C++ - How to write a qimessaging client

Introduction

This guide will teach you how to write a qimessaging client in C++, to interact with the various services offered by the robot.

Prerequisites

• An installed NAOqi SDK for your operating system.
• A C++ project setup in your favorite C++ development environment, ready to use the headers and libraries provided by the NAOqi SDK.

Creating a session

The first step to interact with qimessaging services is to connect a qi::Session to the Service Directory of the robot. The Service Directory address is represented by a standard URL.

One simple way to achieve this is to use the helper class ApplicationSession, which will fetch the URL from the command line (using the –qi-url option), or use a default value of localhost:

#include <iostream>
#include <qi/applicationsession.hpp>

int main(int argc, char** argv)
{
  qi::ApplicationSession app(argc, argv);
  qi::SessionPtr session = app.session();
  std::cerr << "Ready to roll!" << std::endl;
}

Using a service

You can use the service() method to get access to a service (local or remote). This method will return a qi::AnyObject.

#include <qi/applicationsession.hpp>

int main(int argc, char** argv)
{
  qi::ApplicationSession app(argc, argv);
  app.start();
  qi::SessionPtr session = app.session();
  qi::AnyObject tts = session->service("ALTextToSpeech");
  tts.call<void>("say", "Hello world!");
}

The tts object works as any other qi::AnyObject, please refer to its documentation for more detail.