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