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/TempFile.h"
  42
  43 #include <atomic>
  44 #include <fstream>
  45 #include <iomanip>
  46 #include <memory>
  47 #include <mutex>
  48 #include <sstream>
  49
  50 #include <QTimer>
  51
  52 using namespace std;
  53 using namespace lyx::support;
  54
  55
  56
  57 namespace {
  58
  59 typedef pair<string, FileName> SnippetPair;
  60
  61 // A list of all snippets to be converted to previews
  62 typedef list<string> PendingSnippets;
  63
  64 // Each item in the vector is a pair<snippet, image file name>.
  65 typedef vector<SnippetPair> BitmapFile;
  66
  67
  68 FileName const unique_tex_filename(FileName const & bufferpath)
  69 {
  70         TempFile tempfile(bufferpath, "lyxpreviewXXXXXX.tex");
  71         tempfile.setAutoRemove(false);
  72         return tempfile.name();
  73 }
  74
  75
  76 void setAscentFractions(vector<double> & ascent_fractions,
  77                         FileName const & metrics_file)
  78 {
  79         // If all else fails, then the images will have equal ascents and
  80         // descents.
  81         vector<double>::iterator it  = ascent_fractions.begin();
  82         vector<double>::iterator end = ascent_fractions.end();
  83         fill(it, end, 0.5);
  84
  85         ifstream in(metrics_file.toFilesystemEncoding().c_str());
  86         if (!in.good()) {
  87                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
  88                         << "Unable to open file!");
  89                 return;
  90         }
  91
  92         bool error = false;
  93
  94         int snippet_counter = 1;
  95         while (!in.eof() && it != end) {
  96                 string snippet;
  97                 int id;
  98                 double ascent_fraction;
  99
 100                 in >> snippet >> id >> ascent_fraction;
 101
 102                 if (!in.good())
 103                         // eof after all
 104                         break;
 105
 106                 error = snippet != "Snippet";
 107                 if (error)
 108                         break;
 109
 110                 error = id != snippet_counter;
 111                 if (error)
 112                         break;
 113
 114                 *it = ascent_fraction;
 115
 116                 ++snippet_counter;
 117                 ++it;
 118         }
 119
 120         if (error) {
 121                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 122                         << "Error reading file!\n");
 123         }
 124 }
 125
 126
 127 std::function <bool (SnippetPair const &)> FindFirst(string const & comp)
 128 {
 129         return [&comp](SnippetPair const & sp) { return sp.first == comp; };
 130 }
 131
 132
 133 /// Store info on a currently executing, forked process.
 134 class InProgress {
 135 public:
 136         ///
 137         InProgress() : pid(0) {}
 138         ///
 139         InProgress(string const & filename_base,
 140                    PendingSnippets const & pending,
 141                    string const & to_format);
 142         /// Remove any files left lying around and kill the forked process.
 143         void stop() const;
 144
 145         ///
 146         string command;
 147         ///
 148         FileName metrics_file;
 149         ///
 150         BitmapFile snippets;
 151         ///
 152         pid_t pid;
 153 };
 154
 155 typedef map<pid_t, InProgress>  InProgressProcesses;
 156
 157 typedef InProgressProcesses::value_type InProgressProcess;
 158
 159 } // namespace
 160
 161
 162 namespace lyx {
 163 namespace graphics {
 164
 165 class PreviewLoader::Impl {
 166 public:
 167         ///
 168         Impl(PreviewLoader & p, Buffer const & b);
 169         /// Stop any InProgress items still executing.
 170         ~Impl();
 171         ///
 172         PreviewImage const * preview(string const & latex_snippet) const;
 173         ///
 174         PreviewLoader::Status status(string const & latex_snippet) const;
 175         ///
 176         void add(string const & latex_snippet);
 177         ///
 178         void remove(string const & latex_snippet);
 179         /// \p wait whether to wait for the process to complete or, instead,
 180         /// to do it in the background.
 181         void startLoading(bool wait = false);
 182         ///
 183         void refreshPreviews();
 184
 185         /// Emit this signal when an image is ready for display.
 186         signals2::signal<void(PreviewImage const &)> imageReady;
 187
 188         Buffer const & buffer() const { return buffer_; }
 189
 190         lyx::Converter const * setConverter(string const & from);
 191
 192 private:
 193         /// Called by the ForkedCall process that generated the bitmap files.
 194         void finishedGenerating(pid_t, int);
 195         ///
 196         void dumpPreamble(otexstream &, OutputParams::FLAVOR) const;
 197         ///
 198         void dumpData(odocstream &, BitmapFile const &) const;
 199
 200         /** cache_ allows easy retrieval of already-generated images
 201          *  using the LaTeX snippet as the identifier.
 202          */
 203         typedef std::shared_ptr<PreviewImage> PreviewImagePtr;
 204         ///
 205         typedef map<string, PreviewImagePtr> Cache;
 206         ///
 207         Cache cache_;
 208
 209         /** pending_ stores the LaTeX snippets in anticipation of them being
 210          *  sent to the converter.
 211          */
 212         PendingSnippets pending_;
 213
 214         /** in_progress_ stores all forked processes so that we can proceed
 215          *  thereafter.
 216          */
 217         InProgressProcesses in_progress_;
 218
 219         ///
 220         PreviewLoader & parent_;
 221         ///
 222         Buffer const & buffer_;
 223         ///
 224         mutable int font_scaling_factor_;
 225         ///
 226         mutable int fg_color_;
 227         ///
 228         mutable int bg_color_;
 229         ///
 230         QTimer * delay_refresh_;
 231         ///
 232         Trackable trackable_;
 233         ///
 234         bool finished_generating_;
 235
 236         /// We don't own this
 237         static lyx::Converter const * pconverter_;
 238
 239 };
 240
 241
 242 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 243
 244
 245 //
 246 // The public interface, defined in PreviewLoader.h
 247 //
 248
 249 PreviewLoader::PreviewLoader(Buffer const & b)
 250         : pimpl_(new Impl(*this, b))
 251 {}
 252
 253
 254 PreviewLoader::~PreviewLoader()
 255 {
 256         delete pimpl_;
 257 }
 258
 259
 260 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 261 {
 262         return pimpl_->preview(latex_snippet);
 263 }
 264
 265
 266 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 267 {
 268         return pimpl_->status(latex_snippet);
 269 }
 270
 271
 272 void PreviewLoader::add(string const & latex_snippet) const
 273 {
 274         pimpl_->add(latex_snippet);
 275 }
 276
 277
 278 void PreviewLoader::remove(string const & latex_snippet) const
 279 {
 280         pimpl_->remove(latex_snippet);
 281 }
 282
 283
 284 void PreviewLoader::startLoading(bool wait) const
 285 {
 286         pimpl_->startLoading(wait);
 287 }
 288
 289
 290 void PreviewLoader::refreshPreviews()
 291 {
 292         pimpl_->refreshPreviews();
 293 }
 294
 295
 296 signals2::connection PreviewLoader::connect(slot const & slot) const
 297 {
 298         return pimpl_->imageReady.connect(slot);
 299 }
 300
 301
 302 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 303 {
 304         pimpl_->imageReady(pimage);
 305 }
 306
 307
 308 Buffer const & PreviewLoader::buffer() const
 309 {
 310         return pimpl_->buffer();
 311 }
 312
 313 } // namespace graphics
 314 } // namespace lyx
 315
 316
 317 // The details of the Impl
 318 // =======================
 319
 320 namespace {
 321
 322 class IncrementedFileName {
 323 public:
 324         IncrementedFileName(string const & to_format,
 325                             string const & filename_base)
 326                 : to_format_(to_format), base_(filename_base), counter_(1)
 327         {}
 328
 329         SnippetPair const operator()(string const & snippet)
 330         {
 331                 ostringstream os;
 332                 os << base_ << counter_++ << '.' << to_format_;
 333                 string const file_name = os.str();
 334                 return make_pair(snippet, FileName(file_name));
 335         }
 336
 337 private:
 338         string const & to_format_;
 339         string const & base_;
 340         int counter_;
 341 };
 342
 343
 344 InProgress::InProgress(string const & filename_base,
 345                        PendingSnippets const & pending,
 346                        string const & to_format)
 347         : metrics_file(filename_base + ".metrics"),
 348           snippets(pending.size()), pid(0)
 349 {
 350         PendingSnippets::const_iterator pit  = pending.begin();
 351         PendingSnippets::const_iterator pend = pending.end();
 352         BitmapFile::iterator sit = snippets.begin();
 353
 354         transform(pit, pend, sit,
 355                        IncrementedFileName(to_format, filename_base));
 356 }
 357
 358
 359 void InProgress::stop() const
 360 {
 361         if (pid)
 362                 ForkedCallsController::kill(pid, 0);
 363
 364         if (!metrics_file.empty())
 365                 metrics_file.removeFile();
 366
 367         BitmapFile::const_iterator vit  = snippets.begin();
 368         BitmapFile::const_iterator vend = snippets.end();
 369         for (; vit != vend; ++vit) {
 370                 if (!vit->second.empty())
 371                         vit->second.removeFile();
 372         }
 373 }
 374
 375 } // namespace
 376
 377
 378 namespace lyx {
 379 namespace graphics {
 380
 381 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 382         : parent_(p), buffer_(b), finished_generating_(true)
 383 {
 384         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 385         if (theApp()) {
 386                 fg_color_ = convert(theApp()->hexName(foregroundColor()).c_str(), 16);
 387                 bg_color_ = convert(theApp()->hexName(backgroundColor()).c_str(), 16);
 388         } else {
 389                 fg_color_ = 0x0;
 390                 bg_color_ = 0xffffff;
 391         }
 392         if (!pconverter_)
 393                 pconverter_ = setConverter("lyxpreview");
 394
 395         delay_refresh_ = new QTimer(&parent_);
 396         delay_refresh_->setSingleShot(true);
 397         QObject::connect(delay_refresh_, SIGNAL(timeout()),
 398                          &parent_, SLOT(refreshPreviews()));
 399 }
 400
 401
 402 lyx::Converter const * PreviewLoader::Impl::setConverter(string const & from)
 403 {
 404         typedef vector<string> FmtList;
 405         FmtList const & loadableFormats = graphics::Cache::get().loadableFormats();
 406         FmtList::const_iterator it = loadableFormats.begin();
 407         FmtList::const_iterator const end = loadableFormats.end();
 408
 409         for (; it != end; ++it) {
 410                 string const to = *it;
 411                 if (from == to)
 412                         continue;
 413
 414                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
 415                 if (ptr)
 416                         return ptr;
 417         }
 418
 419         // Show the error only once. This is thread-safe.
 420         static nullptr_t no_conv = [&]{
 421                 LYXERR0("PreviewLoader::startLoading()\n"
 422                         << "No converter from \"" << from
 423                         << "\" format has been defined.");
 424                 return nullptr;
 425         } ();
 426
 427         return no_conv;
 428 }
 429
 430
 431 PreviewLoader::Impl::~Impl()
 432 {
 433         delete delay_refresh_;
 434
 435         InProgressProcesses::iterator ipit  = in_progress_.begin();
 436         InProgressProcesses::iterator ipend = in_progress_.end();
 437
 438         for (; ipit != ipend; ++ipit)
 439                 ipit->second.stop();
 440 }
 441
 442
 443 PreviewImage const *
 444 PreviewLoader::Impl::preview(string const & latex_snippet) const
 445 {
 446         int fs = int(buffer_.fontScalingFactor());
 447         int fg = 0x0;
 448         int bg = 0xffffff;
 449         if (theApp()) {
 450                 fg = convert(theApp()->hexName(foregroundColor()).c_str(), 16);
 451                 bg = convert(theApp()->hexName(backgroundColor()).c_str(), 16);
 452         }
 453         if (font_scaling_factor_ != fs || fg_color_ != fg || bg_color_ != bg) {
 454                 // Schedule refresh of all previews on zoom or color changes.
 455                 // The previews are regenerated only after the zoom factor
 456                 // has not been changed for about 1 second.
 457                 fg_color_ = fg;
 458                 bg_color_ = bg;
 459                 delay_refresh_->start(1000);
 460         }
 461         // Don't try to access the cache until we are done.
 462         if (delay_refresh_->isActive() || !finished_generating_)
 463                 return nullptr;
 464
 465         Cache::const_iterator it = cache_.find(latex_snippet);
 466         return (it == cache_.end()) ? nullptr : it->second.get();
 467 }
 468
 469
 470 void PreviewLoader::Impl::refreshPreviews()
 471 {
 472         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 473         // Reschedule refresh until the previous process completed.
 474         if (!finished_generating_) {
 475                 delay_refresh_->start(1000);
 476                 return;
 477         }
 478         Cache::const_iterator cit = cache_.begin();
 479         Cache::const_iterator cend = cache_.end();
 480         while (cit != cend)
 481                 parent_.remove((cit++)->first);
 482         finished_generating_ = false;
 483         buffer_.updatePreviews();
 484 }
 485
 486
 487 namespace {
 488
 489 std::function<bool (InProgressProcess const &)> FindSnippet(string const & s)
 490 {
 491         return [&s](InProgressProcess const & process) {
 492                 BitmapFile const & snippets = process.second.snippets;
 493                 BitmapFile::const_iterator beg  = snippets.begin();
 494                 BitmapFile::const_iterator end = snippets.end();
 495                 return find_if(beg, end, FindFirst(s)) != end;
 496         };
 497 }
 498
 499 } // namespace
 500
 501 PreviewLoader::Status
 502 PreviewLoader::Impl::status(string const & latex_snippet) const
 503 {
 504         Cache::const_iterator cit = cache_.find(latex_snippet);
 505         if (cit != cache_.end())
 506                 return Ready;
 507
 508         PendingSnippets::const_iterator pit  = pending_.begin();
 509         PendingSnippets::const_iterator pend = pending_.end();
 510
 511         pit = find(pit, pend, latex_snippet);
 512         if (pit != pend)
 513                 return InQueue;
 514
 515         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 516         InProgressProcesses::const_iterator ipend = in_progress_.end();
 517
 518         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 519         if (ipit != ipend)
 520                 return Processing;
 521
 522         return NotFound;
 523 }
 524
 525
 526 void PreviewLoader::Impl::add(string const & latex_snippet)
 527 {
 528         if (!pconverter_ || status(latex_snippet) != NotFound)
 529                 return;
 530
 531         string const snippet = trim(latex_snippet);
 532         if (snippet.empty())
 533                 return;
 534
 535         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
 536
 537         pending_.push_back(snippet);
 538 }
 539
 540
 541 namespace {
 542
 543 std::function<void (InProgressProcess &)> EraseSnippet(string const & s) {
 544         return [&s](InProgressProcess & process) {
 545                 BitmapFile & snippets = process.second.snippets;
 546                 BitmapFile::iterator it  = snippets.begin();
 547                 BitmapFile::iterator end = snippets.end();
 548
 549                 it = find_if(it, end, FindFirst(s));
 550                 if (it != end)
 551                         snippets.erase(it, it+1);
 552         };
 553 };
 554
 555 } // namespace
 556
 557
 558 void PreviewLoader::Impl::remove(string const & latex_snippet)
 559 {
 560         Cache::iterator cit = cache_.find(latex_snippet);
 561         if (cit != cache_.end())
 562                 cache_.erase(cit);
 563
 564         PendingSnippets::iterator pit  = pending_.begin();
 565         PendingSnippets::iterator pend = pending_.end();
 566
 567         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 568
 569         InProgressProcesses::iterator ipit  = in_progress_.begin();
 570         InProgressProcesses::iterator ipend = in_progress_.end();
 571
 572         for_each(ipit, ipend, EraseSnippet(latex_snippet));
 573
 574         while (ipit != ipend) {
 575                 InProgressProcesses::iterator curr = ipit++;
 576                 if (curr->second.snippets.empty())
 577                         in_progress_.erase(curr);
 578         }
 579 }
 580
 581
 582 void PreviewLoader::Impl::startLoading(bool wait)
 583 {
 584         if (pending_.empty() || !pconverter_)
 585                 return;
 586
 587         // Only start the process off after the buffer is loaded from file.
 588         if (!buffer_.isFullyLoaded())
 589                 return;
 590
 591         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 592
 593         // As used by the LaTeX file and by the resulting image files
 594         FileName const directory(buffer_.temppath());
 595
 596         FileName const latexfile = unique_tex_filename(directory);
 597         string const filename_base = removeExtension(latexfile.absFileName());
 598
 599         // Create an InProgress instance to place in the map of all
 600         // such processes if it starts correctly.
 601         InProgress inprogress(filename_base, pending_, pconverter_->to());
 602
 603         // clear pending_, so we're ready to start afresh.
 604         pending_.clear();
 605
 606         // Output the LaTeX file.
 607         // we use the encoding of the buffer
 608         Encoding const & enc = buffer_.params().encoding();
 609         ofdocstream of;
 610         try { of.reset(enc.iconvName()); }
 611         catch (iconv_codecvt_facet_exception const & e) {
 612                 LYXERR0("Caught iconv exception: " << e.what()
 613                         << "\nUnable to create LaTeX file: " << latexfile);
 614                 return;
 615         }
 616
 617         otexstream os(of);
 618         OutputParams runparams(&enc);
 619         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 620
 621         if (!openFileWrite(of, latexfile))
 622                 return;
 623
 624         if (!of) {
 625                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 626                                         << "Unable to create LaTeX file\n" << latexfile);
 627                 return;
 628         }
 629         of << "\\batchmode\n";
 630
 631         // Set \jobname of previews to the document name (see bug 9627)
 632         of << "\\def\\jobname{"
 633            << from_utf8(changeExtension(buffer_.latexName(true), ""))
 634            << "}\n";
 635
 636         LYXERR(Debug::LATEX, "Format = " << buffer_.params().getDefaultOutputFormat());
 637         string latexparam = "";
 638         bool docformat = !buffer_.params().default_output_format.empty()
 639                         && buffer_.params().default_output_format != "default";
 640         // Use LATEX flavor if the document does not specify a specific
 641         // output format (see bug 9371).
 642         OutputParams::FLAVOR flavor = docformat
 643                                         ? buffer_.params().getOutputFlavor()
 644                                         : OutputParams::LATEX;
 645         if (buffer_.params().encoding().package() == Encoding::japanese) {
 646                 latexparam = " --latex=platex";
 647                 flavor = OutputParams::LATEX;
 648         }
 649         else if (buffer_.params().useNonTeXFonts) {
 650                 if (flavor == OutputParams::LUATEX)
 651                         latexparam = " --latex=lualatex";
 652                 else {
 653                         flavor = OutputParams::XETEX;
 654                         latexparam = " --latex=xelatex";
 655                 }
 656         }
 657         else {
 658                 switch (flavor) {
 659                         case OutputParams::PDFLATEX:
 660                                 latexparam = " --latex=pdflatex";
 661                                 break;
 662                         case OutputParams::XETEX:
 663                                 latexparam = " --latex=xelatex";
 664                                 break;
 665                         case OutputParams::LUATEX:
 666                                 latexparam = " --latex=lualatex";
 667                                 break;
 668                         case OutputParams::DVILUATEX:
 669                                 latexparam = " --latex=dvilualatex";
 670                                 break;
 671                         default:
 672                                 flavor = OutputParams::LATEX;
 673                 }
 674         }
 675         dumpPreamble(os, flavor);
 676         // handle inputenc etc.
 677         // I think this is already handled by dumpPreamble(): Kornel
 678         // buffer_.params().writeEncodingPreamble(os, features);
 679         of << "\n\\begin{document}\n";
 680         dumpData(of, inprogress.snippets);
 681         of << "\n\\end{document}\n";
 682         of.close();
 683         if (of.fail()) {
 684                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 685                                          << "File was not closed properly.");
 686                 return;
 687         }
 688
 689         // The conversion command.
 690         ostringstream cs;
 691         cs << pconverter_->command()
 692            << " " << quoteName(latexfile.toFilesystemEncoding())
 693            << " --dpi " << font_scaling_factor_;
 694
 695         // FIXME XHTML
 696         // The colors should be customizable.
 697         if (!buffer_.isExporting()) {
 698                 ColorCode const fg = PreviewLoader::foregroundColor();
 699                 ColorCode const bg = PreviewLoader::backgroundColor();
 700                 cs << " --fg " << theApp()->hexName(fg)
 701                    << " --bg " << theApp()->hexName(bg);
 702         }
 703
 704         cs << latexparam;
 705         cs << " --bibtex=" << quoteName(buffer_.params().bibtexCommand());
 706         if (buffer_.params().bufferFormat() == "lilypond-book")
 707                 cs << " --lilypond";
 708
 709         string const command = cs.str();
 710
 711         if (wait) {
 712                 ForkedCall call(buffer_.filePath(), buffer_.layoutPos());
 713                 int ret = call.startScript(ForkedProcess::Wait, command);
 714                 // PID_MAX_LIMIT is 2^22 so we start one after that
 715                 static atomic_int fake((1 << 22) + 1);
 716                 int pid = fake++;
 717                 inprogress.pid = pid;
 718                 inprogress.command = command;
 719                 in_progress_[pid] = inprogress;
 720                 finishedGenerating(pid, ret);
 721                 return;
 722         }
 723
 724         // Initiate the conversion from LaTeX to bitmap images files.
 725         ForkedCall::sigPtr convert_ptr = make_shared<ForkedCall::sig>();
 726         convert_ptr->connect(ForkedProcess::slot([this](pid_t pid, int retval){
 727                                 finishedGenerating(pid, retval);
 728                         }).track_foreign(trackable_.p()));
 729
 730         ForkedCall call(buffer_.filePath());
 731         int ret = call.startScript(command, convert_ptr);
 732
 733         if (ret != 0) {
 734                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 735                                         << "Unable to start process\n" << command);
 736                 return;
 737         }
 738
 739         // Store the generation process in a list of all such processes
 740         inprogress.pid = call.pid();
 741         inprogress.command = command;
 742         in_progress_[inprogress.pid] = inprogress;
 743 }
 744
 745
 746 double PreviewLoader::displayPixelRatio() const
 747 {
 748         return buffer().params().display_pixel_ratio;
 749 }
 750
 751 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 752 {
 753         // Paranoia check!
 754         InProgressProcesses::iterator git = in_progress_.find(pid);
 755         if (git == in_progress_.end()) {
 756                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 757                         "data for PID " << pid << endl;
 758                 finished_generating_ = true;
 759                 return;
 760         }
 761
 762         string const command = git->second.command;
 763         string const status = retval > 0 ? "failed" : "succeeded";
 764         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 765                                 << retval << "): processing " << status
 766                                 << " for " << command);
 767         if (retval > 0) {
 768                 in_progress_.erase(git);
 769                 finished_generating_ = true;
 770                 return;
 771         }
 772
 773         // Read the metrics file, if it exists
 774         vector<double> ascent_fractions(git->second.snippets.size());
 775         setAscentFractions(ascent_fractions, git->second.metrics_file);
 776
 777         // Add these newly generated bitmap files to the cache and
 778         // start loading them into LyX.
 779         BitmapFile::const_iterator it  = git->second.snippets.begin();
 780         BitmapFile::const_iterator end = git->second.snippets.end();
 781
 782         list<PreviewImagePtr> newimages;
 783
 784         size_t metrics_counter = 0;
 785         for (; it != end; ++it, ++metrics_counter) {
 786                 string const & snip = it->first;
 787                 FileName const & file = it->second;
 788                 double af = ascent_fractions[metrics_counter];
 789
 790                 // Add the image to the cache only if it's actually present
 791                 // and not empty (an empty image is signaled by af < 0)
 792                 if (af >= 0 && file.isReadableFile()) {
 793                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 794                         cache_[snip] = ptr;
 795
 796                         newimages.push_back(ptr);
 797                 }
 798
 799         }
 800
 801         // Remove the item from the list of still-executing processes.
 802         in_progress_.erase(git);
 803
 804         // Tell the outside world
 805         list<PreviewImagePtr>::const_reverse_iterator
 806                 nit  = newimages.rbegin();
 807         list<PreviewImagePtr>::const_reverse_iterator
 808                 nend = newimages.rend();
 809         for (; nit != nend; ++nit) {
 810                 imageReady(*nit->get());
 811         }
 812         finished_generating_ = true;
 813 }
 814
 815
 816 void PreviewLoader::Impl::dumpPreamble(otexstream & os, OutputParams::FLAVOR flavor) const
 817 {
 818         // Dump the preamble only.
 819         LYXERR(Debug::LATEX, "dumpPreamble, flavor == " << flavor);
 820         OutputParams runparams(&buffer_.params().encoding());
 821         runparams.flavor = flavor;
 822         runparams.nice = true;
 823         runparams.moving_arg = true;
 824         runparams.free_spacing = true;
 825         runparams.is_child = buffer_.parent();
 826         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 827
 828         // FIXME! This is a HACK! The proper fix is to control the 'true'
 829         // passed to WriteStream below:
 830         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 831         //                          OutputParams const & runparams) const
 832         // {
 833         //      WriteStream wi(os, runparams.moving_arg, true);
 834         //      par_->write(wi);
 835         //      return wi.line();
 836         // }
 837         os << "\n"
 838            << "\\def\\lyxlock{}\n"
 839            << "\n";
 840
 841         // All equation labels appear as "(#)" + preview.sty's rendering of
 842         // the label name
 843         if (lyxrc.preview_hashed_labels)
 844                 os << "\\renewcommand{\\theequation}{\\#}\n";
 845
 846         // Use the preview style file to ensure that each snippet appears on a
 847         // fresh page.
 848         // Also support PDF output (automatically generated e.g. when
 849         // \usepackage[pdftex]{hyperref} is used and XeTeX.
 850         os << "\n"
 851            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
 852            << "\n";
 853 }
 854
 855
 856 void PreviewLoader::Impl::dumpData(odocstream & os,
 857                                    BitmapFile const & vec) const
 858 {
 859         if (vec.empty())
 860                 return;
 861
 862         BitmapFile::const_iterator it  = vec.begin();
 863         BitmapFile::const_iterator end = vec.end();
 864
 865         for (; it != end; ++it) {
 866                 // FIXME UNICODE
 867                 os << "\\begin{preview}\n"
 868                    << from_utf8(it->first)
 869                    << "\n\\end{preview}\n\n";
 870         }
 871 }
 872
 873 } // namespace graphics
 874 } // namespace lyx
 875
 876 #include "moc_PreviewLoader.cpp"