我可以使用boost.statecharts自定义对不同正交区域中多个状态的事件的反应吗？

Question

My use case is similar to this SSCCE. The problem is that if no transition occurs I need to forward the events, which seems unnatural, for them to be processed by the other orthogonal regions. More importantly though in the case I need to transition I can't find a way to allow the event to be reacted to in other regions. How should I restructure to work around this?

I am using boost 1.53 in case this is important.

namespace sc = boost::statechart;
struct Active;
struct Keyboard : sc::state_machine< Keyboard, Active > {};

struct NumLockOff;
struct CapsLockOff;
struct ScrollLockOff;
struct Active: sc::simple_state< Active, Keyboard, boost::mpl::list< NumLockOff, CapsLockOff, ScrollLockOff > > {};

struct EvNumLockPressed : sc::event< EvNumLockPressed > {};
struct EvCapsLockPressed : sc::event< EvCapsLockPressed > {};
struct EvScrollLockPressed : sc::event< EvScrollLockPressed > {};
struct EvAllLocksOffPressed : sc::event< EvAllLocksOffPressed > {
    int i_;
    EvAllLocksOffPressed(int i):sc::event< EvAllLocksOffPressed >(),i_(i){}
};

struct NumLockOn : sc::simple_state< NumLockOn, Active::orthogonal< 0 > >
{
    typedef boost::mpl::list<sc::transition< EvNumLockPressed, NumLockOff >, sc::custom_reaction<EvAllLocksOffPressed>> reactions;
    sc::result react( const EvAllLocksOffPressed & e)
    {
        if(e.i_ == 42)
            return transit< NumLockOff >();
        return forward_event();
    }
};

struct NumLockOff : sc::simple_state< NumLockOff, Active::orthogonal< 0 > >
{
    typedef sc::transition< EvNumLockPressed, NumLockOn > reactions;
};

struct CapsLockOn : sc::simple_state< CapsLockOn, Active::orthogonal< 1 > >
{
    typedef boost::mpl::list<sc::transition< EvCapsLockPressed, CapsLockOff >, sc::custom_reaction<EvAllLocksOffPressed>> reactions;
    sc::result react( const EvAllLocksOffPressed & e)
    {
        if(e.i_ == 42)
            return transit< CapsLockOff >();
        return forward_event();
    }
};

struct CapsLockOff : sc::simple_state< CapsLockOff, Active::orthogonal< 1 > >
{
    typedef sc::transition< EvCapsLockPressed, CapsLockOn > reactions;
};

struct ScrollLockOn : sc::simple_state< ScrollLockOn, Active::orthogonal< 2 > >
{
    typedef boost::mpl::list<sc::transition< EvScrollLockPressed, ScrollLockOff >, sc::custom_reaction<EvAllLocksOffPressed>> reactions;
    sc::result react( const EvAllLocksOffPressed & e)
    {
        if(e.i_ == 42)
            return transit< ScrollLockOff >();
        return forward_event();
    }
};

struct ScrollLockOff : sc::simple_state< ScrollLockOff, Active::orthogonal< 2 > >
{
    typedef sc::transition< EvScrollLockPressed, ScrollLockOn > reactions; 
};

int main(){
    Keyboard k;
    k.initiate();
    k.process_event(EvNumLockPressed());
    k.process_event(EvCapsLockPressed());
    k.process_event(EvScrollLockPressed());
    k.process_event(EvAllLocksOffPressed(1));
    k.process_event(EvAllLocksOffPressed(42));
}

Answer 1

This question was answered by the library author. The reference he meant is Event dispatch to orthogonal regions .