subscription.h

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#ifndef ROSRTT_SUBSCRIPTION_H
#define ROSRTT_SUBSCRIPTION_H

#include "oro/channel_data_element.hpp"
#include "boost/function.hpp"
#include "connection_base.h"

namespace hpcl_rtt
{  

template<class M>
class Subscription : public ConnectionBase
{
public:
  //typedef boost::intrusive_ptr< Subscription<M> > shared_ptr;
  Subscription(const std::string& topic) : ConnectionBase(topic) {};
  Subscription(const std::string& topic, boost::function<void(M)> fp) : ConnectionBase(topic)
  {
    callback = fp;
  }
  ~Subscription() {};
  
  void setCallback(boost::function<void(M)> fp)
  {
    callback = fp;
  }
  
  bool channelReady( ChannelElementBase::shared_ptr end_port) 
  {
    if (end_port->inputReady ()) 
    {
      return true;
    }
    return false;
  }
  
  bool call()
  {
    FlowStatus result;
    M sample;
    typename ChannelElement<M>::shared_ptr input = static_cast< ChannelElement<M>* >( this->getChannelElement().get() );
    if ( input ) 
    {
      FlowStatus tresult = input->read(sample, false);
      // the result trickery is for not overwriting OldData with NoData.
      if (tresult == NewData) 
      {
        result = tresult;
        callback(sample);
        return true;
      }
      // stores OldData result
      if (tresult > result)
        result = tresult;
    }
    return false;
  }
private:
  boost::function<void(M)> callback;
};
  
  
}

#endif