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