1.1 --- a/src/lemon/smart_graph.h	Fri Nov 19 18:17:25 2004 +0000
     1.2 +++ b/src/lemon/smart_graph.h	Sat Nov 20 10:19:06 2004 +0000
     1.3 @@ -260,50 +260,11 @@
     1.4        return _findEdge(u,v,prev);
     1.5      }
     1.6      
     1.7 -    ///Internal data structure to store snapshots
     1.8 -    
     1.9 -    ///\ingroup graphs
    1.10 -    ///\sa makeSnapShot()
    1.11 -    ///\sa rollBack()
    1.12 -    struct SnapShot 
    1.13 -    {
    1.14 -      unsigned int node_num;
    1.15 -      unsigned int edge_num;
    1.16 -    };
    1.17 -    
    1.18 -    ///Make a snapshot of the graph.
    1.19 +    class SnapShot;
    1.20 +    friend class SnapShot;
    1.21  
    1.22 -    ///Make a snapshot of the graph.
    1.23 -    ///
    1.24 -    ///The newly added nodes and edges can be removed using the
    1.25 -    ///rollBack() function.
    1.26 -    ///
    1.27 -    ///\return An stucture SnapShot describing the pesent state of the
    1.28 -    ///graph.
    1.29 -    ///\note After you rolled back to a state, you cannot roll "back" to
    1.30 -    ///a later state, in other word you cannot add again the edges deleted
    1.31 -    ///by rollBack().
    1.32 -    ///\todo This function might be called saveState() or getState().
    1.33 -    SnapShot makeSnapShot() 
    1.34 -    {
    1.35 -      SnapShot s;
    1.36 -      s.node_num=nodes.size();
    1.37 -      s.edge_num=edges.size();
    1.38 -      return s;
    1.39 -    }
    1.40 -    
    1.41 -    ///Undo the changes until a snapshot.
    1.42 -
    1.43 -    ///Undo the changes until a snapshot created by makeSnapShot().
    1.44 -    ///
    1.45 -    ///\param s an internal stucture given back by makeSnapShot()
    1.46 -    ///\note After you rolled back to a state, you cannot "roll forward" to
    1.47 -    ///a later state, in other word you cannot add again the edges deleted
    1.48 -    ///by rollBack().
    1.49 -    ///
    1.50 -    ///\todo This function might be called undo().
    1.51 -    
    1.52 -    void rollBack(const SnapShot &s)
    1.53 +  protected:
    1.54 +    void restoreSnapShot(const SnapShot &s)
    1.55      {
    1.56        while(s.edge_num>edges.size()) {
    1.57  	edge_observers.erase(Edge(edges.size()-1));
    1.58 @@ -316,7 +277,73 @@
    1.59  	node_observers.erase(Node(nodes.size()-1));
    1.60  	nodes.pop_back();
    1.61        }
    1.62 -    }
    1.63 +    }    
    1.64 +
    1.65 +  public:
    1.66 +    ///Class to make a snapshot of the graph and to restrore to it later.
    1.67 +
    1.68 +    ///Class to make a snapshot of the graph and to restrore to it later.
    1.69 +    ///
    1.70 +    ///The newly added nodes and edges can be removed using the
    1.71 +    ///restore() function.
    1.72 +    ///\note After you restore a state, you cannot restore
    1.73 +    ///a later state, in other word you cannot add again the edges deleted
    1.74 +    ///by restore() using another SnapShot instance.
    1.75 +    ///
    1.76 +    ///\ingroup graphs
    1.77 +    class SnapShot 
    1.78 +    {
    1.79 +      SmartGraph *g;
    1.80 +    protected:
    1.81 +      friend class SmartGraph;
    1.82 +      unsigned int node_num;
    1.83 +      unsigned int edge_num;
    1.84 +    public:
    1.85 +      ///Default constructur.
    1.86 +      
    1.87 +      ///Default constructur.
    1.88 +      ///To actually make a snapshot you must call save().
    1.89 +      ///
    1.90 +      SnapShot() : g(0) {}
    1.91 +      ///Constructor that immediately makes a snapshot
    1.92 +      
    1.93 +      ///This constructor immediately makes a snapshot of the graph.
    1.94 +      ///\param _g The graph we make a snapshot of.
    1.95 +      SnapShot(SmartGraph &_g) :g(&_g) {
    1.96 +	node_num=g->nodes.size();
    1.97 +	edge_num=g->edges.size();
    1.98 +      }
    1.99 +
   1.100 +      ///Make a snapshot.
   1.101 +
   1.102 +      ///Make a snapshot of the graph.
   1.103 +      ///
   1.104 +      ///This function can be called more than once. In case of a repeated
   1.105 +      ///call, the previous snapshot gets lost.
   1.106 +      ///\param _g The graph we make the snapshot of.
   1.107 +      void save(SmartGraph &_g) 
   1.108 +      {
   1.109 +	g=&_g;
   1.110 +	node_num=g->nodes.size();
   1.111 +	edge_num=g->edges.size();
   1.112 +      }
   1.113 +
   1.114 +      ///Undo the changes until a snapshot.
   1.115 +      
   1.116 +      ///Undo the changes until a snapshot created by save().
   1.117 +      ///
   1.118 +      ///\param s an internal stucture given back by save()
   1.119 +      ///\note After you restored a state, you cannot restore
   1.120 +      ///a later state, in other word you cannot add again the edges deleted
   1.121 +      ///by restore().
   1.122 +      ///
   1.123 +      ///\todo This function might be called undo().
   1.124 +      
   1.125 +      void restore()
   1.126 +      {
   1.127 +	g->restoreSnapShot(*this);
   1.128 +      }
   1.129 +    };
   1.130    };
   1.131    
   1.132    /// @}