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