text: // Copyright 2016 Proyectos y Sistemas de Mantenimiento SL (eProsima).
  //
  // 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.
  
  /**
   * @file ReaderListener.h
   *
   */
  
  #ifndef _FASTDDS_RTPS_READERLISTENER_H_
  #define _FASTDDS_RTPS_READERLISTENER_H_
  
  #include <fastdds/rtps/common/MatchingInfo.h>
  #include <fastrtps/qos/LivelinessChangedStatus.h>
  #include <fastdds/dds/core/status/SubscriptionMatchedStatus.hpp>
  #include <fastdds/dds/core/status/IncompatibleQosStatus.hpp>
  
  #include <mutex>
  
  namespace eprosima {
  namespace fastrtps {
  namespace rtps {
  
  class RTPSReader;
  struct CacheChange_t;
  
  /**
   * Class ReaderListener, to be used by the user to override some of is virtual method to program actions to
   * certain events.
   * @ingroup READER_MODULE
   */
  class RTPS_DllAPI ReaderListener
  {
  public:
  
      ReaderListener() = default;
  
      virtual ~ReaderListener() = default;
  
      /**
       * This method is invoked when a new reader matches
       * @param reader Matching reader
       * @param info Matching information of the reader
       */
      virtual void onReaderMatched(
              RTPSReader* reader,
              MatchingInfo& info)
      {
          (void)reader;
          (void)info;
      }
  
      /**
       * This method is invoked when a new reader matches
       * @param reader Matching reader
       * @param info Subscription matching information
       */
      virtual void onReaderMatched(
              RTPSReader* reader,
              const fastdds::dds::SubscriptionMatchedStatus& info)
      {
          (void)reader;
          (void)info;
      }
  
      /**
       * This method is called when a new CacheChange_t is added to the ReaderHistory.
       * @param reader Pointer to the reader.
       * @param change Pointer to the CacheChange_t. This is a const pointer to const data
       * to indicate that the user should not dispose of this data himself.
       * To remove the data call the remove_change method of the ReaderHistory.
       * reader->getHistory()->remove_change((CacheChange_t*)change).
       */
      virtual void onNewCacheChangeAdded(
              RTPSReader* reader,
              const CacheChange_t* const change)
      {
          (void)reader;
          (void)change;
      }
  
      /**
       * @brief Method called when the livelivess of a reader changes
       * @param reader The reader
       * @param status The liveliness changed status
       */
      virtual void on_liveliness_changed(
              RTPSReader* reader,
              const LivelinessChangedStatus& status)
      {
          (void)reader;
          (void)status;
      }
  
      /**
       * This method is called when a new Writer is discovered, with a Topic that
       * matches that of a local reader, but with an offered QoS that is incompatible
       * with the one requested by the local reader
       * @param reader Pointer to the RTPSReader.
       * @param qos A mask with the bits of all incompatible Qos activated.
       */
      virtual void on_requested_incompatible_qos(
              RTPSReader* reader,
              eprosima::fastdds::dds::PolicyMask qos)
      {
          (void)reader;
          (void)qos;
      }
  
  };
  
  } // namespace rtps
  } // namespace fastrtps
  } // namespace eprosima
  
  #endif /* _FASTDDS_RTPS_READERLISTENER_H_ */
  