// @(#)root/geom:$Id$

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#ifndef ROOT_TGeoGlobalMagField
#define ROOT_TGeoGlobalMagField

#include "TObject.h"

#include "TVirtualMagField.h"

class TGeoGlobalMagField : public TObject {
private:
   static TGeoGlobalMagField *fgInstance; // Static pointer to the field manager;
   TVirtualMagField *fField{nullptr};     // Magnetic field
   Bool_t fLock{kFALSE};                  // Lock flag for global field.

protected:
   TGeoGlobalMagField(const TGeoGlobalMagField &) = delete;
   TGeoGlobalMagField &operator=(const TGeoGlobalMagField &) = delete;
   void Unlock() { fLock = kFALSE; }

public:
   TGeoGlobalMagField();
   ~TGeoGlobalMagField() override;

   // Using SetField() makes a given field global. The field manager owns it from now on.
   TVirtualMagField *GetField() const { return fField; }
   void SetField(TVirtualMagField *field);
   Bool_t IsLocked() { return fLock; }
   void Lock();

   // The field manager should be accessed via TGeoGlobalMagField::Instance()
   static TGeoGlobalMagField *Instance();
   static TGeoGlobalMagField *GetInstance();

   // Inline access to Field() method
   void Field(const Double_t *x, Double_t *B)
   {
      if (fField)
         fField->Field(x, B);
   }

   ClassDefOverride(TGeoGlobalMagField, 0) // Global field manager
};

#endif