include/opencascade/TObj_TReference.hxx

0001 // Created on: 2004-11-23
0002 // Created by: Pavel TELKOV
0003 // Copyright (c) 2004-2014 OPEN CASCADE SAS
0004 //
0005 // This file is part of Open CASCADE Technology software library.
0006 //
0007 // This library is free software; you can redistribute it and/or modify it under
0008 // the terms of the GNU Lesser General Public License version 2.1 as published
0009 // by the Free Software Foundation, with special exception defined in the file
0010 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0011 // distribution for complete text of the license and disclaimer of any warranty.
0012 //
0013 // Alternatively, this file may be used under the terms of Open CASCADE
0014 // commercial license or contractual agreement.
0015
0016 // The original implementation Copyright: (C) RINA S.p.A
0017
0018 #ifndef TObj_TReference_HeaderFile
0019 #define TObj_TReference_HeaderFile
0020
0021 #include <TDF_Attribute.hxx>
0022 #include <TDF_Label.hxx>
0023
0024 class TObj_Object;
0025 class Standard_GUID;
0026
0027 /**
0028  * Attribute for storing references to the objects which implement
0029  * TObj_Object interface in the OCAF tree.
0030  * Its persistency mechanism provides transparent method for storing
0031  * cross-model references.
0032  * Each reference, when created, registers itself in the referred object,
0033  * to support back references
0034  */
0035
0036 class TObj_TReference : public TDF_Attribute
0037 {
0038 public:
0039   //! Standard methods of OCAF attribute
0040
0041   //! Empty constructor
0042   Standard_EXPORT TObj_TReference();
0043
0044   //! This method is used in implementation of ID()
0045   static Standard_EXPORT const Standard_GUID& GetID();
0046
0047   //! Returns the ID of TObj_TReference attribute.
0048   Standard_EXPORT const Standard_GUID& ID() const override;
0049
0050 public:
0051   //! Method for create TObj_TReference object
0052
0053   //! Creates reference on TDF_Label <theLabel> to the object <theObject> and
0054   //! creates backreference from the object <theObject> to <theMaster> one.
0055   static Standard_EXPORT occ::handle<TObj_TReference> Set(
0056     const TDF_Label&                theLabel,
0057     const occ::handle<TObj_Object>& theObject,
0058     const occ::handle<TObj_Object>& theMaster);
0059
0060 public:
0061   //! Methods for setting and obtaining referenced object
0062
0063   //! Sets the reference to the theObject
0064   Standard_EXPORT void Set(const occ::handle<TObj_Object>& theObject,
0065                            const TDF_Label&                theMasterLabel);
0066
0067   //! Sets the reference to the theObject at indicated Label.
0068   //! It is method for persistent only. Don`t use anywhere else.
0069   Standard_EXPORT void Set(const TDF_Label& theLabel, const TDF_Label& theMasterLabel);
0070
0071   //! Returns the referenced theObject
0072   Standard_EXPORT occ::handle<TObj_Object> Get() const;
0073
0074   //! Returns the Label of master object.
0075   TDF_Label GetMasterLabel() const { return myMasterLabel; }
0076
0077   //! Returns the referred label.
0078   TDF_Label GetLabel() const { return myLabel; }
0079
0080 public:
0081   //! Redefined OCAF abstract methods
0082
0083   //! Returns an new empty TObj_TReference attribute. It is used by the
0084   //! copy algorithm.
0085   Standard_EXPORT occ::handle<TDF_Attribute> NewEmpty() const override;
0086
0087   //! Restores the backuped contents from <theWith> into this one. It is used
0088   //! when aborting a transaction.
0089   Standard_EXPORT void Restore(const occ::handle<TDF_Attribute>& theWith) override;
0090
0091   //! This method is used when copying an attribute from a source structure
0092   //! into a target structure.
0093   Standard_EXPORT void Paste(const occ::handle<TDF_Attribute>&       theInto,
0094                              const occ::handle<TDF_RelocationTable>& theRT) const override;
0095
0096   //! Remove back references of it reference if it is in other document.
0097   Standard_EXPORT void BeforeForget() override;
0098
0099   //! It is necessary for tranzaction mechanism (Undo/Redo).
0100   Standard_EXPORT bool BeforeUndo(const occ::handle<TDF_AttributeDelta>& theDelta,
0101                                   const bool                             isForced = false) override;
0102
0103   //! It is necessary for tranzaction mechanism (Undo/Redo).
0104   Standard_EXPORT bool AfterUndo(const occ::handle<TDF_AttributeDelta>& theDelta,
0105                                  const bool                             isForced = false) override;
0106
0107   //! Check if back reference exists for reference.
0108   Standard_EXPORT void AfterResume() override;
0109
0110   //! Called after retrieval reference from file.
0111   Standard_EXPORT bool AfterRetrieval(const bool forceIt = false) override;
0112
0113 private:
0114   //! Fields
0115   TDF_Label myLabel;       //!< Label that indicate referenced object
0116   TDF_Label myMasterLabel; //!< Label of object that have this reference.
0117
0118 public:
0119   //! CASCADE RTTI
0120   DEFINE_STANDARD_RTTIEXT(TObj_TReference, TDF_Attribute)
0121 };
0122
0123 //! Define handle class for TObj_TReference
0124 #endif
0125
0126 #ifdef _MSC_VER
0127 #pragma once
0128 #endif