[946] | 1 | /* -*- C++ -*- |
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[1038] | 2 | * src/lemon/notifier.h - Part of LEMON, a generic C++ optimization library |
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[946] | 3 | * |
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[1164] | 4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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[946] | 5 | * (Egervary Combinatorial Optimization Research Group, EGRES). |
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| 6 | * |
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| 7 | * Permission to use, modify and distribute this software is granted |
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| 8 | * provided that this copyright notice appears in all copies. For |
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| 9 | * precise terms see the accompanying LICENSE file. |
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| 10 | * |
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| 11 | * This software is provided "AS IS" with no warranty of any kind, |
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| 12 | * express or implied, and with no claim as to its suitability for any |
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| 13 | * purpose. |
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| 14 | * |
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| 15 | */ |
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| 16 | |
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| 17 | #ifndef LEMON_ALTERATION_OBSERVER_REGISTRY_H |
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| 18 | #define LEMON_ALTERATION_OBSERVER_REGISTRY_H |
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| 19 | |
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| 20 | #include <vector> |
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| 21 | #include <algorithm> |
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| 22 | |
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| 23 | ///\ingroup graphmaps |
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| 24 | ///\file |
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| 25 | ///\brief Observer registry for graph alteration observers. |
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| 26 | |
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| 27 | using namespace std; |
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| 28 | |
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| 29 | namespace lemon { |
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| 30 | |
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| 31 | /// \addtogroup graphmaps |
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| 32 | /// @{ |
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| 33 | |
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| 34 | /// Registry class to register objects observes alterations in the graph. |
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| 35 | |
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| 36 | /// This class is a registry for the objects which observe the |
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| 37 | /// alterations in a container. The alteration observers can be attached |
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| 38 | /// to and detached from the registry. The observers have to inherit |
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[1038] | 39 | /// from the \ref AlterationNotifier::ObserverBase and override |
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[946] | 40 | /// the virtual functions in that. |
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| 41 | /// |
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| 42 | /// The most important application of the alteration observing is the |
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| 43 | /// dynamic map implementation when the observers are observing the |
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| 44 | /// alterations in the graph. |
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| 45 | /// |
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| 46 | /// \param _Item The item type what the observers are observing, usually |
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| 47 | /// edge or node. |
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| 48 | /// |
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| 49 | /// \author Balazs Dezso |
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| 50 | |
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| 51 | template <typename _Item> |
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[1038] | 52 | class AlterationNotifier { |
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[946] | 53 | public: |
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| 54 | typedef _Item Item; |
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| 55 | |
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| 56 | /// ObserverBase is the base class for the observers. |
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| 57 | |
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| 58 | /// ObserverBase is the abstract base class for the observers. |
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| 59 | /// It will be notified about an item was inserted into or |
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| 60 | /// erased from the graph. |
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| 61 | /// |
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| 62 | /// The observer interface contains some pure virtual functions |
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| 63 | /// to override. The add() and erase() functions are |
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| 64 | /// to notify the oberver when one item is added or |
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| 65 | /// erased. |
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| 66 | /// |
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| 67 | /// The build() and clear() members are to notify the observer |
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[1204] | 68 | /// about the container is built from an empty container or |
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[946] | 69 | /// is cleared to an empty container. |
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| 70 | /// |
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| 71 | /// \author Balazs Dezso |
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| 72 | |
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| 73 | class ObserverBase { |
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| 74 | protected: |
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[1038] | 75 | typedef AlterationNotifier Registry; |
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[946] | 76 | |
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[1038] | 77 | friend class AlterationNotifier; |
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[946] | 78 | |
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| 79 | /// Default constructor. |
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| 80 | |
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| 81 | /// Default constructor for ObserverBase. |
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| 82 | /// |
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| 83 | ObserverBase() : registry(0) {} |
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| 84 | |
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| 85 | virtual ~ObserverBase() {} |
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| 86 | |
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[1038] | 87 | /// Attaches the observer into an AlterationNotifier. |
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[946] | 88 | |
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[1038] | 89 | /// This member attaches the observer into an AlterationNotifier. |
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[946] | 90 | /// |
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[1038] | 91 | void attach(AlterationNotifier& r) { |
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[946] | 92 | registry = &r; |
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| 93 | registry->attach(*this); |
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| 94 | } |
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| 95 | |
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[1038] | 96 | /// Detaches the observer into an AlterationNotifier. |
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[946] | 97 | |
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[1038] | 98 | /// This member detaches the observer from an AlterationNotifier. |
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[946] | 99 | /// |
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| 100 | void detach() { |
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| 101 | if (registry) { |
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| 102 | registry->detach(*this); |
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| 103 | } |
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| 104 | } |
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| 105 | |
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| 106 | |
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| 107 | /// Gives back a pointer to the registry what the map attached into. |
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| 108 | |
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| 109 | /// This function gives back a pointer to the registry what the map |
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| 110 | /// attached into. |
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| 111 | /// |
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| 112 | Registry* getRegistry() const { return const_cast<Registry*>(registry); } |
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| 113 | |
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| 114 | /// Gives back true when the observer is attached into a registry. |
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| 115 | bool attached() const { return registry != 0; } |
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| 116 | |
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| 117 | private: |
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| 118 | |
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| 119 | ObserverBase(const ObserverBase& copy); |
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| 120 | ObserverBase& operator=(const ObserverBase& copy); |
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| 121 | |
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| 122 | protected: |
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| 123 | |
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| 124 | Registry* registry; |
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| 125 | int registry_index; |
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| 126 | |
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| 127 | public: |
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| 128 | |
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| 129 | /// \brief The member function to notificate the observer about an |
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| 130 | /// item is added to the container. |
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| 131 | /// |
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| 132 | /// The add() member function notificates the observer about an item |
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| 133 | /// is added to the container. It have to be overrided in the |
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| 134 | /// subclasses. |
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| 135 | |
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| 136 | virtual void add(const Item&) = 0; |
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| 137 | |
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| 138 | |
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| 139 | /// \brief The member function to notificate the observer about an |
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| 140 | /// item is erased from the container. |
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| 141 | /// |
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| 142 | /// The erase() member function notificates the observer about an |
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| 143 | /// item is erased from the container. It have to be overrided in |
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| 144 | /// the subclasses. |
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| 145 | |
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| 146 | virtual void erase(const Item&) = 0; |
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| 147 | |
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| 148 | /// \brief The member function to notificate the observer about the |
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[1204] | 149 | /// container is built. |
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[946] | 150 | /// |
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| 151 | /// The build() member function notificates the observer about the |
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[1204] | 152 | /// container is built from an empty container. It have to be |
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[946] | 153 | /// overrided in the subclasses. |
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| 154 | |
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| 155 | virtual void build() = 0; |
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| 156 | |
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| 157 | /// \brief The member function to notificate the observer about all |
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| 158 | /// items are erased from the container. |
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| 159 | /// |
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| 160 | /// The clear() member function notificates the observer about all |
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| 161 | /// items are erased from the container. It have to be overrided in |
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| 162 | /// the subclasses. |
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| 163 | |
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| 164 | virtual void clear() = 0; |
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| 165 | |
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| 166 | }; |
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| 167 | |
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| 168 | protected: |
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| 169 | |
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| 170 | |
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| 171 | typedef std::vector<ObserverBase*> Container; |
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| 172 | |
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| 173 | Container container; |
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| 174 | |
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| 175 | |
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| 176 | public: |
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| 177 | |
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| 178 | /// Default constructor. |
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| 179 | |
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| 180 | /// |
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[1038] | 181 | /// The default constructor of the AlterationNotifier. |
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[946] | 182 | /// It creates an empty registry. |
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[1038] | 183 | AlterationNotifier() {} |
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[946] | 184 | |
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[1038] | 185 | /// Copy Constructor of the AlterationNotifier. |
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[946] | 186 | |
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[1038] | 187 | /// Copy constructor of the AlterationNotifier. |
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[946] | 188 | /// It creates only an empty registry because the copiable |
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| 189 | /// registry's observers have to be registered still into that registry. |
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[1039] | 190 | AlterationNotifier(const AlterationNotifier&) {} |
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[946] | 191 | |
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| 192 | /// Assign operator. |
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| 193 | |
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[1038] | 194 | /// Assign operator for the AlterationNotifier. |
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[1040] | 195 | /// It makes the notifier only empty because the copiable |
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| 196 | /// notifier's observers have to be registered still into that registry. |
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[1039] | 197 | AlterationNotifier& operator=(const AlterationNotifier&) { |
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[946] | 198 | typename Container::iterator it; |
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| 199 | for (it = container.begin(); it != container.end(); ++it) { |
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| 200 | (*it)->registry = 0; |
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| 201 | } |
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| 202 | } |
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| 203 | |
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| 204 | /// Destructor. |
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| 205 | |
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[1038] | 206 | /// Destructor of the AlterationNotifier. |
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[946] | 207 | /// |
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[1038] | 208 | ~AlterationNotifier() { |
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[946] | 209 | typename Container::iterator it; |
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| 210 | for (it = container.begin(); it != container.end(); ++it) { |
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| 211 | (*it)->registry = 0; |
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| 212 | } |
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| 213 | } |
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| 214 | |
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| 215 | |
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| 216 | protected: |
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| 217 | |
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| 218 | void attach(ObserverBase& observer) { |
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| 219 | container.push_back(&observer); |
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| 220 | observer.registry = this; |
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| 221 | observer.registry_index = container.size()-1; |
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| 222 | } |
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| 223 | |
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| 224 | void detach(ObserverBase& base) { |
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| 225 | container.back()->registry_index = base.registry_index; |
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| 226 | container[base.registry_index] = container.back(); |
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| 227 | container.pop_back(); |
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| 228 | base.registry = 0; |
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| 229 | } |
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| 230 | |
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| 231 | public: |
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| 232 | |
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| 233 | /// Notifies all the registered observers about an Item added to the container. |
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| 234 | |
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| 235 | /// It notifies all the registered observers about an Item added to the container. |
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| 236 | /// |
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| 237 | void add(const Item& key) { |
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| 238 | typename Container::iterator it; |
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| 239 | for (it = container.begin(); it != container.end(); ++it) { |
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| 240 | (*it)->add(key); |
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| 241 | } |
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| 242 | } |
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| 243 | |
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| 244 | /// Notifies all the registered observers about an Item erased from the container. |
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| 245 | |
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| 246 | /// It notifies all the registered observers about an Item erased from the container. |
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| 247 | /// |
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| 248 | void erase(const Item& key) { |
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| 249 | typename Container::iterator it; |
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| 250 | for (it = container.begin(); it != container.end(); ++it) { |
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| 251 | (*it)->erase(key); |
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| 252 | } |
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| 253 | } |
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| 254 | |
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| 255 | |
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[1204] | 256 | /// Notifies all the registered observers about the container is built. |
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[946] | 257 | |
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[1204] | 258 | /// Notifies all the registered observers about the container is built |
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[946] | 259 | /// from an empty container. |
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| 260 | void build() { |
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| 261 | typename Container::iterator it; |
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| 262 | for (it = container.begin(); it != container.end(); ++it) { |
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| 263 | (*it)->build(); |
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| 264 | } |
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| 265 | } |
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| 266 | |
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| 267 | |
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| 268 | /// Notifies all the registered observers about all Items are erased. |
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| 269 | |
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| 270 | /// Notifies all the registered observers about all Items are erased |
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| 271 | /// from the container. |
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| 272 | void clear() { |
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| 273 | typename Container::iterator it; |
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| 274 | for (it = container.begin(); it != container.end(); ++it) { |
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| 275 | (*it)->clear(); |
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| 276 | } |
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| 277 | } |
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| 278 | }; |
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| 279 | |
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| 280 | |
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[962] | 281 | /// \brief Class to extend a graph with the functionality of alteration |
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| 282 | /// observing. |
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| 283 | /// |
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| 284 | /// AlterableGraphExtender extends the _Base graphs functionality with |
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| 285 | /// the possibility of alteration observing. It defines two observer |
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| 286 | /// registrys for the nodes and mapes. |
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| 287 | /// |
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| 288 | /// \todo Document what "alteration observing" is. And probably find a |
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| 289 | /// better (shorter) name. |
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[946] | 290 | /// |
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| 291 | /// \param _Base is the base class to extend. |
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| 292 | /// |
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| 293 | /// \pre _Base is conform to the BaseGraphComponent concept. |
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| 294 | /// |
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[962] | 295 | /// \post AlterableGraphExtender<_Base> is conform to the |
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| 296 | /// AlterableGraphComponent concept. |
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[946] | 297 | /// |
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| 298 | /// \author Balazs Dezso |
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| 299 | |
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| 300 | template <typename _Base> |
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| 301 | class AlterableGraphExtender : public _Base { |
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| 302 | public: |
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| 303 | |
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| 304 | typedef AlterableGraphExtender Graph; |
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| 305 | typedef _Base Parent; |
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| 306 | |
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| 307 | typedef typename Parent::Node Node; |
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| 308 | typedef typename Parent::Edge Edge; |
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| 309 | |
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[962] | 310 | /// The edge observer registry. |
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[1039] | 311 | typedef AlterationNotifier<Edge> EdgeNotifier; |
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[946] | 312 | /// The node observer registry. |
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[1039] | 313 | typedef AlterationNotifier<Node> NodeNotifier; |
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[946] | 314 | |
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| 315 | |
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| 316 | protected: |
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| 317 | |
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[1040] | 318 | mutable EdgeNotifier edge_notifier; |
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[946] | 319 | |
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[1040] | 320 | mutable NodeNotifier node_notifier; |
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[946] | 321 | |
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| 322 | public: |
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| 323 | |
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[1134] | 324 | /// \brief Gives back the edge alteration notifier. |
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| 325 | /// |
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| 326 | /// Gives back the edge alteration notifier. |
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| 327 | EdgeNotifier& getNotifier(Edge) const { |
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[1040] | 328 | return edge_notifier; |
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[946] | 329 | } |
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| 330 | |
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[1134] | 331 | /// \brief Gives back the node alteration notifier. |
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| 332 | /// |
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| 333 | /// Gives back the node alteration notifier. |
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| 334 | NodeNotifier& getNotifier(Node) const { |
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[1040] | 335 | return node_notifier; |
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[946] | 336 | } |
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| 337 | |
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| 338 | ~AlterableGraphExtender() { |
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[1040] | 339 | node_notifier.clear(); |
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| 340 | edge_notifier.clear(); |
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[946] | 341 | } |
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| 342 | |
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| 343 | }; |
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| 344 | |
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[962] | 345 | /// \brief Class to extend an undirected graph with the functionality of |
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| 346 | /// alteration observing. |
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| 347 | /// |
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| 348 | /// \todo Document. |
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| 349 | /// |
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| 350 | /// \sa AlterableGraphExtender |
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| 351 | /// |
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| 352 | /// \bug This should be done some other way. Possibilities: template |
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| 353 | /// specialization (not very easy, if at all possible); some kind of |
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| 354 | /// enable_if boost technique? |
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| 355 | |
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| 356 | template <typename _Base> |
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| 357 | class AlterableUndirGraphExtender |
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| 358 | : public AlterableGraphExtender<_Base> { |
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| 359 | public: |
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| 360 | |
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| 361 | typedef AlterableUndirGraphExtender Graph; |
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| 362 | typedef AlterableGraphExtender<_Base> Parent; |
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| 363 | |
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| 364 | typedef typename Parent::UndirEdge UndirEdge; |
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| 365 | |
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| 366 | /// The edge observer registry. |
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[1039] | 367 | typedef AlterationNotifier<UndirEdge> UndirEdgeNotifier; |
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[962] | 368 | |
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| 369 | protected: |
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| 370 | |
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[1040] | 371 | mutable UndirEdgeNotifier undir_edge_notifier; |
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[962] | 372 | |
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[1022] | 373 | public: |
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| 374 | |
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[1038] | 375 | using Parent::getNotifier; |
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[1039] | 376 | UndirEdgeNotifier& getNotifier(UndirEdge) const { |
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[1040] | 377 | return undir_edge_notifier; |
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[962] | 378 | } |
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| 379 | |
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| 380 | ~AlterableUndirGraphExtender() { |
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[1040] | 381 | undir_edge_notifier.clear(); |
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[962] | 382 | } |
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| 383 | }; |
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[946] | 384 | |
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| 385 | /// @} |
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| 386 | |
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| 387 | |
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| 388 | } |
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| 389 | |
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| 390 | #endif |
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