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