/* -*- c++ -*- */

/*

 * Copyright 2004,2010 Free Software Foundation, Inc.

 * 

 * This file is part of GNU Radio

 * 

 * GNU Radio is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3, or (at your option)

 * any later version.

 * 

 * GNU Radio is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with GNU Radio; see the file COPYING.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street,

 * Boston, MA 02110-1301, USA.

 */

#ifndef INCLUDED_GR_NULL_SOURCE_H

#define INCLUDED_GR_NULL_SOURCE_H

#include <gr_core_api.h>

#include <gr_sync_block.h>

class gr_null_source;

typedef boost::shared_ptr<gr_null_source> gr_null_source_sptr;

GR_CORE_API gr_null_source_sptr

gr_make_null_source (size_t sizeof_stream_item);

/*!

 * \brief A source of zeros.

 * \ingroup source_blk

 */

class GR_CORE_API gr_null_source : public gr_sync_block

{

  friend GR_CORE_API gr_null_source_sptr gr_make_null_source (size_t sizeof_stream_item);

  gr_null_source (size_t sizeof_stream_item);

 public:

  virtual int work (int noutput_items,

                    gr_vector_const_void_star &input_items,

                    gr_vector_void_star &output_items);

};

#endif /* INCLUDED_GR_NULL_SOURCE_H */