source: src/CodePatterns/Observer/Graveyard.hpp@ c1e104

/*
 * Graveyard.hpp
 *
 *  Created on: Sep 5, 2013
 *      Author: heber
 */

#ifndef GRAVEYARD_HPP_
#define GRAVEYARD_HPP_

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <map>

#include "CodePatterns/Observer/Zombie.hpp"

class GraveyardUnitTest;
class Observable;

/** The Graveyard takes of Observables instances that are about to get
 * destroyed but where it is necessary that all Observers that are still
 * signOn()'ed signOff() before the instance actually vanishes.
 *
 * For this the Graveyard takes Observable and turns/wraps them into a
 * Zombie class (that is basically just an Attorney pattern so far)
 * informing the Observable of a present Graveyard.
 *
 * \section graveyard-usage Usage
 *
 *   The Graveyard is really easy to use. Have an instance that lives
 *   long enough and use
 *   \code
 *    Observable *_obs = new Observable("_obs");
 *    Graveyard::turnZombies(_obs);
 *   \endcode
 *   in place pf
 *   \code
 *   delete _obs;
 *   \endcode
 *   The instance is fully destroyed as soon as all Observers are signOff()'d
 *
 */
class Graveyard
{
  //!> grant unit test access to private parts
  friend class GraveyardUnitTest;
public:
  Graveyard();
  ~Graveyard();

  /** This turns an Observable into a Zombie and takes over the ptr.
   *
   * \param _observable Observable to take control of
   */
  void turnZombie(Observable *&_observable);

private:
  friend class Observable;
  /** Function to be called by Observables if Observer's have signOff()ed.
   *
   * \param _observable calling Observable
   */
  void ObserverLeft(const Observable *_observable);

private:
  //!> typedef for internal list of zombies
  typedef std::map<const Observable*,Zombie::ptr> graveyard_t;
  //!> the list of currently active zombies
  graveyard_t graveyard;

  //!> static function to inform observer
  Observable::graveyard_informer_t graveyard_informer;
};

#endif /* GRAVEYARD_HPP_ */