/* -*- c++ -*- */
/*
 * Copyright 2004,2013 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_THRESHOLD_FF_H
#define INCLUDED_GR_THRESHOLD_FF_H

#include <blocks/api.h>
#include <gr_sync_block.h>

namespace gr {
  namespace blocks {

    /*!
     * \brief Output a 1 or zero based on a threshold value.
     * \ingroup misc_blk
     *
     * Test the incoming signal against a threshold. If the signal
     * excedes the \p hi value, it will output a 1 until the signal
     * falls below the \p lo value.
     */
    class BLOCKS_API threshold_ff : virtual public gr_sync_block
    {
    public:
      // gr::blocks::threshold_ff::sptr
      typedef boost::shared_ptr<threshold_ff> sptr;

      /* \brief Create a threadshold block.
       * \param lo Threshold input signal needs to drop below to
       *           change state to 0.
       * \param hi Threshold input signal needs to rise above to
       *           change state to 1.
       * \param initial_state Initial state of the block (0 or 1).
       */
      static sptr make(float lo, float hi, float initial_state=0);

      virtual float lo () const = 0;
      virtual void set_lo (float lo) = 0;
      virtual float hi () const = 0;
      virtual void set_hi (float hi) = 0;
      virtual float last_state () const = 0;
      virtual void set_last_state (float last_state) = 0;
    };

  } /* namespace blocks */
} /* namespace gr */

#endif /* INCLUDED_GR_THRESHOLD_FF_H */