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 namespace graphics {
 214
 215 class PreviewLoader::Impl : public boost::signals::trackable {
 216 public:
 217         ///
 218         Impl(PreviewLoader & p, Buffer const & b);
 219         /// Stop any InProgress items still executing.
 220         ~Impl();
 221         ///
 222         PreviewImage const * preview(string const & latex_snippet) const;
 223         ///
 224         PreviewLoader::Status status(string const & latex_snippet) const;
 225         ///
 226         void add(string const & latex_snippet);
 227         ///
 228         void remove(string const & latex_snippet);
 229         ///
 230         void startLoading();
 231
 232         /// Emit this signal when an image is ready for display.
 233         boost::signal<void(PreviewImage const &)> imageReady;
 234
 235         Buffer const & buffer() const { return buffer_; }
 236
 237 private:
 238         /// Called by the Forkedcall process that generated the bitmap files.
 239         void finishedGenerating(pid_t, int);
 240         ///
 241         void dumpPreamble(odocstream &) const;
 242         ///
 243         void dumpData(odocstream &, BitmapFile const &) const;
 244
 245         /** cache_ allows easy retrieval of already-generated images
 246          *  using the LaTeX snippet as the identifier.
 247          */
 248         typedef boost::shared_ptr<PreviewImage> PreviewImagePtr;
 249         ///
 250         typedef map<string, PreviewImagePtr> Cache;
 251         ///
 252         Cache cache_;
 253
 254         /** pending_ stores the LaTeX snippets in anticipation of them being
 255          *  sent to the converter.
 256          */
 257         PendingSnippets pending_;
 258
 259         /** in_progress_ stores all forked processes so that we can proceed
 260          *  thereafter.
 261             The map uses the conversion commands as its identifiers.
 262          */
 263         InProgressProcesses in_progress_;
 264
 265         ///
 266         PreviewLoader & parent_;
 267         ///
 268         Buffer const & buffer_;
 269         ///
 270         double font_scaling_factor_;
 271
 272         /// We don't own this
 273         static lyx::Converter const * pconverter_;
 274 };
 275
 276
 277 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 278
 279
 280 //
 281 // The public interface, defined in PreviewLoader.h
 282 //
 283
 284 PreviewLoader::PreviewLoader(Buffer const & b)
 285         : pimpl_(new Impl(*this, b))
 286 {}
 287
 288
 289 PreviewLoader::~PreviewLoader()
 290 {
 291         delete pimpl_;
 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_);
 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);
 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_.isFullyLoaded())
 558                 return;
 559
 560         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 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" << latexfile);
 590                 return;
 591         }
 592         of << "\\batchmode\n";
 593         dumpPreamble(of);
 594         // handle inputenc etc.
 595         buffer_.params().writeEncodingPreamble(of, features, texrow);
 596         of << "\n\\begin{document}\n";
 597         dumpData(of, inprogress.snippets);
 598         of << "\n\\end{document}\n";
 599         of.close();
 600         if (of.fail()) {
 601                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 602                                          << "File was not closed properly.");
 603                 return;
 604         }
 605
 606         // The conversion command.
 607         ostringstream cs;
 608         cs << pconverter_->command << ' ' << pconverter_->to << ' '
 609            << support::quoteName(latexfile.toFilesystemEncoding()) << ' '
 610            << int(font_scaling_factor_) << ' '
 611            << theApp()->hexName(Color_preview) << ' '
 612            << theApp()->hexName(Color_background);
 613
 614         string const command = support::libScriptSearch(cs.str());
 615
 616         // Initiate the conversion from LaTeX to bitmap images files.
 617         support::Forkedcall::SignalTypePtr
 618                 convert_ptr(new support::Forkedcall::SignalType);
 619         convert_ptr->connect(bind(&Impl::finishedGenerating, this, _1, _2));
 620
 621         support::Forkedcall call;
 622         int ret = call.startscript(command, convert_ptr);
 623
 624         if (ret != 0) {
 625                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 626                                         << "Unable to start process\n" << command);
 627                 return;
 628         }
 629
 630         // Store the generation process in a list of all such processes
 631         inprogress.pid = call.pid();
 632         inprogress.command = command;
 633         in_progress_[inprogress.pid] = inprogress;
 634 }
 635
 636
 637 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 638 {
 639         // Paranoia check!
 640         InProgressProcesses::iterator git = in_progress_.find(pid);
 641         if (git == in_progress_.end()) {
 642                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 643                         "data for PID " << pid << endl;
 644                 return;
 645         }
 646
 647         string const command = git->second.command;
 648         string const status = retval > 0 ? "failed" : "succeeded";
 649         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 650                                 << retval << "): processing " << status
 651                                 << " for " << command);
 652         if (retval > 0)
 653                 return;
 654
 655         // Read the metrics file, if it exists
 656         vector<double> ascent_fractions(git->second.snippets.size());
 657         setAscentFractions(ascent_fractions, git->second.metrics_file);
 658
 659         // Add these newly generated bitmap files to the cache and
 660         // start loading them into LyX.
 661         BitmapFile::const_iterator it  = git->second.snippets.begin();
 662         BitmapFile::const_iterator end = git->second.snippets.end();
 663
 664         std::list<PreviewImagePtr> newimages;
 665
 666         int metrics_counter = 0;
 667         for (; it != end; ++it, ++metrics_counter) {
 668                 string const & snip = it->first;
 669                 FileName const & file = it->second;
 670                 double af = ascent_fractions[metrics_counter];
 671
 672                 PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 673                 cache_[snip] = ptr;
 674
 675                 newimages.push_back(ptr);
 676         }
 677
 678         // Remove the item from the list of still-executing processes.
 679         in_progress_.erase(git);
 680
 681         // Tell the outside world
 682         std::list<PreviewImagePtr>::const_reverse_iterator
 683                 nit  = newimages.rbegin();
 684         std::list<PreviewImagePtr>::const_reverse_iterator
 685                 nend = newimages.rend();
 686         for (; nit != nend; ++nit) {
 687                 imageReady(*nit->get());
 688         }
 689 }
 690
 691
 692 void PreviewLoader::Impl::dumpPreamble(odocstream & os) const
 693 {
 694         // Why on earth is Buffer::makeLaTeXFile a non-const method?
 695         Buffer & tmp = const_cast<Buffer &>(buffer_);
 696         // Dump the preamble only.
 697         // We don't need an encoding for runparams since it is not used by
 698         // the preamble.
 699         OutputParams runparams(0);
 700         runparams.flavor = OutputParams::LATEX;
 701         runparams.nice = true;
 702         runparams.moving_arg = true;
 703         runparams.free_spacing = true;
 704         tmp.writeLaTeXSource(os, buffer_.filePath(), runparams, true, false);
 705
 706         // FIXME! This is a HACK! The proper fix is to control the 'true'
 707         // passed to WriteStream below:
 708         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 709         //                          OutputParams const & runparams) const
 710         // {
 711         //      WriteStream wi(os, runparams.moving_arg, true);
 712         //      par_->write(wi);
 713         //      return wi.line();
 714         // }
 715         os << "\n"
 716            << "\\def\\lyxlock{}\n"
 717            << "\n";
 718
 719         // Loop over the insets in the buffer and dump all the math-macros.
 720         Inset & inset = buffer_.inset();
 721         InsetIterator it = inset_iterator_begin(inset);
 722         InsetIterator const end = inset_iterator_end(inset);
 723
 724         for (; it != end; ++it)
 725                 if (it->lyxCode() == MATHMACRO_CODE)
 726                         it->latex(buffer_, os, runparams);
 727
 728         // All equation labels appear as "(#)" + preview.sty's rendering of
 729         // the label name
 730         if (lyxrc.preview_hashed_labels)
 731                 os << "\\renewcommand{\\theequation}{\\#}\n";
 732
 733         // Use the preview style file to ensure that each snippet appears on a
 734         // fresh page.
 735         os << "\n"
 736            << "\\usepackage[active,delayed,dvips,showlabels,lyx]{preview}\n"
 737            << "\n";
 738 }
 739
 740
 741 void PreviewLoader::Impl::dumpData(odocstream & os,
 742                                    BitmapFile const & vec) const
 743 {
 744         if (vec.empty())
 745                 return;
 746
 747         BitmapFile::const_iterator it  = vec.begin();
 748         BitmapFile::const_iterator end = vec.end();
 749
 750         for (; it != end; ++it) {
 751                 // FIXME UNICODE
 752                 os << "\\begin{preview}\n"
 753                    << from_utf8(it->first)
 754                    << "\n\\end{preview}\n\n";
 755         }
 756 }
 757
 758 } // namespace graphics
 759 } // namespace lyx