plugin_factory.hpp

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// Copyright 2024 Kotaro Uetake.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#ifndef AWVIZ_COMMON__PLUGIN_FACTORY_HPP_
#define AWVIZ_COMMON__PLUGIN_FACTORY_HPP_
 
#include <pluginlib/class_loader.hpp>
 
#include <iostream>
#include <memory>
#include <string>
#include <vector>
 
namespace awviz_common
{
struct PluginInfo
{
  std::string id;           
  std::string name;         
  std::string type;         
  std::string package;      
  std::string description;  
};
 
template <typename T>
class PluginFactory
{
public:
  PluginFactory(const std::string & package, const std::string & base_class_type)
  {
    class_loader_ = std::make_shared<pluginlib::ClassLoader<T>>(package, base_class_type);
  }
 
  std::string get_plugin_manifest_path(const std::string & lookup_name) const
  {
    return class_loader_->getPluginManifestPath(lookup_name);
  }
 
  PluginInfo get_plugin_info(const std::string & lookup_name) const
  {
    auto name = class_loader_->getName(lookup_name);
    auto type = class_loader_->getClassType(lookup_name);
    auto package = class_loader_->getClassPackage(lookup_name);
    auto description = class_loader_->getClassDescription(lookup_name);
    return {lookup_name, name, type, package, description};
  }
 
  virtual std::shared_ptr<T> create_instance(const std::string & lookup_name) const
  {
    try {
      return class_loader_->createSharedInstance(lookup_name);
    } catch (pluginlib::PluginlibException & ex) {
      std::cerr << "[PluginlibException]: " << ex.what() << std::endl;
      return nullptr;
    }
  }
 
  std::vector<std::string> get_declared_classes() const
  {
    return class_loader_->getDeclaredClasses();
  }
 
private:
  std::shared_ptr<pluginlib::ClassLoader<T>> class_loader_;  
};
}  // namespace awviz_common
#endif  // AWVIZ_COMMON__PLUGIN_FACTORY_HPP_