// This code implementation is the intellectual property of
// the GEANT4 collaboration.
//
// By copying, distributing or modifying the Program (or any work
// based on the Program) you indicate your acceptance of this statement,
// and all its terms.
//
// $Id: EXPO_Primary.icc,v 1.3 1999/12/15 14:48:41 gunter Exp $
// GEANT4 tag $Name: geant4-03-01 $
//
//  See also G4/run/example/EXPO_PrimaryGeneratorAction.cc.

#include <G4VUserPrimaryGeneratorAction.hh>

#include <globals.hh>
#include <G4Event.hh>
#include <G4ParticleGun.hh>
#include <G4ParticleTable.hh>
#include <G4ParticleDefinition.hh>

class EXPO_PrimaryGeneratorAction : public G4VUserPrimaryGeneratorAction
{
  private:
    G4ParticleGun* particleGun;
  public:
    EXPO_PrimaryGeneratorAction()  
      {
	G4int                 n_particle = 1;
	G4String              particleName;
	particleGun           = new G4ParticleGun(n_particle);
	G4ParticleTable*      particleTable = G4ParticleTable::GetParticleTable();
	G4ParticleDefinition* particle      = particleTable->FindParticle(particleName="e-");
	particleGun->SetParticleDefinition        (particle);
	particleGun->SetParticleEnergy            (1.*GeV);
	particleGun->SetParticleMomentumDirection (G4ThreeVector(1.,0.,0.));
	particleGun->SetParticlePosition          (G4ThreeVector(0.*cm,0.*cm,0.*cm));
      }
    ~EXPO_PrimaryGeneratorAction()
      {
	delete particleGun;
      }
    void GeneratePrimaries(G4Event* anEvent)
      {
	particleGun->GeneratePrimaryVertex(anEvent);
      }

};