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::endl;
  25 using std::string;
  26 using std::max;
  27
  28 /*
  29  * Class Change has a changetime field that specifies the exact time at which
  30  * a specific change was made. The change time is used as a guidance for the
  31  * user while editing his document. Presently, it is not considered for LaTeX
  32  * export. To avoid that every keystroke results in a separate change, a
  33  * tolerance interval of 5 minutes is used. That means if there are two adjacent
  34  * changes that only differ in their change time with abs(ct1 - ct2) < 300 sec,
  35  * they will be merged (and the later change time is preserved).
  36  * Technically, the check for equality (or similarity) is made in operator==(...).
  37  * The merging of similar changes happens in method merge().
  38  */
  39
  40 bool operator==(Change const & l, Change const & r)
  41 {
  42         if (l.type != r.type) {
  43                 return false;
  44         }
  45
  46         if (l.type == Change::UNCHANGED) {
  47                 return true;
  48         }
  49
  50         return l.author == r.author
  51                // both changes made within 5 minutes?
  52                && abs(l.changetime - r.changetime) < 300;
  53 }
  54
  55
  56 bool operator!=(Change const & l, Change const & r)
  57 {
  58         return !(l == r);
  59 }
  60
  61
  62 bool operator==(Changes::Range const & r1, Changes::Range const & r2)
  63 {
  64         return r1.start == r2.start && r1.end == r2.end;
  65 }
  66
  67
  68 bool operator!=(Changes::Range const & r1, Changes::Range const & r2)
  69 {
  70         return !(r1 == r2);
  71 }
  72
  73
  74 bool Changes::Range::contains(Range const & r) const
  75 {
  76         return r.start >= start && r.end <= end;
  77 }
  78
  79
  80 bool Changes::Range::contains(pos_type const pos) const
  81 {
  82         return pos >= start && pos < end;
  83 }
  84
  85
  86 bool Changes::Range::intersects(Range const & r) const
  87 {
  88         return r.start < end && r.end > start; // end itself is not in the range!
  89 }
  90
  91
  92 void Changes::set(Change const & change, pos_type const pos)
  93 {
  94         set(change, pos, pos + 1);
  95 }
  96
  97
  98 void Changes::set(Change const & change, pos_type const start, pos_type const end)
  99 {
 100         if (lyxerr.debugging(Debug::CHANGES)) {
 101                 lyxerr[Debug::CHANGES] << "setting change (type: " << change.type
 102                         << ", author: " << change.author << ", time: " << change.changetime
 103                         << ") in range (" << start << ", " << end << ")" << endl;
 104         }
 105
 106         Range const newRange(start, end);
 107
 108         ChangeTable::iterator it = table_.begin();
 109
 110         for (; it != table_.end(); ) {
 111                 // current change starts like or follows new change
 112                 if (it->range.start >= start) {
 113                         break;
 114                 }
 115
 116                 // new change intersects with existing change
 117                 if (it->range.end > start) {
 118                         pos_type oldEnd = it->range.end;
 119                         it->range.end = start;
 120                         if (lyxerr.debugging(Debug::CHANGES)) {
 121                                 lyxerr[Debug::CHANGES] << "  cutting tail of type " << it->change.type
 122                                         << " resulting in range (" << it->range.start << ", "
 123                                         << it->range.end << ")" << endl;
 124                         }
 125                         ++it;
 126                         if (oldEnd >= end) {
 127                                 if (lyxerr.debugging(Debug::CHANGES)) {
 128                                         lyxerr[Debug::CHANGES] << "  inserting tail in range ("
 129                                                 << end << ", " << oldEnd << ")" << endl;
 130                                 }
 131                                 it = table_.insert(it, ChangeRange((it-1)->change, Range(end, oldEnd)));
 132                         }
 133                         continue;
 134                 }
 135
 136                 ++it;
 137         }
 138
 139         if (change.type != Change::UNCHANGED) {
 140                 if (lyxerr.debugging(Debug::CHANGES)) {
 141                         lyxerr[Debug::CHANGES] << "  inserting change" << endl;
 142                 }
 143                 it = table_.insert(it, ChangeRange(change, Range(start, end)));
 144                 ++it;
 145         }
 146
 147         for (; it != table_.end(); ) {
 148                 // new change 'contains' existing change
 149                 if (newRange.contains(it->range)) {
 150                         if (lyxerr.debugging(Debug::CHANGES)) {
 151                                 lyxerr[Debug::CHANGES] << "  removing subrange ("
 152                                         << it->range.start << ", " << it->range.end << ")" << endl;
 153                         }
 154                         it = table_.erase(it);
 155                         continue;
 156                 }
 157
 158                 // new change precedes existing change
 159                 if (it->range.start >= end) {
 160                         break;
 161                 }
 162
 163                 // new change intersects with existing change
 164                 it->range.start = end;
 165                 if (lyxerr.debugging(Debug::CHANGES)) {
 166                         lyxerr[Debug::CHANGES] << "  cutting head of type "
 167                                 << it->change.type << " resulting in range ("
 168                                 << end << ", " << it->range.end << ")" << endl;
 169                 }
 170                 break; // no need for another iteration
 171         }
 172
 173         merge();
 174 }
 175
 176
 177 void Changes::erase(pos_type const pos)
 178 {
 179         if (lyxerr.debugging(Debug::CHANGES)) {
 180                 lyxerr[Debug::CHANGES] << "Erasing change at position " << pos << endl;
 181         }
 182
 183         ChangeTable::iterator it = table_.begin();
 184         ChangeTable::iterator end = table_.end();
 185
 186         for (; it != end; ++it) {
 187                 // range (pos,pos+x) becomes (pos,pos+x-1)
 188                 if (it->range.start > pos) {
 189                         --(it->range.start);
 190                 }
 191                 // range (pos-x,pos) stays (pos-x,pos)
 192                 if (it->range.end > pos) {
 193                         --(it->range.end);
 194                 }
 195         }
 196
 197         merge();
 198 }
 199
 200
 201 void Changes::insert(Change const & change, lyx::pos_type pos)
 202 {
 203         if (lyxerr.debugging(Debug::CHANGES)) {
 204                 lyxerr[Debug::CHANGES] << "Inserting change of type " << change.type
 205                         << " at position " << pos << endl;
 206         }
 207
 208         ChangeTable::iterator it = table_.begin();
 209         ChangeTable::iterator end = table_.end();
 210
 211         for (; it != end; ++it) {
 212                 // range (pos,pos+x) becomes (pos+1,pos+x+1)
 213                 if (it->range.start >= pos) {
 214                         ++(it->range.start);
 215                 }
 216
 217                 // range (pos-x,pos) stays as it is
 218                 if (it->range.end > pos) {
 219                         ++(it->range.end);
 220                 }
 221         }
 222
 223         set(change, pos, pos + 1); // set will call merge
 224 }
 225
 226
 227 Change const Changes::lookup(pos_type const pos) const
 228 {
 229         if (table_.empty()) {
 230                 return Change(Change::UNCHANGED);
 231         }
 232         ChangeTable::const_iterator it = table_.begin();
 233         ChangeTable::const_iterator const end = table_.end();
 234
 235         for (; it != end; ++it) {
 236                 if (it->range.contains(pos))
 237                         return it->change;
 238         }
 239
 240         return Change(Change::UNCHANGED);
 241 }
 242
 243
 244 bool Changes::isChanged(pos_type const start, pos_type const end) const
 245 {
 246         ChangeTable::const_iterator it = table_.begin();
 247         ChangeTable::const_iterator const itend = table_.end();
 248
 249         for (; it != itend; ++it) {
 250                 if (it->range.intersects(Range(start, end))) {
 251                         if (lyxerr.debugging(Debug::CHANGES)) {
 252                                 lyxerr[Debug::CHANGES] << "found intersection of range ("
 253                                         << start << ", " << end << ") with ("
 254                                         << it->range.start << ", " << it->range.end
 255                                         << ") of type " << it->change.type << endl;
 256                         }
 257                         return true;
 258                 }
 259         }
 260         return false;
 261 }
 262
 263
 264 void Changes::merge()
 265 {
 266         if (lyxerr.debugging(Debug::CHANGES)) {
 267                 lyxerr[Debug::CHANGES] << "merging changes..." << endl;
 268         }
 269
 270         ChangeTable::iterator it = table_.begin();
 271
 272         while (it != table_.end()) {
 273                 if (lyxerr.debugging(Debug::CHANGES)) {
 274                         lyxerr[Debug::CHANGES] << "  found change of type " << it->change.type
 275                                 << " and range (" << it->range.start << ", " << it->range.end
 276                                 << ")" << endl;
 277                 }
 278
 279                 if (it->range.start == it->range.end) {
 280                         if (lyxerr.debugging(Debug::CHANGES)) {
 281                                 lyxerr[Debug::CHANGES] << "  removing empty range for pos "
 282                                         << it->range.start << endl;
 283                         }
 284
 285                         table_.erase(it);
 286                         // start again
 287                         it = table_.begin();
 288                         continue;
 289                 }
 290
 291                 if (it + 1 == table_.end())
 292                         break;
 293
 294                 if (it->change == (it + 1)->change && it->range.end == (it + 1)->range.start) {
 295                         if (lyxerr.debugging(Debug::CHANGES)) {
 296                                 lyxerr[Debug::CHANGES] << "  merging ranges (" << it->range.start << ", "
 297                                         << it->range.end << ") and (" << (it + 1)->range.start << ", "
 298                                         << (it + 1)->range.end << ")" << endl;
 299                         }
 300                         (it + 1)->range.start = it->range.start;
 301                         (it + 1)->change.changetime = max(it->change.changetime,
 302                                                           (it + 1)->change.changetime);
 303                         table_.erase(it);
 304                         // start again
 305                         it = table_.begin();
 306                         continue;
 307                 }
 308
 309                 ++it;
 310         }
 311 }
 312
 313
 314 int Changes::latexMarkChange(odocstream & os,
 315                              Change::Type const oldChangeType, Change::Type const changeType,
 316                              bool const & output)
 317 {
 318         if (!output || oldChangeType == changeType)
 319                 return 0;
 320
 321         static docstring const start(from_ascii("\\changestart{}"));
 322         static docstring const end(from_ascii("\\changeend{}"));
 323         static docstring const son(from_ascii("\\overstrikeon{}"));
 324         static docstring const soff(from_ascii("\\overstrikeoff{}"));
 325
 326         int column = 0;
 327
 328         if (oldChangeType == Change::DELETED) {
 329                 os << soff;
 330                 column += soff.length();
 331         }
 332
 333         switch (changeType) {
 334                 case Change::UNCHANGED:
 335                         os << end;
 336                         column += end.length();
 337                         break;
 338
 339                 case Change::DELETED:
 340                         if (oldChangeType == Change::UNCHANGED) {
 341                                 os << start;
 342                                 column += start.length();
 343                         }
 344                         os << son;
 345                         column += son.length();
 346                         break;
 347
 348                 case Change::INSERTED:
 349                         if (oldChangeType == Change::UNCHANGED) {
 350                                 os << start;
 351                                 column += start.length();
 352                         }
 353                         break;
 354         }
 355
 356         return column;
 357 }
 358
 359
 360 void Changes::lyxMarkChange(std::ostream & os, int & column,
 361                             Change const & old, Change const & change)
 362 {
 363         if (old == change)
 364                 return;
 365
 366         column = 0;
 367
 368         switch (change.type) {
 369                 case Change::UNCHANGED:
 370                         os << "\n\\change_unchanged\n";
 371                         break;
 372
 373                 case Change::DELETED: {
 374                         os << "\n\\change_deleted " << change.author
 375                                 << " " << change.changetime << "\n";
 376                         break;
 377                 }
 378
 379                 case Change::INSERTED: {
 380                         os << "\n\\change_inserted " << change.author
 381                                 << " " << change.changetime << "\n";
 382                         break;
 383                 }
 384         }
 385 }
 386
 387
 388 } // namespace lyx