subscriber_impl.h

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#ifndef MESSAGE_TRANSPORT_SUBSCRIBER_IMPL_H
#define MESSAGE_TRANSPORT_SUBSCRIBER_IMPL_H

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#include "message_transport/subscriber_plugin.h"
#include <pluginlib/class_loader.h>
#include <boost/scoped_ptr.hpp>

namespace message_transport {

        class  SubscriberImplGen
        {
                public :
                        SubscriberImplGen() : unsubscribed_(false) { }

                        ~SubscriberImplGen()
                        {
                        }

                        bool isValid() const
                        {
                                return !unsubscribed_;
                        }

                        virtual void reset(const TransportHints& transport_hints) = 0;
                        void shutdown() {
                                this->shutdownImpl();
                        }
                        virtual void shutdownImpl() = 0;
                        virtual boost::shared_ptr< SubscriberPluginGen > getSubscriber() = 0;

                        template <class M> 
                                boost::shared_ptr< SubscriberPlugin<M> > getTemplateSubscriber() {
                    return boost::dynamic_pointer_cast< SubscriberPlugin<M> >(getSubscriber());
                                }


                        virtual std::vector<std::string> getDeclaredClasses() = 0;
                protected :

                        bool unsubscribed_;
        };

        template <class M>
                class  SubscriberImpl : public SubscriberImplGen
        {
                public:
                        SubscriberImpl(const std::string & packageName,const std::string & className)
                                : loader_(packageName, 
                                                std::string("message_transport::SubscriberPlugin<")+className+">") { }

                        ~SubscriberImpl() {
                                shutdownImpl();
                        }

                        virtual void shutdownImpl()
                        {
                                if (!unsubscribed_) {
                                        unsubscribed_ = true;
                                        subscriber_->shutdown();
                                }
                        }

                        virtual void reset(const TransportHints& transport_hints) {
                                std::string lookup_name = SubscriberPluginGen::getLookupName(transport_hints.getTransport());
#if ROS_VERSION_MINIMUM(1, 7, 0) // if current ros version is >= 1.7.0
                                subscriber_ = loader_.createInstance(lookup_name);
#else
                                subscriber_.reset(loader_.createClassInstance(lookup_name));
#endif
                        }

                        virtual boost::shared_ptr< SubscriberPluginGen > getSubscriber() {
                                return subscriber_;
                        }

                        virtual std::vector<std::string> getDeclaredClasses() {
                                return loader_.getDeclaredClasses();
                        }

                protected:

                        pluginlib::ClassLoader< SubscriberPlugin<M> > loader_;
            boost::shared_ptr< SubscriberPlugin<M> > subscriber_;
        };
};

#endif // MESSAGE_TRANSPORT_SUBSCRIBER_IMPL_H