org.springframework.statemachine.listener.StateMachineListener.java Source code

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Here is the source code for org.springframework.statemachine.listener.StateMachineListener.java

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/*
 * 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
 *
 * https://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);

}