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//
// $Id: G4FieldManagerStore.hh,v 1.3 2008/01/17 09:39:08 gcosmo Exp $
// GEANT4 tag $Name: geant4-09-03 $
//
// class G4FieldManagerStore
//
// Class description:
//
// Container for all FieldManagers, with functionality derived from
// std::vector<T>. The class is a `singleton', in that only
// one can exist, and access is provided via the static function
// G4FieldManagerStore::GetInstance()
//
// All FieldManagers should be registered with G4FieldManagerStore,
// and removed on their destruction. 
// Intended principally to enable resetting of 'state' at start of event.
// The underlying container initially has a capacity of 100.
//
// Member data:
//
// static G4FieldManagerStore* fgInstance
//   - Ptr to the single G4FieldManagerStore.

// History:
// 07.12.07 J.Apostolakis  Initial version
// --------------------------------------------------------------------
#ifndef G4FIELDMANAGERSTORE_HH
#define G4FIELDMANAGERSTORE_HH

#include <vector>

#include "G4FieldManager.hh"

class G4FieldManagerStore : public std::vector<G4FieldManager*>
{
  public:  // with description

    static void Register(G4FieldManager* pVolume);
      // Add the logical volume to the collection.
    static void DeRegister(G4FieldManager* pVolume);
      // Remove the logical volume from the collection.
    static G4FieldManagerStore* GetInstance();
      // Get a ptr to the unique G4FieldManagerStore, creating it if necessary.
    static void Clean();
      // Delete all volumes from the store.

    void ClearAllChordFindersState();
      // Looping over all field managers, call each one to reset step estimate

    virtual ~G4FieldManagerStore();
      // Destructor: takes care to delete allocated field managers.

  protected:
  
    G4FieldManagerStore();

  private:

    static G4FieldManagerStore* fgInstance;
    static G4bool locked;
};

#endif
