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 #include "texstream.h"
  29
  30 #include "frontends/Application.h" // hexName
  31
  32 #include "insets/Inset.h"
  33
  34 #include "support/convert.h"
  35 #include "support/debug.h"
  36 #include "support/FileName.h"
  37 #include "support/filetools.h"
  38 #include "support/ForkedCalls.h"
  39 #include "support/lstrings.h"
  40
  41 #include "support/bind.h"
  42 #include "support/TempFile.h"
  43
  44 #include <atomic>
  45 #include <fstream>
  46 #include <iomanip>
  47 #include <memory>
  48 #include <mutex>
  49 #include <sstream>
  50
  51 #include <QTimer>
  52
  53 using namespace std;
  54 using namespace lyx::support;
  55
  56
  57
  58 namespace {
  59
  60 typedef pair<string, FileName> SnippetPair;
  61
  62 // A list of all snippets to be converted to previews
  63 typedef list<string> PendingSnippets;
  64
  65 // Each item in the vector is a pair<snippet, image file name>.
  66 typedef vector<SnippetPair> BitmapFile;
  67
  68
  69 FileName const unique_tex_filename(FileName const & bufferpath)
  70 {
  71         TempFile tempfile(bufferpath, "lyxpreviewXXXXXX.tex");
  72         tempfile.setAutoRemove(false);
  73         return tempfile.name();
  74 }
  75
  76
  77 lyx::Converter const * setConverter(string const & from)
  78 {
  79         typedef vector<string> FmtList;
  80         typedef lyx::graphics::Cache GCache;
  81         FmtList const & loadableFormats = GCache::get().loadableFormats();
  82         FmtList::const_iterator it = loadableFormats.begin();
  83         FmtList::const_iterator const end = loadableFormats.end();
  84
  85         for (; it != end; ++it) {
  86                 string const to = *it;
  87                 if (from == to)
  88                         continue;
  89
  90                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
  91                 if (ptr)
  92                         return ptr;
  93         }
  94
  95         // Show the error only once
  96 #ifdef LYX_USE_STD_CALL_ONCE
  97         // This is thread-safe.
  98         static once_flag flag;
  99         call_once(flag, [&](){
 100                         LYXERR0("PreviewLoader::startLoading()\n"
 101                                 << "No converter from \"" << from
 102                                 << "\" format has been defined.");
 103                 });
 104 #else
 105         // This is also thread-safe according to §6.7.4 of the C++11 standard.
 106         static bool once = ([&]{
 107                         LYXERR0("PreviewLoader::startLoading()\n"
 108                                 << "No converter from \"" << from
 109                                 << "\" format has been defined.");
 110                 } (), true);
 111 #endif
 112         return 0;
 113 }
 114
 115
 116 void setAscentFractions(vector<double> & ascent_fractions,
 117                         FileName const & metrics_file)
 118 {
 119         // If all else fails, then the images will have equal ascents and
 120         // descents.
 121         vector<double>::iterator it  = ascent_fractions.begin();
 122         vector<double>::iterator end = ascent_fractions.end();
 123         fill(it, end, 0.5);
 124
 125         ifstream in(metrics_file.toFilesystemEncoding().c_str());
 126         if (!in.good()) {
 127                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 128                         << "Unable to open file!");
 129                 return;
 130         }
 131
 132         bool error = false;
 133
 134         int snippet_counter = 1;
 135         while (!in.eof() && it != end) {
 136                 string snippet;
 137                 int id;
 138                 double ascent_fraction;
 139
 140                 in >> snippet >> id >> ascent_fraction;
 141
 142                 if (!in.good())
 143                         // eof after all
 144                         break;
 145
 146                 error = snippet != "Snippet";
 147                 if (error)
 148                         break;
 149
 150                 error = id != snippet_counter;
 151                 if (error)
 152                         break;
 153
 154                 *it = ascent_fraction;
 155
 156                 ++snippet_counter;
 157                 ++it;
 158         }
 159
 160         if (error) {
 161                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 162                         << "Error reading file!\n");
 163         }
 164 }
 165
 166
 167 class FindFirst
 168 {
 169 public:
 170         FindFirst(string const & comp) : comp_(comp) {}
 171         bool operator()(SnippetPair const & sp) const { return sp.first == comp_; }
 172 private:
 173         string const comp_;
 174 };
 175
 176
 177 /// Store info on a currently executing, forked process.
 178 class InProgress {
 179 public:
 180         ///
 181         InProgress() : pid(0) {}
 182         ///
 183         InProgress(string const & filename_base,
 184                    PendingSnippets const & pending,
 185                    string const & to_format);
 186         /// Remove any files left lying around and kill the forked process.
 187         void stop() const;
 188
 189         ///
 190         pid_t pid;
 191         ///
 192         string command;
 193         ///
 194         FileName metrics_file;
 195         ///
 196         BitmapFile snippets;
 197 };
 198
 199 typedef map<pid_t, InProgress>  InProgressProcesses;
 200
 201 typedef InProgressProcesses::value_type InProgressProcess;
 202
 203 } // namespace anon
 204
 205
 206
 207 namespace lyx {
 208 namespace graphics {
 209
 210 class PreviewLoader::Impl : public boost::signals2::trackable {
 211 public:
 212         ///
 213         Impl(PreviewLoader & p, Buffer const & b);
 214         /// Stop any InProgress items still executing.
 215         ~Impl();
 216         ///
 217         PreviewImage const * preview(string const & latex_snippet) const;
 218         ///
 219         PreviewLoader::Status status(string const & latex_snippet) const;
 220         ///
 221         void add(string const & latex_snippet);
 222         ///
 223         void remove(string const & latex_snippet);
 224         /// \p wait whether to wait for the process to complete or, instead,
 225         /// to do it in the background.
 226         void startLoading(bool wait = false);
 227         ///
 228         void refreshPreviews();
 229
 230         /// Emit this signal when an image is ready for display.
 231         boost::signals2::signal<void(PreviewImage const &)> imageReady;
 232
 233         Buffer const & buffer() const { return buffer_; }
 234
 235 private:
 236         /// Called by the ForkedCall process that generated the bitmap files.
 237         void finishedGenerating(pid_t, int);
 238         ///
 239         void dumpPreamble(otexstream &, OutputParams::FLAVOR) const;
 240         ///
 241         void dumpData(odocstream &, BitmapFile const &) const;
 242
 243         /** cache_ allows easy retrieval of already-generated images
 244          *  using the LaTeX snippet as the identifier.
 245          */
 246         typedef std::shared_ptr<PreviewImage> PreviewImagePtr;
 247         ///
 248         typedef map<string, PreviewImagePtr> Cache;
 249         ///
 250         Cache cache_;
 251
 252         /** pending_ stores the LaTeX snippets in anticipation of them being
 253          *  sent to the converter.
 254          */
 255         PendingSnippets pending_;
 256
 257         /** in_progress_ stores all forked processes so that we can proceed
 258          *  thereafter.
 259             The map uses the conversion commands as its identifiers.
 260          */
 261         InProgressProcesses in_progress_;
 262
 263         ///
 264         PreviewLoader & parent_;
 265         ///
 266         Buffer const & buffer_;
 267         ///
 268         mutable int font_scaling_factor_;
 269         ///
 270         mutable int fg_color_;
 271         ///
 272         mutable int bg_color_;
 273         ///
 274         QTimer * delay_refresh_;
 275         ///
 276         bool finished_generating_;
 277
 278         /// We don't own this
 279         static lyx::Converter const * pconverter_;
 280 };
 281
 282
 283 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 284
 285
 286 //
 287 // The public interface, defined in PreviewLoader.h
 288 //
 289
 290 PreviewLoader::PreviewLoader(Buffer const & b)
 291         : pimpl_(new Impl(*this, b))
 292 {}
 293
 294
 295 PreviewLoader::~PreviewLoader()
 296 {
 297         delete pimpl_;
 298 }
 299
 300
 301 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 302 {
 303         return pimpl_->preview(latex_snippet);
 304 }
 305
 306
 307 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 308 {
 309         return pimpl_->status(latex_snippet);
 310 }
 311
 312
 313 void PreviewLoader::add(string const & latex_snippet) const
 314 {
 315         pimpl_->add(latex_snippet);
 316 }
 317
 318
 319 void PreviewLoader::remove(string const & latex_snippet) const
 320 {
 321         pimpl_->remove(latex_snippet);
 322 }
 323
 324
 325 void PreviewLoader::startLoading(bool wait) const
 326 {
 327         pimpl_->startLoading(wait);
 328 }
 329
 330
 331 void PreviewLoader::refreshPreviews()
 332 {
 333         pimpl_->refreshPreviews();
 334 }
 335
 336
 337 boost::signals2::connection PreviewLoader::connect(slot_type const & slot) const
 338 {
 339         return pimpl_->imageReady.connect(slot);
 340 }
 341
 342
 343 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 344 {
 345         pimpl_->imageReady(pimage);
 346 }
 347
 348
 349 Buffer const & PreviewLoader::buffer() const
 350 {
 351         return pimpl_->buffer();
 352 }
 353
 354 } // namespace graphics
 355 } // namespace lyx
 356
 357
 358 // The details of the Impl
 359 // =======================
 360
 361 namespace {
 362
 363 class IncrementedFileName {
 364 public:
 365         IncrementedFileName(string const & to_format,
 366                             string const & filename_base)
 367                 : to_format_(to_format), base_(filename_base), counter_(1)
 368         {}
 369
 370         SnippetPair const operator()(string const & snippet)
 371         {
 372                 ostringstream os;
 373                 os << base_ << counter_++ << '.' << to_format_;
 374                 string const file = os.str();
 375
 376                 return make_pair(snippet, FileName(file));
 377         }
 378
 379 private:
 380         string const & to_format_;
 381         string const & base_;
 382         int counter_;
 383 };
 384
 385
 386 InProgress::InProgress(string const & filename_base,
 387                        PendingSnippets const & pending,
 388                        string const & to_format)
 389         : pid(0),
 390           metrics_file(filename_base + ".metrics"),
 391           snippets(pending.size())
 392 {
 393         PendingSnippets::const_iterator pit  = pending.begin();
 394         PendingSnippets::const_iterator pend = pending.end();
 395         BitmapFile::iterator sit = snippets.begin();
 396
 397         transform(pit, pend, sit,
 398                        IncrementedFileName(to_format, filename_base));
 399 }
 400
 401
 402 void InProgress::stop() const
 403 {
 404         if (pid)
 405                 ForkedCallsController::kill(pid, 0);
 406
 407         if (!metrics_file.empty())
 408                 metrics_file.removeFile();
 409
 410         BitmapFile::const_iterator vit  = snippets.begin();
 411         BitmapFile::const_iterator vend = snippets.end();
 412         for (; vit != vend; ++vit) {
 413                 if (!vit->second.empty())
 414                         vit->second.removeFile();
 415         }
 416 }
 417
 418 } // namespace anon
 419
 420
 421 namespace lyx {
 422 namespace graphics {
 423
 424 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 425         : parent_(p), buffer_(b), finished_generating_(true)
 426 {
 427         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 428         if (theApp()) {
 429                 fg_color_ = strtol(theApp()->hexName(foregroundColor()).c_str(), 0, 16);
 430                 bg_color_ = strtol(theApp()->hexName(backgroundColor()).c_str(), 0, 16);
 431         } else {
 432                 fg_color_ = 0x0;
 433                 bg_color_ = 0xffffff;
 434         }
 435         if (!pconverter_)
 436                 pconverter_ = setConverter("lyxpreview");
 437
 438         delay_refresh_ = new QTimer(&parent_);
 439         delay_refresh_->setSingleShot(true);
 440         QObject::connect(delay_refresh_, SIGNAL(timeout()),
 441                          &parent_, SLOT(refreshPreviews()));
 442 }
 443
 444
 445 PreviewLoader::Impl::~Impl()
 446 {
 447         delete delay_refresh_;
 448
 449         InProgressProcesses::iterator ipit  = in_progress_.begin();
 450         InProgressProcesses::iterator ipend = in_progress_.end();
 451
 452         for (; ipit != ipend; ++ipit)
 453                 ipit->second.stop();
 454 }
 455
 456
 457 PreviewImage const *
 458 PreviewLoader::Impl::preview(string const & latex_snippet) const
 459 {
 460         int fs = int(buffer_.fontScalingFactor());
 461         int fg = 0x0;
 462         int bg = 0xffffff;
 463         if (theApp()) {
 464                 fg = strtol(theApp()->hexName(foregroundColor()).c_str(), 0, 16);
 465                 bg = strtol(theApp()->hexName(backgroundColor()).c_str(), 0, 16);
 466         }
 467         if (font_scaling_factor_ != fs || fg_color_ != fg || bg_color_ != bg) {
 468                 // Schedule refresh of all previews on zoom or color changes.
 469                 // The previews are regenerated only after the zoom factor
 470                 // has not been changed for about 1 second.
 471                 fg_color_ = fg;
 472                 bg_color_ = bg;
 473                 delay_refresh_->start(1000);
 474         }
 475         // Don't try to access the cache until we are done.
 476         if (delay_refresh_->isActive() || !finished_generating_)
 477                 return 0;
 478         Cache::const_iterator it = cache_.find(latex_snippet);
 479         return (it == cache_.end()) ? 0 : it->second.get();
 480 }
 481
 482
 483 void PreviewLoader::Impl::refreshPreviews()
 484 {
 485         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 486         // Reschedule refresh until the previous process completed.
 487         if (!finished_generating_) {
 488                 delay_refresh_->start(1000);
 489                 return;
 490         }
 491         Cache::const_iterator cit = cache_.begin();
 492         Cache::const_iterator cend = cache_.end();
 493         while (cit != cend)
 494                 parent_.remove((cit++)->first);
 495         finished_generating_ = false;
 496         buffer_.updatePreviews();
 497 }
 498
 499
 500 namespace {
 501
 502 class FindSnippet {
 503 public:
 504         FindSnippet(string const & s) : snippet_(s) {}
 505         bool operator()(InProgressProcess const & process) const
 506         {
 507                 BitmapFile const & snippets = process.second.snippets;
 508                 BitmapFile::const_iterator beg  = snippets.begin();
 509                 BitmapFile::const_iterator end = snippets.end();
 510                 return find_if(beg, end, FindFirst(snippet_)) != end;
 511         }
 512
 513 private:
 514         string const snippet_;
 515 };
 516
 517 } // namespace anon
 518
 519 PreviewLoader::Status
 520 PreviewLoader::Impl::status(string const & latex_snippet) const
 521 {
 522         Cache::const_iterator cit = cache_.find(latex_snippet);
 523         if (cit != cache_.end())
 524                 return Ready;
 525
 526         PendingSnippets::const_iterator pit  = pending_.begin();
 527         PendingSnippets::const_iterator pend = pending_.end();
 528
 529         pit = find(pit, pend, latex_snippet);
 530         if (pit != pend)
 531                 return InQueue;
 532
 533         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 534         InProgressProcesses::const_iterator ipend = in_progress_.end();
 535
 536         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 537         if (ipit != ipend)
 538                 return Processing;
 539
 540         return NotFound;
 541 }
 542
 543
 544 void PreviewLoader::Impl::add(string const & latex_snippet)
 545 {
 546         if (!pconverter_ || status(latex_snippet) != NotFound)
 547                 return;
 548
 549         string const snippet = trim(latex_snippet);
 550         if (snippet.empty())
 551                 return;
 552
 553         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
 554
 555         pending_.push_back(snippet);
 556 }
 557
 558
 559 namespace {
 560
 561 class EraseSnippet {
 562 public:
 563         EraseSnippet(string const & s) : snippet_(s) {}
 564         void operator()(InProgressProcess & process)
 565         {
 566                 BitmapFile & snippets = process.second.snippets;
 567                 BitmapFile::iterator it  = snippets.begin();
 568                 BitmapFile::iterator end = snippets.end();
 569
 570                 it = find_if(it, end, FindFirst(snippet_));
 571                 if (it != end)
 572                         snippets.erase(it, it+1);
 573         }
 574
 575 private:
 576         string const & snippet_;
 577 };
 578
 579 } // namespace anon
 580
 581
 582 void PreviewLoader::Impl::remove(string const & latex_snippet)
 583 {
 584         Cache::iterator cit = cache_.find(latex_snippet);
 585         if (cit != cache_.end())
 586                 cache_.erase(cit);
 587
 588         PendingSnippets::iterator pit  = pending_.begin();
 589         PendingSnippets::iterator pend = pending_.end();
 590
 591         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 592
 593         InProgressProcesses::iterator ipit  = in_progress_.begin();
 594         InProgressProcesses::iterator ipend = in_progress_.end();
 595
 596         for_each(ipit, ipend, EraseSnippet(latex_snippet));
 597
 598         while (ipit != ipend) {
 599                 InProgressProcesses::iterator curr = ipit++;
 600                 if (curr->second.snippets.empty())
 601                         in_progress_.erase(curr);
 602         }
 603 }
 604
 605
 606 void PreviewLoader::Impl::startLoading(bool wait)
 607 {
 608         if (pending_.empty() || !pconverter_)
 609                 return;
 610
 611         // Only start the process off after the buffer is loaded from file.
 612         if (!buffer_.isFullyLoaded())
 613                 return;
 614
 615         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 616
 617         // As used by the LaTeX file and by the resulting image files
 618         FileName const directory(buffer_.temppath());
 619
 620         FileName const latexfile = unique_tex_filename(directory);
 621         string const filename_base = removeExtension(latexfile.absFileName());
 622
 623         // Create an InProgress instance to place in the map of all
 624         // such processes if it starts correctly.
 625         InProgress inprogress(filename_base, pending_, pconverter_->to());
 626
 627         // clear pending_, so we're ready to start afresh.
 628         pending_.clear();
 629
 630         // Output the LaTeX file.
 631         // we use the encoding of the buffer
 632         Encoding const & enc = buffer_.params().encoding();
 633         ofdocstream of;
 634         try { of.reset(enc.iconvName()); }
 635         catch (iconv_codecvt_facet_exception const & e) {
 636                 LYXERR0("Caught iconv exception: " << e.what()
 637                         << "\nUnable to create LaTeX file: " << latexfile);
 638                 return;
 639         }
 640
 641         otexstream os(of);
 642         OutputParams runparams(&enc);
 643         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 644
 645         if (!openFileWrite(of, latexfile))
 646                 return;
 647
 648         if (!of) {
 649                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 650                                         << "Unable to create LaTeX file\n" << latexfile);
 651                 return;
 652         }
 653         of << "\\batchmode\n";
 654
 655         // Set \jobname of previews to the document name (see bug 9627)
 656         of << "\\def\\jobname{"
 657            << from_utf8(changeExtension(buffer_.latexName(true), ""))
 658            << "}\n";
 659
 660         LYXERR(Debug::LATEX, "Format = " << buffer_.params().getDefaultOutputFormat());
 661         string latexparam = "";
 662         bool docformat = !buffer_.params().default_output_format.empty()
 663                         && buffer_.params().default_output_format != "default";
 664         // Use LATEX flavor if the document does not specify a specific
 665         // output format (see bug 9371).
 666         OutputParams::FLAVOR flavor = docformat
 667                                         ? buffer_.params().getOutputFlavor()
 668                                         : OutputParams::LATEX;
 669         if (buffer_.params().encoding().package() == Encoding::japanese) {
 670                 latexparam = " --latex=platex";
 671                 flavor = OutputParams::LATEX;
 672         }
 673         else if (buffer_.params().useNonTeXFonts) {
 674                 if (flavor == OutputParams::LUATEX)
 675                         latexparam = " --latex=lualatex";
 676                 else {
 677                         flavor = OutputParams::XETEX;
 678                         latexparam = " --latex=xelatex";
 679                 }
 680         }
 681         else {
 682                 switch (flavor) {
 683                         case OutputParams::PDFLATEX:
 684                                 latexparam = " --latex=pdflatex";
 685                                 break;
 686                         case OutputParams::XETEX:
 687                                 latexparam = " --latex=xelatex";
 688                                 break;
 689                         case OutputParams::LUATEX:
 690                                 latexparam = " --latex=lualatex";
 691                                 break;
 692                         case OutputParams::DVILUATEX:
 693                                 latexparam = " --latex=dvilualatex";
 694                                 break;
 695                         default:
 696                                 flavor = OutputParams::LATEX;
 697                 }
 698         }
 699         dumpPreamble(os, flavor);
 700         // handle inputenc etc.
 701         // I think, this is already hadled by dumpPreamble(): Kornel
 702         // buffer_.params().writeEncodingPreamble(os, features);
 703         of << "\n\\begin{document}\n";
 704         dumpData(of, inprogress.snippets);
 705         of << "\n\\end{document}\n";
 706         of.close();
 707         if (of.fail()) {
 708                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 709                                          << "File was not closed properly.");
 710                 return;
 711         }
 712
 713         // The conversion command.
 714         ostringstream cs;
 715         cs << pconverter_->command()
 716            << " " << quoteName(latexfile.toFilesystemEncoding())
 717            << " --dpi " << font_scaling_factor_;
 718
 719         // FIXME XHTML
 720         // The colors should be customizable.
 721         if (!buffer_.isExporting()) {
 722                 ColorCode const fg = PreviewLoader::foregroundColor();
 723                 ColorCode const bg = PreviewLoader::backgroundColor();
 724                 cs << " --fg " << theApp()->hexName(fg)
 725                    << " --bg " << theApp()->hexName(bg);
 726         }
 727
 728         cs << latexparam;
 729         if (buffer_.params().bibtex_command != "default")
 730                 cs << " --bibtex=" << quoteName(buffer_.params().bibtex_command);
 731         else if (buffer_.params().encoding().package() == Encoding::japanese)
 732                 cs << " --bibtex=" << quoteName(lyxrc.jbibtex_command);
 733         else
 734                 cs << " --bibtex=" << quoteName(lyxrc.bibtex_command);
 735         if (buffer_.params().bufferFormat() == "lilypond-book")
 736                 cs << " --lilypond";
 737
 738         string const command = cs.str();
 739
 740         if (wait) {
 741                 ForkedCall call(buffer_.filePath(), buffer_.layoutPos());
 742                 int ret = call.startScript(ForkedProcess::Wait, command);
 743                 static atomic_int fake((2^20) + 1);
 744                 int pid = fake++;
 745                 inprogress.pid = pid;
 746                 inprogress.command = command;
 747                 in_progress_[pid] = inprogress;
 748                 finishedGenerating(pid, ret);
 749                 return;
 750         }
 751
 752         // Initiate the conversion from LaTeX to bitmap images files.
 753         ForkedCall::SignalTypePtr
 754                 convert_ptr(new ForkedCall::SignalType);
 755         convert_ptr->connect(bind(&Impl::finishedGenerating, this, _1, _2));
 756
 757         ForkedCall call(buffer_.filePath());
 758         int ret = call.startScript(command, convert_ptr);
 759
 760         if (ret != 0) {
 761                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 762                                         << "Unable to start process\n" << command);
 763                 return;
 764         }
 765
 766         // Store the generation process in a list of all such processes
 767         inprogress.pid = call.pid();
 768         inprogress.command = command;
 769         in_progress_[inprogress.pid] = inprogress;
 770 }
 771
 772
 773 double PreviewLoader::displayPixelRatio() const
 774 {
 775         return buffer().params().display_pixel_ratio;
 776 }
 777
 778 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 779 {
 780         // Paranoia check!
 781         InProgressProcesses::iterator git = in_progress_.find(pid);
 782         if (git == in_progress_.end()) {
 783                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 784                         "data for PID " << pid << endl;
 785                 finished_generating_ = true;
 786                 return;
 787         }
 788
 789         string const command = git->second.command;
 790         string const status = retval > 0 ? "failed" : "succeeded";
 791         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 792                                 << retval << "): processing " << status
 793                                 << " for " << command);
 794         if (retval > 0) {
 795                 in_progress_.erase(git);
 796                 finished_generating_ = true;
 797                 return;
 798         }
 799
 800         // Read the metrics file, if it exists
 801         vector<double> ascent_fractions(git->second.snippets.size());
 802         setAscentFractions(ascent_fractions, git->second.metrics_file);
 803
 804         // Add these newly generated bitmap files to the cache and
 805         // start loading them into LyX.
 806         BitmapFile::const_iterator it  = git->second.snippets.begin();
 807         BitmapFile::const_iterator end = git->second.snippets.end();
 808
 809         list<PreviewImagePtr> newimages;
 810
 811         int metrics_counter = 0;
 812         for (; it != end; ++it, ++metrics_counter) {
 813                 string const & snip = it->first;
 814                 FileName const & file = it->second;
 815                 double af = ascent_fractions[metrics_counter];
 816
 817                 // Add the image to the cache only if it's actually present
 818                 // and not empty (an empty image is signaled by af < 0)
 819                 if (af >= 0 && file.isReadableFile()) {
 820                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 821                         cache_[snip] = ptr;
 822
 823                         newimages.push_back(ptr);
 824                 }
 825
 826         }
 827
 828         // Remove the item from the list of still-executing processes.
 829         in_progress_.erase(git);
 830
 831         // Tell the outside world
 832         list<PreviewImagePtr>::const_reverse_iterator
 833                 nit  = newimages.rbegin();
 834         list<PreviewImagePtr>::const_reverse_iterator
 835                 nend = newimages.rend();
 836         for (; nit != nend; ++nit) {
 837                 imageReady(*nit->get());
 838         }
 839         finished_generating_ = true;
 840 }
 841
 842
 843 void PreviewLoader::Impl::dumpPreamble(otexstream & os, OutputParams::FLAVOR flavor) const
 844 {
 845         // Dump the preamble only.
 846         LYXERR(Debug::LATEX, "dumpPreamble, flavor == " << flavor);
 847         OutputParams runparams(&buffer_.params().encoding());
 848         runparams.flavor = flavor;
 849         runparams.nice = true;
 850         runparams.moving_arg = true;
 851         runparams.free_spacing = true;
 852         runparams.is_child = buffer_.parent();
 853         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 854
 855         // FIXME! This is a HACK! The proper fix is to control the 'true'
 856         // passed to WriteStream below:
 857         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 858         //                          OutputParams const & runparams) const
 859         // {
 860         //      WriteStream wi(os, runparams.moving_arg, true);
 861         //      par_->write(wi);
 862         //      return wi.line();
 863         // }
 864         os << "\n"
 865            << "\\def\\lyxlock{}\n"
 866            << "\n";
 867
 868         // All equation labels appear as "(#)" + preview.sty's rendering of
 869         // the label name
 870         if (lyxrc.preview_hashed_labels)
 871                 os << "\\renewcommand{\\theequation}{\\#}\n";
 872
 873         // Use the preview style file to ensure that each snippet appears on a
 874         // fresh page.
 875         // Also support PDF output (automatically generated e.g. when
 876         // \usepackage[pdftex]{hyperref} is used and XeTeX.
 877         os << "\n"
 878            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
 879            << "\n";
 880 }
 881
 882
 883 void PreviewLoader::Impl::dumpData(odocstream & os,
 884                                    BitmapFile const & vec) const
 885 {
 886         if (vec.empty())
 887                 return;
 888
 889         BitmapFile::const_iterator it  = vec.begin();
 890         BitmapFile::const_iterator end = vec.end();
 891
 892         for (; it != end; ++it) {
 893                 // FIXME UNICODE
 894                 os << "\\begin{preview}\n"
 895                    << from_utf8(it->first)
 896                    << "\n\\end{preview}\n\n";
 897         }
 898 }
 899
 900 } // namespace graphics
 901 } // namespace lyx
 902
 903 #include "moc_PreviewLoader.cpp"