libs/pbd/stateful_diff_command.cc

   1 /*
   2     Copyright (C) 2010 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 */
  19
  20 #include <iostream>
  21
  22 #include "pbd/stateful_diff_command.h"
  23 #include "pbd/property_list.h"
  24 #include "pbd/demangle.h"
  25 #include "i18n.h"
  26
  27 using namespace std;
  28 using namespace PBD;
  29
  30 /** Create a new StatefulDiffCommand by examining the changes made to a Stateful
  31  *  since the last time that clear_history was called on it.
  32  *  @param s Stateful object.
  33  */
  34
  35 StatefulDiffCommand::StatefulDiffCommand (boost::shared_ptr<StatefulDestructible> s)
  36         : _object (s)
  37         , _undo (new PropertyList)
  38         , _redo (new PropertyList)
  39 {
  40         s->diff (*_undo, *_redo, this);
  41
  42         /* if the stateful object that this command refers to goes away,
  43            be sure to notify owners of this command.
  44         */
  45
  46         s->DropReferences.connect_same_thread (*this, boost::bind (&Destructible::drop_references, this));
  47 }
  48
  49 StatefulDiffCommand::StatefulDiffCommand (boost::shared_ptr<StatefulDestructible> s, XMLNode const & n)
  50         : _object (s)
  51         , _undo (0)
  52         , _redo (0)
  53 {
  54         const XMLNodeList& children (n.children());
  55
  56         for (XMLNodeList::const_iterator i = children.begin(); i != children.end(); ++i) {
  57                 if ((*i)->name() == X_("Undo")) {
  58                         _undo = s->property_factory (**i);
  59                 } else if ((*i)->name() == X_("Do")) {
  60                         _redo = s->property_factory (**i);
  61                 }
  62         }
  63
  64         assert (_undo != 0);
  65         assert (_redo != 0);
  66
  67         /* if the stateful object that this command refers to goes away,
  68            be sure to notify owners of this command.
  69         */
  70
  71         s->DropReferences.connect_same_thread (*this, boost::bind (&Destructible::drop_references, this));
  72 }
  73
  74 StatefulDiffCommand::~StatefulDiffCommand ()
  75 {
  76         drop_references ();
  77
  78         delete _undo;
  79         delete _redo;
  80 }
  81
  82 void
  83 StatefulDiffCommand::operator() ()
  84 {
  85         boost::shared_ptr<Stateful> s (_object.lock());
  86
  87         if (s) {
  88                 s->set_properties (*_redo);
  89         }
  90 }
  91
  92 void
  93 StatefulDiffCommand::undo ()
  94 {
  95         boost::shared_ptr<Stateful> s (_object.lock());
  96
  97         if (s) {
  98                 std::cerr << "Undoing a stateful diff command\n";
  99                 s->set_properties (*_undo);
 100         }
 101 }
 102
 103 XMLNode&
 104 StatefulDiffCommand::get_state ()
 105 {
 106         boost::shared_ptr<Stateful> s (_object.lock());
 107
 108         if (!s) {
 109                 /* XXX should we throw? */
 110                 return * new XMLNode("");
 111         }
 112
 113         XMLNode* node = new XMLNode (X_("StatefulDiffCommand"));
 114
 115         node->add_property ("obj-id", s->id().to_s());
 116         node->add_property ("type-name", demangled_name (*s.get()));
 117
 118         XMLNode* undo = new XMLNode (X_("Undo"));
 119         XMLNode* redo = new XMLNode (X_("Do"));
 120
 121         _undo->add_history_state (undo);
 122         _redo->add_history_state (redo);
 123
 124         node->add_child_nocopy (*undo);
 125         node->add_child_nocopy (*redo);
 126
 127         return *node;
 128 }