/*
* Copyright 2015 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.statemachine.listener;
import org.springframework.messaging.Message;
import org.springframework.statemachine.StateContext;
import org.springframework.statemachine.StateContext.Stage;
import org.springframework.statemachine.StateMachine;
import org.springframework.statemachine.state.State;
import org.springframework.statemachine.transition.Transition;
/**
* {@code StateMachineListener} for various state machine events.
*
* @author Janne Valkealahti
*
* @param <S> the type of state
* @param <E> the type of event
*/
public interface StateMachineListener<S,E> {
/**
* Notified when state is changed.
*
* @param from the source state
* @param to the target state
*/
void stateChanged(State<S,E> from, State<S,E> to);
/**
* Notified when state is entered.
*
* @param state the state
*/
void stateEntered(State<S,E> state);
/**
* Notified when state is exited.
*
* @param state the state
*/
void stateExited(State<S,E> state);
/**
* Notified when event was not accepted.
*
* @param event the event
*/
void eventNotAccepted(Message<E> event);
/**
* Notified when transition happened.
*
* @param transition the transition
*/
void transition(Transition<S, E> transition);
/**
* Notified when transition started.
*
* @param transition the transition
*/
void transitionStarted(Transition<S, E> transition);
/**
* Notified when transition ended.
*
* @param transition the transition
*/
void transitionEnded(Transition<S, E> transition);
/**
* Notified when statemachine starts
*
* @param stateMachine the statemachine
*/
void stateMachineStarted(StateMachine<S, E> stateMachine);
/**
* Notified when statemachine stops
*
* @param stateMachine the statemachine
*/
void stateMachineStopped(StateMachine<S, E> stateMachine);
/**
* Notified when statemachine enters error it can't recover from.
*
* @param stateMachine the state machine
* @param exception the exception
*/
void stateMachineError(StateMachine<S, E> stateMachine, Exception exception);
/**
* Notified when extended state variable is either added, modified or removed.
*
* @param key the variable key
* @param value the variable value
*/
void extendedStateChanged(Object key, Object value);
/**
* Notified on various {@link Stage}s about a {@link StateContext}.
*
* @param stateContext the state context
*/
void stateContext(StateContext<S, E> stateContext);
}