display_factory.cpp

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/*
 * Copyright (c) 2012, Willow Garage, Inc.
 * 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 Willow Garage, Inc. 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 OWNER 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 <rviz/display_group.h>
 
#include <rviz/display_factory.h>
 
#include <tinyxml2.h>
 
namespace rviz
{
static Display* newDisplayGroup()
{
  return new DisplayGroup();
}
 
DisplayFactory::DisplayFactory() : PluginlibFactory<Display>("rviz", "rviz::Display")
{
  addBuiltInClass("rviz", "Group", "A container for Displays", &newDisplayGroup);
}
 
Display* DisplayFactory::makeRaw(const QString& class_id, QString* error_return)
{
  Display* display = PluginlibFactory<Display>::makeRaw(class_id, error_return);
  if (display)
  {
    display->setIcon(getIcon(class_id));
  }
  return display;
}
 
QSet<QString> DisplayFactory::getMessageTypes(const QString& class_id)
{
  // lookup in cache
  if (message_type_cache_.find(class_id) != message_type_cache_.end())
  {
    return message_type_cache_[class_id];
  }
 
  // Always initialize cache as empty so if we don't find it, next time
  // we won't look for it anymore either.
  message_type_cache_[class_id] = QSet<QString>();
 
  // parse xml plugin description to find out message types of all displays in it.
  QString xml_file = getPluginManifestPath(class_id);
 
  if (!xml_file.isEmpty())
  {
    ROS_DEBUG_STREAM("Parsing " << xml_file.toStdString());
    tinyxml2::XMLDocument document;
    document.LoadFile(xml_file.toStdString().c_str());
    tinyxml2::XMLElement* config = document.RootElement();
    if (config == nullptr)
    {
      ROS_ERROR("Skipping XML Document \"%s\" which had no Root Element.  This likely means the XML is "
                "malformed or missing.",
                xml_file.toStdString().c_str());
      return QSet<QString>();
    }
    if (std::string(config->Name()) != "library" && std::string(config->Name()) != "class_libraries")
    {
      ROS_ERROR("The XML document \"%s\" given to add must have either \"library\" or \
          \"class_libraries\" as the root tag",
                xml_file.toStdString().c_str());
      return QSet<QString>();
    }
    // Step into the filter list if necessary
    if (std::string(config->Name()) == "class_libraries")
    {
      config = config->FirstChildElement("library");
    }
 
    tinyxml2::XMLElement* library = config;
    while (library != nullptr)
    {
      tinyxml2::XMLElement* class_element = library->FirstChildElement("class");
      while (class_element)
      {
        std::string derived_class = class_element->Attribute("type");
 
        std::string current_class_id;
        if (class_element->Attribute("name") != nullptr)
        {
          current_class_id = class_element->Attribute("name");
          ROS_DEBUG("XML file specifies lookup name (i.e. magic name) = %s.", current_class_id.c_str());
        }
        else
        {
          ROS_DEBUG("XML file has no lookup name (i.e. magic name) for class %s, assuming class_id == "
                    "real class name.",
                    derived_class.c_str());
          current_class_id = derived_class;
        }
 
        QSet<QString> message_types;
        tinyxml2::XMLElement* message_type = class_element->FirstChildElement("message_type");
 
        while (message_type)
        {
          if (message_type->GetText())
          {
            const char* message_type_str = message_type->GetText();
            ROS_DEBUG_STREAM(current_class_id << " supports message type " << message_type_str);
            message_types.insert(QString(message_type_str));
          }
          message_type = message_type->NextSiblingElement("message_type");
        }
 
        message_type_cache_[QString::fromStdString(current_class_id)] = message_types;
 
        // step to next class_element
        class_element = class_element->NextSiblingElement("class");
      }
      library = library->NextSiblingElement("library");
    }
  }
 
  // search cache again.
  if (message_type_cache_.find(class_id) != message_type_cache_.end())
  {
    return message_type_cache_[class_id];
  }
 
  return QSet<QString>();
}
 
 
} // end namespace rviz