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.aries.blueprint.ext;
  
  /**
   * Metadata for custom components that need to plug in to the
   * Blueprint container lifecycle for beans
   */
  public interface DependentComponentFactoryMetadata extends ComponentFactoryMetadata {
      /**
       * Interface that allows to notify the container when the dependencies of the component
       * become satisfied or unsatified.
       */
      interface SatisfactionCallback {
          /**
           * Alert the container that the satisfaction status has changed. isSatisfied() should reflect this.
           */
          void notifyChanged();
      }
      
      /**
       * Start tracking the dependencies for this component.
       * @param observer The container callback for alerting the container of status changes
       */
      void startTracking(SatisfactionCallback observer);
      
      /**
       * Stop tracking the dependencies for this component.
       */
      void stopTracking();
      
      /**
       * Return a string representation of the dependencies of this component. This will be used
       * in diagnostics as well as the GRACE_PERIOD event.
       * @return
       */
      String getDependencyDescriptor();
  
      /**
       * Are all dependencies of this component satisfied?
       * @return
       */
      boolean isSatisfied();
  }
  