Merge pull request #2 from sakshikakde/ros_pub_sub

Ros pub sub

CMakeLists.txt

@@ -2,16 +2,18 @@ cmake_minimum_required(VERSION 2.8.3)
 project(beginner_tutorials)
 
 ## Find catkin and any catkin packages
-find_package(catkin REQUIRED COMPONENTS roscpp rospy std_msgs genmsg)
+find_package(catkin REQUIRED COMPONENTS roscpp rospy std_msgs)
 
 ## Declare a catkin package
-catkin_package()
+catkin_package(
+  INCLUDE_DIRS include
+)
 
 ## Build talker and listener
 include_directories(include ${catkin_INCLUDE_DIRS})
 
-add_executable(talker src/talker.cpp)
+add_executable(talker src/talker.cpp src/talker_node.cpp)
 target_link_libraries(talker ${catkin_LIBRARIES})
 
-add_executable(listener src/listener.cpp)
+add_executable(listener src/listener.cpp src/listener_node.cpp)
 target_link_libraries(listener ${catkin_LIBRARIES})

README.md

@@ -1 +1,67 @@
 # beginner_tutorials
+## Introduction
+This repository provides a simple example to run ROS publisher and sibscriber
+
+## File Structure
+- include       
+-- listener.hpp    
+-- talker.hpp   
+
+- src    
+-- listener.cpp    
+-- talker.cpp    
+-- listener_node.cpp     
+-- talker_node.cpp     
+
+listener_node.cpp and talker_node.cpp are the files where the objectes for the classes Listener and Talker are created.
+
+## Building the package
+1) Create a catkin workspace catkin_ws
+2) Clone the package inside catkin_ws/src using 
+
+``` 
+git clone https://github.com/sakshikakde/beginner_tutorials.git 
+```
+4) Change the directory
+```
+cd catkin_ws
+
+```
+5) run 
+
+``` 
+catkin build 
+```
+
+## How to run the code
+1) Change the directory 
+
+``` 
+cd catkin_ws
+
+```
+2)Source the workspace
+
+```
+sourcedevel/setup.bash
+```
+3) In a terminal, run 
+```
+roscore
+```
+5) In a new terminal, run the talker by using
+
+```
+rosrun beginner_tutorials talker
+
+```
+5) In a new terminal, run the listener by using
+```
+rosrun beginner_tutorials listener
+```
+
+
+
+
+
+

include/beginner_tutorials/listener.hpp

@@ -0,0 +1,58 @@
+/**
+ * @file listener.hpp
+ * @author Sakshi Kakde
+ * @brief A class to subscribe to a topic of type string
+ * @version 0.1
+ * @date 2021-10-31
+ * 
+ * @copyright Copyright (c) 2021
+ * 
+ */
+#ifndef INCLUDE_BEGINNER_TUTORIALS_LISTENER_HPP_
+#define INCLUDE_BEGINNER_TUTORIALS_LISTENER_HPP_
+
+#include <ros/ros.h>
+#include <std_msgs/String.h>
+#include <sstream>
+#include <string>
+
+class Listener {
+ public:
+    /**
+     * @brief Construct a new Listener object
+     * 
+     */
+    Listener();
+    /**
+     * @brief Destroy the Listener object
+     * 
+     */
+    ~Listener();
+    /**
+     * @brief waits for publisher to publish 
+     * 
+     */
+    void runNode();
+    ros::NodeHandle* nh_p;  // nodehandle
+
+ private:
+    std::string subscriber_topic_name;  // ROS subscriber topic name
+    ros::Subscriber chatter_sub;  // ROS Subscriber object
+    /**
+     * @brief Function to init params
+     * 
+     */
+    void initParams();
+    /**
+     * @brief Function to init subscribers
+     * 
+     */
+    void initSubscribers();
+    /**
+     * @brief Callback function for subscriber
+     * 
+     * @param msg Message received from publisher
+     */
+    void chatter_callback(const std_msgs::String::ConstPtr& msg);
+};
+#endif  // INCLUDE_BEGINNER_TUTORIALS_LISTENER_HPP_

include/beginner_tutorials/talker.hpp

@@ -0,0 +1,53 @@
+/**
+ * @file talker.hpp
+ * @author Sakshi Kakde
+ * @brief A class to publish string data on a topic
+ * @version 0.1
+ * @date 2021-10-31
+ * 
+ * @copyright Copyright (c) 2021
+ * 
+ */
+#ifndef INCLUDE_BEGINNER_TUTORIALS_TALKER_HPP_
+#define INCLUDE_BEGINNER_TUTORIALS_TALKER_HPP_
+
+#include <ros/ros.h>
+#include <std_msgs/String.h>
+#include <sstream>
+#include <string>
+
+class Talker {
+ public:
+    /**
+     * @brief Construct a new Talker object
+     * 
+     */
+    Talker();
+    /**
+     * @brief Destroy the Talker object
+     * 
+     */
+    ~Talker();
+    /**
+     * @brief Runs the ros::ok loop and publishes data at a predefined rate
+     * 
+     */
+    void runNode();
+    ros::NodeHandle* nh_p;  // nodehandle
+
+ private:
+    std::string publisher_topic_name;  // ROS publisher topic name
+    ros::Publisher chatter_pub;  // ROS publisher object
+    int publisher_rate;  // rate of publishing
+    /**
+     * @brief Function to init params
+     * 
+     */
+    void initParams();
+    /**
+     * @brief Function to init publishers
+     * 
+     */
+    void initPublishers();
+};
+#endif  // INCLUDE_BEGINNER_TUTORIALS_TALKER_HPP_

results/cppcheck_process.txt

@@ -0,0 +1,5 @@
+[include/beginner_tutorials/listener.hpp:19]: (style) class 'Listener' does not have a copy constructor which is recommended since the class contains a pointer to allocated memory.
+[src/talker.cpp:13]: (warning) Member variable 'Talker::publisher_rate' is not initialized in the constructor.
+[src/talker.cpp:19]: (warning) Member variable 'Talker::publisher_rate' is not initialized in the constructor.
+[src/talker.cpp:20]: (style) Value of pointer 'nh_p', which points to allocated memory, is copied in copy constructor instead of allocating new memory.
+[include/beginner_tutorials/talker.hpp:19]: (warning) The class 'Talker' has 'copy constructor' but lack of 'operator='.

results/cppcheck_result.txt

@@ -0,0 +1,8 @@
+Checking src/listener.cpp ...
+1/4 files checked 31% done
+Checking src/listener_node.cpp ...
+2/4 files checked 44% done
+Checking src/talker.cpp ...
+3/4 files checked 86% done
+Checking src/talker_node.cpp ...
+4/4 files checked 100% done

results/cpplint_result.txt

@@ -0,0 +1,6 @@
+Done processing ./include/beginner_tutorials/listener.hpp
+Done processing ./include/beginner_tutorials/talker.hpp
+Done processing ./src/listener.cpp
+Done processing ./src/listener_node.cpp
+Done processing ./src/talker.cpp
+Done processing ./src/talker_node.cpp

run_cppcheck.sh

@@ -0,0 +1,2 @@
+cppcheck --enable=all --std=c++11 -I include/ --suppress=missingIncludeSystem $( find . -name *.cpp | grep -vE -e "^./build/" -e "^./vendor/") --output-file=results/cppcheck_process.txt > results/cppcheck_result.txt
+echo "Done Processing. Results are stored in results/cppcheck_process.txt, results/cppcheck_result.txt"

run_cpplint.sh

@@ -0,0 +1,2 @@
+cpplint $( find . -name *.cpp | grep -vE -e "^./build/" -e "^./vendor/") $( find . -name *.hpp | grep -vE -e "^./build/" -e "^./vendor/") > results/cpplint_result.txt
+echo "Done Processing. Results are stored in results/cpplint_result.txt"

src/listener.cpp

@@ -1,58 +1,38 @@
-#include "ros/ros.h"
-#include "std_msgs/String.h"
-
 /**
- * This tutorial demonstrates simple receipt of messages over the ROS system.
+ * @file listener.cpp
+ * @author Sakshi Kakde
+ * @brief A class to subscribe to a topic of type string
+ * @version 0.1
+ * @date 2021-10-31
+ * 
+ * @copyright Copyright (c) 2021
+ * 
  */
-void chatterCallback(const std_msgs::String::ConstPtr& msg)
-{
-  ROS_INFO("I heard: [%s]", msg->data.c_str());
+#include <beginner_tutorials/listener.hpp>
+
+Listener::Listener() {
+    this->nh_p = new ros::NodeHandle("~");
+    initParams();
+    initSubscribers();
 }
 
-int main(int argc, char **argv)
-{
-  /**
-   * The ros::init() function needs to see argc and argv so that it can perform
-   * any ROS arguments and name remapping that were provided at the command line.
-   * For programmatic remappings you can use a different version of init() which takes
-   * remappings directly, but for most command-line programs, passing argc and argv is
-   * the easiest way to do it.  The third argument to init() is the name of the node.
-   *
-   * You must call one of the versions of ros::init() before using any other
-   * part of the ROS system.
-   */
-  ros::init(argc, argv, "listener");
+Listener::~Listener() {
+}
 
-  /**
-   * NodeHandle is the main access point to communications with the ROS system.
-   * The first NodeHandle constructed will fully initialize this node, and the last
-   * NodeHandle destructed will close down the node.
-   */
-  ros::NodeHandle n;
+void Listener::initParams() {
+    this->nh_p->param<std::string>("subscriber_topic_name",
+     this->subscriber_topic_name, "/chatter");
+}
 
-  /**
-   * The subscribe() call is how you tell ROS that you want to receive messages
-   * on a given topic.  This invokes a call to the ROS
-   * master node, which keeps a registry of who is publishing and who
-   * is subscribing.  Messages are passed to a callback function, here
-   * called chatterCallback.  subscribe() returns a Subscriber object that you
-   * must hold on to until you want to unsubscribe.  When all copies of the Subscriber
-   * object go out of scope, this callback will automatically be unsubscribed from
-   * this topic.
-   *
-   * The second parameter to the subscribe() function is the size of the message
-   * queue.  If messages are arriving faster than they are being processed, this
-   * is the number of messages that will be buffered up before beginning to throw
-   * away the oldest ones.
-   */
-  ros::Subscriber sub = n.subscribe("chatter", 1000, chatterCallback);
+void Listener::initSubscribers() {
+    this->chatter_sub = this->nh_p->subscribe(this->subscriber_topic_name,
+     1, &Listener::chatter_callback, this);
+}
 
-  /**
-   * ros::spin() will enter a loop, pumping callbacks.  With this version, all
-   * callbacks will be called from within this thread (the main one).  ros::spin()
-   * will exit when Ctrl-C is pressed, or the node is shutdown by the master.
-   */
-  ros::spin();
+void Listener::chatter_callback(const std_msgs::String::ConstPtr& msg) {
+    ROS_INFO("Yes, I heard [%s]", msg->data.c_str());
+}
 
-  return 0;
-}
+void Listener::runNode() {
+  ros::spin();
+}

src/listener_node.cpp

@@ -0,0 +1,18 @@
+/**
+ * @file listener_node.cpp
+ * @author Sakshi Kakde
+ * @brief Code to subscibe to a topic
+ * @version 0.1
+ * @date 2021-10-31
+ * 
+ * @copyright Copyright (c) 2021
+ * 
+ */
+#include <beginner_tutorials/listener.hpp>
+
+int main(int argc, char **argv) {
+  ros::init(argc, argv, "listener_node");
+  Listener listener;
+  listener.runNode();
+  return 0;
+}