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 {
 545         return [&s](InProgressProcess & process) {
 546                 BitmapFile & snippets = process.second.snippets;
 547                 BitmapFile::iterator it  = snippets.begin();
 548                 BitmapFile::iterator end = snippets.end();
 549
 550                 it = find_if(it, end, FindFirst(s));
 551                 if (it != end)
 552                         snippets.erase(it, it+1);
 553         };
 554 }
 555
 556 } // namespace
 557
 558
 559 void PreviewLoader::Impl::remove(string const & latex_snippet)
 560 {
 561         Cache::iterator cit = cache_.find(latex_snippet);
 562         if (cit != cache_.end())
 563                 cache_.erase(cit);
 564
 565         PendingSnippets::iterator pit  = pending_.begin();
 566         PendingSnippets::iterator pend = pending_.end();
 567
 568         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 569
 570         InProgressProcesses::iterator ipit  = in_progress_.begin();
 571         InProgressProcesses::iterator ipend = in_progress_.end();
 572
 573         for_each(ipit, ipend, EraseSnippet(latex_snippet));
 574
 575         while (ipit != ipend) {
 576                 InProgressProcesses::iterator curr = ipit++;
 577                 if (curr->second.snippets.empty())
 578                         in_progress_.erase(curr);
 579         }
 580 }
 581
 582
 583 void PreviewLoader::Impl::startLoading(bool wait)
 584 {
 585         if (pending_.empty() || !pconverter_)
 586                 return;
 587
 588         // Only start the process off after the buffer is loaded from file.
 589         if (!buffer_.isFullyLoaded())
 590                 return;
 591
 592         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 593
 594         // As used by the LaTeX file and by the resulting image files
 595         FileName const directory(buffer_.temppath());
 596
 597         FileName const latexfile = unique_tex_filename(directory);
 598         string const filename_base = removeExtension(latexfile.absFileName());
 599
 600         // Create an InProgress instance to place in the map of all
 601         // such processes if it starts correctly.
 602         InProgress inprogress(filename_base, pending_, pconverter_->to());
 603
 604         // clear pending_, so we're ready to start afresh.
 605         pending_.clear();
 606
 607         // Output the LaTeX file.
 608         // we use the encoding of the buffer
 609         Encoding const & enc = buffer_.params().encoding();
 610         ofdocstream of;
 611         try { of.reset(enc.iconvName()); }
 612         catch (iconv_codecvt_facet_exception const & e) {
 613                 LYXERR0("Caught iconv exception: " << e.what()
 614                         << "\nUnable to create LaTeX file: " << latexfile);
 615                 return;
 616         }
 617
 618         otexstream os(of);
 619         OutputParams runparams(&enc);
 620         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 621
 622         if (!openFileWrite(of, latexfile))
 623                 return;
 624
 625         if (!of) {
 626                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 627                                         << "Unable to create LaTeX file\n" << latexfile);
 628                 return;
 629         }
 630         of << "\\batchmode\n";
 631
 632         // Set \jobname of previews to the document name (see bug 9627)
 633         of << "\\def\\jobname{"
 634            << from_utf8(changeExtension(buffer_.latexName(true), ""))
 635            << "}\n";
 636
 637         LYXERR(Debug::LATEX, "Format = " << buffer_.params().getDefaultOutputFormat());
 638         string latexparam = "";
 639         bool docformat = !buffer_.params().default_output_format.empty()
 640                         && buffer_.params().default_output_format != "default";
 641         // Use LATEX flavor if the document does not specify a specific
 642         // output format (see bug 9371).
 643         OutputParams::FLAVOR flavor = docformat
 644                                         ? buffer_.params().getOutputFlavor()
 645                                         : OutputParams::LATEX;
 646         if (buffer_.params().encoding().package() == Encoding::japanese) {
 647                 latexparam = " --latex=platex";
 648                 flavor = OutputParams::LATEX;
 649         }
 650         else if (buffer_.params().useNonTeXFonts) {
 651                 if (flavor == OutputParams::LUATEX)
 652                         latexparam = " --latex=lualatex";
 653                 else {
 654                         flavor = OutputParams::XETEX;
 655                         latexparam = " --latex=xelatex";
 656                 }
 657         }
 658         else {
 659                 switch (flavor) {
 660                         case OutputParams::PDFLATEX:
 661                                 latexparam = " --latex=pdflatex";
 662                                 break;
 663                         case OutputParams::XETEX:
 664                                 latexparam = " --latex=xelatex";
 665                                 break;
 666                         case OutputParams::LUATEX:
 667                                 latexparam = " --latex=lualatex";
 668                                 break;
 669                         case OutputParams::DVILUATEX:
 670                                 latexparam = " --latex=dvilualatex";
 671                                 break;
 672                         default:
 673                                 flavor = OutputParams::LATEX;
 674                 }
 675         }
 676         dumpPreamble(os, flavor);
 677         // handle inputenc etc.
 678         // I think this is already handled by dumpPreamble(): Kornel
 679         // buffer_.params().writeEncodingPreamble(os, features);
 680         of << "\n\\begin{document}\n";
 681         dumpData(of, inprogress.snippets);
 682         of << "\n\\end{document}\n";
 683         of.close();
 684         if (of.fail()) {
 685                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 686                                          << "File was not closed properly.");
 687                 return;
 688         }
 689
 690         // The conversion command.
 691         ostringstream cs;
 692         cs << pconverter_->command()
 693            << " " << quoteName(latexfile.toFilesystemEncoding())
 694            << " --dpi " << font_scaling_factor_;
 695
 696         // FIXME XHTML
 697         // The colors should be customizable.
 698         if (!buffer_.isExporting()) {
 699                 ColorCode const fg = PreviewLoader::foregroundColor();
 700                 ColorCode const bg = PreviewLoader::backgroundColor();
 701                 cs << " --fg " << theApp()->hexName(fg)
 702                    << " --bg " << theApp()->hexName(bg);
 703         }
 704
 705         cs << latexparam;
 706         cs << " --bibtex=" << quoteName(buffer_.params().bibtexCommand());
 707         if (buffer_.params().bufferFormat() == "lilypond-book")
 708                 cs << " --lilypond";
 709
 710         string const command = cs.str();
 711
 712         if (wait) {
 713                 ForkedCall call(buffer_.filePath(), buffer_.layoutPos());
 714                 int ret = call.startScript(ForkedProcess::Wait, command);
 715                 // PID_MAX_LIMIT is 2^22 so we start one after that
 716                 static atomic_int fake((1 << 22) + 1);
 717                 int pid = fake++;
 718                 inprogress.pid = pid;
 719                 inprogress.command = command;
 720                 in_progress_[pid] = inprogress;
 721                 finishedGenerating(pid, ret);
 722                 return;
 723         }
 724
 725         // Initiate the conversion from LaTeX to bitmap images files.
 726         ForkedCall::sigPtr convert_ptr = make_shared<ForkedCall::sig>();
 727         convert_ptr->connect(ForkedProcess::slot([this](pid_t pid, int retval){
 728                                 finishedGenerating(pid, retval);
 729                         }).track_foreign(trackable_.p()));
 730
 731         ForkedCall call(buffer_.filePath());
 732         int ret = call.startScript(command, convert_ptr);
 733
 734         if (ret != 0) {
 735                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 736                                         << "Unable to start process\n" << command);
 737                 return;
 738         }
 739
 740         // Store the generation process in a list of all such processes
 741         inprogress.pid = call.pid();
 742         inprogress.command = command;
 743         in_progress_[inprogress.pid] = inprogress;
 744 }
 745
 746
 747 double PreviewLoader::displayPixelRatio() const
 748 {
 749         return buffer().params().display_pixel_ratio;
 750 }
 751
 752 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 753 {
 754         // Paranoia check!
 755         InProgressProcesses::iterator git = in_progress_.find(pid);
 756         if (git == in_progress_.end()) {
 757                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 758                         "data for PID " << pid << endl;
 759                 finished_generating_ = true;
 760                 return;
 761         }
 762
 763         string const command = git->second.command;
 764         string const status = retval > 0 ? "failed" : "succeeded";
 765         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 766                                 << retval << "): processing " << status
 767                                 << " for " << command);
 768         if (retval > 0) {
 769                 in_progress_.erase(git);
 770                 finished_generating_ = true;
 771                 return;
 772         }
 773
 774         // Read the metrics file, if it exists
 775         vector<double> ascent_fractions(git->second.snippets.size());
 776         setAscentFractions(ascent_fractions, git->second.metrics_file);
 777
 778         // Add these newly generated bitmap files to the cache and
 779         // start loading them into LyX.
 780         BitmapFile::const_iterator it  = git->second.snippets.begin();
 781         BitmapFile::const_iterator end = git->second.snippets.end();
 782
 783         list<PreviewImagePtr> newimages;
 784
 785         size_t metrics_counter = 0;
 786         for (; it != end; ++it, ++metrics_counter) {
 787                 string const & snip = it->first;
 788                 FileName const & file = it->second;
 789                 double af = ascent_fractions[metrics_counter];
 790
 791                 // Add the image to the cache only if it's actually present
 792                 // and not empty (an empty image is signaled by af < 0)
 793                 if (af >= 0 && file.isReadableFile()) {
 794                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 795                         cache_[snip] = ptr;
 796
 797                         newimages.push_back(ptr);
 798                 }
 799
 800         }
 801
 802         // Remove the item from the list of still-executing processes.
 803         in_progress_.erase(git);
 804
 805         // Tell the outside world
 806         list<PreviewImagePtr>::const_reverse_iterator
 807                 nit  = newimages.rbegin();
 808         list<PreviewImagePtr>::const_reverse_iterator
 809                 nend = newimages.rend();
 810         for (; nit != nend; ++nit) {
 811                 imageReady(*nit->get());
 812         }
 813         finished_generating_ = true;
 814 }
 815
 816
 817 void PreviewLoader::Impl::dumpPreamble(otexstream & os, OutputParams::FLAVOR flavor) const
 818 {
 819         // Dump the preamble only.
 820         LYXERR(Debug::LATEX, "dumpPreamble, flavor == " << flavor);
 821         OutputParams runparams(&buffer_.params().encoding());
 822         runparams.flavor = flavor;
 823         runparams.nice = true;
 824         runparams.moving_arg = true;
 825         runparams.free_spacing = true;
 826         runparams.is_child = buffer_.parent();
 827         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 828
 829         // FIXME! This is a HACK! The proper fix is to control the 'true'
 830         // passed to WriteStream below:
 831         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 832         //                          OutputParams const & runparams) const
 833         // {
 834         //      WriteStream wi(os, runparams.moving_arg, true);
 835         //      par_->write(wi);
 836         //      return wi.line();
 837         // }
 838         os << "\n"
 839            << "\\def\\lyxlock{}\n"
 840            << "\n";
 841
 842         // All equation labels appear as "(#)" + preview.sty's rendering of
 843         // the label name
 844         if (lyxrc.preview_hashed_labels)
 845                 os << "\\renewcommand{\\theequation}{\\#}\n";
 846
 847         // Use the preview style file to ensure that each snippet appears on a
 848         // fresh page.
 849         // Also support PDF output (automatically generated e.g. when
 850         // \usepackage[pdftex]{hyperref} is used and XeTeX.
 851         os << "\n"
 852            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
 853            << "\n";
 854 }
 855
 856
 857 void PreviewLoader::Impl::dumpData(odocstream & os,
 858                                    BitmapFile const & vec) const
 859 {
 860         if (vec.empty())
 861                 return;
 862
 863         BitmapFile::const_iterator it  = vec.begin();
 864         BitmapFile::const_iterator end = vec.end();
 865
 866         for (; it != end; ++it) {
 867                 // FIXME UNICODE
 868                 os << "\\begin{preview}\n"
 869                    << from_utf8(it->first)
 870                    << "\n\\end{preview}\n\n";
 871         }
 872 }
 873
 874 } // namespace graphics
 875 } // namespace lyx
 876
 877 #include "moc_PreviewLoader.cpp"