OCCT

// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

// #include <Interface_Recognizer.ixx>
#include <Standard_NoSuchObject.hxx>

//  WARNING: TransRecognizer has exactly the same code ...
//  But produces a Transient instead of a Persistent

// Principle: from a starting object (key), a Recognizer attempts to associate a
// result. The Recognizer class provides the general mechanism managing this
// Each particular class (once the instantiation is defined) must provide
// a specific Eval method, which performs the correspondence
// Eval considers the object by all appropriate means, and in case of success,
// calls SetOK(result) then exits (return)
// in case of failure, following the return from Eval, Recognizer knows that SetOK was not
// called

Interface_Recognizer::Interface_Recognizer()
{
  hasnext = false;
}

// thekey.Nullify();  useless, done by the constructor ...

bool Interface_Recognizer::Evaluate(const TheKey& akey, occ::handle<TheResul>& res)
{
  theres.Nullify();
  Eval(akey);
  if (!theres.IsNull())
  {
    res = theres;
    return true;
  }
  else if (hasnext)
    return thenext->Evaluate(akey, res);
  return false;
}

occ::handle<TheResul> Interface_Recognizer::Result() const
{
  if (!theres.IsNull())
    return theres;
  if (hasnext)
    return thenext->Result();
  throw Standard_NoSuchObject("Recognizer evaluation has failed");
}

void Interface_Recognizer::Add(const occ::handle<Interface_Recognizer>& reco)
{
  thenext = reco;
  hasnext = true;
}

void Interface_Recognizer::SetOK(const occ::handle<TheResul>& aresult)
{
  theres = aresult;
}

void Interface_Recognizer::SetKO()
{
  theres.Nullify();
}