cp_topic_subscriber.hpp

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// Copyright 2025 Robosoft 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/client_bases/smacc_subscriber_client.hpp>
#include <smacc2/component.hpp>
#include <smacc2/smacc_signal.hpp>
 
namespace smacc2
{
namespace client_core_components
{
using namespace smacc2::default_events;
 
template <typename MessageType>
class CpTopicSubscriber : public smacc2::ISmaccComponent
{
public:
  std::optional<int> queueSize;
 
  typedef MessageType TMessageType;
 
  CpTopicSubscriber() { initialized_ = false; }
 
  CpTopicSubscriber(std::string topicname)
  {
    topicName_ = topicname;
    initialized_ = false;
  }
 
  virtual ~CpTopicSubscriber() {}
 
  std::function<void(const MessageType &)> postMessageEvent;
  std::function<void(const MessageType &)> postInitialMessageEvent;
 
  smacc2::SmaccSignal<void(const MessageType &)> onFirstMessageReceived_;
  smacc2::SmaccSignal<void(const MessageType &)> onMessageReceived_;
 
  // signal subscription method. This signal will be triggered when the first message is received
  template <typename T>
  smacc2::SmaccSignalConnection onMessageReceived(
    void (T::*callback)(const MessageType &), T * object)
  {
    return this->getStateMachine()->createSignalConnection(onMessageReceived_, callback, object);
  }
 
  // signal subscription method. This signal will be triggered when the first message is received
  template <typename T>
  smacc2::SmaccSignalConnection onFirstMessageReceived(
    void (T::*callback)(const MessageType &), T * object)
  {
    return this->getStateMachine()->createSignalConnection(
      onFirstMessageReceived_, callback, object);
  }
 
  template <typename TOrthogonal, typename TSourceObject>
  void onStateOrthogonalAllocation()
  {
    this->postMessageEvent = [=](auto msg)
    {
      auto event = new EvTopicMessage<TSourceObject, TOrthogonal, MessageType>();
      event->msgData = msg;
      this->postEvent(event);
    };
 
    this->postInitialMessageEvent = [=](auto msg)
    {
      auto event = new EvTopicInitialMessage<TSourceObject, TOrthogonal, MessageType>();
      event->msgData = msg;
      this->postEvent(event);
    };
  }
 
  void onInitialize() override
  {
    if (!initialized_)
    {
      firstMessage_ = true;
 
      if (!queueSize) queueSize = 1;
 
      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_ = this->getNode()->template create_subscription<MessageType>(topicName_, qos, fn);
      this->initialized_ = true;
    }
  }
 
private:
  typename rclcpp::Subscription<MessageType>::SharedPtr sub_;
  bool firstMessage_;
  bool initialized_;
  std::string topicName_;
 
  void messageCallback(const MessageType & msg)
  {
    if (firstMessage_)
    {
      postInitialMessageEvent(msg);
      onFirstMessageReceived_(msg);
      firstMessage_ = false;
    }
 
    postMessageEvent(msg);
    onMessageReceived_(msg);
  }
};
}  // namespace client_core_components
}  // namespace smacc2