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 class FindFirst
 128 {
 129 public:
 130         FindFirst(string const & comp) : comp_(comp) {}
 131         bool operator()(SnippetPair const & sp) const { return sp.first == comp_; }
 132 private:
 133         string const comp_;
 134 };
 135
 136
 137 /// Store info on a currently executing, forked process.
 138 class InProgress {
 139 public:
 140         ///
 141         InProgress() : pid(0) {}
 142         ///
 143         InProgress(string const & filename_base,
 144                    PendingSnippets const & pending,
 145                    string const & to_format);
 146         /// Remove any files left lying around and kill the forked process.
 147         void stop() const;
 148
 149         ///
 150         pid_t pid;
 151         ///
 152         string command;
 153         ///
 154         FileName metrics_file;
 155         ///
 156         BitmapFile snippets;
 157 };
 158
 159 typedef map<pid_t, InProgress>  InProgressProcesses;
 160
 161 typedef InProgressProcesses::value_type InProgressProcess;
 162
 163 } // namespace
 164
 165
 166 namespace lyx {
 167 namespace graphics {
 168
 169 class PreviewLoader::Impl {
 170 public:
 171         ///
 172         Impl(PreviewLoader & p, Buffer const & b);
 173         /// Stop any InProgress items still executing.
 174         ~Impl();
 175         ///
 176         PreviewImage const * preview(string const & latex_snippet) const;
 177         ///
 178         PreviewLoader::Status status(string const & latex_snippet) const;
 179         ///
 180         void add(string const & latex_snippet);
 181         ///
 182         void remove(string const & latex_snippet);
 183         /// \p wait whether to wait for the process to complete or, instead,
 184         /// to do it in the background.
 185         void startLoading(bool wait = false);
 186         ///
 187         void refreshPreviews();
 188
 189         /// Emit this signal when an image is ready for display.
 190         signals2::signal<void(PreviewImage const &)> imageReady;
 191
 192         Buffer const & buffer() const { return buffer_; }
 193
 194         lyx::Converter const * setConverter(string const & from);
 195
 196 private:
 197         /// Called by the ForkedCall process that generated the bitmap files.
 198         void finishedGenerating(pid_t, int);
 199         ///
 200         void dumpPreamble(otexstream &, OutputParams::FLAVOR) const;
 201         ///
 202         void dumpData(odocstream &, BitmapFile const &) const;
 203
 204         /** cache_ allows easy retrieval of already-generated images
 205          *  using the LaTeX snippet as the identifier.
 206          */
 207         typedef std::shared_ptr<PreviewImage> PreviewImagePtr;
 208         ///
 209         typedef map<string, PreviewImagePtr> Cache;
 210         ///
 211         Cache cache_;
 212
 213         /** pending_ stores the LaTeX snippets in anticipation of them being
 214          *  sent to the converter.
 215          */
 216         PendingSnippets pending_;
 217
 218         /** in_progress_ stores all forked processes so that we can proceed
 219          *  thereafter.
 220          */
 221         InProgressProcesses in_progress_;
 222
 223         ///
 224         PreviewLoader & parent_;
 225         ///
 226         Buffer const & buffer_;
 227         ///
 228         mutable int font_scaling_factor_;
 229         ///
 230         mutable int fg_color_;
 231         ///
 232         mutable int bg_color_;
 233         ///
 234         QTimer * delay_refresh_;
 235         ///
 236         bool finished_generating_;
 237
 238         /// We don't own this
 239         static lyx::Converter const * pconverter_;
 240
 241         Trackable trackable_;
 242 };
 243
 244
 245 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 246
 247
 248 //
 249 // The public interface, defined in PreviewLoader.h
 250 //
 251
 252 PreviewLoader::PreviewLoader(Buffer const & b)
 253         : pimpl_(new Impl(*this, b))
 254 {}
 255
 256
 257 PreviewLoader::~PreviewLoader()
 258 {
 259         delete pimpl_;
 260 }
 261
 262
 263 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 264 {
 265         return pimpl_->preview(latex_snippet);
 266 }
 267
 268
 269 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 270 {
 271         return pimpl_->status(latex_snippet);
 272 }
 273
 274
 275 void PreviewLoader::add(string const & latex_snippet) const
 276 {
 277         pimpl_->add(latex_snippet);
 278 }
 279
 280
 281 void PreviewLoader::remove(string const & latex_snippet) const
 282 {
 283         pimpl_->remove(latex_snippet);
 284 }
 285
 286
 287 void PreviewLoader::startLoading(bool wait) const
 288 {
 289         pimpl_->startLoading(wait);
 290 }
 291
 292
 293 void PreviewLoader::refreshPreviews()
 294 {
 295         pimpl_->refreshPreviews();
 296 }
 297
 298
 299 signals2::connection PreviewLoader::connect(slot const & slot) const
 300 {
 301         return pimpl_->imageReady.connect(slot);
 302 }
 303
 304
 305 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 306 {
 307         pimpl_->imageReady(pimage);
 308 }
 309
 310
 311 Buffer const & PreviewLoader::buffer() const
 312 {
 313         return pimpl_->buffer();
 314 }
 315
 316 } // namespace graphics
 317 } // namespace lyx
 318
 319
 320 // The details of the Impl
 321 // =======================
 322
 323 namespace {
 324
 325 class IncrementedFileName {
 326 public:
 327         IncrementedFileName(string const & to_format,
 328                             string const & filename_base)
 329                 : to_format_(to_format), base_(filename_base), counter_(1)
 330         {}
 331
 332         SnippetPair const operator()(string const & snippet)
 333         {
 334                 ostringstream os;
 335                 os << base_ << counter_++ << '.' << to_format_;
 336                 string const file = os.str();
 337
 338                 return make_pair(snippet, FileName(file));
 339         }
 340
 341 private:
 342         string const & to_format_;
 343         string const & base_;
 344         int counter_;
 345 };
 346
 347
 348 InProgress::InProgress(string const & filename_base,
 349                        PendingSnippets const & pending,
 350                        string const & to_format)
 351         : pid(0),
 352           metrics_file(filename_base + ".metrics"),
 353           snippets(pending.size())
 354 {
 355         PendingSnippets::const_iterator pit  = pending.begin();
 356         PendingSnippets::const_iterator pend = pending.end();
 357         BitmapFile::iterator sit = snippets.begin();
 358
 359         transform(pit, pend, sit,
 360                        IncrementedFileName(to_format, filename_base));
 361 }
 362
 363
 364 void InProgress::stop() const
 365 {
 366         if (pid)
 367                 ForkedCallsController::kill(pid, 0);
 368
 369         if (!metrics_file.empty())
 370                 metrics_file.removeFile();
 371
 372         BitmapFile::const_iterator vit  = snippets.begin();
 373         BitmapFile::const_iterator vend = snippets.end();
 374         for (; vit != vend; ++vit) {
 375                 if (!vit->second.empty())
 376                         vit->second.removeFile();
 377         }
 378 }
 379
 380 } // namespace
 381
 382
 383 namespace lyx {
 384 namespace graphics {
 385
 386 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 387         : parent_(p), buffer_(b), finished_generating_(true)
 388 {
 389         font_scaling_factor_ = int(buffer_.fontScalingFactor());
 390         if (theApp()) {
 391                 fg_color_ = strtol(theApp()->hexName(foregroundColor()).c_str(), 0, 16);
 392                 bg_color_ = strtol(theApp()->hexName(backgroundColor()).c_str(), 0, 16);
 393         } else {
 394                 fg_color_ = 0x0;
 395                 bg_color_ = 0xffffff;
 396         }
 397         if (!pconverter_)
 398                 pconverter_ = setConverter("lyxpreview");
 399
 400         delay_refresh_ = new QTimer(&parent_);
 401         delay_refresh_->setSingleShot(true);
 402         QObject::connect(delay_refresh_, SIGNAL(timeout()),
 403                          &parent_, SLOT(refreshPreviews()));
 404 }
 405
 406
 407 lyx::Converter const * PreviewLoader::Impl::setConverter(string const & from)
 408 {
 409         typedef vector<string> FmtList;
 410         FmtList const & loadableFormats = graphics::Cache::get().loadableFormats();
 411         FmtList::const_iterator it = loadableFormats.begin();
 412         FmtList::const_iterator const end = loadableFormats.end();
 413
 414         for (; it != end; ++it) {
 415                 string const to = *it;
 416                 if (from == to)
 417                         continue;
 418
 419                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
 420                 if (ptr)
 421                         return ptr;
 422         }
 423
 424         // Show the error only once. This is thread-safe.
 425         static nullptr_t no_conv = [&]{
 426                 LYXERR0("PreviewLoader::startLoading()\n"
 427                         << "No converter from \"" << from
 428                         << "\" format has been defined.");
 429                 return nullptr;
 430         } ();
 431
 432         return no_conv;
 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
 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
 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         cs << " --bibtex=" << quoteName(buffer_.params().bibtexCommand());
 721         if (buffer_.params().bufferFormat() == "lilypond-book")
 722                 cs << " --lilypond";
 723
 724         string const command = cs.str();
 725
 726         if (wait) {
 727                 ForkedCall call(buffer_.filePath(), buffer_.layoutPos());
 728                 int ret = call.startScript(ForkedProcess::Wait, command);
 729                 // PID_MAX_LIMIT is 2^22 so we start one after that
 730                 static atomic_int fake((1 << 22) + 1);
 731                 int pid = fake++;
 732                 inprogress.pid = pid;
 733                 inprogress.command = command;
 734                 in_progress_[pid] = inprogress;
 735                 finishedGenerating(pid, ret);
 736                 return;
 737         }
 738
 739         // Initiate the conversion from LaTeX to bitmap images files.
 740         ForkedCall::sigPtr convert_ptr = make_shared<ForkedCall::sig>();
 741         convert_ptr->connect(ForkedProcess::slot([this](pid_t pid, int retval){
 742                                 finishedGenerating(pid, retval);
 743                         }).track_foreign(trackable_.p()));
 744
 745         ForkedCall call(buffer_.filePath());
 746         int ret = call.startScript(command, convert_ptr);
 747
 748         if (ret != 0) {
 749                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 750                                         << "Unable to start process\n" << command);
 751                 return;
 752         }
 753
 754         // Store the generation process in a list of all such processes
 755         inprogress.pid = call.pid();
 756         inprogress.command = command;
 757         in_progress_[inprogress.pid] = inprogress;
 758 }
 759
 760
 761 double PreviewLoader::displayPixelRatio() const
 762 {
 763         return buffer().params().display_pixel_ratio;
 764 }
 765
 766 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 767 {
 768         // Paranoia check!
 769         InProgressProcesses::iterator git = in_progress_.find(pid);
 770         if (git == in_progress_.end()) {
 771                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 772                         "data for PID " << pid << endl;
 773                 finished_generating_ = true;
 774                 return;
 775         }
 776
 777         string const command = git->second.command;
 778         string const status = retval > 0 ? "failed" : "succeeded";
 779         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 780                                 << retval << "): processing " << status
 781                                 << " for " << command);
 782         if (retval > 0) {
 783                 in_progress_.erase(git);
 784                 finished_generating_ = true;
 785                 return;
 786         }
 787
 788         // Read the metrics file, if it exists
 789         vector<double> ascent_fractions(git->second.snippets.size());
 790         setAscentFractions(ascent_fractions, git->second.metrics_file);
 791
 792         // Add these newly generated bitmap files to the cache and
 793         // start loading them into LyX.
 794         BitmapFile::const_iterator it  = git->second.snippets.begin();
 795         BitmapFile::const_iterator end = git->second.snippets.end();
 796
 797         list<PreviewImagePtr> newimages;
 798
 799         int metrics_counter = 0;
 800         for (; it != end; ++it, ++metrics_counter) {
 801                 string const & snip = it->first;
 802                 FileName const & file = it->second;
 803                 double af = ascent_fractions[metrics_counter];
 804
 805                 // Add the image to the cache only if it's actually present
 806                 // and not empty (an empty image is signaled by af < 0)
 807                 if (af >= 0 && file.isReadableFile()) {
 808                         PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 809                         cache_[snip] = ptr;
 810
 811                         newimages.push_back(ptr);
 812                 }
 813
 814         }
 815
 816         // Remove the item from the list of still-executing processes.
 817         in_progress_.erase(git);
 818
 819         // Tell the outside world
 820         list<PreviewImagePtr>::const_reverse_iterator
 821                 nit  = newimages.rbegin();
 822         list<PreviewImagePtr>::const_reverse_iterator
 823                 nend = newimages.rend();
 824         for (; nit != nend; ++nit) {
 825                 imageReady(*nit->get());
 826         }
 827         finished_generating_ = true;
 828 }
 829
 830
 831 void PreviewLoader::Impl::dumpPreamble(otexstream & os, OutputParams::FLAVOR flavor) const
 832 {
 833         // Dump the preamble only.
 834         LYXERR(Debug::LATEX, "dumpPreamble, flavor == " << flavor);
 835         OutputParams runparams(&buffer_.params().encoding());
 836         runparams.flavor = flavor;
 837         runparams.nice = true;
 838         runparams.moving_arg = true;
 839         runparams.free_spacing = true;
 840         runparams.is_child = buffer_.parent();
 841         buffer_.writeLaTeXSource(os, buffer_.filePath(), runparams, Buffer::OnlyPreamble);
 842
 843         // FIXME! This is a HACK! The proper fix is to control the 'true'
 844         // passed to WriteStream below:
 845         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 846         //                          OutputParams const & runparams) const
 847         // {
 848         //      WriteStream wi(os, runparams.moving_arg, true);
 849         //      par_->write(wi);
 850         //      return wi.line();
 851         // }
 852         os << "\n"
 853            << "\\def\\lyxlock{}\n"
 854            << "\n";
 855
 856         // All equation labels appear as "(#)" + preview.sty's rendering of
 857         // the label name
 858         if (lyxrc.preview_hashed_labels)
 859                 os << "\\renewcommand{\\theequation}{\\#}\n";
 860
 861         // Use the preview style file to ensure that each snippet appears on a
 862         // fresh page.
 863         // Also support PDF output (automatically generated e.g. when
 864         // \usepackage[pdftex]{hyperref} is used and XeTeX.
 865         os << "\n"
 866            << "\\usepackage[active,delayed,showlabels,lyx]{preview}\n"
 867            << "\n";
 868 }
 869
 870
 871 void PreviewLoader::Impl::dumpData(odocstream & os,
 872                                    BitmapFile const & vec) const
 873 {
 874         if (vec.empty())
 875                 return;
 876
 877         BitmapFile::const_iterator it  = vec.begin();
 878         BitmapFile::const_iterator end = vec.end();
 879
 880         for (; it != end; ++it) {
 881                 // FIXME UNICODE
 882                 os << "\\begin{preview}\n"
 883                    << from_utf8(it->first)
 884                    << "\n\\end{preview}\n\n";
 885         }
 886 }
 887
 888 } // namespace graphics
 889 } // namespace lyx
 890
 891 #include "moc_PreviewLoader.cpp"