content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.apache.ambari.server.view.events;
  
  import java.util.Collections;
  import java.util.Map;
  
  import org.apache.ambari.view.ViewDefinition;
  import org.apache.ambari.view.ViewInstanceDefinition;
  import org.apache.ambari.view.events.Event;
  
  /**
   * View event implementation.
   */
  public class EventImpl implements Event {
    /**
     * The event id.
     */
    private final String id;
  
    /**
     * The event properties.
     */
    private final Map<String, String> properties;
  
    /**
     * The view subject of the event.
     */
    private final ViewDefinition viewSubject;
  
    /**
     * The instance subject of the event.
     */
    private final ViewInstanceDefinition viewInstanceSubject;
  
  
    // ----- Constructors ------------------------------------------------------
  
    /**
     * Construct an event.
     *
     * @param id           the event id
     * @param properties   the event properties
     * @param viewSubject  the subject of the event
     */
    public EventImpl(String id, Map<String, String> properties, ViewDefinition viewSubject) {
      this(id, properties, viewSubject, null);
    }
  
    /**
     * Construct an event.
     *
     * @param id                   the event id
     * @param properties           the event properties
     * @param viewInstanceSubject  the subject of the event
     */
    public EventImpl(String id, Map<String, String> properties, ViewInstanceDefinition viewInstanceSubject) {
      this(id, properties, viewInstanceSubject.getViewDefinition(), viewInstanceSubject);
    }
  
    // private constructor
    private EventImpl(String id, Map<String, String> properties,
                  ViewDefinition viewSubject, ViewInstanceDefinition viewInstanceSubject) {
      this.id                  = id;
      this.viewSubject         = viewSubject;
      this.viewInstanceSubject = viewInstanceSubject;
      this.properties          = properties == null ? Collections.emptyMap() :
          Collections.unmodifiableMap(properties);
    }
  
  
    // ----- Event -------------------------------------------------------------
  
    /**
     * Get the event identifier.
     *
     * @return the id
     */
    @Override
    public String getId() {
      return id;
    }
  
    /**
     * Get the event properties.
     *
     * @return the properties
     */
    @Override
    public Map<String, String> getProperties() {
      return properties;
    }
  
    /**
     * Get the view subject of the event.
     *
     * @return the view subject
     */
    @Override
    public ViewDefinition getViewSubject() {
      return viewSubject;
    }
  
    /**
     * Get the instance subject of the event.
     *
     * @return the instance subject; null if this is a view level event
     */
    @Override
    public ViewInstanceDefinition getViewInstanceSubject() {
      return viewInstanceSubject;
    }
  
    // ----- Object overrides --------------------------------------------------
  
    @Override
    public String toString() {
      return "View Event " + id;
    }
  }
  