src/changes.C

   1 /**
   2  * \file changes.C
   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
  19 #include <boost/assert.hpp>
  20
  21
  22 namespace lyx {
  23
  24 using std::abs;
  25 using std::endl;
  26 using std::string;
  27 using std::max;
  28
  29 /*
  30  * Class Change has a changetime field that specifies the exact time at which
  31  * a specific change was made. The change time is used as a guidance for the
  32  * user while editing his document. Presently, it is not considered for LaTeX
  33  * export.
  34  * When merging two adjacent changes, the changetime is not considered,
  35  * only the equality of the change type and author is checked (in method
  36  * isSimilarTo(...)). If two changes are in fact merged (in method merge()),
  37  * the later change time is preserved.
  38  */
  39
  40 bool Change::isSimilarTo(Change const & change)
  41 {
  42         if (type != change.type) {
  43                 return false;
  44         }
  45
  46         if (type == Change::UNCHANGED) {
  47                 return true;
  48         }
  49
  50         return author == change.author;
  51 }
  52
  53
  54 bool operator==(Change const & l, Change const & r)
  55 {
  56         return l.type == r.type &&
  57                l.author == r.author &&
  58                l.changetime == r.changetime;
  59 }
  60
  61
  62 bool operator!=(Change const & l, Change const & r)
  63 {
  64         return !(l == r);
  65 }
  66
  67
  68 bool operator==(Changes::Range const & r1, Changes::Range const & r2)
  69 {
  70         return r1.start == r2.start && r1.end == r2.end;
  71 }
  72
  73
  74 bool operator!=(Changes::Range const & r1, Changes::Range const & r2)
  75 {
  76         return !(r1 == r2);
  77 }
  78
  79
  80 bool Changes::Range::contains(Range const & r) const
  81 {
  82         return r.start >= start && r.end <= end;
  83 }
  84
  85
  86 bool Changes::Range::contains(pos_type const pos) const
  87 {
  88         return pos >= start && pos < end;
  89 }
  90
  91
  92 bool Changes::Range::intersects(Range const & r) const
  93 {
  94         return r.start < end && r.end > start; // end itself is not in the range!
  95 }
  96
  97
  98 void Changes::set(Change const & change, pos_type const pos)
  99 {
 100         set(change, pos, pos + 1);
 101 }
 102
 103
 104 void Changes::set(Change const & change, pos_type const start, pos_type const end)
 105 {
 106         if (lyxerr.debugging(Debug::CHANGES)) {
 107                 lyxerr[Debug::CHANGES] << "setting change (type: " << change.type
 108                         << ", author: " << change.author << ", time: " << change.changetime
 109                         << ") in range (" << start << ", " << end << ")" << endl;
 110         }
 111
 112         Range const newRange(start, end);
 113
 114         ChangeTable::iterator it = table_.begin();
 115
 116         for (; it != table_.end(); ) {
 117                 // current change starts like or follows new change
 118                 if (it->range.start >= start) {
 119                         break;
 120                 }
 121
 122                 // new change intersects with existing change
 123                 if (it->range.end > start) {
 124                         pos_type oldEnd = it->range.end;
 125                         it->range.end = start;
 126                         if (lyxerr.debugging(Debug::CHANGES)) {
 127                                 lyxerr[Debug::CHANGES] << "  cutting tail of type " << it->change.type
 128                                         << " resulting in range (" << it->range.start << ", "
 129                                         << it->range.end << ")" << endl;
 130                         }
 131                         ++it;
 132                         if (oldEnd >= end) {
 133                                 if (lyxerr.debugging(Debug::CHANGES)) {
 134                                         lyxerr[Debug::CHANGES] << "  inserting tail in range ("
 135                                                 << end << ", " << oldEnd << ")" << endl;
 136                                 }
 137                                 it = table_.insert(it, ChangeRange((it-1)->change, Range(end, oldEnd)));
 138                         }
 139                         continue;
 140                 }
 141
 142                 ++it;
 143         }
 144
 145         if (change.type != Change::UNCHANGED) {
 146                 if (lyxerr.debugging(Debug::CHANGES)) {
 147                         lyxerr[Debug::CHANGES] << "  inserting change" << endl;
 148                 }
 149                 it = table_.insert(it, ChangeRange(change, Range(start, end)));
 150                 ++it;
 151         }
 152
 153         for (; it != table_.end(); ) {
 154                 // new change 'contains' existing change
 155                 if (newRange.contains(it->range)) {
 156                         if (lyxerr.debugging(Debug::CHANGES)) {
 157                                 lyxerr[Debug::CHANGES] << "  removing subrange ("
 158                                         << it->range.start << ", " << it->range.end << ")" << endl;
 159                         }
 160                         it = table_.erase(it);
 161                         continue;
 162                 }
 163
 164                 // new change precedes existing change
 165                 if (it->range.start >= end) {
 166                         break;
 167                 }
 168
 169                 // new change intersects with existing change
 170                 it->range.start = end;
 171                 if (lyxerr.debugging(Debug::CHANGES)) {
 172                         lyxerr[Debug::CHANGES] << "  cutting head of type "
 173                                 << it->change.type << " resulting in range ("
 174                                 << end << ", " << it->range.end << ")" << endl;
 175                 }
 176                 break; // no need for another iteration
 177         }
 178
 179         merge();
 180 }
 181
 182
 183 void Changes::erase(pos_type const pos)
 184 {
 185         if (lyxerr.debugging(Debug::CHANGES)) {
 186                 lyxerr[Debug::CHANGES] << "Erasing change at position " << pos << endl;
 187         }
 188
 189         ChangeTable::iterator it = table_.begin();
 190         ChangeTable::iterator end = table_.end();
 191
 192         for (; it != end; ++it) {
 193                 // range (pos,pos+x) becomes (pos,pos+x-1)
 194                 if (it->range.start > pos) {
 195                         --(it->range.start);
 196                 }
 197                 // range (pos-x,pos) stays (pos-x,pos)
 198                 if (it->range.end > pos) {
 199                         --(it->range.end);
 200                 }
 201         }
 202
 203         merge();
 204 }
 205
 206
 207 void Changes::insert(Change const & change, lyx::pos_type pos)
 208 {
 209         if (lyxerr.debugging(Debug::CHANGES)) {
 210                 lyxerr[Debug::CHANGES] << "Inserting change of type " << change.type
 211                         << " at position " << pos << endl;
 212         }
 213
 214         ChangeTable::iterator it = table_.begin();
 215         ChangeTable::iterator end = table_.end();
 216
 217         for (; it != end; ++it) {
 218                 // range (pos,pos+x) becomes (pos+1,pos+x+1)
 219                 if (it->range.start >= pos) {
 220                         ++(it->range.start);
 221                 }
 222
 223                 // range (pos-x,pos) stays as it is
 224                 if (it->range.end > pos) {
 225                         ++(it->range.end);
 226                 }
 227         }
 228
 229         set(change, pos, pos + 1); // set will call merge
 230 }
 231
 232
 233 Change const Changes::lookup(pos_type const pos) const
 234 {
 235         ChangeTable::const_iterator it = table_.begin();
 236         ChangeTable::const_iterator const end = table_.end();
 237
 238         for (; it != end; ++it) {
 239                 if (it->range.contains(pos))
 240                         return it->change;
 241         }
 242
 243         return Change(Change::UNCHANGED);
 244 }
 245
 246
 247 bool Changes::isChanged(pos_type const start, pos_type const end) const
 248 {
 249         ChangeTable::const_iterator it = table_.begin();
 250         ChangeTable::const_iterator const itend = table_.end();
 251
 252         for (; it != itend; ++it) {
 253                 if (it->range.intersects(Range(start, end))) {
 254                         if (lyxerr.debugging(Debug::CHANGES)) {
 255                                 lyxerr[Debug::CHANGES] << "found intersection of range ("
 256                                         << start << ", " << end << ") with ("
 257                                         << it->range.start << ", " << it->range.end
 258                                         << ") of type " << it->change.type << endl;
 259                         }
 260                         return true;
 261                 }
 262         }
 263         return false;
 264 }
 265
 266
 267 void Changes::merge()
 268 {
 269         if (lyxerr.debugging(Debug::CHANGES)) {
 270                 lyxerr[Debug::CHANGES] << "merging changes..." << endl;
 271         }
 272
 273         ChangeTable::iterator it = table_.begin();
 274
 275         while (it != table_.end()) {
 276                 if (lyxerr.debugging(Debug::CHANGES)) {
 277                         lyxerr[Debug::CHANGES] << "  found change of type " << it->change.type
 278                                 << " and range (" << it->range.start << ", " << it->range.end
 279                                 << ")" << endl;
 280                 }
 281
 282                 if (it->range.start == it->range.end) {
 283                         if (lyxerr.debugging(Debug::CHANGES)) {
 284                                 lyxerr[Debug::CHANGES] << "  removing empty range for pos "
 285                                         << it->range.start << endl;
 286                         }
 287
 288                         table_.erase(it);
 289                         // start again
 290                         it = table_.begin();
 291                         continue;
 292                 }
 293
 294                 if (it + 1 == table_.end())
 295                         break;
 296
 297                 if (it->change.isSimilarTo((it + 1)->change) && it->range.end == (it + 1)->range.start) {
 298                         if (lyxerr.debugging(Debug::CHANGES)) {
 299                                 lyxerr[Debug::CHANGES] << "  merging ranges (" << it->range.start << ", "
 300                                         << it->range.end << ") and (" << (it + 1)->range.start << ", "
 301                                         << (it + 1)->range.end << ")" << endl;
 302                         }
 303                         (it + 1)->range.start = it->range.start;
 304                         (it + 1)->change.changetime = max(it->change.changetime,
 305                                                           (it + 1)->change.changetime);
 306                         table_.erase(it);
 307                         // start again
 308                         it = table_.begin();
 309                         continue;
 310                 }
 311
 312                 ++it;
 313         }
 314 }
 315
 316
 317 int Changes::latexMarkChange(odocstream & os,
 318                              Change::Type const oldChangeType, Change::Type const changeType,
 319                              bool const & output)
 320 {
 321         if (!output || oldChangeType == changeType)
 322                 return 0;
 323
 324         static docstring const start(from_ascii("\\changestart{}"));
 325         static docstring const end(from_ascii("\\changeend{}"));
 326         static docstring const son(from_ascii("\\overstrikeon{}"));
 327         static docstring const soff(from_ascii("\\overstrikeoff{}"));
 328
 329         int column = 0;
 330
 331         if (oldChangeType == Change::DELETED) {
 332                 os << soff;
 333                 column += soff.length();
 334         }
 335
 336         switch (changeType) {
 337                 case Change::UNCHANGED:
 338                         os << end;
 339                         column += end.length();
 340                         break;
 341
 342                 case Change::DELETED:
 343                         if (oldChangeType == Change::UNCHANGED) {
 344                                 os << start;
 345                                 column += start.length();
 346                         }
 347                         os << son;
 348                         column += son.length();
 349                         break;
 350
 351                 case Change::INSERTED:
 352                         if (oldChangeType == Change::UNCHANGED) {
 353                                 os << start;
 354                                 column += start.length();
 355                         }
 356                         break;
 357         }
 358
 359         return column;
 360 }
 361
 362
 363 void Changes::lyxMarkChange(std::ostream & os, int & column,
 364                             Change const & old, Change const & change)
 365 {
 366         if (old == change)
 367                 return;
 368
 369         column = 0;
 370
 371         switch (change.type) {
 372                 case Change::UNCHANGED:
 373                         os << "\n\\change_unchanged\n";
 374                         break;
 375
 376                 case Change::DELETED: {
 377                         os << "\n\\change_deleted " << change.author
 378                                 << " " << change.changetime << "\n";
 379                         break;
 380                 }
 381
 382                 case Change::INSERTED: {
 383                         os << "\n\\change_inserted " << change.author
 384                                 << " " << change.changetime << "\n";
 385                         break;
 386                 }
 387         }
 388 }
 389
 390
 391 } // namespace lyx