com.digitalpetri.strictmachine

Interface FsmContext<S,E>

All Known Subinterfaces:

ActionContext<S,E>

public interface FsmContext<S,E>

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	FsmContext.Key<T>

Method Summary

Modifier and Type	Method and Description
S	currentState() Get the current state of the FSM.
void	fireEvent(E event) Fire an event to be evaluated against the current state of the Fsm.
java.lang.Object	get(FsmContext.Key<?> key) Get the value identified by key from the context, or null if it does not exist.
long	getInstanceId() Get the id assigned to this FSM instance.
void	processShelvedEvents() Drain the event shelf of any queued events and fire them for evaluation.
java.lang.Object	remove(FsmContext.Key<?> key) Get and remove the value identified by key from the context, or null if it does not exist.
void	set(FsmContext.Key<?> key, java.lang.Object value) Set a value identified by key on the context.
void	shelveEvent(E event) Shelve an event to to be evaluated at some later time.

Method Detail

currentState

S currentState()

Get the current state of the FSM.

Returns:

the current state of the FSM.

fireEvent

void fireEvent(E event)

Fire an event to be evaluated against the current state of the Fsm.

Parameters:

event - the event to be evaluated.

shelveEvent

void shelveEvent(E event)

Shelve an event to to be evaluated at some later time.

This is useful e.g. when an event can't be handled in the current state but shouldn't be discarded or ignored with an action-less internal transition.

Parameters:

event - the event to be queued.

See Also:

processShelvedEvents()

processShelvedEvents

void processShelvedEvents()

Drain the event shelf of any queued events and fire them for evaluation.

get

java.lang.Object get(FsmContext.Key<?> key)

Get the value identified by key from the context, or null if it does not exist.

Parameters:

key - the FsmContext.Key.

Returns:

the value identified by key, or null if it does not exist.

remove

java.lang.Object remove(FsmContext.Key<?> key)

Get and remove the value identified by key from the context, or null if it does not exist.

Parameters:

key - the FsmContext.Key.

Returns:

the value identified by key, or null if it did not exist.

set

void set(FsmContext.Key<?> key,
         java.lang.Object value)

Set a value identified by key on the context.

Parameters:

key - the FsmContext.Key.

value - the value.

getInstanceId

long getInstanceId()

Get the id assigned to this FSM instance.

The id is a monotonically increasing value assigned to each new instance to aid in determining which log messages belong to which instance.

Returns:

the id assigned to this FSM instance.