imageReady(*nit->get());
 800         }
 801         finished_generating_ = true;
 802 }
 803
 804
 805 void PreviewLoader::Impl::dumpPreamble(otexstream & os, Flavor flavor) const
 806 {
 807         // Dump the preamble only.
 808         LYXERR(Debug::OUTFILE, "dumpPreamble, flavor == " << static_cast<int>(flavor));
 809         OutputParams runparams(&buffer_.params().encoding());
 810         runparams.flavor = flavor;
 811         runparams.nice = true;
 812         runparams.moving_arg = true;
 813         runparams.free_spacing = true;
 814         runparams.is_child = buffer_.parent();
 815         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 816
 817         // FIXME! This is a HACK! The proper fix is to control the 'true'
 818         // passed to TeXMathStream below:
 819         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 820         //                          OutputParams const & runparams) const
 821         // {
 822         //      TeXMathStream wi(os, runparams.moving_arg, true);
 823         //      par_->write(wi);
 824         //      return wi.line();
 825         // }
 826         os << "\n"
 827            << "\\def\\lyxlock{}\n"
 828            << "\n";
 829
 830         // All equation labels appear as "(#)" + preview.sty's rendering of
 831         // the label name
 832         if (lyxrc.preview_hashed_labels)
 833                 os << "\\renewcommand{\\theequation}{\\#}\n";
 834
 835         // Use the preview style file to ensure that each snippet appears on a
 836         // fresh page.
 837         // Also support PDF output (automatically generated e.g. when
 838         // \usepackage[pdftex]{hyperref} is used and XeTeX.
 839         os << "\n"
 840            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
 841            << "\n";
 842 }
 843
 844
 845 void PreviewLoader::Impl::dumpData(odocstream & os,
 846                                    BitmapFile const & vec) const
 847 {
 848         if (vec.empty())
 849                 return;
 850
 851         BitmapFile::const_iterator it  = vec.begin();
 852         BitmapFile::const_iterator end = vec.end();
 853
 854         for (; it != end; ++it) {
 855                 // FIXME UNICODE
 856                 os << "\\begin{preview}\n"
 857                    << from_utf8(it->first)
 858                    << "\n\\end{preview}\n\n";
 859         }
 860 }
 861
 862 } // namespace graphics
 863 } // namespace lyx
 864
 865 #include "moc_PreviewLoader.cpp"