| // Copyright 2010 Christophe Henry |
| // henry UNDERSCORE christophe AT hotmail DOT com |
| // This is an extended version of the state machine available in the boost::mpl library |
| // Distributed under the same license as the original. |
| // Copyright for the original version: |
| // Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed |
| // under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| |
| #include <iostream> |
| // back-end |
| #include <boost/msm/back/state_machine.hpp> |
| //front-end |
| #include <boost/msm/front/state_machine_def.hpp> |
| // functors |
| #include <boost/msm/front/functor_row.hpp> |
| #include <boost/msm/front/euml/common.hpp> |
| |
| namespace msm = boost::msm; |
| namespace mpl = boost::mpl; |
| using namespace boost::msm::front; |
| |
| namespace |
| { |
| // events |
| struct event1 {}; |
| |
| |
| // front-end: define the FSM structure |
| struct my_machine_ : public msm::front::state_machine_def<my_machine_> |
| { |
| // The list of FSM states |
| struct State1 : public msm::front::state<> |
| { |
| // every (optional) entry/exit methods get the event passed. |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: State1" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: State1" << std::endl;} |
| }; |
| struct State2 : public msm::front::state<> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const& ,FSM&) {std::cout << "entering: State2" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: State2" << std::endl;} |
| }; |
| |
| struct State3 : public msm::front::state<> |
| { |
| // when stopped, the CD is loaded |
| template <class Event,class FSM> |
| void on_entry(Event const& ,FSM&) {std::cout << "entering: State3" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: State3" << std::endl;} |
| }; |
| |
| struct State4 : public msm::front::state<> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: State4" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: State4" << std::endl;} |
| }; |
| |
| // the initial state of the player SM. Must be defined |
| typedef State1 initial_state; |
| |
| // transition actions |
| struct State2ToState3 |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| std::cout << "my_machine::State2ToState3" << std::endl; |
| } |
| }; |
| struct State3ToState4 |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| std::cout << "my_machine::State3ToState4" << std::endl; |
| } |
| }; |
| // guard conditions |
| struct always_true |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| bool operator()(EVT const& evt,FSM& fsm,SourceState& src,TargetState& tgt) |
| { |
| std::cout << "always_true" << std::endl; |
| return true; |
| } |
| }; |
| struct always_false |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| bool operator()(EVT const& evt,FSM& fsm,SourceState& src,TargetState& tgt) |
| { |
| std::cout << "always_false" << std::endl; |
| return true; |
| } |
| }; |
| |
| typedef my_machine_ p; // makes transition table cleaner |
| |
| // Transition table for player |
| struct transition_table : mpl::vector< |
| // Start Event Next Action Guard |
| // +---------+-------------+---------+---------------------+----------------------+ |
| Row < State1 , none , State2 >, |
| Row < State2 , none , State3 , State2ToState3 >, |
| Row < State3 , none , State4 , none , always_false >, |
| // +---------+-------------+---------+---------------------+----------------------+ |
| Row < State3 , none , State4 , State3ToState4 , always_true >, |
| Row < State4 , event1 , State1 > |
| // +---------+-------------+---------+---------------------+----------------------+ |
| > {}; |
| // Replaces the default no-transition response. |
| template <class FSM,class Event> |
| void no_transition(Event const& e, FSM&,int state) |
| { |
| std::cout << "no transition from state " << state |
| << " on event " << typeid(e).name() << std::endl; |
| } |
| }; |
| // Pick a back-end |
| typedef msm::back::state_machine<my_machine_> my_machine; |
| |
| // |
| // Testing utilities. |
| // |
| static char const* const state_names[] = { "State1", "State2", "State3", "State4" }; |
| void pstate(my_machine const& p) |
| { |
| std::cout << " -> " << state_names[p.current_state()[0]] << std::endl; |
| } |
| |
| void test() |
| { |
| my_machine p; |
| |
| // needed to start the highest-level SM. This will call on_entry and mark the start of the SM |
| // in this case it will also immediately trigger all anonymous transitions |
| p.start(); |
| // this event will bring us back to the initial state and thus, a new "loop" will be started |
| p.process_event(event1()); |
| |
| } |
| } |
| |
| int main() |
| { |
| test(); |
| return 0; |
| } |