Example code: Bumper module

On this page

This is an example of a module subscribing to an event. It implements a callback function that makes NAO speak every time its right bumper is pressed.

The whole example is available here: bumper.zip

Here are the sources of the module:

Source:

bumper.cpp


            
             /**
 * Copyright (c) 2011 Aldebaran Robotics
 */

#include "bumper.h"

#include <alvalue/alvalue.h>
#include <alcommon/alproxy.h>
#include <alcommon/albroker.h>
#include <qi/log.hpp>
#include <althread/alcriticalsection.h>

Bumper::Bumper(
  boost::shared_ptr<AL::ALBroker> broker,
  const std::string& name): AL::ALModule(broker, name),
    fCallbackMutex(AL::ALMutex::createALMutex())
{
  setModuleDescription("This module presents how to subscribe to a simple event (here RightBumperPressed) and use a callback method.");

  functionName("onRightBumperPressed", getName(), "Method called when the right bumper is pressed. Makes a LED animation.");
  BIND_METHOD(Bumper::onRightBumperPressed);
}

Bumper::~Bumper() {
  fMemoryProxy.unsubscribeToEvent("onRightBumperPressed", "Bumper");
}

void Bumper::init() {
  try {
    /** Create a proxy to ALMemory.
    */
    fMemoryProxy = AL::ALMemoryProxy(getParentBroker());

    fState = fMemoryProxy.getData("RightBumperPressed");
    /** Subscribe to event LeftBumperPressed
    * Arguments:
    * - name of the event
    * - name of the module to be called for the callback
    * - name of the bound method to be called on event
    */
    fMemoryProxy.subscribeToEvent("RightBumperPressed", "Bumper",
                                  "onRightBumperPressed");
  }
  catch (const AL::ALError& e) {
    qiLogError("module.example") << e.what() << std::endl;
  }
}

void Bumper::onRightBumperPressed() {
  qiLogInfo("module.example") << "Executing callback method on right bumper event" << std::endl;
  /**
  * As long as this is defined, the code is thread-safe.
  */
  AL::ALCriticalSection section(fCallbackMutex);

  /**
  * Check that the bumper is pressed.
  */
  fState =  fMemoryProxy.getData("RightBumperPressed");
  if (fState  > 0.5f) {
    return;
  }
  try {
    fTtsProxy = AL::ALTextToSpeechProxy(getParentBroker());
    fTtsProxy.say("Right bumper pressed");
  }
  catch (const AL::ALError& e) {
    qiLogError("module.example") << e.what() << std::endl;
  }
}

            
           

Main:

main.cpp


            
             /**
 * @author Emilie Wirbel
 *
 * \section Description
 * This file was generated by Aldebaran Robotics ModuleGenerator
 */

#include <signal.h>
#include <boost/shared_ptr.hpp>
#include <alcommon/albroker.h>
#include <alcommon/almodule.h>
#include <alcommon/albrokermanager.h>
#include <alcommon/altoolsmain.h>

#include "bumper.h"


#ifdef BUMPER_IS_REMOTE
# define ALCALL
#else
# ifdef _WIN32
#  define ALCALL __declspec(dllexport)
# else
#  define ALCALL
# endif
#endif

extern "C"
{
  ALCALL int _createModule(boost::shared_ptr<AL::ALBroker> pBroker)
  {
    // init broker with the main broker instance
    // from the parent executable
    AL::ALBrokerManager::setInstance(pBroker->fBrokerManager.lock());
    AL::ALBrokerManager::getInstance()->addBroker(pBroker);
      AL::ALModule::createModule<Bumper>( pBroker, "Bumper" );

    return 0;
  }

  ALCALL int _closeModule()
  {
    return 0;
  }
}

#ifdef BUMPER_IS_REMOTE
  int main(int argc, char *argv[])
  {
    // pointer to createModule
    TMainType sig;
    sig = &_createModule;
    // call main
    ALTools::mainFunction("bumper", argc, argv, sig);
  }
#endif

            
           

CMakeLists.txt:

The corresponding CMakeLists.txt file is:

CMakeLists.txt


            
             cmake_minimum_required(VERSION 2.8)
project(bumper)
find_package(qibuild)

option(BUMPER_IS_REMOTE
  "module is compiled as a remote module (ON or OFF)"
  ON)

set(_srcs
  main.cpp
  bumper.h
  bumper.cpp
)

if(BUMPER_IS_REMOTE)
  add_definitions(" -DBUMPER_IS_REMOTE ")
  qi_create_bin(bumper ${_srcs})
else()
  qi_create_lib(bumper SHARED ${_srcs} SUBFOLDER naoqi)
endif()

qi_use_lib(bumper ALCOMMON ALPROXIES ALTHREAD)