com.almasb.fxgl.ai.fsm

Class StackStateMachine<E,S extends State<E>>

java.lang.Object

com.almasb.fxgl.ai.fsm.DefaultStateMachine<E,S>

com.almasb.fxgl.ai.fsm.StackStateMachine<E,S>

Type Parameters:

E - the type of the entity owning this state machine

S - the type of the states of this state machine

All Implemented Interfaces:

StateMachine<E,S>, Telegraph

public class StackStateMachine<E,S extends State<E>>
extends DefaultStateMachine<E,S>

A StateMachine implementation that keeps track of all previous States via a stack. This makes sense for example in case of a hierarchical menu structure where each menu screen is one state and one wants to navigate back to the main menu anytime, via revertToPreviousState().

Author:

Daniel Holderbaum

Field Summary

Fields inherited from class com.almasb.fxgl.ai.fsm.DefaultStateMachine

currentState, globalState, owner, previousState

Constructor Summary

Constructors

Constructor and Description
StackStateMachine() Creates a StackStateMachine with no owner, initial state and global state.
StackStateMachine(E owner) Creates a StackStateMachine for the specified owner.
StackStateMachine(E owner, S initialState) Creates a StackStateMachine for the specified owner and initial state.
StackStateMachine(E owner, S initialState, S globalState) Creates a StackStateMachine for the specified owner, initial state and global state.

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	getPreviousState() Returns the last state of this state machine.
boolean	revertToPreviousState() Changes the Change state back to the previous state.
void	setInitialState(S state) Sets the initial state of this state machine.

Methods inherited from class com.almasb.fxgl.ai.fsm.DefaultStateMachine

getGlobalState, getOwner, handleMessage, isInState, setGlobalState, setOwner, update

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StackStateMachine

public StackStateMachine()

Creates a StackStateMachine with no owner, initial state and global state.

StackStateMachine

public StackStateMachine(E owner)

Creates a StackStateMachine for the specified owner.

Parameters:

owner - the owner of the state machine

StackStateMachine

public StackStateMachine(E owner,
                         S initialState)

Creates a StackStateMachine for the specified owner and initial state.

Parameters:

owner - the owner of the state machine

initialState - the initial state

StackStateMachine

public StackStateMachine(E owner,
                         S initialState,
                         S globalState)

Creates a StackStateMachine for the specified owner, initial state and global state.

Parameters:

owner - the owner of the state machine

initialState - the initial state

globalState - the global state

Method Detail

setInitialState

public void setInitialState(S state)

Description copied from interface: StateMachine

Sets the initial state of this state machine.

Specified by:

setInitialState in interface StateMachine<E,S extends State<E>>

Overrides:

setInitialState in class DefaultStateMachine<E,S extends State<E>>

Parameters:

state - the initial state.

getCurrentState

public S getCurrentState()

Description copied from interface: StateMachine

Returns the current state of this state machine.

Specified by:

getCurrentState in interface StateMachine<E,S extends State<E>>

Overrides:

getCurrentState in class DefaultStateMachine<E,S extends State<E>>

getPreviousState

public S getPreviousState()

Returns the last state of this state machine. That is the high-most state on the internal stack of previous states.

Specified by:

getPreviousState in interface StateMachine<E,S extends State<E>>

Overrides:

getPreviousState in class DefaultStateMachine<E,S extends State<E>>

changeState

public void changeState(S newState)

Description copied from interface: StateMachine

Performs a transition to the specified state.

Specified by:

changeState in interface StateMachine<E,S extends State<E>>

Overrides:

changeState in class DefaultStateMachine<E,S extends State<E>>

Parameters:

newState - the state to transition to

revertToPreviousState

public boolean revertToPreviousState()

Changes the Change state back to the previous state. That is the high-most state on the internal stack of previous states.

Specified by:

revertToPreviousState in interface StateMachine<E,S extends State<E>>

Overrides:

revertToPreviousState in class DefaultStateMachine<E,S extends State<E>>

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.