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 "debug.h"
  21 #include "Encoding.h"
  22 #include "Format.h"
  23 #include "InsetIterator.h"
  24 #include "LaTeXFeatures.h"
  25 #include "LyXRC.h"
  26 #include "output.h"
  27 #include "OutputParams.h"
  28 #include "TexRow.h"
  29
  30 #include "frontends/Application.h" // hexName
  31
  32 #include "insets/Inset.h"
  33
  34 #include "support/filetools.h"
  35 #include "support/Forkedcall.h"
  36 #include "support/ForkedcallsController.h"
  37 #include "support/lstrings.h"
  38 #include "support/lyxlib.h"
  39 #include "support/convert.h"
  40
  41 #include <boost/bind.hpp>
  42
  43 #include <sstream>
  44 #include <fstream>
  45 #include <iomanip>
  46
  47 using lyx::support::FileName;
  48
  49 using std::endl;
  50 using std::find;
  51 using std::fill;
  52 using std::find_if;
  53 using std::make_pair;
  54
  55 using boost::bind;
  56
  57 using std::ifstream;
  58 using std::list;
  59 using std::map;
  60 using std::ostringstream;
  61 using std::pair;
  62 using std::vector;
  63 using std::string;
  64
  65
  66 namespace {
  67
  68 typedef pair<string, FileName> SnippetPair;
  69
  70 // A list of all snippets to be converted to previews
  71 typedef list<string> PendingSnippets;
  72
  73 // Each item in the vector is a pair<snippet, image file name>.
  74 typedef vector<SnippetPair> BitmapFile;
  75
  76
  77 string const unique_filename(string const & bufferpath)
  78 {
  79         static int theCounter = 0;
  80         string const filename = lyx::convert<string>(theCounter++) + "lyxpreview";
  81         return lyx::support::addName(bufferpath, filename);
  82 }
  83
  84
  85 lyx::Converter const * setConverter()
  86 {
  87         string const from = "lyxpreview";
  88
  89         typedef vector<string> FmtList;
  90         typedef lyx::graphics::Cache GCache;
  91         FmtList const loadableFormats = GCache::get().loadableFormats();
  92         FmtList::const_iterator it = loadableFormats.begin();
  93         FmtList::const_iterator const end = loadableFormats.end();
  94
  95         for (; it != end; ++it) {
  96                 string const to = *it;
  97                 if (from == to)
  98                         continue;
  99
 100                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
 101                 if (ptr)
 102                         return ptr;
 103         }
 104
 105         static bool first = true;
 106         if (first) {
 107                 first = false;
 108                 lyx::lyxerr << "PreviewLoader::startLoading()\n"
 109                        << "No converter from \"lyxpreview\" format has been "
 110                         "defined."
 111                        << endl;
 112         }
 113         return 0;
 114 }
 115
 116
 117 void setAscentFractions(vector<double> & ascent_fractions,
 118                         FileName const & metrics_file)
 119 {
 120         // If all else fails, then the images will have equal ascents and
 121         // descents.
 122         vector<double>::iterator it  = ascent_fractions.begin();
 123         vector<double>::iterator end = ascent_fractions.end();
 124         fill(it, end, 0.5);
 125
 126         ifstream in(metrics_file.toFilesystemEncoding().c_str());
 127         if (!in.good()) {
 128                 lyx::lyxerr[lyx::Debug::GRAPHICS]
 129                         << "setAscentFractions(" << metrics_file << ")\n"
 130                         << "Unable to open file!" << endl;
 131                 return;
 132         }
 133
 134         bool error = false;
 135
 136         int snippet_counter = 1;
 137         while (!in.eof() && it != end) {
 138                 string snippet;
 139                 int id;
 140                 double ascent_fraction;
 141
 142                 in >> snippet >> id >> ascent_fraction;
 143
 144                 if (!in.good())
 145                         // eof after all
 146                         break;
 147
 148                 error = snippet != "Snippet";
 149                 if (error)
 150                         break;
 151
 152                 error = id != snippet_counter;
 153                 if (error)
 154                         break;
 155
 156                 *it = ascent_fraction;
 157
 158                 ++snippet_counter;
 159                 ++it;
 160         }
 161
 162         if (error) {
 163                 lyx::lyxerr[lyx::Debug::GRAPHICS]
 164                         << "setAscentFractions(" << metrics_file << ")\n"
 165                         << "Error reading file!\n" << endl;
 166         }
 167 }
 168
 169
 170 class FindFirst : public std::unary_function<SnippetPair, bool> {
 171 public:
 172         FindFirst(string const & comp) : comp_(comp) {}
 173         bool operator()(SnippetPair const & sp) const
 174         {
 175                 return sp.first == comp_;
 176         }
 177 private:
 178         string const comp_;
 179 };
 180
 181
 182 /// Store info on a currently executing, forked process.
 183 class InProgress {
 184 public:
 185         ///
 186         InProgress() : pid(0) {}
 187         ///
 188         InProgress(string const & filename_base,
 189                    PendingSnippets const & pending,
 190                    string const & to_format);
 191         /// Remove any files left lying around and kill the forked process.
 192         void stop() const;
 193
 194         ///
 195         pid_t pid;
 196         ///
 197         string command;
 198         ///
 199         FileName metrics_file;
 200         ///
 201         BitmapFile snippets;
 202 };
 203
 204 typedef map<pid_t, InProgress>  InProgressProcesses;
 205
 206 typedef InProgressProcesses::value_type InProgressProcess;
 207
 208 } // namespace anon
 209
 210
 211
 212 namespace lyx {
 213
 214 namespace graphics {
 215
 216 class PreviewLoader::Impl : public boost::signals::trackable {
 217 public:
 218         ///
 219         Impl(PreviewLoader & p, Buffer const & b);
 220         /// Stop any InProgress items still executing.
 221         ~Impl();
 222         ///
 223         PreviewImage const * preview(string const & latex_snippet) const;
 224         ///
 225         PreviewLoader::Status status(string const & latex_snippet) const;
 226         ///
 227         void add(string const & latex_snippet);
 228         ///
 229         void remove(string const & latex_snippet);
 230         ///
 231         void startLoading();
 232
 233         /// Emit this signal when an image is ready for display.
 234         boost::signal<void(PreviewImage const &)> imageReady;
 235
 236         Buffer const & buffer() const { return buffer_; }
 237
 238 private:
 239         /// Called by the Forkedcall process that generated the bitmap files.
 240         void finishedGenerating(pid_t, int);
 241         ///
 242         void dumpPreamble(odocstream &) const;
 243         ///
 244         void dumpData(odocstream &, BitmapFile const &) const;
 245
 246         /** cache_ allows easy retrieval of already-generated images
 247          *  using the LaTeX snippet as the identifier.
 248          */
 249         typedef boost::shared_ptr<PreviewImage> PreviewImagePtr;
 250         ///
 251         typedef map<string, PreviewImagePtr> Cache;
 252         ///
 253         Cache cache_;
 254
 255         /** pending_ stores the LaTeX snippets in anticipation of them being
 256          *  sent to the converter.
 257          */
 258         PendingSnippets pending_;
 259
 260         /** in_progress_ stores all forked processes so that we can proceed
 261          *  thereafter.
 262             The map uses the conversion commands as its identifiers.
 263          */
 264         InProgressProcesses in_progress_;
 265
 266         ///
 267         PreviewLoader & parent_;
 268         ///
 269         Buffer const & buffer_;
 270         ///
 271         double font_scaling_factor_;
 272
 273         /// We don't own this
 274         static lyx::Converter const * pconverter_;
 275 };
 276
 277
 278 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 279
 280
 281 //
 282 // The public interface, defined in PreviewLoader.h
 283 //
 284
 285 PreviewLoader::PreviewLoader(Buffer const & b)
 286         : pimpl_(new Impl(*this, b))
 287 {}
 288
 289
 290 PreviewLoader::~PreviewLoader()
 291 {}
 292
 293
 294 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 295 {
 296         return pimpl_->preview(latex_snippet);
 297 }
 298
 299
 300 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 301 {
 302         return pimpl_->status(latex_snippet);
 303 }
 304
 305
 306 void PreviewLoader::add(string const & latex_snippet) const
 307 {
 308         pimpl_->add(latex_snippet);
 309 }
 310
 311
 312 void PreviewLoader::remove(string const & latex_snippet) const
 313 {
 314         pimpl_->remove(latex_snippet);
 315 }
 316
 317
 318 void PreviewLoader::startLoading() const
 319 {
 320         pimpl_->startLoading();
 321 }
 322
 323
 324 boost::signals::connection PreviewLoader::connect(slot_type const & slot) const
 325 {
 326         return pimpl_->imageReady.connect(slot);
 327 }
 328
 329
 330 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 331 {
 332         pimpl_->imageReady(pimage);
 333 }
 334
 335
 336 Buffer const & PreviewLoader::buffer() const
 337 {
 338         return pimpl_->buffer();
 339 }
 340
 341 } // namespace graphics
 342 } // namespace lyx
 343
 344
 345 // The details of the Impl
 346 // =======================
 347
 348 namespace {
 349
 350 class IncrementedFileName {
 351 public:
 352         IncrementedFileName(string const & to_format,
 353                             string const & filename_base)
 354                 : to_format_(to_format), base_(filename_base), counter_(1)
 355         {}
 356
 357         SnippetPair const operator()(string const & snippet)
 358         {
 359                 ostringstream os;
 360                 os << base_ << counter_++ << '.' << to_format_;
 361                 string const file = os.str();
 362
 363                 return make_pair(snippet, FileName(file));
 364         }
 365
 366 private:
 367         string const & to_format_;
 368         string const & base_;
 369         int counter_;
 370 };
 371
 372
 373 InProgress::InProgress(string const & filename_base,
 374                        PendingSnippets const & pending,
 375                        string const & to_format)
 376         : pid(0),
 377           metrics_file(FileName(filename_base + ".metrics")),
 378           snippets(pending.size())
 379 {
 380         PendingSnippets::const_iterator pit  = pending.begin();
 381         PendingSnippets::const_iterator pend = pending.end();
 382         BitmapFile::iterator sit = snippets.begin();
 383
 384         std::transform(pit, pend, sit,
 385                        IncrementedFileName(to_format, filename_base));
 386 }
 387
 388
 389 void InProgress::stop() const
 390 {
 391         if (pid)
 392                 lyx::support::ForkedcallsController::get().kill(pid, 0);
 393
 394         if (!metrics_file.empty())
 395                 lyx::support::unlink(metrics_file);
 396
 397         BitmapFile::const_iterator vit  = snippets.begin();
 398         BitmapFile::const_iterator vend = snippets.end();
 399         for (; vit != vend; ++vit) {
 400                 if (!vit->second.empty())
 401                         lyx::support::unlink(vit->second);
 402         }
 403 }
 404
 405 } // namespace anon
 406
 407
 408 namespace lyx {
 409 namespace graphics {
 410
 411 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 412         : parent_(p), buffer_(b), font_scaling_factor_(0.0)
 413 {
 414         font_scaling_factor_ = 0.01 * lyxrc.dpi * lyxrc.zoom *
 415                 convert<double>(lyxrc.preview_scale_factor);
 416
 417         LYXERR(Debug::GRAPHICS, "The font scaling factor is "
 418                                 << font_scaling_factor_);
 419
 420         if (!pconverter_)
 421                 pconverter_ = setConverter();
 422 }
 423
 424
 425 PreviewLoader::Impl::~Impl()
 426 {
 427         InProgressProcesses::iterator ipit  = in_progress_.begin();
 428         InProgressProcesses::iterator ipend = in_progress_.end();
 429
 430         for (; ipit != ipend; ++ipit) {
 431                 ipit->second.stop();
 432         }
 433 }
 434
 435
 436 PreviewImage const *
 437 PreviewLoader::Impl::preview(string const & latex_snippet) const
 438 {
 439         Cache::const_iterator it = cache_.find(latex_snippet);
 440         return (it == cache_.end()) ? 0 : it->second.get();
 441 }
 442
 443
 444 namespace {
 445
 446 class FindSnippet : public std::unary_function<InProgressProcess, bool> {
 447 public:
 448         FindSnippet(string const & s) : snippet_(s) {}
 449         bool operator()(InProgressProcess const & process) const
 450         {
 451                 BitmapFile const & snippets = process.second.snippets;
 452                 BitmapFile::const_iterator beg  = snippets.begin();
 453                 BitmapFile::const_iterator end = snippets.end();
 454                 return find_if(beg, end, FindFirst(snippet_)) != end;
 455         }
 456
 457 private:
 458         string const snippet_;
 459 };
 460
 461 } // namespace anon
 462
 463 PreviewLoader::Status
 464 PreviewLoader::Impl::status(string const & latex_snippet) const
 465 {
 466         Cache::const_iterator cit = cache_.find(latex_snippet);
 467         if (cit != cache_.end())
 468                 return Ready;
 469
 470         PendingSnippets::const_iterator pit  = pending_.begin();
 471         PendingSnippets::const_iterator pend = pending_.end();
 472
 473         pit = find(pit, pend, latex_snippet);
 474         if (pit != pend)
 475                 return InQueue;
 476
 477         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 478         InProgressProcesses::const_iterator ipend = in_progress_.end();
 479
 480         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 481         if (ipit != ipend)
 482                 return Processing;
 483
 484         return NotFound;
 485 }
 486
 487
 488 void PreviewLoader::Impl::add(string const & latex_snippet)
 489 {
 490         if (!pconverter_ || status(latex_snippet) != NotFound)
 491                 return;
 492
 493         string const snippet = support::trim(latex_snippet);
 494         if (snippet.empty())
 495                 return;
 496
 497         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
 498
 499         pending_.push_back(snippet);
 500 }
 501
 502
 503 namespace {
 504
 505 class EraseSnippet {
 506 public:
 507         EraseSnippet(string const & s) : snippet_(s) {}
 508         void operator()(InProgressProcess & process)
 509         {
 510                 BitmapFile & snippets = process.second.snippets;
 511                 BitmapFile::iterator it  = snippets.begin();
 512                 BitmapFile::iterator end = snippets.end();
 513
 514                 it = find_if(it, end, FindFirst(snippet_));
 515                 if (it != end)
 516                         snippets.erase(it, it+1);
 517         }
 518
 519 private:
 520         string const & snippet_;
 521 };
 522
 523 } // namespace anon
 524
 525
 526 void PreviewLoader::Impl::remove(string const & latex_snippet)
 527 {
 528         Cache::iterator cit = cache_.find(latex_snippet);
 529         if (cit != cache_.end())
 530                 cache_.erase(cit);
 531
 532         PendingSnippets::iterator pit  = pending_.begin();
 533         PendingSnippets::iterator pend = pending_.end();
 534
 535         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 536
 537         InProgressProcesses::iterator ipit  = in_progress_.begin();
 538         InProgressProcesses::iterator ipend = in_progress_.end();
 539
 540         std::for_each(ipit, ipend, EraseSnippet(latex_snippet));
 541
 542         while (ipit != ipend) {
 543                 InProgressProcesses::iterator curr = ipit++;
 544                 if (curr->second.snippets.empty())
 545                         in_progress_.erase(curr);
 546         }
 547 }
 548
 549
 550 void PreviewLoader::Impl::startLoading()
 551 {
 552         if (pending_.empty() || !pconverter_)
 553                 return;
 554
 555         // Only start the process off after the buffer is loaded from file.
 556         if (!buffer_.isFullyLoaded())
 557                 return;
 558
 559         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 560
 561         // As used by the LaTeX file and by the resulting image files
 562         string const directory = buffer_.temppath();
 563
 564         string const filename_base = unique_filename(directory);
 565
 566         // Create an InProgress instance to place in the map of all
 567         // such processes if it starts correctly.
 568         InProgress inprogress(filename_base, pending_, pconverter_->to);
 569
 570         // clear pending_, so we're ready to start afresh.
 571         pending_.clear();
 572
 573         // Output the LaTeX file.
 574         FileName const latexfile(filename_base + ".tex");
 575
 576         // we use the encoding of the buffer
 577         Encoding const & enc = buffer_.params().encoding();
 578         odocfstream of(enc.iconvName());
 579         TexRow texrow;
 580         OutputParams runparams(&enc);
 581         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 582
 583         if (!openFileWrite(of, latexfile))
 584                 return;
 585
 586         if (!of) {
 587                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 588                                         << "Unable to create LaTeX file\n" << latexfile);
 589                 return;
 590         }
 591         of << "\\batchmode\n";
 592         dumpPreamble(of);
 593         // handle inputenc etc.
 594         buffer_.params().writeEncodingPreamble(of, features, texrow);
 595         of << "\n\\begin{document}\n";
 596         dumpData(of, inprogress.snippets);
 597         of << "\n\\end{document}\n";
 598         of.close();
 599         if (of.fail()) {
 600                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 601                                          << "File was not closed properly.");
 602                 return;
 603         }
 604
 605         // The conversion command.
 606         ostringstream cs;
 607         cs << pconverter_->command << ' ' << pconverter_->to << ' '
 608            << support::quoteName(latexfile.toFilesystemEncoding()) << ' '
 609            << int(font_scaling_factor_) << ' '
 610            << theApp()->hexName(Color_preview) << ' '
 611            << theApp()->hexName(Color_background);
 612
 613         string const command = support::libScriptSearch(cs.str());
 614
 615         // Initiate the conversion from LaTeX to bitmap images files.
 616         support::Forkedcall::SignalTypePtr
 617                 convert_ptr(new support::Forkedcall::SignalType);
 618         convert_ptr->connect(bind(&Impl::finishedGenerating, this, _1, _2));
 619
 620         support::Forkedcall call;
 621         int ret = call.startscript(command, convert_ptr);
 622
 623         if (ret != 0) {
 624                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 625                                         << "Unable to start process\n" << command);
 626                 return;
 627         }
 628
 629         // Store the generation process in a list of all such processes
 630         inprogress.pid = call.pid();
 631         inprogress.command = command;
 632         in_progress_[inprogress.pid] = inprogress;
 633 }
 634
 635
 636 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 637 {
 638         // Paranoia check!
 639         InProgressProcesses::iterator git = in_progress_.find(pid);
 640         if (git == in_progress_.end()) {
 641                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 642                         "data for PID " << pid << endl;
 643                 return;
 644         }
 645
 646         string const command = git->second.command;
 647         string const status = retval > 0 ? "failed" : "succeeded";
 648         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 649                                 << retval << "): processing " << status
 650                                 << " for " << command);
 651         if (retval > 0)
 652                 return;
 653
 654         // Read the metrics file, if it exists
 655         vector<double> ascent_fractions(git->second.snippets.size());
 656         setAscentFractions(ascent_fractions, git->second.metrics_file);
 657
 658         // Add these newly generated bitmap files to the cache and
 659         // start loading them into LyX.
 660         BitmapFile::const_iterator it  = git->second.snippets.begin();
 661         BitmapFile::const_iterator end = git->second.snippets.end();
 662
 663         std::list<PreviewImagePtr> newimages;
 664
 665         int metrics_counter = 0;
 666         for (; it != end; ++it, ++metrics_counter) {
 667                 string const & snip = it->first;
 668                 FileName const & file = it->second;
 669                 double af = ascent_fractions[metrics_counter];
 670
 671                 PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 672                 cache_[snip] = ptr;
 673
 674                 newimages.push_back(ptr);
 675         }
 676
 677         // Remove the item from the list of still-executing processes.
 678         in_progress_.erase(git);
 679
 680         // Tell the outside world
 681         std::list<PreviewImagePtr>::const_reverse_iterator
 682                 nit  = newimages.rbegin();
 683         std::list<PreviewImagePtr>::const_reverse_iterator
 684                 nend = newimages.rend();
 685         for (; nit != nend; ++nit) {
 686                 imageReady(*nit->get());
 687         }
 688 }
 689
 690
 691 void PreviewLoader::Impl::dumpPreamble(odocstream & os) const
 692 {
 693         // Why on earth is Buffer::makeLaTeXFile a non-const method?
 694         Buffer & tmp = const_cast<Buffer &>(buffer_);
 695         // Dump the preamble only.
 696         // We don't need an encoding for runparams since it is not used by
 697         // the preamble.
 698         OutputParams runparams(0);
 699         runparams.flavor = OutputParams::LATEX;
 700         runparams.nice = true;
 701         runparams.moving_arg = true;
 702         runparams.free_spacing = true;
 703         tmp.writeLaTeXSource(os, buffer_.filePath(), runparams, true, false);
 704
 705         // FIXME! This is a HACK! The proper fix is to control the 'true'
 706         // passed to WriteStream below:
 707         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 708         //                          OutputParams const & runparams) const
 709         // {
 710         //      WriteStream wi(os, runparams.moving_arg, true);
 711         //      par_->write(wi);
 712         //      return wi.line();
 713         // }
 714         os << "\n"
 715            << "\\def\\lyxlock{}\n"
 716            << "\n";
 717
 718         // Loop over the insets in the buffer and dump all the math-macros.
 719         Inset & inset = buffer_.inset();
 720         InsetIterator it = inset_iterator_begin(inset);
 721         InsetIterator const end = inset_iterator_end(inset);
 722
 723         for (; it != end; ++it)
 724                 if (it->lyxCode() == MATHMACRO_CODE)
 725                         it->latex(buffer_, os, runparams);
 726
 727         // All equation labels appear as "(#)" + preview.sty's rendering of
 728         // the label name
 729         if (lyxrc.preview_hashed_labels)
 730                 os << "\\renewcommand{\\theequation}{\\#}\n";
 731
 732         // Use the preview style file to ensure that each snippet appears on a
 733         // fresh page.
 734         os << "\n"
 735            << "\\usepackage[active,delayed,dvips,showlabels,lyx]{preview}\n"
 736            << "\n";
 737 }
 738
 739
 740 void PreviewLoader::Impl::dumpData(odocstream & os,
 741                                    BitmapFile const & vec) const
 742 {
 743         if (vec.empty())
 744                 return;
 745
 746         BitmapFile::const_iterator it  = vec.begin();
 747         BitmapFile::const_iterator end = vec.end();
 748
 749         for (; it != end; ++it) {
 750                 // FIXME UNICODE
 751                 os << "\\begin{preview}\n"
 752                    << from_utf8(it->first)
 753                    << "\n\\end{preview}\n\n";
 754         }
 755 }
 756
 757 } // namespace graphics
 758 } // namespace lyx