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