com.almasb.fxgl.ai.fsm

Interface StateMachine<E,S extends State<E>>

Type Parameters:

E - the type of the entity owning this state machine

S - the type of the states of this state machine

All Superinterfaces:

Telegraph

All Known Implementing Classes:

DefaultStateMachine, StackStateMachine

public interface StateMachine<E,S extends State<E>>
extends Telegraph

A state machine manages the state transitions of its entity. Additionally, the state machine may be delegated by the entity to handle its messages.

Author:

davebaol

Method Summary

Modifier and Type	Method and Description
void	changeState(S newState) Performs a transition to the specified state.
S	getCurrentState() Returns the current state of this state machine.
S	getGlobalState() Returns the global state of this state machine.
S	getPreviousState() Returns the last state of this state machine.
boolean	handleMessage(Telegram telegram) Handles received telegrams.
boolean	isInState(S state) Indicates whether the state machine is in the given state.
boolean	revertToPreviousState() Changes the state back to the previous state.
void	setGlobalState(S state) Sets the global state of this state machine.
void	setInitialState(S state) Sets the initial state of this state machine.
void	update() Updates the state machine.

Method Detail

update

void update()

Updates the state machine.

Implementation classes should invoke first the update method of the global state (if any) then the update method of the current state.

changeState

void changeState(S newState)

Performs a transition to the specified state.

Parameters:

newState - the state to transition to

revertToPreviousState

boolean revertToPreviousState()

Changes the state back to the previous state.

Returns:

true in case there was a previous state that we were able to revert to. In case there is no previous state, no state change occurs and false will be returned.

setInitialState

void setInitialState(S state)

Sets the initial state of this state machine.

Parameters:

state - the initial state.

setGlobalState

void setGlobalState(S state)

Sets the global state of this state machine.

Parameters:

state - the global state.

getCurrentState

S getCurrentState()

Returns the current state of this state machine.

getGlobalState

S getGlobalState()

Returns the global state of this state machine.

Implementation classes should invoke the update method of the global state every time the FSM is updated. Also, they should never invoke its enter and exit method.

getPreviousState

S getPreviousState()

Returns the last state of this state machine.

isInState

boolean isInState(S state)

Indicates whether the state machine is in the given state.

Parameters:

state - the state to be compared with the current state

Returns:

true if the current state's type is equal to the type of the class passed as a parameter.

handleMessage

boolean handleMessage(Telegram telegram)

Handles received telegrams.

Implementation classes should first route the telegram to the current state. If the current state does not deal with the message, it should be routed to the global state.

Specified by:

handleMessage in interface Telegraph

Parameters:

telegram - the received telegram

Returns:

true if telegram has been successfully handled; false otherwise.