/**************************************************************************\
 *
 *  This file is part of the Coin 3D visualization library.
 *  Copyright (C) 1998-2006 by Systems in Motion.  All rights reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  ("GPL") version 2 as published by the Free Software Foundation.
 *  See the file LICENSE.GPL at the root directory of this source
 *  distribution for additional information about the GNU GPL.
 *
 *  For using Coin with software that can not be combined with the GNU
 *  GPL, and for taking advantage of the additional benefits of our
 *  support services, please contact Systems in Motion about acquiring
 *  a Coin Professional Edition License.
 *
 *  See http://www.coin3d.org/ for more information.
 *
 *  Systems in Motion, Postboks 1283, Pirsenteret, 7462 Trondheim, NORWAY.
 *  http://www.sim.no/  sales@sim.no  coin-support@coin3d.org
 *
\**************************************************************************/

/*!
  \class SoFieldConverter SoFieldConverter.h Inventor/engines/SoFieldConverter.h
  \brief The SoFieldConverter class is the abstract base class for field converters.
  \ingroup engines

  When fields of different types are attempted connected, the Coin
  library tries to find a field converter class which can be inserted
  between them, acting as a filter converting values from the master
  field to values matching the type of the slave field.

  If a value type conversion is possible (like between an SoSFFloat
  field and an SoSFInt32 field, for instance, where we could do a
  simple typecast for converting the value of one to the other), an
  SoFieldConverter derived object is inserted.

  This class is the abstract base superclass which all such field
  converters needs to inherit.

  Coin comes with one built-in field converter class which takes care
  of all possible field-to-field conversions we know about. This means
  applications programmers should seldom need to care about this
  class, it will probably only be useful if you expand the Coin
  library with your own field type classes. (Doing so is considered
  advanced use of the library.)

  \sa SoDB::addConverter()
 */

#include <Inventor/engines/SoFieldConverter.h>

#include <Inventor/fields/SoField.h>
#include <Inventor/engines/SoOutputData.h>
#include <Inventor/engines/SoConvertAll.h>
#include <Inventor/lists/SoTypeList.h>
#include <Inventor/lists/SoEngineOutputList.h>
#include <assert.h>
#include <Inventor/engines/SoSubEngineP.h>
#include <coindefs.h> // COIN_OBSOLETED

#if COIN_DEBUG
#include <Inventor/errors/SoDebugError.h>
#endif // COIN_DEBUG

/*!
  \fn SoField * SoFieldConverter::getInput(SoType type)

  Returns input field for the converter engine. Must be overridden in
  non-abstract converter engine classes.
*/
/*!
  \fn SoEngineOutput * SoFieldConverter::getOutput(SoType type)

  Returns output for the converter engine. Must be overridden in
  non-abstract converter engine classes.
*/


SO_ENGINE_ABSTRACT_SOURCE(SoFieldConverter);


/*!
  Default constructor.
*/
SoFieldConverter::SoFieldConverter(void)
{
#if COIN_DEBUG && 0 // debug
  SoDebugError::postInfo("SoFieldConverter::SoFieldConverter", "%p", this);
#endif // debug
}

/*!
  Default destructor.
*/
SoFieldConverter::~SoFieldConverter()
{
}

// doc in super
void
SoFieldConverter::initClass(void)
{
  SO_ENGINE_INTERNAL_INIT_ABSTRACT_CLASS(SoFieldConverter);
  SoFieldConverter::initClasses();
}

void
SoFieldConverter::initClasses(void)
{
  SoConvertAll::initClass();
}

/*!  
  This method is obsoleted in Coin. It should probably have been
  private in OIV.  
*/
SoField *
SoFieldConverter::getConnectedInput(void)
{
  COIN_OBSOLETED();
  return NULL;
}

/*!
  Returns fields which are connected as slaves of the engine output.
*/
int
SoFieldConverter::getForwardConnections(SoFieldList & l) const
{
  SoEngineOutputList outputlist;
  int n = 0;
  (void) this->getOutputs(outputlist);
  
  for (int i = 0; i < outputlist.getLength(); i++) {
    n += outputlist[i]->getForwardConnections(l);
  }
  return n;
}
