content: /* Copyright 2010, Object Management Group, Inc.
   * Copyright 2010, PrismTech, Inc.
   * Copyright 2010, Real-Time Innovations, Inc.
   * All rights reserved.
   *
   * 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.
   */
  
  package org.omg.dds.core.policy;
  
  
  
  /**
   * User data not known by the middleware, but distributed by means of
   * built-in topics. The default value is an empty (zero-sized) sequence.
   *<p>
   * <b>Concerns:</b> {@link org.omg.dds.pub.Publisher}, {@link org.omg.dds.sub.Subscriber}
   *<p>
   * <b>RxO:</b> No
   *<p>
   * <b>Changeable:</b> Yes
   *<p>
   * The purpose of this QoS is to allow the application to attach additional
   * information to the created {@link org.omg.dds.pub.Publisher} or {@link org.omg.dds.sub.Subscriber}. The
   * value of the GROUP_DATA is available to the application on the
   * {@link org.omg.dds.sub.DataReader} and {@link org.omg.dds.pub.DataWriter} entities and is propagated by
   * means of the built-in topics.
   * <p>
   * This QoS can be used by an application combination with the
   * {@link org.omg.dds.sub.DataReaderListener} and {@link org.omg.dds.pub.DataWriterListener} to implement
   * matching policies similar to those of the {@link org.omg.dds.core.policy.Partition}
   * except the decision can be made based on an application-defined policy.
   */
  public interface GroupData
  extends QosPolicy.ForPublisher, QosPolicy.ForSubscriber
  {
      /**
       * Get a copy of the data.
       */
      public byte[] getValue();
  
  
      // --- Modification: -----------------------------------------------------
  
      /**
       *  copy this policy and override the value of the property.
       *  @param value        A sequence of bytes that holds the application group data. By default, the sequence has length 0.
       *  @param offset       Not used can have any int value.
       *  @param length       Not used can have any int value.
       *
       * @return  a new policy
       */
      public GroupData withValue(byte value[], int offset, int length);
  }
  