src/graphics/PreviewLoader.cpp

   1 /**
   2  * \file PreviewLoader.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Angus Leeming
   7  *
   8  * Full author contact details are available in file CREDITS.
   9  */
  10
  11 #include <config.h>
  12
  13 #include "PreviewLoader.h"
  14 #include "PreviewImage.h"
  15 #include "GraphicsCache.h"
  16
  17 #include "Buffer.h"
  18 #include "BufferParams.h"
  19 #include "Converter.h"
  20 #include "Encoding.h"
  21 #include "Format.h"
  22 #include "InsetIterator.h"
  23 #include "LaTeXFeatures.h"
  24 #include "LyXRC.h"
  25 #include "output.h"
  26 #include "OutputParams.h"
  27 #include "TexRow.h"
  28
  29 #include "frontends/Application.h" // hexName
  30
  31 #include "insets/Inset.h"
  32
  33 #include "support/convert.h"
  34 #include "support/debug.h"
  35 #include "support/FileName.h"
  36 #include "support/filetools.h"
  37 #include "support/ForkedCalls.h"
  38 #include "support/lstrings.h"
  39
  40 #include <boost/bind.hpp>
  41
  42 #include <sstream>
  43 #include <fstream>
  44 #include <iomanip>
  45
  46 using namespace std;
  47 using namespace lyx::support;
  48
  49 using boost::bind;
  50
  51 namespace {
  52
  53 typedef pair<string, FileName> SnippetPair;
  54
  55 // A list of all snippets to be converted to previews
  56 typedef list<string> PendingSnippets;
  57
  58 // Each item in the vector is a pair<snippet, image file name>.
  59 typedef vector<SnippetPair> BitmapFile;
  60
  61
  62 string const unique_filename(string const & bufferpath)
  63 {
  64         static int theCounter = 0;
  65         string const filename = lyx::convert<string>(theCounter++) + "lyxpreview";
  66         return addName(bufferpath, filename);
  67 }
  68
  69
  70 lyx::Converter const * setConverter()
  71 {
  72         string const from = "lyxpreview";
  73
  74         typedef vector<string> FmtList;
  75         typedef lyx::graphics::Cache GCache;
  76         FmtList const & loadableFormats = GCache::get().loadableFormats();
  77         FmtList::const_iterator it = loadableFormats.begin();
  78         FmtList::const_iterator const end = loadableFormats.end();
  79
  80         for (; it != end; ++it) {
  81                 string const to = *it;
  82                 if (from == to)
  83                         continue;
  84
  85                 lyx::Converter const * ptr = lyx::theConverters().getConverter(from, to);
  86                 if (ptr)
  87                         return ptr;
  88         }
  89
  90         static bool first = true;
  91         if (first) {
  92                 first = false;
  93                 LYXERR0("PreviewLoader::startLoading()\n"
  94                   << "No converter from \"lyxpreview\" format has been defined.");
  95         }
  96         return 0;
  97 }
  98
  99
 100 void setAscentFractions(vector<double> & ascent_fractions,
 101                         FileName const & metrics_file)
 102 {
 103         // If all else fails, then the images will have equal ascents and
 104         // descents.
 105         vector<double>::iterator it  = ascent_fractions.begin();
 106         vector<double>::iterator end = ascent_fractions.end();
 107         fill(it, end, 0.5);
 108
 109         ifstream in(metrics_file.toFilesystemEncoding().c_str());
 110         if (!in.good()) {
 111                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 112                         << "Unable to open file!");
 113                 return;
 114         }
 115
 116         bool error = false;
 117
 118         int snippet_counter = 1;
 119         while (!in.eof() && it != end) {
 120                 string snippet;
 121                 int id;
 122                 double ascent_fraction;
 123
 124                 in >> snippet >> id >> ascent_fraction;
 125
 126                 if (!in.good())
 127                         // eof after all
 128                         break;
 129
 130                 error = snippet != "Snippet";
 131                 if (error)
 132                         break;
 133
 134                 error = id != snippet_counter;
 135                 if (error)
 136                         break;
 137
 138                 *it = ascent_fraction;
 139
 140                 ++snippet_counter;
 141                 ++it;
 142         }
 143
 144         if (error) {
 145                 LYXERR(lyx::Debug::GRAPHICS, "setAscentFractions(" << metrics_file << ")\n"
 146                         << "Error reading file!\n");
 147         }
 148 }
 149
 150
 151 class FindFirst
 152 {
 153 public:
 154         FindFirst(string const & comp) : comp_(comp) {}
 155         bool operator()(SnippetPair const & sp) const { return sp.first == comp_; }
 156 private:
 157         string const comp_;
 158 };
 159
 160
 161 /// Store info on a currently executing, forked process.
 162 class InProgress {
 163 public:
 164         ///
 165         InProgress() : pid(0) {}
 166         ///
 167         InProgress(string const & filename_base,
 168                    PendingSnippets const & pending,
 169                    string const & to_format);
 170         /// Remove any files left lying around and kill the forked process.
 171         void stop() const;
 172
 173         ///
 174         pid_t pid;
 175         ///
 176         string command;
 177         ///
 178         FileName metrics_file;
 179         ///
 180         BitmapFile snippets;
 181 };
 182
 183 typedef map<pid_t, InProgress>  InProgressProcesses;
 184
 185 typedef InProgressProcesses::value_type InProgressProcess;
 186
 187 } // namespace anon
 188
 189
 190
 191 namespace lyx {
 192 namespace graphics {
 193
 194 class PreviewLoader::Impl : public boost::signals::trackable {
 195 public:
 196         ///
 197         Impl(PreviewLoader & p, Buffer const & b);
 198         /// Stop any InProgress items still executing.
 199         ~Impl();
 200         ///
 201         PreviewImage const * preview(string const & latex_snippet) const;
 202         ///
 203         PreviewLoader::Status status(string const & latex_snippet) const;
 204         ///
 205         void add(string const & latex_snippet);
 206         ///
 207         void remove(string const & latex_snippet);
 208         ///
 209         void startLoading();
 210
 211         /// Emit this signal when an image is ready for display.
 212         boost::signal<void(PreviewImage const &)> imageReady;
 213
 214         Buffer const & buffer() const { return buffer_; }
 215
 216 private:
 217         /// Called by the ForkedCall process that generated the bitmap files.
 218         void finishedGenerating(pid_t, int);
 219         ///
 220         void dumpPreamble(odocstream &) const;
 221         ///
 222         void dumpData(odocstream &, BitmapFile const &) const;
 223
 224         /** cache_ allows easy retrieval of already-generated images
 225          *  using the LaTeX snippet as the identifier.
 226          */
 227         typedef boost::shared_ptr<PreviewImage> PreviewImagePtr;
 228         ///
 229         typedef map<string, PreviewImagePtr> Cache;
 230         ///
 231         Cache cache_;
 232
 233         /** pending_ stores the LaTeX snippets in anticipation of them being
 234          *  sent to the converter.
 235          */
 236         PendingSnippets pending_;
 237
 238         /** in_progress_ stores all forked processes so that we can proceed
 239          *  thereafter.
 240             The map uses the conversion commands as its identifiers.
 241          */
 242         InProgressProcesses in_progress_;
 243
 244         ///
 245         PreviewLoader & parent_;
 246         ///
 247         Buffer const & buffer_;
 248         ///
 249         double font_scaling_factor_;
 250
 251         /// We don't own this
 252         static lyx::Converter const * pconverter_;
 253 };
 254
 255
 256 lyx::Converter const * PreviewLoader::Impl::pconverter_;
 257
 258
 259 //
 260 // The public interface, defined in PreviewLoader.h
 261 //
 262
 263 PreviewLoader::PreviewLoader(Buffer const & b)
 264         : pimpl_(new Impl(*this, b))
 265 {}
 266
 267
 268 PreviewLoader::~PreviewLoader()
 269 {
 270         delete pimpl_;
 271 }
 272
 273
 274 PreviewImage const * PreviewLoader::preview(string const & latex_snippet) const
 275 {
 276         return pimpl_->preview(latex_snippet);
 277 }
 278
 279
 280 PreviewLoader::Status PreviewLoader::status(string const & latex_snippet) const
 281 {
 282         return pimpl_->status(latex_snippet);
 283 }
 284
 285
 286 void PreviewLoader::add(string const & latex_snippet) const
 287 {
 288         pimpl_->add(latex_snippet);
 289 }
 290
 291
 292 void PreviewLoader::remove(string const & latex_snippet) const
 293 {
 294         pimpl_->remove(latex_snippet);
 295 }
 296
 297
 298 void PreviewLoader::startLoading() const
 299 {
 300         pimpl_->startLoading();
 301 }
 302
 303
 304 boost::signals::connection PreviewLoader::connect(slot_type const & slot) const
 305 {
 306         return pimpl_->imageReady.connect(slot);
 307 }
 308
 309
 310 void PreviewLoader::emitSignal(PreviewImage const & pimage) const
 311 {
 312         pimpl_->imageReady(pimage);
 313 }
 314
 315
 316 Buffer const & PreviewLoader::buffer() const
 317 {
 318         return pimpl_->buffer();
 319 }
 320
 321 } // namespace graphics
 322 } // namespace lyx
 323
 324
 325 // The details of the Impl
 326 // =======================
 327
 328 namespace {
 329
 330 class IncrementedFileName {
 331 public:
 332         IncrementedFileName(string const & to_format,
 333                             string const & filename_base)
 334                 : to_format_(to_format), base_(filename_base), counter_(1)
 335         {}
 336
 337         SnippetPair const operator()(string const & snippet)
 338         {
 339                 ostringstream os;
 340                 os << base_ << counter_++ << '.' << to_format_;
 341                 string const file = os.str();
 342
 343                 return make_pair(snippet, FileName(file));
 344         }
 345
 346 private:
 347         string const & to_format_;
 348         string const & base_;
 349         int counter_;
 350 };
 351
 352
 353 InProgress::InProgress(string const & filename_base,
 354                        PendingSnippets const & pending,
 355                        string const & to_format)
 356         : pid(0),
 357           metrics_file(filename_base + ".metrics"),
 358           snippets(pending.size())
 359 {
 360         PendingSnippets::const_iterator pit  = pending.begin();
 361         PendingSnippets::const_iterator pend = pending.end();
 362         BitmapFile::iterator sit = snippets.begin();
 363
 364         transform(pit, pend, sit,
 365                        IncrementedFileName(to_format, filename_base));
 366 }
 367
 368
 369 void InProgress::stop() const
 370 {
 371         if (pid)
 372                 ForkedCallsController::kill(pid, 0);
 373
 374         if (!metrics_file.empty())
 375                 metrics_file.removeFile();
 376
 377         BitmapFile::const_iterator vit  = snippets.begin();
 378         BitmapFile::const_iterator vend = snippets.end();
 379         for (; vit != vend; ++vit) {
 380                 if (!vit->second.empty())
 381                         vit->second.removeFile();
 382         }
 383 }
 384
 385 } // namespace anon
 386
 387
 388 namespace lyx {
 389 namespace graphics {
 390
 391 PreviewLoader::Impl::Impl(PreviewLoader & p, Buffer const & b)
 392         : parent_(p), buffer_(b), font_scaling_factor_(0.0)
 393 {
 394         font_scaling_factor_ = 0.01 * lyxrc.dpi * lyxrc.zoom *
 395                 convert<double>(lyxrc.preview_scale_factor);
 396
 397         LYXERR(Debug::GRAPHICS, "The font scaling factor is "
 398                                 << font_scaling_factor_);
 399
 400         if (!pconverter_)
 401                 pconverter_ = setConverter();
 402 }
 403
 404
 405 PreviewLoader::Impl::~Impl()
 406 {
 407         InProgressProcesses::iterator ipit  = in_progress_.begin();
 408         InProgressProcesses::iterator ipend = in_progress_.end();
 409
 410         for (; ipit != ipend; ++ipit)
 411                 ipit->second.stop();
 412 }
 413
 414
 415 PreviewImage const *
 416 PreviewLoader::Impl::preview(string const & latex_snippet) const
 417 {
 418         Cache::const_iterator it = cache_.find(latex_snippet);
 419         return (it == cache_.end()) ? 0 : it->second.get();
 420 }
 421
 422
 423 namespace {
 424
 425 class FindSnippet {
 426 public:
 427         FindSnippet(string const & s) : snippet_(s) {}
 428         bool operator()(InProgressProcess const & process) const
 429         {
 430                 BitmapFile const & snippets = process.second.snippets;
 431                 BitmapFile::const_iterator beg  = snippets.begin();
 432                 BitmapFile::const_iterator end = snippets.end();
 433                 return find_if(beg, end, FindFirst(snippet_)) != end;
 434         }
 435
 436 private:
 437         string const snippet_;
 438 };
 439
 440 } // namespace anon
 441
 442 PreviewLoader::Status
 443 PreviewLoader::Impl::status(string const & latex_snippet) const
 444 {
 445         Cache::const_iterator cit = cache_.find(latex_snippet);
 446         if (cit != cache_.end())
 447                 return Ready;
 448
 449         PendingSnippets::const_iterator pit  = pending_.begin();
 450         PendingSnippets::const_iterator pend = pending_.end();
 451
 452         pit = find(pit, pend, latex_snippet);
 453         if (pit != pend)
 454                 return InQueue;
 455
 456         InProgressProcesses::const_iterator ipit  = in_progress_.begin();
 457         InProgressProcesses::const_iterator ipend = in_progress_.end();
 458
 459         ipit = find_if(ipit, ipend, FindSnippet(latex_snippet));
 460         if (ipit != ipend)
 461                 return Processing;
 462
 463         return NotFound;
 464 }
 465
 466
 467 void PreviewLoader::Impl::add(string const & latex_snippet)
 468 {
 469         if (!pconverter_ || status(latex_snippet) != NotFound)
 470                 return;
 471
 472         string const snippet = trim(latex_snippet);
 473         if (snippet.empty())
 474                 return;
 475
 476         LYXERR(Debug::GRAPHICS, "adding snippet:\n" << snippet);
 477
 478         pending_.push_back(snippet);
 479 }
 480
 481
 482 namespace {
 483
 484 class EraseSnippet {
 485 public:
 486         EraseSnippet(string const & s) : snippet_(s) {}
 487         void operator()(InProgressProcess & process)
 488         {
 489                 BitmapFile & snippets = process.second.snippets;
 490                 BitmapFile::iterator it  = snippets.begin();
 491                 BitmapFile::iterator end = snippets.end();
 492
 493                 it = find_if(it, end, FindFirst(snippet_));
 494                 if (it != end)
 495                         snippets.erase(it, it+1);
 496         }
 497
 498 private:
 499         string const & snippet_;
 500 };
 501
 502 } // namespace anon
 503
 504
 505 void PreviewLoader::Impl::remove(string const & latex_snippet)
 506 {
 507         Cache::iterator cit = cache_.find(latex_snippet);
 508         if (cit != cache_.end())
 509                 cache_.erase(cit);
 510
 511         PendingSnippets::iterator pit  = pending_.begin();
 512         PendingSnippets::iterator pend = pending_.end();
 513
 514         pending_.erase(std::remove(pit, pend, latex_snippet), pend);
 515
 516         InProgressProcesses::iterator ipit  = in_progress_.begin();
 517         InProgressProcesses::iterator ipend = in_progress_.end();
 518
 519         for_each(ipit, ipend, EraseSnippet(latex_snippet));
 520
 521         while (ipit != ipend) {
 522                 InProgressProcesses::iterator curr = ipit++;
 523                 if (curr->second.snippets.empty())
 524                         in_progress_.erase(curr);
 525         }
 526 }
 527
 528
 529 void PreviewLoader::Impl::startLoading()
 530 {
 531         if (pending_.empty() || !pconverter_)
 532                 return;
 533
 534         // Only start the process off after the buffer is loaded from file.
 535         if (!buffer_.isFullyLoaded())
 536                 return;
 537
 538         LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()");
 539
 540         // As used by the LaTeX file and by the resulting image files
 541         string const directory = buffer_.temppath();
 542
 543         string const filename_base = unique_filename(directory);
 544
 545         // Create an InProgress instance to place in the map of all
 546         // such processes if it starts correctly.
 547         InProgress inprogress(filename_base, pending_, pconverter_->to);
 548
 549         // clear pending_, so we're ready to start afresh.
 550         pending_.clear();
 551
 552         // Output the LaTeX file.
 553         FileName const latexfile(filename_base + ".tex");
 554
 555         // we use the encoding of the buffer
 556         Encoding const & enc = buffer_.params().encoding();
 557         odocfstream of;
 558         try { of.reset(enc.iconvName()); }
 559         catch (iconv_codecvt_facet_exception & e) {
 560                 LYXERR0("Caught iconv exception: " << e.what()
 561                         << "\nUnable to create LaTeX file: " << latexfile);
 562                 return;
 563         }
 564
 565         TexRow texrow;
 566         OutputParams runparams(&enc);
 567         LaTeXFeatures features(buffer_, buffer_.params(), runparams);
 568
 569         if (!openFileWrite(of, latexfile))
 570                 return;
 571
 572         if (!of) {
 573                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 574                                         << "Unable to create LaTeX file\n" << latexfile);
 575                 return;
 576         }
 577         of << "\\batchmode\n";
 578         dumpPreamble(of);
 579         // handle inputenc etc.
 580         buffer_.params().writeEncodingPreamble(of, features, texrow);
 581         of << "\n\\begin{document}\n";
 582         dumpData(of, inprogress.snippets);
 583         of << "\n\\end{document}\n";
 584         of.close();
 585         if (of.fail()) {
 586                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 587                                          << "File was not closed properly.");
 588                 return;
 589         }
 590
 591         // The conversion command.
 592         ostringstream cs;
 593         cs << pconverter_->command << ' ' << pconverter_->to << ' '
 594            << quoteName(latexfile.toFilesystemEncoding()) << ' '
 595            << int(font_scaling_factor_) << ' '
 596            << theApp()->hexName(Color_preview) << ' '
 597            << theApp()->hexName(Color_background);
 598
 599         string const command = libScriptSearch(cs.str());
 600
 601         // Initiate the conversion from LaTeX to bitmap images files.
 602         ForkedCall::SignalTypePtr
 603                 convert_ptr(new ForkedCall::SignalType);
 604         convert_ptr->connect(bind(&Impl::finishedGenerating, this, _1, _2));
 605
 606         ForkedCall call;
 607         int ret = call.startScript(command, convert_ptr);
 608
 609         if (ret != 0) {
 610                 LYXERR(Debug::GRAPHICS, "PreviewLoader::startLoading()\n"
 611                                         << "Unable to start process\n" << command);
 612                 return;
 613         }
 614
 615         // Store the generation process in a list of all such processes
 616         inprogress.pid = call.pid();
 617         inprogress.command = command;
 618         in_progress_[inprogress.pid] = inprogress;
 619 }
 620
 621
 622 void PreviewLoader::Impl::finishedGenerating(pid_t pid, int retval)
 623 {
 624         // Paranoia check!
 625         InProgressProcesses::iterator git = in_progress_.find(pid);
 626         if (git == in_progress_.end()) {
 627                 lyxerr << "PreviewLoader::finishedGenerating(): unable to find "
 628                         "data for PID " << pid << endl;
 629                 return;
 630         }
 631
 632         string const command = git->second.command;
 633         string const status = retval > 0 ? "failed" : "succeeded";
 634         LYXERR(Debug::GRAPHICS, "PreviewLoader::finishedInProgress("
 635                                 << retval << "): processing " << status
 636                                 << " for " << command);
 637         if (retval > 0)
 638                 return;
 639
 640         // Read the metrics file, if it exists
 641         vector<double> ascent_fractions(git->second.snippets.size());
 642         setAscentFractions(ascent_fractions, git->second.metrics_file);
 643
 644         // Add these newly generated bitmap files to the cache and
 645         // start loading them into LyX.
 646         BitmapFile::const_iterator it  = git->second.snippets.begin();
 647         BitmapFile::const_iterator end = git->second.snippets.end();
 648
 649         list<PreviewImagePtr> newimages;
 650
 651         int metrics_counter = 0;
 652         for (; it != end; ++it, ++metrics_counter) {
 653                 string const & snip = it->first;
 654                 FileName const & file = it->second;
 655                 double af = ascent_fractions[metrics_counter];
 656
 657                 PreviewImagePtr ptr(new PreviewImage(parent_, snip, file, af));
 658                 cache_[snip] = ptr;
 659
 660                 newimages.push_back(ptr);
 661         }
 662
 663         // Remove the item from the list of still-executing processes.
 664         in_progress_.erase(git);
 665
 666         // Tell the outside world
 667         list<PreviewImagePtr>::const_reverse_iterator
 668                 nit  = newimages.rbegin();
 669         list<PreviewImagePtr>::const_reverse_iterator
 670                 nend = newimages.rend();
 671         for (; nit != nend; ++nit) {
 672                 imageReady(*nit->get());
 673         }
 674 }
 675
 676
 677 void PreviewLoader::Impl::dumpPreamble(odocstream & os) const
 678 {
 679         // Why on earth is Buffer::makeLaTeXFile a non-const method?
 680         Buffer & tmp = const_cast<Buffer &>(buffer_);
 681         // Dump the preamble only.
 682         // We don't need an encoding for runparams since it is not used by
 683         // the preamble.
 684         OutputParams runparams(0);
 685         runparams.flavor = OutputParams::LATEX;
 686         runparams.nice = true;
 687         runparams.moving_arg = true;
 688         runparams.free_spacing = true;
 689         tmp.writeLaTeXSource(os, buffer_.filePath(), runparams, true, false);
 690
 691         // FIXME! This is a HACK! The proper fix is to control the 'true'
 692         // passed to WriteStream below:
 693         // int InsetMathNest::latex(Buffer const &, odocstream & os,
 694         //                          OutputParams const & runparams) const
 695         // {
 696         //      WriteStream wi(os, runparams.moving_arg, true);
 697         //      par_->write(wi);
 698         //      return wi.line();
 699         // }
 700         os << "\n"
 701            << "\\def\\lyxlock{}\n"
 702            << "\n";
 703
 704         // Loop over the insets in the buffer and dump all the math-macros.
 705         Inset & inset = buffer_.inset();
 706         InsetIterator it = inset_iterator_begin(inset);
 707         InsetIterator const end = inset_iterator_end(inset);
 708
 709         for (; it != end; ++it)
 710                 if (it->lyxCode() == MATHMACRO_CODE)
 711                         it->latex(os, runparams);
 712
 713         // All equation labels appear as "(#)" + preview.sty's rendering of
 714         // the label name
 715         if (lyxrc.preview_hashed_labels)
 716                 os << "\\renewcommand{\\theequation}{\\#}\n";
 717
 718         // Use the preview style file to ensure that each snippet appears on a
 719         // fresh page.
 720         // Also support PDF output (automatically generated e.g. when
 721         // \usepackage[pdftex]{hyperref} is used.
 722         os << "\n"
 723            << "\\newif\\ifpdf\n"
 724            << "\\ifx\\pdfoutput\\undefined\n"
 725            << "\\else\\ifx\\pdfoutput\\relax\n"
 726            << "\\else\\ifnum0=\\pdfoutput\n"
 727            << "\\else\\pdftrue\\fi\\fi\\fi\n"
 728            << "\\ifpdf\n"
 729            << "  \\usepackage[active,delayed,tightpage,showlabels,lyx,pdftex]{preview}\n"
 730            << "\\else\n"
 731            << "  \\usepackage[active,delayed,showlabels,lyx,dvips]{preview}\n"
 732            << "\\fi\n"
 733            << "\n";
 734 }
 735
 736
 737 void PreviewLoader::Impl::dumpData(odocstream & os,
 738                                    BitmapFile const & vec) const
 739 {
 740         if (vec.empty())
 741                 return;
 742
 743         BitmapFile::const_iterator it  = vec.begin();
 744         BitmapFile::const_iterator end = vec.end();
 745
 746         for (; it != end; ++it) {
 747                 // FIXME UNICODE
 748                 os << "\\begin{preview}\n"
 749                    << from_utf8(it->first)
 750                    << "\n\\end{preview}\n\n";
 751         }
 752 }
 753
 754 } // namespace graphics
 755 } // namespace lyx