.. _program_listing_file__tmp_ws_src_image_common_image_transport_include_image_transport_simple_subscriber_plugin.hpp:

Program Listing for File simple_subscriber_plugin.hpp
=====================================================

|exhale_lsh| :ref:`Return to documentation for file <file__tmp_ws_src_image_common_image_transport_include_image_transport_simple_subscriber_plugin.hpp>` (``/tmp/ws/src/image_common/image_transport/include/image_transport/simple_subscriber_plugin.hpp``)

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

.. code-block:: cpp

   // Copyright (c) 2009, Willow Garage, Inc.
   //
   // Redistribution and use in source and binary forms, with or without
   // modification, are permitted provided that the following conditions are met:
   //
   //    * Redistributions of source code must retain the above copyright
   //      notice, this list of conditions and the following disclaimer.
   //
   //    * Redistributions in binary form must reproduce the above copyright
   //      notice, this list of conditions and the following disclaimer in the
   //      documentation and/or other materials provided with the distribution.
   //
   //    * Neither the name of the Willow Garage nor the names of its
   //      contributors may be used to endorse or promote products derived from
   //      this software without specific prior written permission.
   //
   // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
   // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   // POSSIBILITY OF SUCH DAMAGE.
   
   #ifndef IMAGE_TRANSPORT__SIMPLE_SUBSCRIBER_PLUGIN_HPP_
   #define IMAGE_TRANSPORT__SIMPLE_SUBSCRIBER_PLUGIN_HPP_
   
   #include <functional>
   #include <memory>
   #include <string>
   
   #include "rclcpp/subscription.hpp"
   
   #include "image_transport/subscriber_plugin.hpp"
   #include "image_transport/visibility_control.hpp"
   
   namespace image_transport
   {
   
   template<class M>
   class SimpleSubscriberPlugin : public SubscriberPlugin
   {
   public:
     virtual ~SimpleSubscriberPlugin() {}
   
     std::string getTopic() const override
     {
       if (impl_) {
         return impl_->sub_->get_topic_name();
       }
       return std::string();
     }
   
     size_t getNumPublishers() const override
     {
       if (impl_) {
         return impl_->sub_->get_publisher_count();
       }
       return 0;
     }
   
     void shutdown() override
     {
       impl_.reset();
     }
   
   protected:
     virtual void internalCallback(
       const typename std::shared_ptr<const M> & message,
       const Callback & user_cb) = 0;
   
     virtual std::string getTopicToSubscribe(const std::string & base_topic) const
     {
       return base_topic + "/" + getTransportName();
     }
   
     void subscribeImpl(
       rclcpp::Node * node,
       const std::string & base_topic,
       const Callback & callback,
       rmw_qos_profile_t custom_qos) override
     {
       impl_ = std::make_unique<Impl>();
       // Push each group of transport-specific parameters into a separate sub-namespace
       // ros::NodeHandle param_nh(transport_hints.getParameterNH(), getTransportName());
       //
       auto qos = rclcpp::QoS(rclcpp::QoSInitialization::from_rmw(custom_qos), custom_qos);
       impl_->sub_ = node->create_subscription<M>(
         getTopicToSubscribe(base_topic), qos,
         [this, callback](const typename std::shared_ptr<const M> msg) {
           internalCallback(msg, callback);
         });
     }
   
     void subscribeImplWithOptions(
       rclcpp::Node * node,
       const std::string & base_topic,
       const Callback & callback,
       rmw_qos_profile_t custom_qos,
       rclcpp::SubscriptionOptions options)
     {
       impl_ = std::make_unique<Impl>();
       // Push each group of transport-specific parameters into a separate sub-namespace
       // ros::NodeHandle param_nh(transport_hints.getParameterNH(), getTransportName());
       //
       auto qos = rclcpp::QoS(rclcpp::QoSInitialization::from_rmw(custom_qos), custom_qos);
       impl_->sub_ = node->create_subscription<M>(
         getTopicToSubscribe(base_topic), qos,
         [this, callback](const typename std::shared_ptr<const M> msg) {
           internalCallback(msg, callback);
         },
         options);
     }
   
   private:
     struct Impl
     {
       rclcpp::SubscriptionBase::SharedPtr sub_;
     };
   
     std::unique_ptr<Impl> impl_;
   };
   
   }  // namespace image_transport
   
   #endif  // IMAGE_TRANSPORT__SIMPLE_SUBSCRIBER_PLUGIN_HPP_