src/Changes.cpp

   1 /**
   2  * \file Changes.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author John Levon
   7  * \author Michael Gerz
   8  *
   9  * Full author contact details are available in file CREDITS.
  10  *
  11  * Record changes in a paragraph.
  12  */
  13
  14 #include <config.h>
  15
  16 #include "Changes.h"
  17 #include "debug.h"
  18 #include "Author.h"
  19 #include "BufferParams.h"
  20 #include "LaTeXFeatures.h"
  21
  22 #include <boost/assert.hpp>
  23
  24 using std::abs;
  25 using std::endl;
  26 using std::string;
  27 using std::max;
  28
  29 namespace lyx {
  30
  31 /*
  32  * Class Change has a changetime field that specifies the exact time at which
  33  * a specific change was made. The change time is used as a guidance for the
  34  * user while editing his document. Presently, it is not considered for LaTeX
  35  * export.
  36  * When merging two adjacent changes, the changetime is not considered,
  37  * only the equality of the change type and author is checked (in method
  38  * isSimilarTo(...)). If two changes are in fact merged (in method merge()),
  39  * the later change time is preserved.
  40  */
  41
  42 bool Change::isSimilarTo(Change const & change)
  43 {
  44         if (type != change.type)
  45                 return false;
  46
  47         if (type == Change::UNCHANGED)
  48                 return true;
  49
  50         return author == change.author;
  51 }
  52
  53
  54 bool operator==(Change const & l, Change const & r)
  55 {
  56         if (l.type != r.type)
  57                 return false;
  58
  59         // two changes of type UNCHANGED are always equal
  60         if (l.type == Change::UNCHANGED)
  61                 return true;
  62
  63         return l.author == r.author && l.changetime == r.changetime;
  64 }
  65
  66
  67 bool operator!=(Change const & l, Change const & r)
  68 {
  69         return !(l == r);
  70 }
  71
  72
  73 bool operator==(Changes::Range const & r1, Changes::Range const & r2)
  74 {
  75         return r1.start == r2.start && r1.end == r2.end;
  76 }
  77
  78
  79 bool operator!=(Changes::Range const & r1, Changes::Range const & r2)
  80 {
  81         return !(r1 == r2);
  82 }
  83
  84
  85 bool Changes::Range::intersects(Range const & r) const
  86 {
  87         return r.start < end && r.end > start; // end itself is not in the range!
  88 }
  89
  90
  91 void Changes::set(Change const & change, pos_type const pos)
  92 {
  93         set(change, pos, pos + 1);
  94 }
  95
  96
  97 void Changes::set(Change const & change, pos_type const start, pos_type const end)
  98 {
  99         if (change.type != Change::UNCHANGED) {
 100                 LYXERR(Debug::CHANGES) << "setting change (type: " << change.type
 101                         << ", author: " << change.author << ", time: " << change.changetime
 102                         << ") in range (" << start << ", " << end << ")" << endl;
 103         }
 104
 105         Range const newRange(start, end);
 106
 107         ChangeTable::iterator it = table_.begin();
 108
 109         for (; it != table_.end(); ) {
 110                 // current change starts like or follows new change
 111                 if (it->range.start >= start) {
 112                         break;
 113                 }
 114
 115                 // new change intersects with existing change
 116                 if (it->range.end > start) {
 117                         pos_type oldEnd = it->range.end;
 118                         it->range.end = start;
 119
 120                         LYXERR(Debug::CHANGES) << "  cutting tail of type " << it->change.type
 121                                 << " resulting in range (" << it->range.start << ", "
 122                                 << it->range.end << ")" << endl;
 123
 124                         ++it;
 125                         if (oldEnd >= end) {
 126                                 LYXERR(Debug::CHANGES) << "  inserting tail in range ("
 127                                         << end << ", " << oldEnd << ")" << endl;
 128                                 it = table_.insert(it, ChangeRange((it-1)->change, Range(end, oldEnd)));
 129                         }
 130                         continue;
 131                 }
 132
 133                 ++it;
 134         }
 135
 136         if (change.type != Change::UNCHANGED) {
 137                 LYXERR(Debug::CHANGES) << "  inserting change" << endl;
 138                 it = table_.insert(it, ChangeRange(change, Range(start, end)));
 139                 ++it;
 140         }
 141
 142         for (; it != table_.end(); ) {
 143                 // new change 'contains' existing change
 144                 if (newRange.contains(it->range)) {
 145                         LYXERR(Debug::CHANGES) << "  removing subrange ("
 146                                 << it->range.start << ", " << it->range.end << ")" << endl;
 147                         it = table_.erase(it);
 148                         continue;
 149                 }
 150
 151                 // new change precedes existing change
 152                 if (it->range.start >= end)
 153                         break;
 154
 155                 // new change intersects with existing change
 156                 it->range.start = end;
 157                 LYXERR(Debug::CHANGES) << "  cutting head of type "
 158                         << it->change.type << " resulting in range ("
 159                         << end << ", " << it->range.end << ")" << endl;
 160                 break; // no need for another iteration
 161         }
 162
 163         merge();
 164 }
 165
 166
 167 void Changes::erase(pos_type const pos)
 168 {
 169         LYXERR(Debug::CHANGES) << "Erasing change at position " << pos << endl;
 170
 171         ChangeTable::iterator it = table_.begin();
 172         ChangeTable::iterator end = table_.end();
 173
 174         for (; it != end; ++it) {
 175                 // range (pos,pos+x) becomes (pos,pos+x-1)
 176                 if (it->range.start > pos)
 177                         --(it->range.start);
 178                 // range (pos-x,pos) stays (pos-x,pos)
 179                 if (it->range.end > pos)
 180                         --(it->range.end);
 181         }
 182
 183         merge();
 184 }
 185
 186
 187 void Changes::insert(Change const & change, lyx::pos_type pos)
 188 {
 189         if (change.type != Change::UNCHANGED) {
 190                 LYXERR(Debug::CHANGES) << "Inserting change of type " << change.type
 191                         << " at position " << pos << endl;
 192         }
 193
 194         ChangeTable::iterator it = table_.begin();
 195         ChangeTable::iterator end = table_.end();
 196
 197         for (; it != end; ++it) {
 198                 // range (pos,pos+x) becomes (pos+1,pos+x+1)
 199                 if (it->range.start >= pos)
 200                         ++(it->range.start);
 201
 202                 // range (pos-x,pos) stays as it is
 203                 if (it->range.end > pos)
 204                         ++(it->range.end);
 205         }
 206
 207         set(change, pos, pos + 1); // set will call merge
 208 }
 209
 210
 211 Change const & Changes::lookup(pos_type const pos) const
 212 {
 213         static Change const noChange = Change(Change::UNCHANGED);
 214
 215         ChangeTable::const_iterator it = table_.begin();
 216         ChangeTable::const_iterator const end = table_.end();
 217
 218         for (; it != end; ++it) {
 219                 if (it->range.contains(pos))
 220                         return it->change;
 221         }
 222
 223         return noChange;
 224 }
 225
 226
 227 bool Changes::isChanged(pos_type const start, pos_type const end) const
 228 {
 229         ChangeTable::const_iterator it = table_.begin();
 230         ChangeTable::const_iterator const itend = table_.end();
 231
 232         for (; it != itend; ++it) {
 233                 if (it->range.intersects(Range(start, end))) {
 234                         LYXERR(Debug::CHANGES) << "found intersection of range ("
 235                                 << start << ", " << end << ") with ("
 236                                 << it->range.start << ", " << it->range.end
 237                                 << ") of type " << it->change.type << endl;
 238                         return true;
 239                 }
 240         }
 241         return false;
 242 }
 243
 244
 245 void Changes::merge()
 246 {
 247         ChangeTable::iterator it = table_.begin();
 248
 249         while (it != table_.end()) {
 250                 LYXERR(Debug::CHANGES) << "found change of type " << it->change.type
 251                         << " and range (" << it->range.start << ", " << it->range.end
 252                         << ")" << endl;
 253
 254                 if (it->range.start == it->range.end) {
 255                         LYXERR(Debug::CHANGES) << "removing empty range for pos "
 256                                 << it->range.start << endl;
 257
 258                         table_.erase(it);
 259                         // start again
 260                         it = table_.begin();
 261                         continue;
 262                 }
 263
 264                 if (it + 1 == table_.end())
 265                         break;
 266
 267                 if (it->change.isSimilarTo((it + 1)->change) && it->range.end == (it + 1)->range.start) {
 268                         LYXERR(Debug::CHANGES) << "merging ranges (" << it->range.start << ", "
 269                                 << it->range.end << ") and (" << (it + 1)->range.start << ", "
 270                                 << (it + 1)->range.end << ")" << endl;
 271
 272                         (it + 1)->range.start = it->range.start;
 273                         (it + 1)->change.changetime = max(it->change.changetime,
 274                                                           (it + 1)->change.changetime);
 275                         table_.erase(it);
 276                         // start again
 277                         it = table_.begin();
 278                         continue;
 279                 }
 280
 281                 ++it;
 282         }
 283 }
 284
 285
 286 int Changes::latexMarkChange(odocstream & os, BufferParams const & bparams,
 287                              Change const & oldChange, Change const & change)
 288 {
 289         if (!bparams.outputChanges || oldChange == change)
 290                 return 0;
 291
 292         int column = 0;
 293
 294         if (oldChange.type != Change::UNCHANGED) {
 295                 os << '}'; // close \lyxadded or \lyxdeleted
 296                 column++;
 297         }
 298
 299         docstring chgTime;
 300         chgTime += ctime(&change.changetime);
 301         chgTime.erase(chgTime.end() - 1); // remove trailing '\n'
 302
 303         if (change.type == Change::DELETED) {
 304                 docstring str = "\\lyxdeleted{" +
 305                         bparams.authors().get(change.author).name() + "}{" +
 306                         chgTime + "}{";
 307                 os << str;
 308                 column += str.size();
 309         } else if (change.type == Change::INSERTED) {
 310                 docstring str = "\\lyxadded{" +
 311                         bparams.authors().get(change.author).name() + "}{" +
 312                         chgTime + "}{";
 313                 os << str;
 314                 column += str.size();
 315         }
 316
 317         return column;
 318 }
 319
 320
 321 void Changes::lyxMarkChange(std::ostream & os, int & column,
 322                             Change const & old, Change const & change)
 323 {
 324         if (old == change)
 325                 return;
 326
 327         column = 0;
 328
 329         switch (change.type) {
 330                 case Change::UNCHANGED:
 331                         os << "\n\\change_unchanged\n";
 332                         break;
 333
 334                 case Change::DELETED: {
 335                         os << "\n\\change_deleted " << change.author
 336                                 << " " << change.changetime << "\n";
 337                         break;
 338                 }
 339
 340                 case Change::INSERTED: {
 341                         os << "\n\\change_inserted " << change.author
 342                                 << " " << change.changetime << "\n";
 343                         break;
 344                 }
 345         }
 346 }
 347
 348
 349 void Changes::checkAuthors(AuthorList const & authorList)
 350 {
 351         ChangeTable::const_iterator it = table_.begin();
 352         ChangeTable::const_iterator endit = table_.end();
 353         for ( ; it != endit ; ++it)
 354                 if (it->change.type != Change::UNCHANGED)
 355                         authorList.get(it->change.author).setUsed(true);
 356 }
 357
 358 } // namespace lyx