text: /*
   * Copyright 2015-2019 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;
  
  import java.util.List;
  import java.util.Map;
  
  /**
   * {@code StateMachineContext} represents a current state of a state machine.
   *
   * @author Janne Valkealahti
   *
   * @param <S> the type of state
   * @param <E> the type of event
   */
  public interface StateMachineContext<S, E> {
  
  	/**
  	 * Gets the machine id.
  	 *
  	 * @return the machine id
  	 */
  	String getId();
  
  	/**
  	 * Gets the child contexts if any.
  	 *
  	 * @return the child contexts
  	 */
  	List<StateMachineContext<S, E>> getChilds();
  
  	/**
  	 * Gets the child context references if any.
  	 *
  	 * @return the child context references
  	 */
  	List<String> getChildReferences();
  
  	/**
  	 * Gets the state.
  	 *
  	 * @return the state
  	 */
  	S getState();
  
  	/**
  	 * Gets the event.
  	 *
  	 * @return the event
  	 */
  	E getEvent();
  
  	/**
  	 * Gets the history state mappings
  	 *
  	 * @return the history state mappings
  	 */
  	Map<S, S> getHistoryStates();
  
  	/**
  	 * Gets the event headers.
  	 *
  	 * @return the event headers
  	 */
  	Map<String, Object> getEventHeaders();
  
  	/**
  	 * Gets the extended state.
  	 *
  	 * @return the extended state
  	 */
  	ExtendedState getExtendedState();
  }
  