create STIR loop over listmode events

[EveLMedPhys]

roughly...

 shared_ptr<ListModeData> lm(stir::read_from_file<ListModeData>(filename));
  shared_ptr <ListRecord> record_sptr = lm_data_ptr->get_empty_record_sptr();
  ListRecord& record = *record_sptr;
 while(true)
{
		 if (lm_data_ptr->get_next_record(record) == Succeeded::no) 
		   {
		     // no more events in file for some reason
		     break; //get out of while loop
		   }
         if (record.is_time() )
		   {
		     current_time = record.time().get_time_in_secs();
                     // do something
		   }
		 if (record.is_event())
		   {
                     // going to bins, but probably best to use record.event().get_LOR()
		     Bin bin;
                     bin.time_frame_num() = current_frame_num;
                    get_bin_from_event(bin, record.event());
		     		       
		     // check if it's inside the range we want to store
		     if (bin.get_bin_value()>0
			    {
			   }
		       }
		   } // end of spatial event processing
	       } // end of while loop over all events

``

[ghost]

This comes from here: https://github.com/UCL/STIR/blob/master/src/listmode_buildblock/LmToProjData.cxx#L592-L866

[ghost]

We need access to the empty records. Currently we can get a shared smart point to one via lm_data_ptr->get_empty_record_sptr(). However, we need to likely expend stir::ListModeData (in swig) to give us the following.

%extend stir::ListModeData {
    % Cut other methods...
    static ListRecord& get_empty_record()
    {
      using namespace stir;
      shared_ptr <ListRecord> record_sptr = lm_data_ptr->get_empty_record_sptr()
      return *record_sptr;
    }
}

[KrisThielemans]

should just be

%shared_ptr(stir:ListRecord)
%include "stir/listmode/ListRecord.h"

somewhere here

[KrisThielemans]

Actually, the listmode loop is documented in the stir::ListmodeData doxygen: https://github.com/UCL/STIR/blob/734a0d713df4318cea10f1a8ec5aea90ca093254/src/include/stir/listmode/ListModeData.h#L44

[KrisThielemans]

See UCL/STIR#1288 (WIP)

[KrisThielemans]

The STIR PR is merged. However, we could abandon the Python effort, so I'm going to close this.