//
// ********************************************************************
// * License and Disclaimer                                           *
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//
//
// $Id$
//
//

#ifndef G4VRTScanner_H
#define G4VRTScanner_H 1

// class description:
//
// G4VRTScanner
// Interface class for provider of a sequence of window coordinates.

#include "globals.hh"

class G4VRTScanner {

public: // with description

  G4VRTScanner();
  virtual ~G4VRTScanner();
  
  virtual const G4String& GetGSName() const = 0;
  // Get name that acts as graphics system name.

  virtual const G4String& GetGSNickname() const = 0;
  // Get name that acts as graphics system nickname.  It is this that
  // the user specifies on the /vis/open and /vis/sceneHandler/create
  // commands.

  virtual void Initialize(G4int nRow, G4int nColumn) = 0;
  // Intialises scanner for window with nRow rows and nColumn columns.

  virtual G4bool Coords(G4int& iRow, G4int& iColumn) = 0;
  // Supplies coordinate (iRow,iColumn) and returns false when the
  // sequence has finished, i.e., on the call *after* suplying the
  // last valid coordinate.

  virtual void Draw
  (unsigned char red, unsigned char green, unsigned char blue);
  // Draw coloured square at current position.

};

inline
void G4VRTScanner::Draw(unsigned char, unsigned char, unsigned char) {}

#endif