org.glassfish.pfl.basic.fsm
Interface FSM

All Known Implementing Classes:

FSMImpl

public interface FSM

An FSM is used to represent an instance of a finite state machine which has a transition function represented by an instance of StateEngine. An instance of an FSM may be created either by calling StateEngine.makeFSM( startState ) on a state engine, or by extending FSMImpl and using a constructor. Using FSMImpl as a base class is convenient if additional state is associated with the FSM beyond that encoded by the current state. This is especially convenient if an action needs some additional information. For example, counters are best handled by special actions rather than encoding a bounded counter in a state machine. It is also possible to create a class that implements the FSM interface by delegating to an FSM instance created by StateEngine.makeFSM.

Author:

Ken Cavanaugh

Method Summary

FSM	getParent() Get the parent state machine.
State	getState() Get the current state of this FSM.
StateEngine	getStateEngine() Return the state engine used to create this FSM.
void	setParent(FSM fsm) Set the parent state machine.
void	setState(State state) Set the current state of this FSM.

Method Detail

getStateEngine

StateEngine getStateEngine()

Return the state engine used to create this FSM.

getParent

FSM getParent()

Get the parent state machine.

setParent

void setParent(FSM fsm)

Set the parent state machine.

setState

void setState(State state)

Set the current state of this FSM. May not be called inside a transition action, or from a State method. Only here for use by the StateEngine.

getState

State getState()

Get the current state of this FSM.