pluginlib_factory.h

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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
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef PLUGINLIB_FACTORY_H
#define PLUGINLIB_FACTORY_H

#include <QHash>
#include <QString>
#include <QStringList>

#include <string>
#include <vector>

#ifndef Q_MOC_RUN
#include <pluginlib/class_loader.hpp>
#endif

#include "rviz/class_id_recording_factory.h"
#include "rviz/load_resource.h"

namespace rviz
{
template <class Type>
class PluginlibFactory : public ClassIdRecordingFactory<Type>
{
private:
  struct BuiltInClassRecord
  {
    QString class_id_;
    QString package_;
    QString name_;
    QString description_;
    Type* (*factory_function_)();
  };

public:
  PluginlibFactory(const QString& package, const QString& base_class_type)
  {
    class_loader_ =
        new pluginlib::ClassLoader<Type>(package.toStdString(), base_class_type.toStdString());
  }
  ~PluginlibFactory() override
  {
    delete class_loader_;
  }

  QStringList getDeclaredClassIds() override
  {
    QStringList ids;
    std::vector<std::string> std_ids = class_loader_->getDeclaredClasses();
    for (size_t i = 0; i < std_ids.size(); i++)
    {
      ids.push_back(QString::fromStdString(std_ids[i]));
    }
    typename QHash<QString, BuiltInClassRecord>::const_iterator iter;
    for (iter = built_ins_.begin(); iter != built_ins_.end(); iter++)
    {
      ids.push_back(iter.key());
    }
    return ids;
  }

  QString getClassDescription(const QString& class_id) const override
  {
    typename QHash<QString, BuiltInClassRecord>::const_iterator iter = built_ins_.find(class_id);
    if (iter != built_ins_.end())
    {
      return iter->description_;
    }
    return QString::fromStdString(class_loader_->getClassDescription(class_id.toStdString()));
  }

  QString getClassName(const QString& class_id) const override
  {
    typename QHash<QString, BuiltInClassRecord>::const_iterator iter = built_ins_.find(class_id);
    if (iter != built_ins_.end())
    {
      return iter->name_;
    }
    return QString::fromStdString(class_loader_->getName(class_id.toStdString()));
  }

  QString getClassPackage(const QString& class_id) const override
  {
    typename QHash<QString, BuiltInClassRecord>::const_iterator iter = built_ins_.find(class_id);
    if (iter != built_ins_.end())
    {
      return iter->package_;
    }
    return QString::fromStdString(class_loader_->getClassPackage(class_id.toStdString()));
  }

  virtual QString getPluginManifestPath(const QString& class_id) const
  {
    typename QHash<QString, BuiltInClassRecord>::const_iterator iter = built_ins_.find(class_id);
    if (iter != built_ins_.end())
    {
      return "";
    }
    return QString::fromStdString(class_loader_->getPluginManifestPath(class_id.toStdString()));
  }

  QIcon getIcon(const QString& class_id) const override
  {
    QString package = getClassPackage(class_id);
    QString class_name = getClassName(class_id);
    QIcon icon = loadPixmap("package://" + package + "/icons/classes/" + class_name + ".svg");
    if (icon.isNull())
    {
      icon = loadPixmap("package://" + package + "/icons/classes/" + class_name + ".png");
      if (icon.isNull())
      {
        icon = loadPixmap("package://rviz/icons/default_class_icon.png");
      }
    }
    return icon;
  }

  virtual void addBuiltInClass(const QString& package,
                               const QString& name,
                               const QString& description,
                               Type* (*factory_function)())
  {
    BuiltInClassRecord record;
    record.class_id_ = package + "/" + name;
    record.package_ = package;
    record.name_ = name;
    record.description_ = description;
    record.factory_function_ = factory_function;
    built_ins_[record.class_id_] = record;
  }

protected:
  Type* makeRaw(const QString& class_id, QString* error_return = nullptr) override
  {
    typename QHash<QString, BuiltInClassRecord>::const_iterator iter = built_ins_.find(class_id);
    if (iter != built_ins_.end())
    {
      Type* instance = iter->factory_function_();
      if (instance == nullptr && error_return != nullptr)
      {
        *error_return = "Factory function for built-in class '" + class_id + "' returned NULL.";
      }
      return instance;
    }
    try
    {
      return class_loader_->createUnmanagedInstance(class_id.toStdString());
    }
    catch (pluginlib::PluginlibException& ex)
    {
      ROS_ERROR("PluginlibFactory: The plugin for class '%s' failed to load.  Error: %s",
                qPrintable(class_id), ex.what());
      if (error_return)
      {
        *error_return = QString::fromStdString(ex.what());
      }
      return nullptr;
    }
  }

private:
  pluginlib::ClassLoader<Type>* class_loader_;
  QHash<QString, BuiltInClassRecord> built_ins_;
};

} // end namespace rviz

#endif // PLUGINLIB_FACTORY_H