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         _timestamp = rhs._timestamp;
  45         clear ();
  46         actions.insert(actions.end(),rhs.actions.begin(),rhs.actions.end());
  47 }
  48
  49 UndoTransaction::~UndoTransaction ()
  50 {
  51         drop_references ();
  52         clear ();
  53 }
  54
  55 void
  56 command_death (UndoTransaction* ut, Command* c)
  57 {
  58         if (ut->clearing()) {
  59                 return;
  60         }
  61
  62         ut->remove_command (c);
  63
  64         if (ut->empty()) {
  65                 delete ut;
  66         }
  67 }
  68
  69 UndoTransaction&
  70 UndoTransaction::operator= (const UndoTransaction& rhs)
  71 {
  72         if (this == &rhs) return *this;
  73         _name = rhs._name;
  74         clear ();
  75         actions.insert(actions.end(),rhs.actions.begin(),rhs.actions.end());
  76         return *this;
  77 }
  78
  79 void
  80 UndoTransaction::add_command (Command *const cmd)
  81 {
  82         /* catch death of command (e.g. caused by death of object to
  83            which it refers. command_death() is a normal static function
  84            so there is no need to manage this connection.
  85          */
  86
  87         cmd->DropReferences.connect_same_thread (*this, boost::bind (&command_death, this, cmd));
  88         actions.push_back (cmd);
  89 }
  90
  91 void
  92 UndoTransaction::remove_command (Command* const action)
  93 {
  94         actions.remove (action);
  95 }
  96
  97 bool
  98 UndoTransaction::empty () const
  99 {
 100         return actions.empty();
 101 }
 102
 103 void
 104 UndoTransaction::clear ()
 105 {
 106         _clearing = true;
 107         for (list<Command*>::iterator i = actions.begin(); i != actions.end(); ++i) {
 108                 delete *i;
 109         }
 110         actions.clear ();
 111         _clearing = false;
 112 }
 113
 114 void
 115 UndoTransaction::operator() ()
 116 {
 117         for (list<Command*>::iterator i = actions.begin(); i != actions.end(); ++i) {
 118                 (*(*i))();
 119         }
 120 }
 121
 122 void
 123 UndoTransaction::undo ()
 124 {
 125         for (list<Command*>::reverse_iterator i = actions.rbegin(); i != actions.rend(); ++i) {
 126                 (*i)->undo();
 127         }
 128 }
 129
 130 void
 131 UndoTransaction::redo ()
 132 {
 133         (*this)();
 134 }
 135
 136 XMLNode &UndoTransaction::get_state()
 137 {
 138     XMLNode *node = new XMLNode ("UndoTransaction");
 139     stringstream ss;
 140     ss << _timestamp.tv_sec;
 141     node->add_property("tv_sec", ss.str());
 142     ss.str("");
 143     ss << _timestamp.tv_usec;
 144     node->add_property("tv_usec", ss.str());
 145     node->add_property("name", _name);
 146
 147     list<Command*>::iterator it;
 148     for (it=actions.begin(); it!=actions.end(); it++)
 149         node->add_child_nocopy((*it)->get_state());
 150
 151     return *node;
 152 }
 153
 154 class UndoRedoSignaller {
 155 public:
 156     UndoRedoSignaller (UndoHistory& uh)
 157             : _history (uh) {
 158             _history.BeginUndoRedo();
 159     }
 160     ~UndoRedoSignaller() {
 161             _history.EndUndoRedo();
 162     }
 163
 164 private:
 165     UndoHistory& _history;
 166 };
 167
 168 UndoHistory::UndoHistory ()
 169 {
 170         _clearing = false;
 171         _depth = 0;
 172 }
 173
 174 void
 175 UndoHistory::set_depth (uint32_t d)
 176 {
 177         UndoTransaction* ut;
 178         uint32_t current_depth = UndoList.size();
 179
 180         _depth = d;
 181
 182         if (d > current_depth) {
 183                 /* not even transactions to meet request */
 184                 return;
 185         }
 186
 187         if (_depth > 0) {
 188
 189                 uint32_t cnt = current_depth - d;
 190
 191                 while (cnt--) {
 192                         ut = UndoList.front();
 193                         UndoList.pop_front ();
 194                         delete ut;
 195                 }
 196         }
 197 }
 198
 199 void
 200 UndoHistory::add (UndoTransaction* const ut)
 201 {
 202         uint32_t current_depth = UndoList.size();
 203
 204         ut->DropReferences.connect_same_thread (*this, boost::bind (&UndoHistory::remove, this, ut));
 205
 206         /* if the current undo history is larger than or equal to the currently
 207            requested depth, then pop off at least 1 element to make space
 208            at the back for new one.
 209         */
 210
 211         if ((_depth > 0) && current_depth && (current_depth >= _depth)) {
 212
 213                 uint32_t cnt = 1 + (current_depth - _depth);
 214
 215                 while (cnt--) {
 216                         UndoTransaction* ut;
 217                         ut = UndoList.front ();
 218                         UndoList.pop_front ();
 219                         delete ut;
 220                 }
 221         }
 222
 223         UndoList.push_back (ut);
 224
 225         /* we are now owners of the transaction and must delete it when finished with it */
 226
 227         Changed (); /* EMIT SIGNAL */
 228 }
 229
 230 void
 231 UndoHistory::remove (UndoTransaction* const ut)
 232 {
 233         if (_clearing) {
 234                 return;
 235         }
 236
 237         UndoList.remove (ut);
 238         RedoList.remove (ut);
 239
 240         Changed (); /* EMIT SIGNAL */
 241 }
 242
 243 /** Undo some transactions.
 244  * @param n Number of transactions to undo.
 245  */
 246 void
 247 UndoHistory::undo (unsigned int n)
 248 {
 249         if (n == 0) {
 250                 return;
 251         }
 252
 253         {
 254                 UndoRedoSignaller exception_safe_signaller (*this);
 255
 256                 while (n--) {
 257                         if (UndoList.size() == 0) {
 258                                 return;
 259                         }
 260                         UndoTransaction* ut = UndoList.back ();
 261                         UndoList.pop_back ();
 262                         ut->undo ();
 263                         RedoList.push_back (ut);
 264                 }
 265         }
 266
 267         Changed (); /* EMIT SIGNAL */
 268 }
 269
 270 void
 271 UndoHistory::redo (unsigned int n)
 272 {
 273         if (n == 0) {
 274                 return;
 275         }
 276
 277         {
 278                 UndoRedoSignaller exception_safe_signaller (*this);
 279
 280                 while (n--) {
 281                         if (RedoList.size() == 0) {
 282                                 return;
 283                         }
 284                         UndoTransaction* ut = RedoList.back ();
 285                         RedoList.pop_back ();
 286                         ut->redo ();
 287                         UndoList.push_back (ut);
 288                 }
 289         }
 290
 291         Changed (); /* EMIT SIGNAL */
 292 }
 293
 294 void
 295 UndoHistory::clear_redo ()
 296 {
 297         _clearing = true;
 298         for (std::list<UndoTransaction*>::iterator i = RedoList.begin(); i != RedoList.end(); ++i) {
 299                 delete *i;
 300         }
 301         RedoList.clear ();
 302         _clearing = false;
 303
 304         Changed (); /* EMIT SIGNAL */
 305
 306 }
 307
 308 void
 309 UndoHistory::clear_undo ()
 310 {
 311         _clearing = true;
 312         for (std::list<UndoTransaction*>::iterator i = UndoList.begin(); i != UndoList.end(); ++i) {
 313                 delete *i;
 314         }
 315         UndoList.clear ();
 316         _clearing = false;
 317
 318         Changed (); /* EMIT SIGNAL */
 319 }
 320
 321 void
 322 UndoHistory::clear ()
 323 {
 324         clear_undo ();
 325         clear_redo ();
 326
 327         Changed (); /* EMIT SIGNAL */
 328 }
 329
 330 XMLNode&
 331 UndoHistory::get_state (int32_t depth)
 332 {
 333     XMLNode *node = new XMLNode ("UndoHistory");
 334
 335     if (depth == 0) {
 336
 337             return (*node);
 338
 339     } else if (depth < 0) {
 340
 341             /* everything */
 342
 343             for (list<UndoTransaction*>::iterator it = UndoList.begin(); it != UndoList.end(); ++it) {
 344                     node->add_child_nocopy((*it)->get_state());
 345             }
 346
 347     } else {
 348
 349             /* just the last "depth" transactions */
 350
 351             list<UndoTransaction*> in_order;
 352
 353             for (list<UndoTransaction*>::reverse_iterator it = UndoList.rbegin(); it != UndoList.rend() && depth; ++it, depth--) {
 354                     in_order.push_front (*it);
 355             }
 356
 357             for (list<UndoTransaction*>::iterator it = in_order.begin(); it != in_order.end(); it++) {
 358                     node->add_child_nocopy((*it)->get_state());
 359             }
 360     }
 361
 362     return *node;
 363 }
 364
 365