src/composite-undo-stack-observer.cpp

   1 /**
   2  * Aggregates undo stack observers for convenient management and triggering in SPDocument
   3  *
   4  * Heavily inspired by Inkscape::XML::CompositeNodeObserver.
   5  *
   6  * Authors:
   7  * David Yip <yipdw@rose-hulman.edu>
   8  *
   9  * Copyright (c) 2005 Authors
  10  *
  11  * Released under GNU GPL, read the file 'COPYING' for more information
  12  */
  13
  14
  15 #include "composite-undo-stack-observer.h"
  16 #include "xml/event.h"
  17
  18 namespace Inkscape {
  19
  20 CompositeUndoStackObserver::CompositeUndoStackObserver() : _iterating(0) { }
  21 CompositeUndoStackObserver::~CompositeUndoStackObserver() { }
  22
  23 void
  24 CompositeUndoStackObserver::add(UndoStackObserver& observer)
  25 {
  26         if (!this->_iterating) {
  27                 this->_active.push_back(UndoStackObserverRecord(observer));
  28         } else {
  29                 this->_pending.push_back(UndoStackObserverRecord(observer));
  30         }
  31 }
  32
  33 void
  34 CompositeUndoStackObserver::remove(UndoStackObserver& observer)
  35 {
  36         if (!this->_iterating) {
  37                 // logical-or operator short-circuits
  38                 this->_remove_one(this->_active, observer) || this->_remove_one(this->_pending, observer);
  39         } else {
  40                 this->_mark_one(this->_active, observer) || this->_mark_one(this->_pending, observer);
  41         }
  42 }
  43
  44 void
  45 CompositeUndoStackObserver::notifyUndoEvent(Event* log)
  46 {
  47         this->_lock();
  48         for(UndoObserverRecordList::iterator i = this->_active.begin(); i != _active.end(); ++i) {
  49                 if (!i->to_remove) {
  50                         i->issueUndo(log);
  51                 }
  52         }
  53         this->_unlock();
  54 }
  55
  56 void
  57 CompositeUndoStackObserver::notifyRedoEvent(Event* log)
  58 {
  59
  60         this->_lock();
  61         for(UndoObserverRecordList::iterator i = this->_active.begin(); i != _active.end(); ++i) {
  62                 if (!i->to_remove) {
  63                         i->issueRedo(log);
  64                 }
  65         }
  66         this->_unlock();
  67 }
  68
  69 void
  70 CompositeUndoStackObserver::notifyUndoCommitEvent(Event* log)
  71 {
  72         this->_lock();
  73         for(UndoObserverRecordList::iterator i = this->_active.begin(); i != _active.end(); ++i) {
  74                 if (!i->to_remove) {
  75                         i->issueUndoCommit(log);
  76                 }
  77         }
  78         this->_unlock();
  79 }
  80
  81 bool
  82 CompositeUndoStackObserver::_remove_one(UndoObserverRecordList& list, UndoStackObserver& o)
  83 {
  84         UndoStackObserverRecord eq_comp(o);
  85
  86         UndoObserverRecordList::iterator i = std::find_if(list.begin(), list.end(), std::bind1st(std::equal_to< UndoStackObserverRecord >(), eq_comp));
  87
  88         if (i != list.end()) {
  89                 list.erase(i);
  90                 return true;
  91         } else {
  92                 return false;
  93         }
  94 }
  95
  96 bool
  97 CompositeUndoStackObserver::_mark_one(UndoObserverRecordList& list, UndoStackObserver& o)
  98 {
  99         UndoStackObserverRecord eq_comp(o);
 100
 101         UndoObserverRecordList::iterator i = std::find_if(list.begin(), list.end(), std::bind1st(std::equal_to< UndoStackObserverRecord >(), eq_comp));
 102
 103         if (i != list.end()) {
 104                 (*i).to_remove = true;
 105                 return true;
 106         } else {
 107                 return false;
 108         }
 109 }
 110
 111 void
 112 CompositeUndoStackObserver::_unlock()
 113 {
 114         if (!--this->_iterating) {
 115                 // Remove marked observers
 116                 UndoObserverRecordList::iterator i = this->_active.begin();
 117                 for(; i != this->_active.begin(); i++) {
 118                         if (i->to_remove) {
 119                                 this->_active.erase(i);
 120                         }
 121                 }
 122
 123                 i = this->_pending.begin();
 124                 for(; i != this->_pending.begin(); i++) {
 125                         if (i->to_remove) {
 126                                 this->_active.erase(i);
 127                         }
 128                 }
 129
 130                 // Merge pending and active
 131                 this->_active.insert(this->_active.end(), this->_pending.begin(), this->_pending.end());
 132                 this->_pending.clear();
 133         }
 134 }
 135
 136 }