[Boost-users] [statechart] How to keep transition actions separated from the interface?

From: Andre Massing (massing_at_[hidden])
Date: 2008-04-06 09:09:39

Hi,

I am implementing a fsm for a kind of a project class, which tracks certain 
changes like adding special files  or starting a computation.  To keep the 
interface as small/clean as possible all interactions with the fsm should be 
soley processed by the process_event method.
But seemingl I have to declare transition actions public in an outer state to 
make them available for inner state reactions/transitions. Is there any nice 
way to avoid this and to keep transition actions separated from the public 
interface? (Declaring *all* inner states which need access to be friend seems 
too ugly to me...) 	

A small code snippet to demonstrate my issue:

In Project.h:

struct Idle;

struct Project :  sc::state_machine< Project, Idle >
{
public:
//....
void solve(const EvSolve &);
//...
};

//...

struct Idle : sc::simple_state< Idle, Project, mpl::list<GeoState, 
SolverState> >
{
    typedef mpl::list<
        sc::custom_reaction< EvCompile >,
        sc::custom_reaction< EvSolve >
	    > reactions;
    sc::result react(const EvCompile &);
    sc::result react(const EvSolve &);
};

In Project.h:

sc::result Idle::react(const EvSolve & ev)
{
//...
return transit<Solve>(&Project::solve, ev);
}

Regards,
Andre