libs/pbd/undo.cc

   1 /*
   2     Copyright (C) 2001 Brett Viren & Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18     $Id$
  19 */
  20
  21 #include <iostream>
  22 #include <string>
  23 #include <sstream>
  24 #include <time.h>
  25
  26 #include "pbd/undo.h"
  27 #include "pbd/xml++.h"
  28
  29 #include <sigc++/bind.h>
  30
  31 using namespace std;
  32 using namespace sigc;
  33
  34 UndoTransaction::UndoTransaction ()
  35         : _clearing(false)
  36 {
  37         gettimeofday (&_timestamp, 0);
  38 }
  39
  40 UndoTransaction::UndoTransaction (const UndoTransaction& rhs)
  41         : Command(rhs._name)
  42         , _clearing(false)
  43 {
  44         clear ();
  45         actions.insert(actions.end(),rhs.actions.begin(),rhs.actions.end());
  46 }
  47
  48 UndoTransaction::~UndoTransaction ()
  49 {
  50         drop_references ();
  51         clear ();
  52 }
  53
  54 void
  55 command_death (UndoTransaction* ut, Command* c)
  56 {
  57         if (ut->clearing()) {
  58                 return;
  59         }
  60
  61         ut->remove_command (c);
  62
  63         if (ut->empty()) {
  64                 delete ut;
  65         }
  66 }
  67
  68 UndoTransaction&
  69 UndoTransaction::operator= (const UndoTransaction& rhs)
  70 {
  71         if (this == &rhs) return *this;
  72         _name = rhs._name;
  73         clear ();
  74         actions.insert(actions.end(),rhs.actions.begin(),rhs.actions.end());
  75         return *this;
  76 }
  77
  78 void
  79 UndoTransaction::add_command (Command *const cmd)
  80 {
  81         /* catch death of command (e.g. caused by death of object to
  82            which it refers. command_death() is a normal static function
  83            so there is no need to manage this connection.
  84          */
  85
  86         cmd->DropReferences.connect_same_thread (*this, boost::bind (&command_death, this, cmd));
  87         actions.push_back (cmd);
  88 }
  89
  90 void
  91 UndoTransaction::remove_command (Command* const action)
  92 {
  93         actions.remove (action);
  94 }
  95
  96 bool
  97 UndoTransaction::empty () const
  98 {
  99         return actions.empty();
 100 }
 101
 102 void
 103 UndoTransaction::clear ()
 104 {
 105         _clearing = true;
 106         for (list<Command*>::iterator i = actions.begin(); i != actions.end(); ++i) {
 107                 delete *i;
 108         }
 109         actions.clear ();
 110         _clearing = false;
 111 }
 112
 113 void
 114 UndoTransaction::operator() ()
 115 {
 116         for (list<Command*>::iterator i = actions.begin(); i != actions.end(); ++i) {
 117                 (*(*i))();
 118         }
 119 }
 120
 121 void
 122 UndoTransaction::undo ()
 123 {
 124         for (list<Command*>::reverse_iterator i = actions.rbegin(); i != actions.rend(); ++i) {
 125                 (*i)->undo();
 126         }
 127 }
 128
 129 void
 130 UndoTransaction::redo ()
 131 {
 132         (*this)();
 133 }
 134
 135 XMLNode &UndoTransaction::get_state()
 136 {
 137     XMLNode *node = new XMLNode ("UndoTransaction");
 138     stringstream ss;
 139     ss << _timestamp.tv_sec;
 140     node->add_property("tv_sec", ss.str());
 141     ss.str("");
 142     ss << _timestamp.tv_usec;
 143     node->add_property("tv_usec", ss.str());
 144     node->add_property("name", _name);
 145
 146     list<Command*>::iterator it;
 147     for (it=actions.begin(); it!=actions.end(); it++)
 148         node->add_child_nocopy((*it)->get_state());
 149
 150     return *node;
 151 }
 152
 153 class UndoRedoSignaller {
 154 public:
 155     UndoRedoSignaller (UndoHistory& uh)
 156             : _history (uh) {
 157             _history.BeginUndoRedo();
 158     }
 159     ~UndoRedoSignaller() {
 160             _history.EndUndoRedo();
 161     }
 162
 163 private:
 164     UndoHistory& _history;
 165 };
 166
 167 UndoHistory::UndoHistory ()
 168 {
 169         _clearing = false;
 170         _depth = 0;
 171 }
 172
 173 void
 174 UndoHistory::set_depth (uint32_t d)
 175 {
 176         UndoTransaction* ut;
 177         uint32_t current_depth = UndoList.size();
 178
 179         _depth = d;
 180
 181         if (d > current_depth) {
 182                 /* not even transactions to meet request */
 183                 return;
 184         }
 185
 186         if (_depth > 0) {
 187
 188                 uint32_t cnt = current_depth - d;
 189
 190                 while (cnt--) {
 191                         ut = UndoList.front();
 192                         UndoList.pop_front ();
 193                         delete ut;
 194                 }
 195         }
 196 }
 197
 198 void
 199 UndoHistory::add (UndoTransaction* const ut)
 200 {
 201         uint32_t current_depth = UndoList.size();
 202
 203         ut->DropReferences.connect_same_thread (*this, boost::bind (&UndoHistory::remove, this, ut));
 204
 205         /* if the current undo history is larger than or equal to the currently
 206            requested depth, then pop off at least 1 element to make space
 207            at the back for new one.
 208         */
 209
 210         if ((_depth > 0) && current_depth && (current_depth >= _depth)) {
 211
 212                 uint32_t cnt = 1 + (current_depth - _depth);
 213
 214                 while (cnt--) {
 215                         UndoTransaction* ut;
 216                         ut = UndoList.front ();
 217                         UndoList.pop_front ();
 218                         delete ut;
 219                 }
 220         }
 221
 222         UndoList.push_back (ut);
 223
 224         /* we are now owners of the transaction and must delete it when finished with it */
 225
 226         Changed (); /* EMIT SIGNAL */
 227 }
 228
 229 void
 230 UndoHistory::remove (UndoTransaction* const ut)
 231 {
 232         if (_clearing) {
 233                 return;
 234         }
 235
 236         UndoList.remove (ut);
 237         RedoList.remove (ut);
 238
 239         Changed (); /* EMIT SIGNAL */
 240 }
 241
 242 /** Undo some transactions.
 243  * @param n Number of transactions to undo.
 244  */
 245 void
 246 UndoHistory::undo (unsigned int n)
 247 {
 248         if (n == 0) {
 249                 return;
 250         }
 251
 252         {
 253                 UndoRedoSignaller exception_safe_signaller (*this);
 254
 255                 while (n--) {
 256                         if (UndoList.size() == 0) {
 257                                 return;
 258                         }
 259                         UndoTransaction* ut = UndoList.back ();
 260                         UndoList.pop_back ();
 261                         ut->undo ();
 262                         RedoList.push_back (ut);
 263                 }
 264         }
 265
 266         Changed (); /* EMIT SIGNAL */
 267 }
 268
 269 void
 270 UndoHistory::redo (unsigned int n)
 271 {
 272         if (n == 0) {
 273                 return;
 274         }
 275
 276         {
 277                 UndoRedoSignaller exception_safe_signaller (*this);
 278
 279                 while (n--) {
 280                         if (RedoList.size() == 0) {
 281                                 return;
 282                         }
 283                         UndoTransaction* ut = RedoList.back ();
 284                         RedoList.pop_back ();
 285                         ut->redo ();
 286                         UndoList.push_back (ut);
 287                 }
 288         }
 289
 290         Changed (); /* EMIT SIGNAL */
 291 }
 292
 293 void
 294 UndoHistory::clear_redo ()
 295 {
 296         _clearing = true;
 297         RedoList.clear ();
 298         _clearing = false;
 299
 300         Changed (); /* EMIT SIGNAL */
 301
 302 }
 303
 304 void
 305 UndoHistory::clear_undo ()
 306 {
 307         _clearing = true;
 308         UndoList.clear ();
 309         _clearing = false;
 310
 311         Changed (); /* EMIT SIGNAL */
 312 }
 313
 314 void
 315 UndoHistory::clear ()
 316 {
 317         clear_undo ();
 318         clear_redo ();
 319
 320         Changed (); /* EMIT SIGNAL */
 321 }
 322
 323 XMLNode&
 324 UndoHistory::get_state (int32_t depth)
 325 {
 326     XMLNode *node = new XMLNode ("UndoHistory");
 327
 328     if (depth == 0) {
 329
 330             return (*node);
 331
 332     } else if (depth < 0) {
 333
 334             /* everything */
 335
 336             for (list<UndoTransaction*>::iterator it = UndoList.begin(); it != UndoList.end(); ++it) {
 337                     node->add_child_nocopy((*it)->get_state());
 338             }
 339
 340     } else {
 341
 342             /* just the last "depth" transactions */
 343
 344             list<UndoTransaction*> in_order;
 345
 346             for (list<UndoTransaction*>::reverse_iterator it = UndoList.rbegin(); it != UndoList.rend() && depth; ++it, depth--) {
 347                     in_order.push_front (*it);
 348             }
 349
 350             for (list<UndoTransaction*>::iterator it = in_order.begin(); it != in_order.end(); it++) {
 351                     node->add_child_nocopy((*it)->get_state());
 352             }
 353     }
 354
 355     return *node;
 356 }
 357
 358