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