com.kangirigungi.jstatemachine

Interface IGuard<StateId,Event>

Type Parameters:

StateId - The type used for referencing states.

Event - The type used for referencing events.

All Known Implementing Classes:

GuardAnd, GuardNot, GuardOr, GuardState

public interface IGuard<StateId,Event>

Callback interface for guards. A guard action should only check conditions, and have no side effects. When using guards to resolve event conflicts, guards for all conflicting transitions must be mutually exclusive, and it cannot be relied on that all guards are executed.

Logical functions of more than one guards can be created by instantiating the GuardAnd, GuardOr and GuardNot classes.

Author:

Peter Szabados

Method Summary

Methods

Modifier and Type	Method and Description
boolean	checkTransition(IState<StateId,Event> fromState, IState<StateId,Event> toState, Event event) Called when the guard is needed to be executed.

Method Detail

checkTransition

boolean checkTransition(IState<StateId,Event> fromState,
                      IState<StateId,Event> toState,
                      Event event)

Called when the guard is needed to be executed.

Parameters:

fromState - The initial state of the transition. In case of an internal transition, it is the state in which the transition happens.

toState - The final state of the transition. In case of an internal transition, its value is null.

event - The event triggering the transition.

Returns:

The result of the transition.