// Created on: 1992-11-02
// Created by: Christian CAILLET
// Copyright (c) 1992-1999 Matra Datavision
// 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.

#ifndef _Interface_EntityList_HeaderFile
#define _Interface_EntityList_HeaderFile

#include "Standard.hxx"
#include "Standard_DefineAlloc.hxx"
#include "Standard_Handle.hxx"

#include "Standard_Integer.hxx"
#include "Standard_Type.hxx"
class Interface_EntityIterator;

//! This class defines a list of Entities (Transient Objects),
//! it can be used as a field of other Transient classes, with
//! these features :
//! - oriented to define a little list, that is, slower than an
//! Array or a Map of Entities for a big count (about 100 and
//! over), but faster than a Sequence
//! - allows to work as a Sequence, limited to Clear, Append,
//! Remove, Access to an Item identified by its rank in the list
//! - space saving, compared to a Sequence, especially for little
//! amounts; better than an Array for a very little amount (less
//! than 10) but less good for a greater amount
//!
//! Works in conjunction with EntityCluster
//! An EntityList gives access to a list of Entity Clusters, which
//! are chained (in one sense : Single List)
//! Remark : a new Item may not be Null, because this is the
//! criterium used for "End of List"
class Interface_EntityList
{
public:
  DEFINE_STANDARD_ALLOC

  //! Creates a List as being empty
  Standard_EXPORT Interface_EntityList();

  //! Clears the List
  Standard_EXPORT void Clear();

  //! Appends an Entity, that is to the END of the list
  //! (keeps order, but works slowerly than Add, see below)
  Standard_EXPORT void Append(const occ::handle<Standard_Transient>& ent);

  //! Adds an Entity to the list, that is, with NO REGARD about the
  //! order (faster than Append if count becomes greater than 10)
  Standard_EXPORT void Add(const occ::handle<Standard_Transient>& ent);

  //! Removes an Entity from the list, if it is there
  Standard_EXPORT void Remove(const occ::handle<Standard_Transient>& ent);

  //! Removes an Entity from the list, given its rank
  Standard_EXPORT void Remove(const int num);

  //! Returns True if the list is empty
  Standard_EXPORT bool IsEmpty() const;

  //! Returns count of recorded Entities
  Standard_EXPORT int NbEntities() const;

  //! Returns an Item given its number. Beware about the way the
  //! list was filled (see above, Add and Append)
  Standard_EXPORT const occ::handle<Standard_Transient>& Value(const int num) const;

  //! Returns an Item given its number. Beware about the way the
  //! list was filled (see above, Add and Append)
  Standard_EXPORT void SetValue(const int num, const occ::handle<Standard_Transient>& ent);

  //! fills an Iterator with the content of the list
  //! (normal way to consult a list which has been filled with Add)
  Standard_EXPORT void FillIterator(Interface_EntityIterator& iter) const;

  //! Returns count of Entities of a given Type (0 : none)
  Standard_EXPORT int NbTypedEntities(const occ::handle<Standard_Type>& atype) const;

  //! Returns the Entity which is of a given type.
  //! If num = 0 (D), there must be ONE AND ONLY ONE
  //! If num > 0, returns the num-th entity of this type
  Standard_EXPORT occ::handle<Standard_Transient> TypedEntity(
    const occ::handle<Standard_Type>& atype,
    const int                         num = 0) const;

private:
  occ::handle<Standard_Transient> theval;
};

#endif // _Interface_EntityList_HeaderFile