roscpp_plugin_provider.cpp

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/*
 * Copyright (c) 2011, Dirk Thomas, TU Darmstadt
 * All rights reserved.
 *
 * 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 TU Darmstadt 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.
 */

#include "roscpp_plugin_provider.h"

#include "nodelet_plugin_provider.h"
#include <rqt_gui_cpp/plugin.h>

#include <qt_gui_cpp/plugin_provider.h>

#include <nodelet/nodelet.h>
#include <pluginlib/class_list_macros.h>
#include <ros/ros.h>

#include <stdexcept>
#include <sys/types.h>
#include <unistd.h>
#include <iostream>

namespace rqt_gui_cpp {

RosCppPluginProvider::RosCppPluginProvider()
  : qt_gui_cpp::CompositePluginProvider()
  , node_initialized_(false)
  , wait_for_master_dialog_(0)
  , wait_for_master_thread_(0)
{
  QList<PluginProvider*> plugin_providers;
  plugin_providers.append(new NodeletPluginProvider("rqt_gui", "rqt_gui_cpp::Plugin"));
  set_plugin_providers(plugin_providers);
}

RosCppPluginProvider::~RosCppPluginProvider()
{
  if (ros::isStarted())
  {
    ros::shutdown();
  }
}

void* RosCppPluginProvider::load(const QString& plugin_id, qt_gui_cpp::PluginContext* plugin_context)
{
  init_node();
  return qt_gui_cpp::CompositePluginProvider::load(plugin_id, plugin_context);
}

qt_gui_cpp::Plugin* RosCppPluginProvider::load_plugin(const QString& plugin_id, qt_gui_cpp::PluginContext* plugin_context)
{
  init_node();
  return qt_gui_cpp::CompositePluginProvider::load_plugin(plugin_id, plugin_context);
}

void RosCppPluginProvider::wait_for_master()
{
  // check if master is available
  if (ros::master::check())
  {
    return;
  }
  // spawn thread to detect when master becomes available
  wait_for_master_dialog_ = new QMessageBox(QMessageBox::Question, QObject::tr("Waiting for ROS master"), QObject::tr("Could not find ROS master. Either start a 'roscore' or abort loading the plugin."), QMessageBox::Abort);
  wait_for_master_thread_ = new WaitForMasterThread(wait_for_master_dialog_);
  wait_for_master_thread_->start();
  QObject::connect(wait_for_master_thread_, SIGNAL(master_found_signal(int)), wait_for_master_dialog_, SLOT(done(int)), Qt::QueuedConnection);
  int button = wait_for_master_dialog_->exec();
  // check if master existence was not detected by background thread
  bool no_master = (button != QMessageBox::Ok);
  if (no_master)
  {
    dynamic_cast<WaitForMasterThread*>(wait_for_master_thread_)->abort = true;
    wait_for_master_thread_->wait();
  }
  wait_for_master_thread_->exit();
  wait_for_master_thread_->deleteLater();
  wait_for_master_dialog_->deleteLater();
  wait_for_master_dialog_ = 0;
  if (no_master)
  {
    throw std::runtime_error("RosCppPluginProvider::init_node() could not find ROS master");
  }
}

void RosCppPluginProvider::init_node()
{
  // initialize ROS node once
  if (!node_initialized_)
  {
    int argc = 0;
    char** argv = 0;
    std::stringstream name;
    name << "rqt_gui_cpp_node_";
    name << getpid();
    qDebug("RosCppPluginProvider::init_node() initialize ROS node '%s'", name.str().c_str());
    ros::init(argc, argv, name.str().c_str(), ros::init_options::NoSigintHandler);
    wait_for_master();
    ros::start();
    node_initialized_ = true;
  }
  else
  {
    wait_for_master();
  }
}

WaitForMasterThread::WaitForMasterThread(QObject* parent)
  : QThread(parent)
  , abort(false)
{}

void WaitForMasterThread::run()
{
  while (true)
  {
    usleep(100000);
    if (abort)
    {
      break;
    }
    if (ros::master::check())
    {
      emit(master_found_signal(QMessageBox::Ok));
      break;
    }
  }
}

}

PLUGINLIB_EXPORT_CLASS(rqt_gui_cpp::RosCppPluginProvider, qt_gui_cpp::PluginProvider)