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.causeway.applib.events.ui;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.causeway.applib.events.EventObjectBase;
  
  /**
   * @since 1.x {@index}
   */
  public abstract class AbstractUiEvent<S> extends EventObjectBase<S> {
  
      /**
       * If used then the framework will set state via (non-API) setters.
       *
       */
      public AbstractUiEvent() {
          this(null);
      }
  
      public AbstractUiEvent(final S source) {
          super(source);
      }
  
      /**
       * Provides a mechanism to pass data around.
       */
      private final Map<Object, Object> userData = new HashMap<>();
  
      /**
       * Obtain user-data, as set by any other subscribers.
       */
      public Object get(Object key) {
          return userData.get(key);
      }
      /**
       * Set user-data, for the use of other subscribers.
       */
      public void put(Object key, Object value) {
          userData.put(key, value);
      }
  
  }
  