package org.codehaus.plexus.component.discovery;
   
   /*
    * Copyright 2001-2006 Codehaus Foundation.
    *
    * 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.
   */
  
  import java.util.ArrayList;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  public class DefaultComponentDiscovererManager implements ComponentDiscovererManager {
      private final List<ComponentDiscoverer> componentDiscoverers = new ArrayList<ComponentDiscoverer>();
  
      // todo dain change this to LinkedHashSet<ComponentDiscoveryListener> (requires change to maven)
      private final Map<ComponentDiscoveryListener, Object> listeners =
              new LinkedHashMap<ComponentDiscoveryListener, Object>();
  
      public synchronized void addComponentDiscoverer(ComponentDiscoverer discoverer) {
          componentDiscoverers.add(discoverer);
      }
  
      // todo this is not thread safe... we are returning the raw collection
      public synchronized List<ComponentDiscoverer> getComponentDiscoverers() {
          return componentDiscoverers;
      }
  
      // Listeners
  
      // todo this is not thread safe... we are returning the raw collection
      public synchronized Map<ComponentDiscoveryListener, Object> getComponentDiscoveryListeners() {
          return listeners;
      }
  
      public synchronized void registerComponentDiscoveryListener(ComponentDiscoveryListener listener) {
          if (!listeners.containsKey(listener)) {
              listeners.put(listener, new Object());
          }
      }
  
      public synchronized void removeComponentDiscoveryListener(ComponentDiscoveryListener listener) {
          listeners.remove(listener);
      }
  
      public void fireComponentDiscoveryEvent(ComponentDiscoveryEvent event) {
          Set<ComponentDiscoveryListener> listeners;
          synchronized (this) {
              listeners = this.listeners.keySet();
          }
  
          for (ComponentDiscoveryListener listener : listeners) {
              listener.componentDiscovered(event);
          }
      }
  }