text: /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
  /*
   * Copyright (c) 2006,2007 INRIA
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation;
   *
   * This program 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 this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
   */
  #ifndef MOBILITY_MODEL_H
  #define MOBILITY_MODEL_H
  
  #include "ns3/vector.h"
  #include "ns3/object.h"
  #include "ns3/traced-callback.h"
  
  namespace ns3 {
  
  /**
   * \ingroup mobility
   * \brief Keep track of the current position and velocity of an object.
   *
   * All space coordinates in this class and its subclasses are
   * understood to be meters or meters/s. i.e., they are all
   * metric international units.
   *
   * This is a base class for all specific mobility models.
   */
  class MobilityModel : public Object
  {
  public:
    static TypeId GetTypeId (void);
    MobilityModel ();
    virtual ~MobilityModel () = 0;
  
    /**
     * \return the current position
     */
    Vector GetPosition (void) const;
    /**
     * \param position the position to set.
     */
    void SetPosition (const Vector &position);
    /**
     * \return the current velocity.
     */
    Vector GetVelocity (void) const;
    /**
     * \param position a reference to another mobility model
     * \return the distance between the two objects. Unit is meters.
     */
    double GetDistanceFrom (Ptr<const MobilityModel> position) const;
  protected:
    /**
     * Must be invoked by subclasses when the course of the
     * position changes to notify course change listeners.
     */
    void NotifyCourseChange (void) const;
  private:
    /**
     * \return the current position.
     *
     * Concrete subclasses of this base class must 
     * implement this method.
     */
    virtual Vector DoGetPosition (void) const = 0;
    /**
     * \param position the position to set.
     *
     * Concrete subclasses of this base class must 
     * implement this method.
     */
    virtual void DoSetPosition (const Vector &position) = 0;
    /**
     * \return the current velocity.
     *
     * Concrete subclasses of this base class must 
     * implement this method.
     */
    virtual Vector DoGetVelocity (void) const = 0;
  
    /**
     * Used to alert subscribers that a change in direction, velocity,
     * or position has occurred.
     */
    TracedCallback<Ptr<const MobilityModel> > m_courseChangeTrace;
  
  };
  
  } // namespace ns3
  
  #endif /* MOBILITY_MODEL_H */
  