Chris@16: // Copyright 2008 Christophe Henry
Chris@16: // henry UNDERSCORE christophe AT hotmail DOT com
Chris@16: // This is an extended version of the state machine available in the boost::mpl library
Chris@16: // Distributed under the same license as the original.
Chris@16: // Copyright for the original version:
Chris@16: // Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed
Chris@16: // under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_MSM_BACK_HISTORY_POLICIES_H
Chris@16: #define BOOST_MSM_BACK_HISTORY_POLICIES_H
Chris@16: 
Chris@16: #include <boost/mpl/contains.hpp>
Chris@16: 
Chris@16: namespace boost { namespace msm { namespace back
Chris@16: {
Chris@16: 
Chris@16: // policy classes
Chris@16: 
Chris@16: // Default: no history used
Chris@16: template <int NumberOfRegions>
Chris@16: class NoHistoryImpl
Chris@16: {
Chris@16: public:
Chris@16:     NoHistoryImpl(){}
Chris@16:     ~NoHistoryImpl(){}
Chris@16:     void set_initial_states(int* const initial_states)
Chris@16:     {
Chris@16:         for (int i=0;i<NumberOfRegions;++i)
Chris@16:             m_initialStates[i] = initial_states[i];
Chris@16:     }
Chris@16:     void history_exit(int* const )
Chris@16:     {
Chris@16:         // ignore
Chris@16:     }
Chris@16:     // returns the state where the state machine should be at start
Chris@16:     template <class Event>
Chris@16:     const int* history_entry(Event const& )
Chris@16:     {
Chris@16:         // always come back to the original state
Chris@16:         return m_initialStates;
Chris@16:     }
Chris@16:     NoHistoryImpl<NumberOfRegions>& operator=(NoHistoryImpl<NumberOfRegions> const& rhs)
Chris@16:     {
Chris@16:          for (int i=0; i<NumberOfRegions;++i)
Chris@16:          {
Chris@16:              m_initialStates[i] = rhs.m_initialStates[i];
Chris@16:          }
Chris@16:          return *this;
Chris@16:     }
Chris@101:     // this policy deletes all waiting deferred events
Chris@101:     template <class Event>
Chris@101:     bool process_deferred_events(Event const&)const
Chris@101:     {
Chris@101:         return false;
Chris@101:     }
Chris@16:     template<class Archive>
Chris@16:     void serialize(Archive & ar, const unsigned int)
Chris@16:     {
Chris@16:         ar & m_initialStates;
Chris@16:     }
Chris@16: private:
Chris@16:     int m_initialStates[NumberOfRegions];
Chris@16: };
Chris@16: 
Chris@16: // not UML standard. Always activates history, no matter which event generated the transition
Chris@16: template <int NumberOfRegions>
Chris@16: class AlwaysHistoryImpl
Chris@16: {
Chris@16: public:
Chris@16:     AlwaysHistoryImpl(){}
Chris@16:     ~AlwaysHistoryImpl(){}
Chris@16:     void set_initial_states(int* const initial_states)
Chris@16:     {
Chris@16:         for (int i=0;i<NumberOfRegions;++i)
Chris@16:             m_initialStates[i] = initial_states[i];
Chris@16:     }
Chris@16:     void history_exit(int* const current_states)
Chris@16:     {
Chris@16:         for (int i=0;i<NumberOfRegions;++i)
Chris@16:             m_initialStates[i] = current_states[i];
Chris@16:     }
Chris@16:     // returns the state where the state machine should be at start
Chris@16:     template <class Event>
Chris@16:     const int* history_entry(Event const& )
Chris@16:     {
Chris@16:         // always load back the last active state
Chris@16:         return m_initialStates;
Chris@16:     }
Chris@16:     AlwaysHistoryImpl<NumberOfRegions>& operator=(AlwaysHistoryImpl<NumberOfRegions> const& rhs)
Chris@16:     {
Chris@16:          for (int i=0; i<NumberOfRegions;++i)
Chris@16:          {
Chris@16:              m_initialStates[i] = rhs.m_initialStates[i];
Chris@16:          }
Chris@16:          return *this;
Chris@16:     }
Chris@101:     // the history policy keeps all deferred events until next reentry
Chris@101:     template <class Event>
Chris@101:     bool process_deferred_events(Event const&)const
Chris@101:     {
Chris@101:         return true;
Chris@101:     }
Chris@101: 
Chris@16:     template<class Archive>
Chris@16:     void serialize(Archive & ar, const unsigned int)
Chris@16:     {
Chris@16:         ar & m_initialStates;
Chris@16:     }
Chris@16: private:
Chris@16:     int m_initialStates[NumberOfRegions];
Chris@16: };
Chris@16: 
Chris@16: // UML Shallow history. For deep history, just use this policy for all the contained state machines
Chris@16: template <class Events,int NumberOfRegions>
Chris@16: class ShallowHistoryImpl
Chris@16: {
Chris@16: public:
Chris@16:     ShallowHistoryImpl(){}
Chris@16:     ~ShallowHistoryImpl(){}
Chris@16:     void set_initial_states(int* const initial_states)
Chris@16:     {
Chris@16:         for (int i=0;i<NumberOfRegions;++i)
Chris@16:         {
Chris@16:             m_currentStates[i] = initial_states[i];
Chris@16:             m_initialStates[i] = initial_states[i];
Chris@16:         }
Chris@16:     }
Chris@16:     void history_exit(int* const current_states)
Chris@16:     {
Chris@16:         for (int i=0;i<NumberOfRegions;++i)
Chris@16:             m_currentStates[i] = current_states[i];
Chris@16:     }
Chris@16:     // returns the state where the state machine should be at start
Chris@16:     template <class Event>
Chris@16:     const int* history_entry(Event const&)
Chris@16:     {
Chris@16:         if ( ::boost::mpl::contains<Events,Event>::value)
Chris@16:         {
Chris@16:             return m_currentStates;
Chris@16:         }
Chris@16:         // not one of our events, no history
Chris@16:         return m_initialStates;
Chris@16:     }
Chris@16:     ShallowHistoryImpl<Events,NumberOfRegions>& operator=(ShallowHistoryImpl<Events,NumberOfRegions> const& rhs)
Chris@16:     {
Chris@16:          for (int i=0; i<NumberOfRegions;++i)
Chris@16:          {
Chris@16:              m_initialStates[i] = rhs.m_initialStates[i];
Chris@16:              m_currentStates[i] = rhs.m_currentStates[i];
Chris@16:          }
Chris@16:          return *this;
Chris@16:     }
Chris@101:     // the history policy keeps deferred events until next reentry if coming from our history event
Chris@101:     template <class Event>
Chris@101:     bool process_deferred_events(Event const&)const
Chris@101:     {
Chris@101:         return ::boost::mpl::contains<Events,Event>::value;
Chris@101:     }
Chris@16:     template<class Archive>
Chris@16:     void serialize(Archive & ar, const unsigned int)
Chris@16:     {
Chris@16:         ar & m_initialStates;
Chris@16:         ar & m_currentStates;
Chris@16:     }
Chris@16: private:
Chris@16:     int m_initialStates[NumberOfRegions];
Chris@16:     int m_currentStates[NumberOfRegions];
Chris@16: };
Chris@16: 
Chris@16: struct NoHistory
Chris@16: {
Chris@16:     typedef int history_policy;
Chris@16:     template <int NumberOfRegions>
Chris@16:     struct apply
Chris@16:     {
Chris@16:         typedef NoHistoryImpl<NumberOfRegions> type;
Chris@16:     };
Chris@16: };
Chris@16: struct AlwaysHistory
Chris@16: {
Chris@16:     typedef int history_policy;
Chris@16:     template <int NumberOfRegions>
Chris@16:     struct apply
Chris@16:     {
Chris@16:         typedef AlwaysHistoryImpl<NumberOfRegions> type;
Chris@16:     };
Chris@16: };
Chris@16: template <class Events>
Chris@16: struct ShallowHistory
Chris@16: {
Chris@16:     typedef int history_policy;
Chris@16:     template <int NumberOfRegions>
Chris@16:     struct apply
Chris@16:     {
Chris@16:         typedef ShallowHistoryImpl<Events,NumberOfRegions> type;
Chris@16:     };
Chris@16: };
Chris@16: } } }//boost::msm::back
Chris@16: #endif //BOOST_MSM_BACK_HISTORY_POLICIES_H