.. _program_listing_file__tmp_ws_src_demos_intra_process_demo_include_image_pipeline_image_view_node.hpp:

Program Listing for File image_view_node.hpp
============================================

|exhale_lsh| :ref:`Return to documentation for file <file__tmp_ws_src_demos_intra_process_demo_include_image_pipeline_image_view_node.hpp>` (``/tmp/ws/src/demos/intra_process_demo/include/image_pipeline/image_view_node.hpp``)

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

.. code-block:: cpp

   // Copyright 2015 Open Source Robotics Foundation, 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.
   
   #ifndef IMAGE_PIPELINE__IMAGE_VIEW_NODE_HPP_
   #define IMAGE_PIPELINE__IMAGE_VIEW_NODE_HPP_
   
   #include <sstream>
   #include <string>
   
   #include "opencv2/highgui/highgui.hpp"
   #include "rclcpp/rclcpp.hpp"
   #include "sensor_msgs/msg/image.hpp"
   
   #include "common.hpp"
   
   class ImageViewNode final : public rclcpp::Node
   {
   public:
     explicit ImageViewNode(
       const std::string & input, const std::string & node_name = "image_view_node",
       bool watermark = true)
     : Node(node_name, rclcpp::NodeOptions().use_intra_process_comms(true))
     {
       // Create a subscription on the input topic.
       sub_ = this->create_subscription<sensor_msgs::msg::Image>(
         input,
         rclcpp::SensorDataQoS(),
         [node_name, watermark](sensor_msgs::msg::Image::ConstSharedPtr msg) {
           // Create a cv::Mat from the image message (without copying).
           cv::Mat cv_mat(
             msg->height, msg->width,
             encoding2mat_type(msg->encoding),
             const_cast<unsigned char *>(msg->data.data()));
           if (watermark) {
             // Annotate with the pid and pointer address.
             std::stringstream ss;
             ss << "pid: " << GETPID() << ", ptr: " << msg.get();
             draw_on_image(cv_mat, ss.str(), 60);
           }
           // Show the image.
           cv::Mat c_mat = cv_mat;
           cv::imshow(node_name.c_str(), c_mat);
           char key = cv::waitKey(1);    // Look for key presses.
           if (key == 27 /* ESC */ || key == 'q') {
             rclcpp::shutdown();
           }
           if (key == ' ') {    // If <space> then pause until another <space>.
             key = '\0';
             while (key != ' ') {
               key = cv::waitKey(1);
               if (key == 27 /* ESC */ || key == 'q') {
                 rclcpp::shutdown();
               }
               if (!rclcpp::ok()) {
                 break;
               }
             }
           }
         });
     }
   
   private:
     rclcpp::Subscription<sensor_msgs::msg::Image>::SharedPtr sub_;
   
     cv::VideoCapture cap_;
     cv::Mat frame_;
   };
   
   #endif  // IMAGE_PIPELINE__IMAGE_VIEW_NODE_HPP_