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