~thumper/nux/next-changes

// -*- Mode: C++; indent-tabs-mode: nil; tab-width: 2 -*-

/*

 * Copyright 2010 Inalogic® Inc.

 *

 * This program is free software: you can redistribute it and/or modify it

 * under the terms of the GNU Lesser General Public License, as

 * published by the  Free Software Foundation; either version 2.1 or 3.0

 * of the License.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranties of

 * MERCHANTABILITY, SATISFACTORY QUALITY or FITNESS FOR A PARTICULAR

 * PURPOSE.  See the applicable version of the GNU Lesser General Public

 * License for more details.

 *

 * You should have received a copy of both the GNU Lesser General Public

 * License along with this program. If not, see <http://www.gnu.org/licenses/>

 *

 * Authored by: Jay Taoko <jaytaoko@inalogic.com>

 *

 */

#ifndef NOBJECTTYPE_H

#define NOBJECTTYPE_H

#include <string>

namespace nux

{

// TODO: write a nice is_instance (and is_derived_instance)

//template <typename T, typename I>

//bool is_instance(T const&

struct NObjectType

{

  const char* name;

  NObjectType* super;

  static const NObjectType  Null_Type;

  NObjectType()

    : name("Null_Type")

    , super(nullptr)

  {

  }

  NObjectType(const char* type_name, NObjectType* super_type)

    : name(type_name)

    , super(super_type)

  {

  }

  //! Return true is this has the same type as the argument type.

  inline bool operator == (const NObjectType &Type) const

  {

    return IsObjectType (Type);

  }

  //! Return true is this has is of a different type than the argument type.

  inline bool operator != (const NObjectType &Type) const

  {

    return !IsObjectType (Type);

  }

  //! Return true is this has the same type as the argument type.

  inline bool IsObjectType (const NObjectType &Type) const

  {

    return this == &Type;

  }

  //! Return true if this has the same type as the argument type or is derived from it.

  inline bool IsDerivedFromType (const NObjectType &Type) const

  {

    const NObjectType *current_type = this;

    while (current_type)

    {

      if (current_type == &Type)

        return true;

      current_type = current_type->super;

    }

    return false;

  }

  inline unsigned int SubClassDepth() const

  {

    const NObjectType* current_type = this;

    unsigned int depth = 0;

    while (current_type)

    {

      depth++;

      current_type = current_type->super;

    }

    return depth;

  }

};

#define NUX_DECLARE_OBJECT_TYPE(TypeName, SuperType)                            \

    public:                                                                 \

    typedef SuperType SuperObject;                                          \

    static ::nux::NObjectType StaticObjectType;                         \

    public:                                                                 \

    virtual ::nux::NObjectType& Type() const { return StaticObjectType; }          \

    ::nux::NObjectType& GetTypeInfo() const { return StaticObjectType; }

#define NUX_IMPLEMENT_OBJECT_TYPE(TypeName)                                     \

    ::nux::NObjectType TypeName::StaticObjectType(#TypeName, &TypeName::SuperObject::StaticObjectType);

#define NUX_DECLARE_ROOT_OBJECT_TYPE(TypeName)                                  \

    public:                                                                 \

    typedef ::nux::NObjectType SuperObject;                                        \

    static ::nux::NObjectType StaticObjectType;                                    \

    public:                                                                 \

    virtual ::nux::NObjectType& Type() const { return StaticObjectType; }          \

    ::nux::NObjectType& GetTypeInfo() const { return StaticObjectType; }

#define NUX_IMPLEMENT_ROOT_OBJECT_TYPE(TypeName)                                \

    ::nux::NObjectType TypeName::StaticObjectType(#TypeName, 0);

} // namespace nux

#endif // NOBJECTTYPE_H