.. _program_listing_file__tmp_ws_src_SMACC2_smacc2_include_smacc2_client_bases_smacc_subscriber_client.hpp:

Program Listing for File smacc_subscriber_client.hpp
====================================================

|exhale_lsh| :ref:`Return to documentation for file <file__tmp_ws_src_SMACC2_smacc2_include_smacc2_client_bases_smacc_subscriber_client.hpp>` (``/tmp/ws/src/SMACC2/smacc2/include/smacc2/client_bases/smacc_subscriber_client.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // Copyright 2021 RobosoftAI Inc.
   //
   // 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.
   
   /*****************************************************************************************************************
    *
    *   Authors: Pablo Inigo Blasco, Brett Aldrich
    *
    ******************************************************************************************************************/
   
   #pragma once
   
   #include <optional>
   #include <smacc2/smacc_client.hpp>
   #include <smacc2/smacc_signal.hpp>
   #include <smacc2/smacc_state_machine.hpp>
   
   namespace smacc2
   {
   namespace client_bases
   {
   using namespace smacc2::default_events;
   
   // This client class warps a ros subscriber and publishes two kind of
   // smacc events: EvTopicMessage (always a ros topic message is received)
   // and EvTopicInitialMessage (only once)
   template <typename MessageType>
   class SmaccSubscriberClient : public smacc2::ISmaccClient
   {
   public:
     std::optional<std::string> topicName;
     std::optional<int> queueSize;
   
     typedef MessageType TMessageType;
   
     SmaccSubscriberClient() { initialized_ = false; }
   
     SmaccSubscriberClient(std::string topicname) { topicName = topicname; }
   
     virtual ~SmaccSubscriberClient() {}
   
     smacc2::SmaccSignal<void(const MessageType &)> onFirstMessageReceived_;
     smacc2::SmaccSignal<void(const MessageType &)> onMessageReceived_;
   
     std::function<void(const MessageType &)> postMessageEvent;
     std::function<void(const MessageType &)> postInitialMessageEvent;
   
     template <typename T>
     boost::signals2::connection onMessageReceived(
       void (T::*callback)(const MessageType &), T * object)
     {
       return this->getStateMachine()->createSignalConnection(onMessageReceived_, callback, object);
     }
   
     template <typename T>
     boost::signals2::connection onFirstMessageReceived(
       void (T::*callback)(const MessageType &), T * object)
     {
       return this->getStateMachine()->createSignalConnection(
         onFirstMessageReceived_, callback, object);
     }
   
     template <typename TOrthogonal, typename TSourceObject>
     void onOrthogonalAllocation()
     {
       // ros topic message received smacc event callback
       this->postMessageEvent = [this](auto msg) {
         auto event = new EvTopicMessage<TSourceObject, TOrthogonal>();
         event->msgData = msg;
         this->postEvent(event);
       };
   
       // initial ros topic message received smacc event callback
       this->postInitialMessageEvent = [this](auto msg) {
         auto event = new EvTopicInitialMessage<TSourceObject, TOrthogonal>();
         event->msgData = msg;
         this->postEvent(event);
       };
     }
   
   protected:
     void onInitialize() override
     {
       if (!initialized_)
       {
         firstMessage_ = true;
   
         if (!queueSize) queueSize = 1;
   
         if (!topicName)
         {
           RCLCPP_ERROR(getLogger(), "topic client with no topic name set. Skipping subscribing");
         }
         else
         {
           RCLCPP_INFO_STREAM(
             getLogger(), "[" << this->getName() << "] Subscribing to topic: " << *topicName);
   
           rclcpp::SensorDataQoS qos;
           if (queueSize) qos.keep_last(*queueSize);
   
           std::function<void(typename MessageType::SharedPtr)> fn = [this](auto msg) {
             this->messageCallback(*msg);
           };
           sub_ = getNode()->create_subscription<MessageType>(*topicName, qos, fn);
           this->initialized_ = true;
         }
       }
     }
   
   private:
     typename rclcpp::Subscription<MessageType>::SharedPtr sub_;
     bool firstMessage_;
     bool initialized_;
   
     void messageCallback(const MessageType & msg)
     {
       if (firstMessage_)
       {
         postInitialMessageEvent(msg);
         onFirstMessageReceived_(msg);
         firstMessage_ = false;
       }
   
       postMessageEvent(msg);
       onMessageReceived_(msg);
     }
   };
   }  // namespace client_bases
   }  // namespace smacc2