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 "Color.h"
  25 #include "LaTeXFeatures.h"
  26 #include "LyXRC.h"
  27 #include "output.h"
  28 #include "OutputParams.h"
  29 #include "TexRow.h"
  30
  31 #include "frontends/Application.h" // hexName
  32
  33 #include "insets/Inset.h"
  34
  35 #include "support/filetools.h"
  36 #include "support/Forkedcall.h"
  37 #include "support/ForkedcallsController.h"
  38 #include "support/lstrings.h"
  39 #include "support/lyxlib.h"
  40 #include "support/convert.h"
  41
  42 #include <boost/bind.hpp>
  43
  44 #include <sstream>
  45 #include <fstream>
  46 #include <iomanip>
  47
  48 using lyx::support::FileName;
  49
  50 using std::endl;
  51 using std::find;
  52 using std::fill;
  53 using std::find_if;
  54 using std::make_pair;
  55
  56 using boost::bind;
  57
  58 using std::ifstream;
  59 using std::list;
  60 using std::map;
  61 using std::ostringstream;
  62 using std::pair;
  63 using std::vector;
  64 using std::string;
  65
  66
  67 namespace {
  68
  69 typedef pair<string, FileName> SnippetPair;
  70
  71 // A list of all snippets to be converted to previews
  72 typedef list<string> PendingSnippets;
  73
  74 // Each item in the vector is a pair<snippet, image file name>.
  75 typedef vector<SnippetPair> BitmapFile;
  76
  77
  78 string const unique_filename(string const & bufferpath)
  79 {
  80         static int theCounter = 0;
  81         string const filename = lyx::convert<string>(theCounter++) + "lyxpreview";
  82         return lyx::support::addName(bufferpath, filename);
  83 }
  84
  85
  86 lyx::Converter const * setConverter()
  87 {
  88         string const from = "lyxpreview";
  89
  90         typedef vector<string> FmtList;
  91         typedef lyx::graphics::Cache GCache;
  92         FmtList const loadableFormats = GCache::get().loadableFormats();
  93         FmtList::const_iterator it = loadableFormats.begin();
  94         FmtList::const_iterator const end = loadableFormats.end();
  95
  96         for (; it != end; ++it) {
  97                 string const to = *it;
  98                 if (from == to)
  99                         continue;
 100
 101                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
 102                 if (ptr)
 103                         return ptr;
 104         }
 105
 106         static bool first = true;
 107         if (first) {
 108                 first = false;
 109                 lyx::lyxerr << "PreviewLoader::startLoading()\n"
 110                        << "No converter from \"lyxpreview\" format has been "
 111                         "defined."
 112                        << endl;
 113         }
 114         return 0;
 115 }
 116
 117
 118 void setAscentFractions(vector<double> & ascent_fractions,
 119                         FileName const & metrics_file)
 120 {
 121         // If all else fails, then the images will have equal ascents and
 122         // descents.
 123         vector<double>::iterator it  = ascent_fractions.begin();
 124         vector<double>::iterator end = ascent_fractions.end();
 125         fill(it, end, 0.5);
 126
 127         ifstream in(metrics_file.toFilesystemEncoding().c_str());
 128         if (!in.good()) {
 129                 lyx::lyxerr[lyx::Debug::GRAPHICS]
 130                         << "setAscentFractions(" << metrics_file << ")\n"
 131                         << "Unable to open file!" << endl;
 132                 return;
 133         }
 134
 135         bool error = false;
 136
 137         int snippet_counter = 1;
 138         while (!in.eof() && it != end) {
 139                 string snippet;
 140                 int id;
 141                 double ascent_fraction;
 142
 143                 in >> snippet >> id >> ascent_fraction;
 144
 145                 if (!in.good())
 146                         // eof after all
 147                         break;
 148
 149                 error = snippet != "Snippet";
 150                 if (error)
 151                         break;
 152
 153                 error = id != snippet_counter;
 154                 if (error)
 155                         break;
 156
 157                 *it = ascent_fraction;
 158
 159                 ++snippet_counter;
 160                 ++it;
 161         }
 162
 163         if (error) {
 164                 lyx::lyxerr[lyx::Debug::GRAPHICS]
 165                         << "setAscentFractions(" << metrics_file << ")\n"
 166                         << "Error reading file!\n" << endl;
 167         }
 168 }
 169
 170
 171 class FindFirst : public std::unary_function<SnippetPair, bool> {
 172 public:
 173         FindFirst(string const & comp) : comp_(comp) {}
 174         bool operator()(SnippetPair const & sp) const
 175         {
 176                 return sp.first == comp_;
 177         }
 178 private:
 179         string const comp_;
 180 };
 181
 182
 183 /// Store info on a currently executing, forked process.
 184 class InProgress {
 185 public:
 186         ///
 187         InProgress() : pid(0) {}
 188         ///
 189         InProgress(string const & filename_base,
 190                    PendingSnippets const & pending,
 191                    string const & to_format);
 192         /// Remove any files left lying around and kill the forked process.
 193         void stop() const;
 194
 195         ///
 196         pid_t pid;
 197         ///
 198         string command;
 199         ///
 200         FileName metrics_file;
 201         ///
 202         BitmapFile snippets;
 203 };
 204
 205 typedef map<pid_t, InProgress>  InProgressProcesses;
 206
 207 typedef InProgressProcesses::value_type InProgressProcess;
 208
 209 } // namespace anon
 210
 211
 212
 213 namespace lyx {
 214
 215 namespace graphics {
 216
 217 class PreviewLoader::Impl : public boost::signals::trackable {
 218 public:
 219         ///
 220         Impl(PreviewLoader & p, Buffer const & b);
 221         /// Stop any InProgress items still executing.
 222         ~Impl();
 223         ///
 224         PreviewImage const * preview(string const & latex_snippet) const;
 225         ///
 226         PreviewLoader::Status status(string const & latex_snippet) const;
 227         ///
 228         void add(string const & latex_snippet);
 229         ///
 230         void remove(string const & latex_snippet);
 231         ///
 232         void startLoading();
 233
 234         /// Emit this signal when an image is ready for display.
 235         boost::signal<void(PreviewImage const &)> imageReady;
 236
 237         Buffer const & buffer() const { return buffer_; }
 238
 239 private:
 240         /// Called by the Forkedcall process that generated the bitmap files.
 241         void finishedGenerating(pid_t, int);
 242         ///
 243         void dumpPreamble(odocstream &) const;
 244         ///
 245         void dumpData(odocstream &, BitmapFile const &) const;
 246
 247         /** cache_ allows easy retrieval of already-generated images
 248          *  using the LaTeX snippet as the identifier.
 249          */
 250         typedef boost::shared_ptr<PreviewImage> PreviewImagePtr;
 251         ///
 252         typedef map<string, PreviewImagePtr> Cache;
 253         ///
 254         Cache cache_;
 255
 256         /** pending_ stores the LaTeX snippets in anticipation of them being
 257          *  sent to the converter.
 258          */
 259         PendingSnippets pending_;
 260
 261         /** in_progress_ stores all forked processes so that we can proceed
 262          *  thereafter.
 263             The map uses the conversion commands as its identifiers.
 264          */
 265         InProgressProcesses in_progress_;
 266
 267         ///
 268         PreviewLoader & parent_;
 269         ///
 270         Buffer const & buffer_;
 271         ///
 272         double font_scaling_factor_;
 273
 274         /// We don't own this
 275         static lyx::Converter const * pconverter_;
 276 };
 277
 278
 279 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 280
 281
 282 //
 283 // The public interface, defined in PreviewLoader.h
 284 //
 285
 286 PreviewLoader::PreviewLoader(Buffer const & b)
 287         : pimpl_(new Impl(*this, b))
 288 {}
 289
 290
 291 PreviewLoader::~PreviewLoader()
 292 {}
 293
 294
 295 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 296 {
 297         return pimpl_->preview(latex_snippet);
 298 }
 299
 300
 301 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 302 {
 303         return pimpl_->status(latex_snippet);
 304 }
 305
 306
 307 void PreviewLoader::add(string const & latex_snippet) const
 308 {
 309         pimpl_->add(latex_snippet);
 310 }
 311
 312
 313 void PreviewLoader::remove(string const & latex_snippet) const
 314 {
 315         pimpl_->remove(latex_snippet);
 316 }
 317
 318
 319 void PreviewLoader::startLoading() const
 320 {
 321         pimpl_->startLoading();
 322 }
 323
 324
 325 boost::signals::connection PreviewLoader::connect(slot_type const & slot) const
 326 {
 327         return pimpl_->imageReady.connect(slot);
 328 }
 329
 330
 331 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 332 {
 333         pimpl_->imageReady(pimage);
 334 }
 335
 336
 337 Buffer const & PreviewLoader::buffer() const
 338 {
 339         return pimpl_->buffer();
 340 }
 341
 342 } // namespace graphics
 343 } // namespace lyx
 344
 345
 346 // The details of the Impl
 347 // =======================
 348
 349 namespace {
 350
 351 class IncrementedFileName {
 352 public:
 353         IncrementedFileName(string const & to_format,
 354                             string const & filename_base)
 355                 : to_format_(to_format), base_(filename_base), counter_(1)
 356         {}
 357
 358         SnippetPair const operator()(string const & snippet)
 359         {
 360                 ostringstream os;
 361                 os << base_ << counter_++ << '.' << to_format_;
 362                 string const file = os.str();
 363
 364                 return make_pair(snippet, FileName(file));
 365         }
 366
 367 private:
 368         string const & to_format_;
 369         string const & base_;
 370         int counter_;
 371 };
 372
 373
 374 InProgress::InProgress(string const & filename_base,
 375                        PendingSnippets const & pending,
 376                        string const & to_format)
 377         : pid(0),
 378           metrics_file(FileName(filename_base + ".metrics")),
 379           snippets(pending.size())
 380 {
 381         PendingSnippets::const_iterator pit  = pending.begin();
 382         PendingSnippets::const_iterator pend = pending.end();
 383         BitmapFile::iterator sit = snippets.begin();
 384
 385         std::transform(pit, pend, sit,
 386                        IncrementedFileName(to_format, filename_base));
 387 }
 388
 389
 390 void InProgress::stop() const
 391 {
 392         if (pid)
 393                 lyx::support::ForkedcallsController::get().kill(pid, 0);
 394
 395         if (!metrics_file.empty())
 396                 lyx::support::unlink(metrics_file);
 397
 398         BitmapFile::const_iterator vit  = snippets.begin();
 399         BitmapFile::const_iterator vend = snippets.end();
 400         for (; vit != vend; ++vit) {
 401                 if (!vit->second.empty())
 402                         lyx::support::unlink(vit->second);
 403         }
 404 }
 405
 406 } // namespace anon
 407
 408
 409 namespace lyx {
 410 namespace graphics {
 411
 412 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 413         : parent_(p), buffer_(b), font_scaling_factor_(0.0)
 414 {
 415         font_scaling_factor_ = 0.01 * lyxrc.dpi * lyxrc.zoom *
 416                 convert<double>(lyxrc.preview_scale_factor);
 417
 418         LYXERR(Debug::GRAPHICS) << "The font scaling factor is "
 419                                 << font_scaling_factor_ << endl;
 420
 421         if (!pconverter_)
 422                 pconverter_ = setConverter();
 423 }
 424
 425
 426 PreviewLoader::Impl::~Impl()
 427 {
 428         InProgressProcesses::iterator ipit  = in_progress_.begin();
 429         InProgressProcesses::iterator ipend = in_progress_.end();
 430
 431         for (; ipit != ipend; ++ipit) {
 432                 ipit->second.stop();
 433         }
 434 }
 435
 436
 437 PreviewImage const *
 438 PreviewLoader::Impl::preview(string const & latex_snippet) const
 439 {
 440         Cache::const_iterator it = cache_.find(latex_snippet);
 441         return (it == cache_.end()) ? 0 : it->second.get();
 442 }
 443
 444
 445 namespace {
 446
 447 class FindSnippet : public std::unary_function<InProgressProcess, bool> {
 448 public:
 449         FindSnippet(string const & s) : snippet_(s) {}
 450         bool operator()(InProgressProcess const & process) const
 451         {
 452                 BitmapFile const & snippets = process.second.snippets;
 453                 BitmapFile::const_iterator beg  = snippets.begin();
 454                 BitmapFile::const_iterator end = snippets.end();
 455                 return find_if(beg, end, FindFirst(snippet_)) != end;
 456         }
 457
 458 private:
 459         string const snippet_;
 460 };
 461
 462 } // namespace anon
 463
 464 PreviewLoader::Status
 465 PreviewLoader::Impl::status(string const & latex_snippet) const
 466 {
 467         Cache::const_iterator cit = cache_.find(latex_snippet);
 468         if (cit != cache_.end())
 469                 return Ready;
 470
 471         PendingSnippets::const_iterator pit  = pending_.begin();
 472         PendingSnippets::const_iterator pend = pending_.end();
 473
 474         pit = find(pit, pend, latex_snippet);
 475         if (pit != pend)
 476                 return InQueue;
 477
 478         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 479         InProgressProcesses::const_iterator ipend = in_progress_.end();
 480
 481         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 482         if (ipit != ipend)
 483                 return Processing;
 484
 485         return NotFound;
 486 }
 487
 488
 489 void PreviewLoader::Impl::add(string const & latex_snippet)
 490 {
 491         if (!pconverter_ || status(latex_snippet) != NotFound)
 492                 return;
 493
 494         string const snippet = support::trim(latex_snippet);
 495         if (snippet.empty())
 496                 return;
 497
 498         LYXERR(Debug::GRAPHICS) << "adding snippet:\n" << snippet << endl;
 499
 500         pending_.push_back(snippet);
 501 }
 502
 503
 504 namespace {
 505
 506 class EraseSnippet {
 507 public:
 508         EraseSnippet(string const & s) : snippet_(s) {}
 509         void operator()(InProgressProcess & process)
 510         {
 511                 BitmapFile & snippets = process.second.snippets;
 512                 BitmapFile::iterator it  = snippets.begin();
 513                 BitmapFile::iterator end = snippets.end();
 514
 515                 it = find_if(it, end, FindFirst(snippet_));
 516                 if (it != end)
 517                         snippets.erase(it, it+1);
 518         }
 519
 520 private:
 521         string const & snippet_;
 522 };
 523
 524 } // namespace anon
 525
 526
 527 void PreviewLoader::Impl::remove(string const & latex_snippet)
 528 {
 529         Cache::iterator cit = cache_.find(latex_snippet);
 530         if (cit != cache_.end())
 531                 cache_.erase(cit);
 532
 533         PendingSnippets::iterator pit  = pending_.begin();
 534         PendingSnippets::iterator pend = pending_.end();
 535
 536         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 537
 538         InProgressProcesses::iterator ipit  = in_progress_.begin();
 539         InProgressProcesses::iterator ipend = in_progress_.end();
 540
 541         std::for_each(ipit, ipend, EraseSnippet(latex_snippet));
 542
 543         while (ipit != ipend) {
 544                 InProgressProcesses::iterator curr = ipit++;
 545                 if (curr->second.snippets.empty())
 546                         in_progress_.erase(curr);
 547         }
 548 }
 549
 550
 551 void PreviewLoader::Impl::startLoading()
 552 {
 553         if (pending_.empty() || !pconverter_)
 554                 return;
 555
 556         // Only start the process off after the buffer is loaded from file.
 557         if (!buffer_.fully_loaded())
 558                 return;
 559
 560         LYXERR(Debug::GRAPHICS) << "PreviewLoader::startLoading()" << endl;
 561
 562         // As used by the LaTeX file and by the resulting image files
 563         string const directory = buffer_.temppath();
 564
 565         string const filename_base = unique_filename(directory);
 566
 567         // Create an InProgress instance to place in the map of all
 568         // such processes if it starts correctly.
 569         InProgress inprogress(filename_base, pending_, pconverter_->to);
 570
 571         // clear pending_, so we're ready to start afresh.
 572         pending_.clear();
 573
 574         // Output the LaTeX file.
 575         FileName const latexfile(filename_base + ".tex");
 576
 577         // we use the encoding of the buffer
 578         Encoding const & enc = buffer_.params().encoding();
 579         odocfstream of(enc.iconvName());
 580         TexRow texrow;
 581         OutputParams runparams(&enc);
 582         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 583
 584         if (!openFileWrite(of, latexfile))
 585                 return;
 586
 587         if (!of) {
 588                 LYXERR(Debug::GRAPHICS) << "PreviewLoader::startLoading()\n"
 589                                         << "Unable to create LaTeX file\n"
 590                                         << latexfile << endl;
 591                 return;
 592         }
 593         of << "\\batchmode\n";
 594         dumpPreamble(of);
 595         // handle inputenc etc.
 596         buffer_.params().writeEncodingPreamble(of, features, texrow);
 597         of << "\n\\begin{document}\n";
 598         dumpData(of, inprogress.snippets);
 599         of << "\n\\end{document}\n";
 600         of.close();
 601         if (of.fail()) {
 602                 LYXERR(Debug::GRAPHICS)  << "PreviewLoader::startLoading()\n"
 603                                          << "File was not closed properly."
 604                                          << endl;
 605                 return;
 606         }
 607
 608         // The conversion command.
 609         ostringstream cs;
 610         cs << pconverter_->command << ' ' << pconverter_->to << ' '
 611            << support::quoteName(latexfile.toFilesystemEncoding()) << ' '
 612            << int(font_scaling_factor_) << ' '
 613            << theApp()->hexName(Color::preview) << ' '
 614            << theApp()->hexName(Color::background);
 615
 616         string const command = support::libScriptSearch(cs.str());
 617
 618         // Initiate the conversion from LaTeX to bitmap images files.
 619         support::Forkedcall::SignalTypePtr
 620                 convert_ptr(new support::Forkedcall::SignalType);
 621         convert_ptr->connect(bind(&Impl::finishedGenerating, this, _1, _2));
 622
 623         support::Forkedcall call;
 624         int ret = call.startscript(command, convert_ptr);
 625
 626         if (ret != 0) {
 627                 LYXERR(Debug::GRAPHICS) << "PreviewLoader::startLoading()\n"
 628                                         << "Unable to start process\n"
 629                                         << command << endl;
 630                 return;
 631         }
 632
 633         // Store the generation process in a list of all such processes
 634         inprogress.pid = call.pid();
 635         inprogress.command = command;
 636         in_progress_[inprogress.pid] = inprogress;
 637 }
 638
 639
 640 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 641 {
 642         // Paranoia check!
 643         InProgressProcesses::iterator git = in_progress_.find(pid);
 644         if (git == in_progress_.end()) {
 645                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 646                         "data for PID " << pid << endl;
 647                 return;
 648         }
 649
 650         string const command = git->second.command;
 651         string const status = retval > 0 ? "failed" : "succeeded";
 652         LYXERR(Debug::GRAPHICS) << "PreviewLoader::finishedInProgress("
 653                                 << retval << "): processing " << status
 654                                 << " for " << command << endl;
 655         if (retval > 0)
 656                 return;
 657
 658         // Read the metrics file, if it exists
 659         vector<double> ascent_fractions(git->second.snippets.size());
 660         setAscentFractions(ascent_fractions, git->second.metrics_file);
 661
 662         // Add these newly generated bitmap files to the cache and
 663         // start loading them into LyX.
 664         BitmapFile::const_iterator it  = git->second.snippets.begin();
 665         BitmapFile::const_iterator end = git->second.snippets.end();
 666
 667         std::list<PreviewImagePtr> newimages;
 668
 669         int metrics_counter = 0;
 670         for (; it != end; ++it, ++metrics_counter) {
 671                 string const & snip = it->first;
 672                 FileName const & file = it->second;
 673                 double af = ascent_fractions[metrics_counter];
 674
 675                 PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 676                 cache_[snip] = ptr;
 677
 678                 newimages.push_back(ptr);
 679         }
 680
 681         // Remove the item from the list of still-executing processes.
 682         in_progress_.erase(git);
 683
 684         // Tell the outside world
 685         std::list<PreviewImagePtr>::const_reverse_iterator
 686                 nit  = newimages.rbegin();
 687         std::list<PreviewImagePtr>::const_reverse_iterator
 688                 nend = newimages.rend();
 689         for (; nit != nend; ++nit) {
 690                 imageReady(*nit->get());
 691         }
 692 }
 693
 694
 695 void PreviewLoader::Impl::dumpPreamble(odocstream & os) const
 696 {
 697         // Why on earth is Buffer::makeLaTeXFile a non-const method?
 698         Buffer & tmp = const_cast<Buffer &>(buffer_);
 699         // Dump the preamble only.
 700         // We don't need an encoding for runparams since it is not used by
 701         // the preamble.
 702         OutputParams runparams(0);
 703         runparams.flavor = OutputParams::LATEX;
 704         runparams.nice = true;
 705         runparams.moving_arg = true;
 706         runparams.free_spacing = true;
 707         tmp.writeLaTeXSource(os, buffer_.filePath(), runparams, true, false);
 708
 709         // FIXME! This is a HACK! The proper fix is to control the 'true'
 710         // passed to WriteStream below:
 711         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 712         //                          OutputParams const & runparams) const
 713         // {
 714         //      WriteStream wi(os, runparams.moving_arg, true);
 715         //      par_->write(wi);
 716         //      return wi.line();
 717         // }
 718         os << "\n"
 719            << "\\def\\lyxlock{}\n"
 720            << "\n";
 721
 722         // Loop over the insets in the buffer and dump all the math-macros.
 723         Inset & inset = buffer_.inset();
 724         InsetIterator it = inset_iterator_begin(inset);
 725         InsetIterator const end = inset_iterator_end(inset);
 726
 727         for (; it != end; ++it)
 728                 if (it->lyxCode() == MATHMACRO_CODE)
 729                         it->latex(buffer_, os, runparams);
 730
 731         // All equation labels appear as "(#)" + preview.sty's rendering of
 732         // the label name
 733         if (lyxrc.preview_hashed_labels)
 734                 os << "\\renewcommand{\\theequation}{\\#}\n";
 735
 736         // Use the preview style file to ensure that each snippet appears on a
 737         // fresh page.
 738         os << "\n"
 739            << "\\usepackage[active,delayed,dvips,showlabels,lyx]{preview}\n"
 740            << "\n";
 741 }
 742
 743
 744 void PreviewLoader::Impl::dumpData(odocstream & os,
 745                                    BitmapFile const & vec) const
 746 {
 747         if (vec.empty())
 748                 return;
 749
 750         BitmapFile::const_iterator it  = vec.begin();
 751         BitmapFile::const_iterator end = vec.end();
 752
 753         for (; it != end; ++it) {
 754                 // FIXME UNICODE
 755                 os << "\\begin{preview}\n"
 756                    << from_utf8(it->first)
 757                    << "\n\\end{preview}\n\n";
 758         }
 759 }
 760
 761 } // namespace graphics
 762 } // namespace lyx