// $Id$
//-----------------------------------------------------------------------
//       The GSI Online Offline Object Oriented (Go4) Project
//         Experiment Data Processing at EE department, GSI
//-----------------------------------------------------------------------
// Copyright (C) 2000- GSI Helmholtzzentrum für Schwerionenforschung GmbH
//                     Planckstr. 1, 64291 Darmstadt, Germany
// Contact:            http://go4.gsi.de
//-----------------------------------------------------------------------
// This software can be used under the license agreements as stated
// in Go4License.txt file which is part of the distribution.
//-----------------------------------------------------------------------

#ifndef TGO4EVENTSOURCE_H
#define TGO4EVENTSOURCE_H

#include "TNamed.h"

/** The abstract interface class for the raw event source.
 * Raw events are delivered from the raw event source, may be stored in a raw event store, and are processed
 * (unpacked) by a subelement factory to construct the user event (the
 * user detector data, respectively)
 * @interface
 * @author J. Adamczewski
 * @since 12/2000 */

class TGo4EventElement;

class TGo4EventSource : public TNamed {
   public:

      TGo4EventSource(const char* name);

      virtual ~TGo4EventSource();

      TGo4EventSource();

      /* We overwrite the default TNamed::Clear that would
       *  erase our name and title!
       * Implement this method in your parameter class
       * if you would like to reset any values with the
       * eraser button in the gui remote browser*/
      virtual void Clear(Option_t* opt="");

      /** Status value of server/file open. */
      Int_t GetCreateStatus() const { return fiCreateStatus; }

      /** Status of the last event. */
      Int_t GetEventStatus() const { return fiEventStatus; }

      /** Status/ error message of the last event. */
      const char* GetErrMess() const { return fxErrMess.Data(); }

      /** Access to the name of the currently active source.
       * for filelist, this is the active input file */
      virtual const char* GetActiveName();

      /** Check that event class is supported by event source */
      virtual Bool_t CheckEventClass(TClass* cl);

      /** Fill the destination event dest. */
      virtual Bool_t BuildEvent(TGo4EventElement* dest) { return kTRUE; }

      /** Default timeout in seconds for event input. */
      static const Int_t fgiTIMEOUTDEFAULT;


   protected:
      /**
       * To be used for modification of the message
       * by the event source implementation.
       */
      void SetErrMess(const char* txt) { fxErrMess = txt; }

      /** Status of the last event. */
      void SetEventStatus(Int_t status) { fiEventStatus=status; }

      /** Status value of event source init (file/server open). */
      void SetCreateStatus(Int_t status) { fiCreateStatus=status; }

      /** Exception thrower. */
      void ThrowError(Int_t creastat, Int_t errstat, const char* message,...);

      /** EOF thrower. */
      void ThrowEOF(Int_t creastat, Int_t errstat, const char* message,...);

      /** text length */
      enum { fguTXTLEN = 256 };

   private:

      /** Contains return value of eventsource open (e.g. f_evt_get_open) call. May be checked by the creating factory after return from source ctor. */
      Int_t fiCreateStatus;

      /** Contains return value of eventsource getevent (e.g. f_evt_get_event)  call. May be checked by the controlling event loop.*/
      Int_t fiEventStatus;

      /** Most recent error message. May be delivered by f_evt_error, for example. */
      TString fxErrMess; //!

      ClassDef(TGo4EventSource,1)
};

#endif //TGO4EVENTSOURCE_H