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[modules/smesh.git] / src / SMESH / SMESH_subMesh.cxx
index 982b8ef54a23142981c67a51afb681f4be689245..128316dcf55c87817dbf3e556cb61bf02a660d35 100644 (file)
-//  SMESH SMESH : implementaion of SMESH idl descriptions
+// Copyright (C) 2007-2016  CEA/DEN, EDF R&D, OPEN CASCADE
+//
+// Copyright (C) 2003-2007  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
+// CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS
 //
-//  Copyright (C) 2003  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
-//  CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS 
-// 
-//  This library 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 of the License. 
-// 
-//  This library is distributed in the hope that it will be useful, 
-//  but WITHOUT ANY WARRANTY; without even the implied warranty of 
-//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
-//  Lesser General Public License for more details. 
-// 
-//  You should have received a copy of the GNU Lesser General Public 
-//  License along with this library; if not, write to the Free Software 
-//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA 
-// 
-//  See http://www.opencascade.org/SALOME/ or email : webmaster.salome@opencascade.org 
+// This library 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 of the License, or (at your option) any later version.
 //
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
 //
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 //
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
+
+//  SMESH SMESH : implementaion of SMESH idl descriptions
 //  File   : SMESH_subMesh.cxx
 //  Author : Paul RASCLE, EDF
 //  Module : SMESH
-//  $Header$
 
-using namespace std;
-using namespace std;
 #include "SMESH_subMesh.hxx"
+
+#include "SMDS_SetIterator.hxx"
+#include "SMESHDS_Mesh.hxx"
+#include "SMESH_Algo.hxx"
+#include "SMESH_Comment.hxx"
 #include "SMESH_Gen.hxx"
-#include "SMESH_Mesh.hxx"
+#include "SMESH_HypoFilter.hxx"
 #include "SMESH_Hypothesis.hxx"
-#include "SMESH_Algo.hxx"
+#include "SMESH_Mesh.hxx"
+#include "SMESH_MesherHelper.hxx"
+#include "SMESH_subMeshEventListener.hxx"
+
+#include <Basics_OCCTVersion.hxx>
+
 #include "utilities.h"
 #include "OpUtil.hxx"
+#include "Basics_Utils.hxx"
 
+#include <BRep_Builder.hxx>
+#include <BRep_Tool.hxx>
 #include <TopExp.hxx>
-#include <TopTools_IndexedDataMapOfShapeListOfShape.hxx>
-#include <TopTools_ListOfShape.hxx>
+#include <TopExp_Explorer.hxx>
+#include <TopTools_IndexedMapOfShape.hxx>
 #include <TopTools_ListIteratorOfListOfShape.hxx>
-#include <TColStd_ListIteratorOfListOfInteger.hxx>
+#include <TopTools_ListOfShape.hxx>
+#include <TopoDS.hxx>
+#include <TopoDS_Compound.hxx>
+#include <TopoDS_Iterator.hxx>
+#include <gp_Pnt.hxx>
+
+#include <Standard_OutOfMemory.hxx>
+#include <Standard_ErrorHandler.hxx>
+
+#include <numeric>
+
+using namespace std;
 
 //=============================================================================
 /*!
- *  default constructor:
+ * \brief Allocate some memory at construction and release it at destruction.
+ * Is used to be able to continue working after mesh generation breaks due to
+ * lack of memory
  */
 //=============================================================================
 
-SMESH_subMesh::SMESH_subMesh(int Id, 
-                            SMESH_Mesh* father,
-                            const Handle(SMESHDS_Mesh)& meshDS,
-                            const TopoDS_Shape & aSubShape)
+struct MemoryReserve
 {
-  //MESSAGE("SMESH_subMesh::SMESH_subMesh");
-  _subShape = aSubShape;
-  _meshDS = meshDS;
-  _subMeshDS =  meshDS->MeshElements(_subShape); // may be null ...
-  _father = father;
-  _Id = Id;
-  _vertexSet = false;        // only for Vertex subMesh
-  _dependenceAnalysed = false;
-  _dependantsFound = false;
+  char* myBuf;
+  MemoryReserve(): myBuf( new char[1024*1024*2] ){}
+  ~MemoryReserve() { delete [] myBuf; }
+};
+
+//=============================================================================
+/*!
+ *  default constructor:
+ */
+//=============================================================================
 
+SMESH_subMesh::SMESH_subMesh(int                  Id,
+                             SMESH_Mesh *         father,
+                             SMESHDS_Mesh *       meshDS,
+                             const TopoDS_Shape & aSubShape)
+{
+  _subShape           = aSubShape;
+  _subMeshDS          = meshDS->MeshElements(_subShape);   // may be null ...
+  _father             = father;
+  _Id                 = Id;
+  _dependenceAnalysed = _alwaysComputed = false;
+  _algo               = 0;
   if (_subShape.ShapeType() == TopAbs_VERTEX)
-    {
-      _algoState = HYP_OK;
-      _computeState = READY_TO_COMPUTE;
-    }
+  {
+    _algoState = HYP_OK;
+    _computeState = READY_TO_COMPUTE;
+  }
   else
-    {
-      _algoState = NO_ALGO;
-      _computeState = NOT_READY;
-    }
+  {
+    _algoState = NO_ALGO;
+    _computeState = NOT_READY;
+  }
+  _computeCost = 0; // how costly is to compute this sub-mesh
+  _realComputeCost = 0;
 }
 
 //=============================================================================
 /*!
- * 
+ *
  */
 //=============================================================================
 
 SMESH_subMesh::~SMESH_subMesh()
 {
-  MESSAGE("SMESH_subMesh::~SMESH_subMesh");
-  // ****
+  deleteOwnListeners();
 }
 
 //=============================================================================
 /*!
- * 
+ *
  */
 //=============================================================================
 
-int  SMESH_subMesh::GetId()
+int SMESH_subMesh::GetId() const
 {
   //MESSAGE("SMESH_subMesh::GetId");
   return _Id;
@@ -101,1315 +134,2456 @@ int  SMESH_subMesh::GetId()
 
 //=============================================================================
 /*!
- * Given a subShape, find the subMesh is associated to this subShape or
- * to a collection of shapes containing this subShape. Collection = compsolid,
- * shell, wire
+ *
  */
 //=============================================================================
 
-// bool SMESH_subMesh::Contains(const TopoDS_Shape & aSubShape)
-//   throw (SALOME_Exception)
-// {
-//   //MESSAGE("SMESH_subMesh::Contains");
-//   bool contains = false;
-//   int type = _subShape.ShapeType();
-//   int typesub = aSubShape.ShapeType();
-//   //SCRUTE(type)
-//   //SCRUTE(typesub)
-//   switch (type)
-//     {
-// //     case TopAbs_COMPOUND:
-// //       {
-// //  //MESSAGE("---");
-// //  throw SALOME_Exception(LOCALIZED("Compound not yet treated"));
-// //  break;
-// //       }
-//     case TopAbs_COMPSOLID:
-//       {
-//     //MESSAGE("---");
-//     for (TopExp_Explorer exp(aSubShape,TopAbs_SOLID);exp.More();exp.Next())
-//       {
-//         contains = _subShape.IsSame(exp.Current());
-//         if (contains) break;
-//       }
-//     break;
-//       }
-//     case TopAbs_SHELL:
-//       {
-//     //MESSAGE("---");
-//     for (TopExp_Explorer exp(aSubShape,TopAbs_FACE);exp.More();exp.Next())
-//       {
-//         contains = _subShape.IsSame(exp.Current());
-//         if (contains) break;
-//       }
-//     break;
-//       }
-//     case TopAbs_WIRE:
-//       {
-//     //MESSAGE("---");
-//     for (TopExp_Explorer exp(aSubShape,TopAbs_EDGE);exp.More();exp.Next())
-//       {
-//         contains = _subShape.IsSame(exp.Current());
-//         if (contains) break;
-//       }
-//     break;
-//       }
-//     case TopAbs_COMPOUND:
-//     case TopAbs_SOLID:
-//     case TopAbs_FACE:
-//     case TopAbs_EDGE:
-//     case TopAbs_VERTEX:
-//       {
-//     //MESSAGE("---");
-//     contains = _subShape.IsSame(aSubShape);
-//     break;
-//       }
-//     default:
-//       {
-//     break;
-//       }
-//     }
-//   //SCRUTE(contains);
-//   return contains;
-// }
+SMESHDS_SubMesh * SMESH_subMesh::GetSubMeshDS()
+{
+  // submesh appears in DS only when a mesher set nodes and elements on a shape
+  return _subMeshDS ? _subMeshDS : _subMeshDS = _father->GetMeshDS()->MeshElements(_subShape); // may be null
+}
 
 //=============================================================================
 /*!
- * 
+ *
  */
 //=============================================================================
 
-const Handle(SMESHDS_SubMesh)& SMESH_subMesh::GetSubMeshDS()
-  throw (SALOME_Exception)
+const SMESHDS_SubMesh * SMESH_subMesh::GetSubMeshDS() const
 {
-  //MESSAGE("SMESH_subMesh::GetSubMeshDS");
-  if (_subMeshDS.IsNull())
-    {
-      //MESSAGE("subMesh pointer still null, trying to get it...");
-      _subMeshDS =  _meshDS->MeshElements(_subShape); // may be null ...
-      if (_subMeshDS.IsNull())
-       {
-         MESSAGE("problem... subMesh still empty");
-         //NRI   ASSERT(0);
-         //NRI   throw SALOME_Exception(LOCALIZED(subMesh still empty));
-       }
-    }
-  return _subMeshDS;
+  return ((SMESH_subMesh*) this )->GetSubMeshDS();
 }
 
 //=============================================================================
 /*!
- * 
+ *
  */
 //=============================================================================
 
-SMESH_subMesh* SMESH_subMesh::GetFirstToCompute()
-  throw (SALOME_Exception)
+SMESHDS_SubMesh* SMESH_subMesh::CreateSubMeshDS()
 {
-  //MESSAGE("SMESH_subMesh::GetFirstToCompute");
-  const map<int, SMESH_subMesh*>& subMeshes = DependsOn();
-  SMESH_subMesh* firstToCompute = 0;
-
-  map<int, SMESH_subMesh*>::const_iterator itsub;
-  for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
-    {
-      SMESH_subMesh* sm = (*itsub).second;
-//       SCRUTE(sm->GetId());
-//       SCRUTE(sm->GetComputeState());
-      bool readyToCompute = (sm->GetComputeState() == READY_TO_COMPUTE);
-      if (readyToCompute)
-       {
-         firstToCompute = sm; 
-         //SCRUTE(sm->GetId());
-         break;
-       }
-    }
-  if (firstToCompute)
-    {
-      //MESSAGE("--- submesh to compute");
-      return firstToCompute;       // a subMesh of this
-    }
-  if (_computeState == READY_TO_COMPUTE)
-    {
-      //MESSAGE("--- this to compute");
-      return this;  // this
-    }
-  //MESSAGE("--- nothing to compute");
-  return 0;                                            // nothing to compute
+  if ( !GetSubMeshDS() ) {
+    SMESHDS_Mesh* meshDS = _father->GetMeshDS();
+    meshDS->NewSubMesh( meshDS->ShapeToIndex( _subShape ) );
+  }
+  return GetSubMeshDS();
 }
 
 //=============================================================================
 /*!
- * 
+ *
  */
 //=============================================================================
 
-bool SMESH_subMesh::SubMeshesComputed()
-  throw (SALOME_Exception)
+SMESH_subMesh *SMESH_subMesh::GetFirstToCompute()
 {
-  //MESSAGE("SMESH_subMesh::SubMeshesComputed");
-  const map<int, SMESH_subMesh*>& subMeshes = DependsOn();
-
-  bool subMeshesComputed = true;
-  map<int, SMESH_subMesh*>::const_iterator itsub;
-  for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
-    {
-      SMESH_subMesh* sm = (*itsub).second;
-//       SCRUTE(sm->GetId());
-//       SCRUTE(sm->GetComputeState());
-      bool computeOk =  (sm->GetComputeState() == COMPUTE_OK);
-      if (! computeOk)
-       {
-         subMeshesComputed = false;
-         SCRUTE(sm->GetId());
-         break;
-       }
-    }
-   return subMeshesComputed; 
+  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(true,false);
+  while ( smIt->more() ) {
+    SMESH_subMesh *sm = smIt->next();
+    if ( sm->GetComputeState() == READY_TO_COMPUTE )
+      return sm;
+  }
+  return 0;                     // nothing to compute
 }
 
-//=============================================================================
+//================================================================================
 /*!
- * 
+ * \brief Returns a current algorithm
  */
-//=============================================================================
+//================================================================================
 
-bool SMESH_subMesh::SubMeshesReady()
+SMESH_Algo* SMESH_subMesh::GetAlgo() const
 {
-  MESSAGE("SMESH_subMesh::SubMeshesReady");
-  const map<int, SMESH_subMesh*>& subMeshes = DependsOn();
+  if ( !_algo )
+  {
+    SMESH_subMesh* me = const_cast< SMESH_subMesh* >( this );
+    me->_algo = _father->GetGen()->GetAlgo( me );
+  }
+  return _algo;
+}
 
-  bool subMeshesReady = true;
-  map<int, SMESH_subMesh*>::const_iterator itsub;
-  for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
-    {
-      SMESH_subMesh* sm = (*itsub).second;
-//       SCRUTE(sm->GetId());
-//       SCRUTE(sm->GetComputeState());
-      bool computeOk = (    (sm->GetComputeState() == COMPUTE_OK)
-                        || (sm->GetComputeState() == READY_TO_COMPUTE)) ;
-      if (! computeOk)
-       {
-         subMeshesReady = false;
-         SCRUTE(sm->GetId());
-         break;
-       }
-    }
-  return subMeshesReady; 
+//================================================================================
+/*!
+ * \brief Allow algo->Compute() if a sub-shape of lower dim is meshed but
+ *        none mesh entity is bound to it (PAL13615, 2nd part)
+ */
+//================================================================================
+
+void SMESH_subMesh::SetIsAlwaysComputed(bool isAlCo)
+{
+  _alwaysComputed = isAlCo;
+  if ( _alwaysComputed )
+    _computeState = COMPUTE_OK;
+  else
+    ComputeStateEngine( CHECK_COMPUTE_STATE );
 }
 
-//=============================================================================
+//=======================================================================
 /*!
- * Construct dependence on first level subMeshes. complex shapes (compsolid, 
- * shell, wire) are not analysed the same way as simple shapes (solid, face,
- * edge). 
- * For collection shapes (compsolid, shell, wire) prepare a list of submeshes
- * with possible multiples occurences. Multiples occurences corresponds to
- * internal frontiers within shapes of the collection and must not be keeped.
- * See FinalizeDependence.
+ * \brief Return true if no mesh entities is bound to the submesh
  */
-//=============================================================================
+//=======================================================================
 
-const map<int, SMESH_subMesh*>& SMESH_subMesh::DependsOn()
+bool SMESH_subMesh::IsEmpty() const
 {
- if (_dependenceAnalysed) return _mapDepend;
+  if (SMESHDS_SubMesh * subMeshDS = ((SMESH_subMesh*)this)->GetSubMeshDS())
+    return (!subMeshDS->NbElements() && !subMeshDS->NbNodes());
+  return true;
+}
+
+//=======================================================================
+//function : IsMeshComputed
+//purpose  : check if _subMeshDS contains mesh elements
+//=======================================================================
 
- //MESSAGE("SMESH_subMesh::DependsOn");
+bool SMESH_subMesh::IsMeshComputed() const
+{
+  if ( _alwaysComputed )
+    return true;
+  // algo may bind a sub-mesh not to _subShape, eg 3D algo
+  // sets nodes on SHELL while _subShape may be SOLID
 
+  SMESHDS_Mesh* meshDS = _father->GetMeshDS();
+  int dim = SMESH_Gen::GetShapeDim( _subShape );
   int type = _subShape.ShapeType();
-  //SCRUTE(type);
-  switch (type)
+  for ( ; type <= TopAbs_VERTEX; type++) {
+    if ( dim == SMESH_Gen::GetShapeDim( (TopAbs_ShapeEnum) type ))
     {
-    case TopAbs_COMPOUND:
-      {
-       //MESSAGE("compound");
-       list<TopoDS_Shape> shellInSolid;
-       for (TopExp_Explorer exp(_subShape,TopAbs_SOLID);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-           for (TopExp_Explorer 
-                  exp2(exp.Current(),TopAbs_SHELL);exp2.More();exp2.Next())
-             {
-               shellInSolid.push_back(exp2.Current()); 
-             }
-         }
-       for (TopExp_Explorer exp(_subShape,TopAbs_SHELL);exp.More();exp.Next())
-         {
-           list<TopoDS_Shape>::iterator it1;
-           bool isInSolid = false;
-           for (it1 = shellInSolid.begin(); it1 != shellInSolid.end(); it1++)
-             {
-               TopoDS_Shape aShape = (*it1);
-               if (aShape.IsSame(exp.Current())) 
-               {
-                 isInSolid = true;
-                 break;
-               }
-             }
-           if (!isInSolid)
-             InsertDependence(exp.Current()); //only shell not in solid
-         }
-       for (TopExp_Explorer exp(_subShape,TopAbs_FACE);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-       for (TopExp_Explorer exp(_subShape,TopAbs_EDGE);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-       break;
-      }
-    case TopAbs_COMPSOLID:
-      {
-       //MESSAGE("compsolid");
-       for (TopExp_Explorer exp(_subShape,TopAbs_SOLID);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-//     list<TopoDS_Shape> shapeList;
-//     for (TopExp_Explorer exp(_subShape,TopAbs_SOLID);exp.More();exp.Next())
-//       {
-//         for (TopExp_Explorer 
-//                exp2(exp.Current(),TopAbs_FACE);exp2.More();exp2.Next())
-//           {
-//             shapeList.push_back(exp2.Current()); 
-//           }
-//       }
-//     FinalizeDependence(shapeList);
-       break;
-      }
-    case TopAbs_SHELL:
-      {
-       //MESSAGE("shell");
-       for (TopExp_Explorer exp(_subShape,TopAbs_FACE);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-//     list<TopoDS_Shape> shapeList;
-//     for (TopExp_Explorer exp(_subShape,TopAbs_FACE);exp.More();exp.Next())
-//       {
-//         for (TopExp_Explorer 
-//                exp2(exp.Current(),TopAbs_EDGE);exp2.More();exp2.Next())
-//           {
-//             shapeList.push_back(exp2.Current()); 
-//           }
-//       }
-//     FinalizeDependence(shapeList);
-       break;
-      }
-    case TopAbs_WIRE:
-      {
-       //MESSAGE("wire");
-       for (TopExp_Explorer exp(_subShape,TopAbs_EDGE);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-//     list<TopoDS_Shape> shapeList;
-//     for (TopExp_Explorer exp(_subShape,TopAbs_EDGE);exp.More();exp.Next())
-//       {
-//         for (TopExp_Explorer 
-//                exp2(exp.Current(),TopAbs_VERTEX);exp2.More();exp2.Next())
-//           {
-//             shapeList.push_back(exp2.Current()); 
-//           }
-//       }
-//     FinalizeDependence(shapeList);
-       break;
-      }
-    case TopAbs_SOLID:
-      {
-       //MESSAGE("solid");
-//     for (TopExp_Explorer exp(_subShape,TopAbs_SHELL);exp.More();exp.Next())
-//       {
-//         InsertDependence(exp.Current());
-//       }
-       for (TopExp_Explorer exp(_subShape,TopAbs_FACE);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-       break;
-      }
-    case TopAbs_FACE:
-      {
-       //MESSAGE("face");
-//     for (TopExp_Explorer exp(_subShape,TopAbs_WIRE);exp.More();exp.Next())
-//       {
-//         InsertDependence(exp.Current());
-//       }
-       for (TopExp_Explorer exp(_subShape,TopAbs_EDGE);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-       break;
-      }
-    case TopAbs_EDGE:
-      {
-       //MESSAGE("edge");
-       for (TopExp_Explorer exp(_subShape,TopAbs_VERTEX);exp.More();exp.Next())
-         {
-           InsertDependence(exp.Current());
-         }
-       break;
-      }
-    case TopAbs_VERTEX:
-      {
-       break;
-      }
-    default:
+      TopExp_Explorer exp( _subShape, (TopAbs_ShapeEnum) type );
+      for ( ; exp.More(); exp.Next() )
       {
-       break;
+        if ( SMESHDS_SubMesh * smDS = meshDS->MeshElements( exp.Current() ))
+        {
+          bool computed = (dim > 0) ? smDS->NbElements() : smDS->NbNodes();
+          if ( computed )
+            return true;
+        }
       }
     }
-  _dependenceAnalysed = true;
-  return _mapDepend;
+    else
+      break;
+  }
+
+  return false;
 }
 
 //=============================================================================
 /*!
- * For simple Shapes (solid, face, edge): add subMesh into dependence list.
+ * Return true if all sub-meshes have been meshed
  */
 //=============================================================================
 
-void SMESH_subMesh::InsertDependence(const TopoDS_Shape aSubShape)
+bool SMESH_subMesh::SubMeshesComputed(bool * isFailedToCompute/*=0*/) const
 {
-  //MESSAGE("SMESH_subMesh::InsertDependence");
-  //SMESH_subMesh* aSubMesh = _father->GetSubMeshContaining(aSubShape);
-  //SCRUTE(aSubMesh);
-  //if (! aSubMesh) aSubMesh = _father->GetSubMesh(aSubShape);
-
-  SMESH_subMesh* aSubMesh = _father->GetSubMesh(aSubShape);
-  int type = aSubShape.ShapeType();
-  int ordType = 9 - type; // 2 = Vertex, 8 = CompSolid
-  int cle = aSubMesh->GetId();
-  cle += 10000000 * ordType; // sort map by ordType then index
-  if (_mapDepend.find(cle) == _mapDepend.end())
-    {
-      _mapDepend[cle] = aSubMesh;
-      const map<int, SMESH_subMesh*>& subMap = aSubMesh->DependsOn();
-      map<int, SMESH_subMesh*>::const_iterator im;
-      for (im = subMap.begin(); im != subMap.end(); im++)
-       {
-         int clesub = (*im).first;
-         SMESH_subMesh* sm = (*im).second;
-         if (_mapDepend.find(clesub) == _mapDepend.end())
-           _mapDepend[clesub] = sm;
-       }
+  int myDim = SMESH_Gen::GetShapeDim( _subShape );
+  int dimToCheck = myDim - 1;
+  bool subMeshesComputed = true;
+  if ( isFailedToCompute ) *isFailedToCompute = false;
+  // check sub-meshes with upper dimension => reverse iteration
+  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,true);
+  while ( smIt->more() )
+  {
+    SMESH_subMesh *sm = smIt->next();
+    if ( sm->_alwaysComputed )
+      continue;
+    const TopoDS_Shape & ss = sm->GetSubShape();
+
+    // MSV 07.04.2006: restrict checking to myDim-1 only. Ex., there is no sense
+    // in checking of existence of edges if the algo needs only faces. Moreover,
+    // degenerated edges may have no sub-mesh, as after computing NETGEN_2D.
+    if ( !_algo || _algo->NeedDiscreteBoundary() ) {
+      int dim = SMESH_Gen::GetShapeDim( ss );
+      if (dim < dimToCheck)
+        break; // the rest sub-meshes are all of less dimension
     }
+    SMESHDS_SubMesh * ds = sm->GetSubMeshDS();
+    bool computeOk = ((sm->GetComputeState() == COMPUTE_OK ) ||
+                      (ds && ( dimToCheck ? ds->NbElements() : ds->NbNodes() )));
+    if (!computeOk)
+    {
+      subMeshesComputed = false;
 
+      if ( isFailedToCompute && !(*isFailedToCompute) )
+        *isFailedToCompute = ( sm->GetComputeState() == FAILED_TO_COMPUTE );
+
+      if ( !isFailedToCompute )
+        break;
+    }
+  }
+  return subMeshesComputed;
 }
-//=============================================================================
+
+//================================================================================
 /*!
- * For collection shapes (compsolid, shell, wire).
- * Add only subMesh figuring only once in multiset to dependence list 
+ * \brief Return cost of computing this sub-mesh. If hypotheses are not well defined,
+ *        zero is returned
+ *  \return int - the computation cost in abstract units.
  */
-//=============================================================================
+//================================================================================
 
-// void SMESH_subMesh::FinalizeDependence(list<TopoDS_Shape>& shapeList)
-// {
-//   //MESSAGE("SMESH_subMesh::FinalizeDependence");
-//   list<TopoDS_Shape>::iterator it1, it2;
-//   for(it1 = shapeList.begin(); it1 != shapeList.end(); it1++)
-//     {
-//       TopoDS_Shape aSubShape = (*it1);
-//       int count = 0;
-//       for(it2 = shapeList.begin(); it2 != shapeList.end(); it2++)
-//     {
-//       TopoDS_Shape other = (*it2);
-//       if (other.IsSame(aSubShape)) count++;
-//     }
-//       if (count == 1) InsertDependence(aSubShape);
-//       SCRUTE(count);
-//     }
-// }
+int SMESH_subMesh::GetComputeCost() const
+{
+  return _realComputeCost;
+}
 
-//=============================================================================
+//================================================================================
 /*!
- * 
+ * \brief Return cost of computing this sub-mesh. The cost depends on the shape type
+ *        and number of sub-meshes this one DependsOn().
+ *  \return int - the computation cost in abstract units.
  */
-//=============================================================================
+//================================================================================
 
- const TopoDS_Shape& SMESH_subMesh::GetSubShape()
+int SMESH_subMesh::computeCost() const
 {
-  //MESSAGE("SMESH_subMesh::GetSubShape");
-  return _subShape;
+  if ( !_computeCost )
+  {
+    int computeCost;
+    switch ( _subShape.ShapeType() ) {
+    case TopAbs_SOLID:
+    case TopAbs_SHELL: computeCost = 5000; break;
+    case TopAbs_FACE:  computeCost = 500; break;
+    case TopAbs_EDGE:  computeCost = 2; break;
+    default:           computeCost = 1;
+    }
+    SMESH_subMeshIteratorPtr childIt = getDependsOnIterator(/*includeSelf=*/false);
+    while ( childIt->more() )
+      computeCost += childIt->next()->computeCost();
+
+    ((SMESH_subMesh*)this)->_computeCost = computeCost;
+  }
+  return _computeCost;
 }
 
 //=============================================================================
 /*!
- * 
+ * Returns all sub-meshes this one depend on
  */
 //=============================================================================
 
-bool SMESH_subMesh::AlgoStateEngine(int event, SMESH_Hypothesis* anHyp)
-  throw (SALOME_Exception)
+const map < int, SMESH_subMesh * >& SMESH_subMesh::DependsOn()
 {
-  //  MESSAGE("SMESH_subMesh::AlgoStateEngine");
-  //SCRUTE(_algoState);
-  //SCRUTE(event);
-
-  // **** les retour des evenement shape sont significatifs
-  // (add ou remove fait ou non)
-  // le retour des evenement father n'indiquent pas que add ou remove fait
-  int dim = SMESH_Gen::GetShapeDim(_subShape);
-
-  if (dim < 1)
-    {
-      _algoState = HYP_OK;
-      //SCRUTE(_algoState);
-      return true;
-    }
-
-  SMESH_Gen* gen =_father->GetGen();
-  bool ret;
-  _oldAlgoState = _algoState;
-  bool modifiedHyp = false;  // if set to true, force event MODIF_ALGO_STATE
-                             // in ComputeStateEngine
+  if ( _dependenceAnalysed || !_father->HasShapeToMesh() )
+    return _mapDepend;
 
-  switch (_algoState)
+  int type = _subShape.ShapeType();
+  switch (type)
+  {
+  case TopAbs_COMPOUND:
+  {
+    list< TopoDS_Shape > compounds( 1, _subShape );
+    list< TopoDS_Shape >::iterator comp = compounds.begin();
+    for ( ; comp != compounds.end(); ++comp )
     {
-
-      // ----------------------------------------------------------------------
-
-    case NO_ALGO:
-      switch (event)
-       {
-       case ADD_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-         ret = _meshDS->AddHypothesis(_subShape, anHyp);
-         break;
-       case ADD_ALGO:
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-         if (anHyp->GetDim() <= SMESH_Gen::GetShapeDim(_subShape))
-           {
-             ret = _meshDS->AddHypothesis(_subShape, anHyp);
-//           if (ret &&(anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape)))
-//           if (ret &&(anHyp->GetShapeType() == _subShape.ShapeType()))
-             if (ret &&(anHyp->GetShapeType() & (1<< _subShape.ShapeType())))
-               {
-                 SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-                 ASSERT(algo);
-                 ret = algo->CheckHypothesis((*_father),_subShape);
-                 if (ret) SetAlgoState(HYP_OK);
-                 else SetAlgoState(MISSING_HYP);
-               }
-           }
-         break;
-       case REMOVE_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-         ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-         break;
-       case REMOVE_ALGO:
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-         ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-         break;
-       case ADD_FATHER_HYP:      // nothing to do
-         break;
-       case ADD_FATHER_ALGO:     // Algo just added in father
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-//       if (anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape))
-//       if (anHyp->GetShapeType() == _subShape.ShapeType())
-         if (anHyp->GetShapeType() & (1<< _subShape.ShapeType()))
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             ASSERT(algo);
-             ret = algo->CheckHypothesis((*_father),_subShape);
-             if (ret) SetAlgoState(HYP_OK);
-             else SetAlgoState(MISSING_HYP);
-           }
-         break;
-       case REMOVE_FATHER_HYP:    // nothing to do
-         break;
-       case REMOVE_FATHER_ALGO:   // nothing to do
-         break;
-       default:
-         ASSERT(0);
-         break;
-       }
-      break;
-
-      // ----------------------------------------------------------------------
-
-    case MISSING_HYP:
-      switch (event)
-       {
-       case ADD_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-         ret = _meshDS->AddHypothesis(_subShape, anHyp);
-         if (ret)
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             ASSERT(algo);
-             ret = algo->CheckHypothesis((*_father),_subShape);
-             if (ret) SetAlgoState(HYP_OK);
-             else SetAlgoState(MISSING_HYP);
-           }
-         break;
-       case ADD_ALGO:            //already existing algo : on father ?
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-         if (anHyp->GetDim() <= SMESH_Gen::GetShapeDim(_subShape))
-           {
-             ret = _meshDS->AddHypothesis(_subShape, anHyp);
-//           if (ret &&(anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape)))
-//           if (ret &&(anHyp->GetShapeType() == _subShape.ShapeType()))
-             if (ret &&(anHyp->GetShapeType() & (1<< _subShape.ShapeType())))
-               {
-                 SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-                 if (algo == NULL) // two algo on the same subShape...
-                   {
-                     MESSAGE("two algo on the same subshape not allowed");
-                     ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-                     ret = false;
-                   }
-                 else
-                   {
-                     ret = algo->CheckHypothesis((*_father),_subShape);
-                     if (ret) SetAlgoState(HYP_OK);
-                     else SetAlgoState(MISSING_HYP);
-                   }
-               }
-           }
-         break;
-       case REMOVE_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);  
-         ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-         break;
-       case REMOVE_ALGO:         // perhaps a father algo applies ?
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-         ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-//       if (ret &&(anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape)))
-//       if (ret &&(anHyp->GetShapeType() == _subShape.ShapeType()))
-         if (ret &&(anHyp->GetShapeType() & (1<<_subShape.ShapeType())))
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             if (algo == NULL)  // no more algo applying on subShape...
-               {
-                 SetAlgoState(NO_ALGO);
-               }
-             else
-               {
-                 ret = algo->CheckHypothesis((*_father),_subShape);
-                 if (ret) SetAlgoState(HYP_OK);
-                 else SetAlgoState(MISSING_HYP);
-               }
-           }
-         break;
-       case ADD_FATHER_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-         {
-           SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-           ASSERT(algo);
-           ret = algo->CheckHypothesis((*_father),_subShape);
-           if (ret) SetAlgoState(HYP_OK);
-           else SetAlgoState(MISSING_HYP);
-         }
-         break;
-       case ADD_FATHER_ALGO:     // detect if two algo of same dim on father
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-//       if (anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape))
-//       if (anHyp->GetShapeType() == _subShape.ShapeType())
-         if (anHyp->GetShapeType() & (1<< _subShape.ShapeType()))
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             if (algo == NULL)  // two applying algo on father
-               {
-                 MESSAGE("two applying algo on fatherShape...");
-                 SetAlgoState(NO_ALGO);
-               }
-             else
-               {
-                 ret = algo->CheckHypothesis((*_father),_subShape);
-                 if (ret) SetAlgoState(HYP_OK);
-                 else SetAlgoState(MISSING_HYP);
-               }
-           }
-         break;
-       case REMOVE_FATHER_HYP:    // nothing to do
-         break;
-       case REMOVE_FATHER_ALGO:
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-//       if (anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape))
-//       if (anHyp->GetShapeType() == _subShape.ShapeType())
-         if (anHyp->GetShapeType() & (1<< _subShape.ShapeType()))
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             if (algo == NULL)  // no more applying algo on father
-               {
-                 SetAlgoState(NO_ALGO);
-               }
-             else
-               {
-                 ret = algo->CheckHypothesis((*_father),_subShape);
-                 if (ret) SetAlgoState(HYP_OK);
-                 else SetAlgoState(MISSING_HYP);
-               }
-           }
-         break;
-       default:
-         ASSERT(0);
-         break;
-       }
-      break;
-
-      // ----------------------------------------------------------------------
-
-    case HYP_OK:
-      switch (event)
-       {
-       case ADD_HYP:
-         {
-           ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-           SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-           ASSERT(algo);
-           list<SMESHDS_Hypothesis*> originalUsedHyps
-             = algo->GetUsedHypothesis((*_father), _subShape); // copy
-           
-           ret = _meshDS->AddHypothesis(_subShape, anHyp);
-           if (ret)
-             {
-               ret = algo->CheckHypothesis((*_father),_subShape);
-               if (! ret) 
-                 {
-                   INFOS("two applying algo on the same shape not allowed");
-                   ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-                   ret = false;
-                 }
-               else  // compare SMESHDS_Hypothesis* lists (order important)
-                 {
-                   MESSAGE("---");
-                   const list<SMESHDS_Hypothesis*>& newUsedHyps
-                     = algo->GetUsedHypothesis((*_father), _subShape);
-                   modifiedHyp = (originalUsedHyps != newUsedHyps); 
-                 }
-             }
-         }
-         break;
-       case ADD_ALGO:            //already existing algo : on father ?
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-         if (anHyp->GetDim() <= SMESH_Gen::GetShapeDim(_subShape))
-           {
-             ret = _meshDS->AddHypothesis(_subShape, anHyp);
-//           if (ret &&(anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape)))
-//           if (ret &&(anHyp->GetShapeType() == _subShape.ShapeType()))
-             if (ret &&(anHyp->GetShapeType() & (1<< _subShape.ShapeType())))
-               {
-                 SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-                 if (algo == NULL) // two algo on the same subShape...
-                   {
-                     INFOS("two algo on the same subshape not allowed");
-                     ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-                     ret = false;
-                   }
-                 else
-                   {
-                     ret = algo->CheckHypothesis((*_father),_subShape);
-                     if (ret) SetAlgoState(HYP_OK);
-                     else SetAlgoState(MISSING_HYP);
-                   }
-               }
-           }
-         break;
-       case REMOVE_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-         ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-         if (ret)
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             ASSERT(algo);
-             ret = algo->CheckHypothesis((*_father),_subShape);
-             if (ret) SetAlgoState(HYP_OK);
-             else SetAlgoState(MISSING_HYP);
-             modifiedHyp = true;
-           }
-         break;
-       case REMOVE_ALGO:         // perhaps a father algo applies ?
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-         ret = _meshDS->RemoveHypothesis(_subShape, anHyp);
-//       if (ret &&(anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape)))
-//       if (ret &&(anHyp->GetShapeType() == _subShape.ShapeType()))
-         if (ret &&(anHyp->GetShapeType() & (1<< _subShape.ShapeType())))
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             if (algo == NULL)   // no more algo applying on subShape...
-               {
-                 SetAlgoState(NO_ALGO);
-               }
-             else
-               {
-                 ret = algo->CheckHypothesis((*_father),_subShape);
-                 if (ret) SetAlgoState(HYP_OK);
-                 else SetAlgoState(MISSING_HYP);
-               }
-           }
-         break;
-       case ADD_FATHER_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-         {
-           SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-           ASSERT(algo);
-           ret = algo->CheckHypothesis((*_father),_subShape);
-           if (ret) SetAlgoState(HYP_OK);
-           else SetAlgoState(MISSING_HYP);
-         }
-         break;
-       case ADD_FATHER_ALGO:     // detect if two algo of same dim on father
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-//       if (anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape))
-//       if (anHyp->GetShapeType() == _subShape.ShapeType())
-         if (anHyp->GetShapeType() & (1<< _subShape.ShapeType()))
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             if (algo == NULL)  // two applying algo on father
-               {
-                 MESSAGE("two applying algo on fatherShape...");
-                 SetAlgoState(NO_ALGO);
-               }
-             else
-               {
-                 ret = algo->CheckHypothesis((*_father),_subShape);
-                 if (ret) SetAlgoState(HYP_OK);
-                 else SetAlgoState(MISSING_HYP);
-               }
-           }
-         break;
-       case REMOVE_FATHER_HYP:
-         ASSERT(anHyp->GetType() == SMESHDS_Hypothesis::PARAM_ALGO);
-         {
-           SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-           ASSERT(algo);
-           ret = algo->CheckHypothesis((*_father),_subShape);
-           if (ret) SetAlgoState(HYP_OK);
-           else SetAlgoState(MISSING_HYP);
-         }
-         break;
-       case REMOVE_FATHER_ALGO:
-         ASSERT(anHyp->GetType() != SMESHDS_Hypothesis::PARAM_ALGO);
-//       if (anHyp->GetDim() == SMESH_Gen::GetShapeDim(_subShape))
-//       if (anHyp->GetShapeType() == _subShape.ShapeType())
-         if (anHyp->GetShapeType() & (1<< _subShape.ShapeType()))
-           {
-             SMESH_Algo* algo = gen->GetAlgo((*_father), _subShape);
-             if (algo == NULL)  // no more applying algo on father
-               {
-                 SetAlgoState(NO_ALGO);
-               }
-             else
-               {
-                 ret = algo->CheckHypothesis((*_father),_subShape);
-                 if (ret) SetAlgoState(HYP_OK);
-                 else SetAlgoState(MISSING_HYP);
-               }
-           }
-         break;
-       default:
-         ASSERT(0);
-         break;
-       }
-      break;
-
-      // ----------------------------------------------------------------------
-
-    default:
-      ASSERT(0);
-      break;
+      for ( TopoDS_Iterator sub( *comp ); sub.More(); sub.Next() )
+        switch ( sub.Value().ShapeType() )
+        {
+        case TopAbs_COMPOUND:  compounds.push_back( sub.Value() ); break;
+        case TopAbs_COMPSOLID: insertDependence( sub.Value(), TopAbs_SOLID ); break;
+        case TopAbs_SOLID:     insertDependence( sub.Value(), TopAbs_SOLID ); break;
+        case TopAbs_SHELL:     insertDependence( sub.Value(), TopAbs_FACE ); break;
+        case TopAbs_FACE:      insertDependence( sub.Value(), TopAbs_FACE ); break;
+        case TopAbs_WIRE:      insertDependence( sub.Value(), TopAbs_EDGE ); break;
+        case TopAbs_EDGE:      insertDependence( sub.Value(), TopAbs_EDGE ); break;
+        case TopAbs_VERTEX:    insertDependence( sub.Value(), TopAbs_VERTEX ); break;
+        default:;
+        }
     }
-  //SCRUTE(_algoState);
-  if ((_algoState != _oldAlgoState) || modifiedHyp)
-    int retc = ComputeStateEngine(MODIF_ALGO_STATE);
-  return ret;
+  }
+  break;
+  case TopAbs_COMPSOLID: insertDependence( _subShape, TopAbs_SOLID ); break;
+  case TopAbs_SOLID:     insertDependence( _subShape, TopAbs_FACE );
+  { /*internal EDGE*/    insertDependence( _subShape, TopAbs_EDGE, TopAbs_WIRE ); break; }
+  case TopAbs_SHELL:     insertDependence( _subShape, TopAbs_FACE ); break;
+  case TopAbs_FACE:      insertDependence( _subShape, TopAbs_EDGE ); break;
+  case TopAbs_WIRE:      insertDependence( _subShape, TopAbs_EDGE ); break;
+  case TopAbs_EDGE:      insertDependence( _subShape, TopAbs_VERTEX ); break;
+  default:;
+  }
+  _dependenceAnalysed = true;
+  return _mapDepend;
 }
 
-//=============================================================================
+//================================================================================
 /*!
- * 
+ * \brief Return a key for SMESH_subMesh::_mapDepend map
  */
-//=============================================================================
+//================================================================================
 
-void SMESH_subMesh::SetAlgoState(int state)
+namespace
 {
-  if (state != _oldAlgoState)
-//     int retc = ComputeStateEngine(MODIF_ALGO_STATE);
-  _algoState = state;
+  int dependsOnMapKey( TopAbs_ShapeEnum type, int shapeID )
+  {
+    int ordType = 9 - int(type);               // 2 = Vertex, 8 = CompSolid
+    int     cle = shapeID;
+    cle += 10000000 * ordType;    // sort map by ordType then index
+    return cle;
+  }
+  int dependsOnMapKey( const SMESH_subMesh* sm )
+  {
+    return dependsOnMapKey( sm->GetSubShape().ShapeType(), sm->GetId() );
+  }
 }
 
 //=============================================================================
 /*!
- * 
+ * Add sub-meshes on sub-shapes of a given type into the dependence map.
  */
 //=============================================================================
 
-void SMESH_subMesh::SubMeshesAlgoStateEngine(int event,
-                                            SMESH_Hypothesis* anHyp)
-    throw (SALOME_Exception)
+void SMESH_subMesh::insertDependence(const TopoDS_Shape aShape,
+                                     TopAbs_ShapeEnum   aSubType,
+                                     TopAbs_ShapeEnum   avoidType)
 {
-  //MESSAGE("SMESH_subMesh::SubMeshesAlgoStateEngine");
-  int dim = SMESH_Gen::GetShapeDim(_subShape);
-  if (dim > 1)
+  TopExp_Explorer sub( aShape, aSubType, avoidType );
+  for ( ; sub.More(); sub.Next() )
+  {
+    SMESH_subMesh *aSubMesh = _father->GetSubMesh( sub.Current() );
+    if ( aSubMesh->GetId() == 0 )
+      continue;  // not a sub-shape of the shape to mesh
+    int cle = dependsOnMapKey( aSubMesh );
+    if ( _mapDepend.find( cle ) == _mapDepend.end())
     {
-      const map<int, SMESH_subMesh*>& subMeshes = DependsOn();
-      
-      map<int, SMESH_subMesh*>::const_iterator itsub;
-      for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
-       {
-         SMESH_subMesh* sm = (*itsub).second;
-         sm->AlgoStateEngine(event, anHyp);
-       }
+      _mapDepend[cle] = aSubMesh;
+      const map < int, SMESH_subMesh * > & subMap = aSubMesh->DependsOn();
+      _mapDepend.insert( subMap.begin(), subMap.end() );
     }
+  }
 }
 
-//=============================================================================
+//================================================================================
 /*!
- * 
+ * \brief Return \c true if \a this sub-mesh depends on \a other
  */
-//=============================================================================
+//================================================================================
 
-void SMESH_subMesh::DumpAlgoState(bool isMain)
+bool SMESH_subMesh::DependsOn( const SMESH_subMesh* other ) const
 {
-  int dim = SMESH_Gen::GetShapeDim(_subShape);
-//   if (dim < 1) return;
-  if (isMain)
-    {
-      const map<int, SMESH_subMesh*>& subMeshes = DependsOn();
-      
-      map<int, SMESH_subMesh*>::const_iterator itsub;
-      for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
-       {
-         SMESH_subMesh* sm = (*itsub).second;
-         sm->DumpAlgoState(false);
-       } 
-    }
-  int type = _subShape.ShapeType();
-  MESSAGE("dim = " << dim << " type of shape " << type);
-  switch(_algoState)
-    {
-    case NO_ALGO: MESSAGE(" AlgoState = NO_ALGO"); break;
-    case MISSING_HYP: MESSAGE(" AlgoState = MISSING_HYP"); break;
-    case HYP_OK: MESSAGE(" AlgoState = HYP_OK"); break;
-    }
-  switch (_computeState)
-    {
-    case NOT_READY: MESSAGE(" ComputeState = NOT_READY"); break;
-    case READY_TO_COMPUTE: MESSAGE(" ComputeState = READY_TO_COMPUTE"); break;
-    case COMPUTE_OK: MESSAGE(" ComputeState = COMPUTE_OK"); break;
-    case FAILED_TO_COMPUTE: MESSAGE(" ComputeState = FAILED_TO_COMPUTE");break;
-    }
+  return other ? _mapDepend.count( dependsOnMapKey( other )) : false;
 }
 
-//=============================================================================
+//================================================================================
 /*!
- * 
+ * \brief Return \c true if \a this sub-mesh depends on a \a shape
  */
-//=============================================================================
+//================================================================================
 
-bool SMESH_subMesh::ComputeStateEngine(int event)
-  throw (SALOME_Exception)
+bool SMESH_subMesh::DependsOn( const int shapeID ) const
 {
-  //MESSAGE("SMESH_subMesh::ComputeStateEngine");
-  //SCRUTE(_computeState);
-  //SCRUTE(event);
-
-  int dim = SMESH_Gen::GetShapeDim(_subShape);
-
-  if (dim < 1)
-    {
-      if (_vertexSet) _computeState = COMPUTE_OK;
-      else _computeState = READY_TO_COMPUTE;
-      //SCRUTE(_computeState);
-      return true;
-    }
-  SMESH_Gen* gen =_father->GetGen();
-  SMESH_Algo* algo = 0;
-  bool ret;
-
-  switch(_computeState)
-    {
-
-      // ----------------------------------------------------------------------
-
-    case NOT_READY:
-      switch (event)
-       {
-       case MODIF_HYP:                // nothing to do
-         break;
-       case MODIF_ALGO_STATE:
-         if (_algoState == HYP_OK)
-           _computeState = READY_TO_COMPUTE;
-         break;
-       case COMPUTE:                  // nothing to do
-         break;
-       case CLEAN:                    // nothing to do
-         break;
-       case CLEANDEP:                 // nothing to do
-         RemoveSubMeshElementsAndNodes(); // recursive call...
-         break;
-       case SUBMESH_COMPUTED:         // nothing to do
-         break;
-       default:
-         ASSERT(0);
-         break;
-       }
-      break;
-
-      // ----------------------------------------------------------------------
-
-    case READY_TO_COMPUTE:
-      switch (event)
-       {
-       case MODIF_HYP:                // nothing to do
-         break;
-       case MODIF_ALGO_STATE:
-         _computeState = NOT_READY;
-         algo = gen->GetAlgo((*_father), _subShape);
-         if (algo)
-           {
-             ret = algo->CheckHypothesis((*_father),_subShape);
-             if (ret) _computeState = READY_TO_COMPUTE;
-           }
-         break;
-       case COMPUTE:
-         {
-           algo = gen->GetAlgo((*_father), _subShape);
-           ASSERT(algo);
-           ret = algo->CheckHypothesis((*_father),_subShape);
-           if (! ret)
-             {
-               MESSAGE("***** verify compute state *****");
-               _computeState = NOT_READY;
-               break;
-             }
-           ret = SubMeshesComputed();
-           if (!ret)
-             {
-               MESSAGE("Some SubMeshes not computed");
-               _computeState = FAILED_TO_COMPUTE;
-               break;
-             }
-           ret = algo->Compute((*_father),_subShape);
-           if (!ret)
-             {
-               MESSAGE("problem in algo execution: failed to compute");
-               _computeState = FAILED_TO_COMPUTE;
-               break;
-             }
-           else
-             {
-               _computeState = COMPUTE_OK;
-               UpdateDependantsState(); // send event SUBMESH_COMPUTED
-             }
-         }
-         break;
-       case CLEAN:
-         _computeState = NOT_READY;
-         algo = gen->GetAlgo((*_father), _subShape);
-         if (algo)
-           {
-             ret = algo->CheckHypothesis((*_father),_subShape);
-             if (ret) _computeState = READY_TO_COMPUTE;
-           }
-         break;
-       case CLEANDEP:
-         RemoveSubMeshElementsAndNodes();
-         _computeState = NOT_READY;
-         algo = gen->GetAlgo((*_father), _subShape);
-         if (algo)
-           {
-             ret = algo->CheckHypothesis((*_father),_subShape);
-             if (ret) _computeState = READY_TO_COMPUTE;
-           }
-         break;
-       case SUBMESH_COMPUTED:         // nothing to do
-         break;
-       default:
-         ASSERT(0);
-         break;
-       }
-      break;
-
-      // ----------------------------------------------------------------------
-
-    case COMPUTE_OK:
-      switch (event)
-       {
-       case MODIF_HYP:
-         CleanDependants();           // recursive recall with event CLEANDEP
-         break;
-       case MODIF_ALGO_STATE:
-         CleanDependants();           // recursive recall with event CLEANDEP
-         break;
-       case COMPUTE:                  // nothing to do
-         break;
-       case CLEAN:
-         CleanDependants();           // recursive recall with event CLEANDEP
-         break;
-       case CLEANDEP:
-         RemoveSubMeshElementsAndNodes();
-         _computeState = NOT_READY;
-         algo = gen->GetAlgo((*_father), _subShape);
-         if (algo)
-           {
-             ret = algo->CheckHypothesis((*_father),_subShape);
-             if (ret) _computeState = READY_TO_COMPUTE;
-           }
-         break;
-       case SUBMESH_COMPUTED:         // nothing to do
-         break;
-       default:
-         ASSERT(0);
-         break;
-       }
-      break;
-
-      // ----------------------------------------------------------------------
-
-    case FAILED_TO_COMPUTE:
-      switch (event)
-       {
-       case MODIF_HYP:
-         if (_algoState == HYP_OK)
-           _computeState = READY_TO_COMPUTE;
-         else _computeState = NOT_READY;
-         break;
-       case MODIF_ALGO_STATE:
-         if (_algoState == HYP_OK)
-           _computeState = READY_TO_COMPUTE;
-         else _computeState = NOT_READY;
-         break;
-       case COMPUTE:                  // nothing to do
-         break;
-       case CLEAN:
-         break;
-       case CLEANDEP:
-         RemoveSubMeshElementsAndNodes();
-         if (_algoState == HYP_OK)
-           _computeState = READY_TO_COMPUTE;
-         else _computeState = NOT_READY;
-         break;
-       case SUBMESH_COMPUTED:         // allow retry compute
-         if (_algoState == HYP_OK)
-           _computeState = READY_TO_COMPUTE;
-         else _computeState = NOT_READY;
-         break;
-       default:
-         ASSERT(0);
-         break;
-       }
-      break;
-
-      // ----------------------------------------------------------------------
-    default:
-      ASSERT(0);
-      break;
-    }
-
-  //SCRUTE(_computeState);
-  return ret;
+  return DependsOn( _father->GetSubMeshContaining( shapeID ));
 }
 
 //=============================================================================
 /*!
- * 
+ * Return a shape of \a this sub-mesh
  */
 //=============================================================================
 
-void SMESH_subMesh::UpdateDependantsState()
+const TopoDS_Shape & SMESH_subMesh::GetSubShape() const
 {
-  //MESSAGE("SMESH_subMesh::UpdateDependantsState");
-
-  const map<int, SMESH_subMesh*>& dependants = Dependants();
-  map<int, SMESH_subMesh*>::const_iterator its;
-  for (its = dependants.begin(); its != dependants.end(); its++)
-    {
-      SMESH_subMesh* sm = (*its).second;
-      //SCRUTE((*its).first);
-      sm->ComputeStateEngine(SUBMESH_COMPUTED);
-    }
+  return _subShape;
 }
 
-//=============================================================================
-/*!
- * 
- */
-//=============================================================================
+//=======================================================================
+//function : CanAddHypothesis
+//purpose  : return true if theHypothesis can be attached to me:
+//           its dimention is checked
+//=======================================================================
 
-void SMESH_subMesh::CleanDependants()
+bool SMESH_subMesh::CanAddHypothesis(const SMESH_Hypothesis* theHypothesis) const
 {
-  MESSAGE("SMESH_subMesh::CleanDependants");
-  // **** parcourir les ancetres dans l'ordre de dépendance
+  int aHypDim   = theHypothesis->GetDim();
+  int aShapeDim = SMESH_Gen::GetShapeDim(_subShape);
+  // issue 21106. Forbid 3D mesh on the SHELL
+  // if (aHypDim == 3 && aShapeDim == 3) {
+  //   // check case of open shell
+  //   //if (_subShape.ShapeType() == TopAbs_SHELL && !_subShape.Closed())
+  //   if (_subShape.ShapeType() == TopAbs_SHELL && !BRep_Tool::IsClosed(_subShape))
+  //     return false;
+  // }
+  if ( aHypDim <= aShapeDim )
+    return true;
+
+  return false;
+}
 
-  const map<int, SMESH_subMesh*>& dependants = Dependants();
-  map<int, SMESH_subMesh*>::const_iterator its;
-  for (its = dependants.begin(); its != dependants.end(); its++)
-    {
-      SMESH_subMesh* sm = (*its).second;
-      SCRUTE((*its).first);
-      sm->ComputeStateEngine(CLEANDEP);
-    }
-  ComputeStateEngine(CLEANDEP);
+//=======================================================================
+//function : IsApplicableHypotesis
+//purpose  :
+//=======================================================================
+
+bool SMESH_subMesh::IsApplicableHypotesis(const SMESH_Hypothesis* theHypothesis,
+                                          const TopAbs_ShapeEnum  theShapeType)
+{
+  if ( theHypothesis->GetType() > SMESHDS_Hypothesis::PARAM_ALGO)
+  {
+    // algorithm
+    if ( theHypothesis->GetShapeType() & (1<< theShapeType))
+      // issue 21106. Forbid 3D mesh on the SHELL
+      return !( theHypothesis->GetDim() == 3 && theShapeType == TopAbs_SHELL );
+    else
+      return false;
+  }
+
+  // hypothesis
+  switch ( theShapeType ) {
+  case TopAbs_VERTEX:
+  case TopAbs_EDGE:
+  case TopAbs_FACE:
+  case TopAbs_SOLID:
+    return SMESH_Gen::GetShapeDim( theShapeType ) == theHypothesis->GetDim();
+
+  case TopAbs_SHELL:
+    // Special case for algorithms, building 2D mesh on a whole shell.
+    // Before this fix there was a problem after restoring from study,
+    // because in that case algorithm is assigned before hypothesis
+    // (on shell in problem case) and hypothesis is checked on faces
+    // (because it is 2D), where we have NO_ALGO state.
+    // Now 2D hypothesis is also applicable to shells.
+    return (theHypothesis->GetDim() == 2 || theHypothesis->GetDim() == 3);
+
+//   case TopAbs_WIRE:
+//   case TopAbs_COMPSOLID:
+//   case TopAbs_COMPOUND:
+  default:;
+  }
+  return false;
 }
-//=============================================================================
+
+//================================================================================
 /*!
+ * \brief Treats modification of hypotheses definition
+ *  \param [in] event - what happens
+ *  \param [in] anHyp - a hypothesis
+ *  \return SMESH_Hypothesis::Hypothesis_Status - a treatment result.
  * 
+ * Optional description of a problematic situation (if any) can be retrieved
+ * via GetComputeError().
  */
-//=============================================================================
+//================================================================================
 
-void SMESH_subMesh::RemoveSubMeshElementsAndNodes()
+SMESH_Hypothesis::Hypothesis_Status
+  SMESH_subMesh::AlgoStateEngine(algo_event event, SMESH_Hypothesis * anHyp)
 {
-  MESSAGE("SMESH_subMesh::RemoveSubMeshElementsAndNodes");
-  SCRUTE(_subShape.ShapeType());
-  SCRUTE(_Id);
+  // **** les retour des evenement shape sont significatifs
+  // (add ou remove fait ou non)
+  // le retour des evenement father n'indiquent pas que add ou remove fait
+
+  SMESH_Hypothesis::Hypothesis_Status aux_ret, ret = SMESH_Hypothesis::HYP_OK;
+  if ( _Id == 0 ) return ret; // not a sub-shape of the shape to mesh
 
-  _subMeshDS =  _meshDS->MeshElements(_subShape);
-  if (!_subMeshDS.IsNull())
+  SMESHDS_Mesh* meshDS =_father->GetMeshDS();
+  SMESH_Algo*   algo   = 0;
+  _algo = 0;
+
+  if (_subShape.ShapeType() == TopAbs_VERTEX )
+  {
+    if ( anHyp->GetDim() != 0) {
+      if (event == ADD_HYP || event == ADD_ALGO)
+        return SMESH_Hypothesis::HYP_BAD_DIM;
+      else
+        return SMESH_Hypothesis::HYP_OK;
+    }
+    // 0D hypothesis
+    else if ( _algoState == HYP_OK ) {
+      // update default _algoState
+      if ( event != REMOVE_FATHER_ALGO )
+      {
+        _algoState = NO_ALGO;
+        algo = GetAlgo();
+        if ( algo ) {
+          _algoState = MISSING_HYP;
+          if ( event == REMOVE_FATHER_HYP ||
+               algo->CheckHypothesis(*_father,_subShape, aux_ret))
+            _algoState = HYP_OK;
+        }
+      }
+    }
+  }
+
+  int oldAlgoState = _algoState;
+  bool modifiedHyp = (event == MODIF_HYP);  // if set to true, force event MODIF_ALGO_STATE
+  SMESH_Algo* algoRequiringCleaning = 0;
+
+  bool isApplicableHyp = IsApplicableHypotesis( anHyp );
+
+  if (event == ADD_ALGO || event == ADD_FATHER_ALGO)
+  {
+    // -------------------------------------------
+    // check if a shape needed by algo is present
+    // -------------------------------------------
+    algo = static_cast< SMESH_Algo* >( anHyp );
+    if ( !_father->HasShapeToMesh() && algo->NeedShape() )
+      return SMESH_Hypothesis::HYP_NEED_SHAPE;
+    // ----------------------
+    // check mesh conformity
+    // ----------------------
+    if (isApplicableHyp && !_father->IsNotConformAllowed() && !IsConform( algo ))
+      return SMESH_Hypothesis::HYP_NOTCONFORM;
+
+    // check if all-dimensional algo is hidden by other local one
+    if ( event == ADD_ALGO ) {
+      SMESH_HypoFilter filter( SMESH_HypoFilter::HasType( algo->GetType() ));
+      filter.Or( SMESH_HypoFilter::HasType( algo->GetType()+1 ));
+      filter.Or( SMESH_HypoFilter::HasType( algo->GetType()+2 ));
+      if ( SMESH_Algo * curAlgo = (SMESH_Algo*)_father->GetHypothesis( this, filter, true ))
+        if ( !curAlgo->NeedDiscreteBoundary() )
+          algoRequiringCleaning = curAlgo;
+    }
+  }
+
+  // ----------------------------------
+  // add a hypothesis to DS if possible
+  // ----------------------------------
+  if (event == ADD_HYP || event == ADD_ALGO)
+  {
+    if ( ! CanAddHypothesis( anHyp )) // check dimension
+      return SMESH_Hypothesis::HYP_BAD_DIM;
+
+    if ( !anHyp->IsAuxiliary() && getSimilarAttached( _subShape, anHyp ) )
+      return SMESH_Hypothesis::HYP_ALREADY_EXIST;
+
+    if ( !meshDS->AddHypothesis(_subShape, anHyp))
+      return SMESH_Hypothesis::HYP_ALREADY_EXIST;
+  }
+
+  // --------------------------
+  // remove a hypothesis from DS
+  // --------------------------
+  if (event == REMOVE_HYP || event == REMOVE_ALGO)
+  {
+    if (!meshDS->RemoveHypothesis(_subShape, anHyp))
+      return SMESH_Hypothesis::HYP_OK; // nothing changes
+
+    if (event == REMOVE_ALGO)
     {
-      const TColStd_ListOfInteger& indElt
-       = _subMeshDS->GetIDElements();
-      TColStd_ListIteratorOfListOfInteger ite(indElt);
-      for (; ite.More(); ite.Next())
-       {
-         int eltId = ite.Value();
-         SCRUTE(eltId);
-         Handle (SMDS_MeshElement) elt = _meshDS->FindElement(eltId);
-         _subMeshDS->RemoveElement(elt);
-         _meshDS->RemoveElement(eltId);
-       }
-  
-      const TColStd_ListOfInteger& indNodes
-       = _subMeshDS->GetIDNodes();
-      TColStd_ListIteratorOfListOfInteger itn(indNodes);
-      for (; itn.More(); itn.Next())
-       {
-         int nodeId = itn.Value();
-         SCRUTE(nodeId);
-         Handle (SMDS_MeshElement) elt = _meshDS->FindNode(nodeId);
-         Handle (SMDS_MeshNode) node = _meshDS->GetNode(1, elt);
-         _subMeshDS->RemoveNode(node);
-         _meshDS->RemoveNode(nodeId);
-       }
+      algo = dynamic_cast<SMESH_Algo*> (anHyp);
+      if (!algo->NeedDiscreteBoundary())
+        algoRequiringCleaning = algo;
     }
-}
+  }
 
-//=============================================================================
-/*!
- * 
- */
-//=============================================================================
+  // ------------------
+  // analyse algo state
+  // ------------------
+  if (!isApplicableHyp)
+    return ret; // not applicable hypotheses do not change algo state
 
-const map<int, SMESH_subMesh*>& SMESH_subMesh::Dependants()
-{
-  if (_dependantsFound) return _mapDependants;
+  if (( algo = GetAlgo()))
+    algo->InitComputeError();
 
-  //MESSAGE("SMESH_subMesh::Dependants");
+  switch (_algoState)
+  {
 
-  int shapeType = _subShape.ShapeType();
-  //SCRUTE(shapeType);
-  TopTools_IndexedDataMapOfShapeListOfShape M;
-  TopoDS_Shape mainShape = _meshDS->ShapeToMesh();
+    // ----------------------------------------------------------------------
 
-  switch (shapeType)
-    {
-    case TopAbs_VERTEX:
-      break;
-    case TopAbs_EDGE:
-    case TopAbs_WIRE:
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_EDGE, TopAbs_WIRE, M);
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_EDGE, TopAbs_FACE, M);
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_EDGE, TopAbs_SHELL, M);
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_EDGE, TopAbs_SOLID, M);
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_EDGE, TopAbs_COMPSOLID, M);
-      ExtractDependants(M, TopAbs_EDGE);
-      break;
-    case TopAbs_FACE:
-    case TopAbs_SHELL:
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_FACE, TopAbs_SHELL, M);
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_FACE, TopAbs_SOLID, M);
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_FACE, TopAbs_COMPSOLID, M);
-      ExtractDependants(M, TopAbs_FACE);
+  case NO_ALGO:
+    switch (event) {
+    case ADD_HYP:
       break;
-    case TopAbs_SOLID:
-    case TopAbs_COMPSOLID:
-      TopExp::MapShapesAndAncestors(mainShape, TopAbs_SOLID, TopAbs_COMPSOLID, M);
-      ExtractDependants(M, TopAbs_SOLID);
+    case ADD_ALGO: {
+      algo = GetAlgo();
+      ASSERT(algo);
+      if (algo->CheckHypothesis((*_father),_subShape, aux_ret))
+        setAlgoState(HYP_OK);
+      else if ( algo->IsStatusFatal( aux_ret )) {
+        meshDS->RemoveHypothesis(_subShape, anHyp);
+        ret = aux_ret;
+      }
+      else
+        setAlgoState(MISSING_HYP);
       break;
-     case TopAbs_COMPOUND:
+    }
+    case REMOVE_HYP:
+    case REMOVE_ALGO:
+    case ADD_FATHER_HYP:
       break;
-   }
-
-  _dependantsFound = true;
-  return _mapDependants;
-}
-
-//=============================================================================
-/*!
- * 
- */
-//=============================================================================
-
-void SMESH_subMesh::ExtractDependants(const TopTools_IndexedDataMapOfShapeListOfShape& M,
-                                     const TopAbs_ShapeEnum etype)
-{
-  //MESSAGE("SMESH_subMesh::ExtractDependants");
+    case ADD_FATHER_ALGO: {    // Algo just added in father
+      algo = GetAlgo();
+      ASSERT(algo);
+      if ( algo == anHyp ) {
+        if ( algo->CheckHypothesis((*_father),_subShape, aux_ret))
+          setAlgoState(HYP_OK);
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    }
+    case REMOVE_FATHER_HYP:
+      break;
+    case REMOVE_FATHER_ALGO: {
+      algo = GetAlgo();
+      if (algo)
+      {
+        if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
+            setAlgoState(HYP_OK);
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    }
+    case MODIF_HYP: break;
+    default:
+      ASSERT(0);
+      break;
+    }
+    break;
 
-  TopoDS_Shape mainShape = _meshDS->ShapeToMesh();
-  int lg = M.Extent();
-  //SCRUTE(lg);
+    // ----------------------------------------------------------------------
 
-  int shapeType = _subShape.ShapeType();
-  switch (shapeType)
+  case MISSING_HYP:
+    switch (event)
     {
-    case TopAbs_VERTEX:
+    case ADD_HYP: {
+      algo = GetAlgo();
+      ASSERT(algo);
+      if ( algo->CheckHypothesis((*_father),_subShape, ret ))
+        setAlgoState(HYP_OK);
+      if (SMESH_Hypothesis::IsStatusFatal( ret ))
+        meshDS->RemoveHypothesis(_subShape, anHyp);
+      else if (!_father->IsUsedHypothesis( anHyp, this ))
+      {
+        meshDS->RemoveHypothesis(_subShape, anHyp);
+        ret = SMESH_Hypothesis::HYP_INCOMPATIBLE;
+      }
       break;
-    case TopAbs_EDGE:
-    case TopAbs_FACE:
-    case TopAbs_SOLID:
+    }
+    case ADD_ALGO: {           //already existing algo : on father ?
+      algo = GetAlgo();
+      ASSERT(algo);
+      if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))// ignore hyp status
+        setAlgoState(HYP_OK);
+      else if ( algo->IsStatusFatal( aux_ret )) {
+        meshDS->RemoveHypothesis(_subShape, anHyp);
+        ret = aux_ret;
+      }
+      else
+        setAlgoState(MISSING_HYP);
+      break;
+    }
+    case REMOVE_HYP:
+      break;
+    case REMOVE_ALGO: {        // perhaps a father algo applies ?
+      algo = GetAlgo();
+      if (algo == NULL)  // no more algo applying on sub-shape...
+      {
+        setAlgoState(NO_ALGO);
+      }
+      else
       {
-       const TopTools_ListOfShape& ancestors = M.FindFromKey(_subShape);
-       TopTools_ListIteratorOfListOfShape it(ancestors);
-       for ( ; it.More();it.Next())
-         {
-           TopoDS_Shape ancestor = it.Value();
-           SMESH_subMesh* aSubMesh = _father->GetSubMeshContaining(ancestor);
-           //      if (! aSubMesh) aSubMesh = _father->GetSubMesh(ancestor);
-           if (aSubMesh)
-             {
-               int type = aSubMesh->_subShape.ShapeType();
-               int cle = aSubMesh->GetId();
-               cle += 10000000 * type; // sort map by ordType then index
-               if (_mapDependants.find(cle) == _mapDependants.end())
-                 {
-                   _mapDependants[cle] = aSubMesh;
-                   //SCRUTE(cle);
-                 }
-             } 
-         }
+        if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
+          setAlgoState(HYP_OK);
+        else
+          setAlgoState(MISSING_HYP);
       }
       break;
-    case TopAbs_WIRE:
-    case TopAbs_SHELL:
-    case TopAbs_COMPSOLID:
-      for (TopExp_Explorer expE(_subShape, etype); expE.More(); expE.Next())
-       {
-         TopoDS_Shape aShape = expE.Current();
-         const TopTools_ListOfShape& ancestors = M.FindFromKey( aShape);
-         TopTools_ListIteratorOfListOfShape it(ancestors);
-         for ( ; it.More();it.Next())
-           {
-             MESSAGE("---");
-             TopoDS_Shape ancestor = it.Value();
-             SMESH_subMesh* aSubMesh = _father->GetSubMeshContaining(ancestor);
-             if (! aSubMesh) aSubMesh = _father->GetSubMesh(ancestor);
-             int type = aSubMesh->_subShape.ShapeType();
-             int cle = aSubMesh->GetId();
-             cle += 10000000 * type; // sort map by ordType then index
-             if (_mapDependants.find(cle) == _mapDependants.end())
-               {
-                 _mapDependants[cle] = aSubMesh;
-                 SCRUTE(cle);
-               }
-           }   
-       } 
-      break;
-     case TopAbs_COMPOUND:
-      break;
-   }
-}
+    }
+    case MODIF_HYP: // assigned hypothesis value may become good
+    case ADD_FATHER_HYP: {
+      algo = GetAlgo();
+      ASSERT(algo);
+      if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
+        setAlgoState(HYP_OK);
+      else
+        setAlgoState(MISSING_HYP);
+      break;
+    }
+    case ADD_FATHER_ALGO: { // new father algo
+      algo = GetAlgo();
+      ASSERT( algo );
+      if ( algo == anHyp ) {
+        if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
+          setAlgoState(HYP_OK);
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    }
+    case REMOVE_FATHER_HYP:    // nothing to do
+      break;
+    case REMOVE_FATHER_ALGO: {
+      algo = GetAlgo();
+      if (algo == NULL)  // no more applying algo on father
+      {
+        setAlgoState(NO_ALGO);
+      }
+      else
+      {
+        if ( algo->CheckHypothesis((*_father),_subShape , aux_ret ))
+          setAlgoState(HYP_OK);
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    }
+    default:
+      ASSERT(0);
+      break;
+    }
+    break;
 
+    // ----------------------------------------------------------------------
+
+  case HYP_OK:
+    switch (event)
+    {
+    case ADD_HYP: {
+      algo = GetAlgo();
+      ASSERT(algo);
+      if (!algo->CheckHypothesis((*_father),_subShape, ret ))
+      {
+        if ( !SMESH_Hypothesis::IsStatusFatal( ret ))
+          // ret should be fatal: anHyp was not added
+          ret = SMESH_Hypothesis::HYP_INCOMPATIBLE;
+      }
+      else if (!_father->IsUsedHypothesis( anHyp, this ))
+        ret = SMESH_Hypothesis::HYP_INCOMPATIBLE;
+
+      if (SMESH_Hypothesis::IsStatusFatal( ret ))
+      {
+        MESSAGE("do not add extra hypothesis");
+        meshDS->RemoveHypothesis(_subShape, anHyp);
+      }
+      else
+      {
+        modifiedHyp = true;
+      }
+      break;
+    }
+    case ADD_ALGO: {           //already existing algo : on father ?
+      algo = GetAlgo();
+      if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
+        // check if algo changes
+        SMESH_HypoFilter f;
+        f.Init(   SMESH_HypoFilter::IsAlgo() );
+        f.And(    SMESH_HypoFilter::IsApplicableTo( _subShape ));
+        f.AndNot( SMESH_HypoFilter::Is( algo ));
+        const SMESH_Hypothesis * prevAlgo = _father->GetHypothesis( this, f, true );
+        if (prevAlgo &&
+            string( algo->GetName()) != prevAlgo->GetName())
+          modifiedHyp = true;
+      }
+      else
+        setAlgoState(MISSING_HYP);
+      break;
+    }
+    case REMOVE_HYP: {
+      algo = GetAlgo();
+      ASSERT(algo);
+      if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
+        setAlgoState(HYP_OK);
+      else
+        setAlgoState(MISSING_HYP);
+      modifiedHyp = true;
+      break;
+    }
+    case REMOVE_ALGO: {         // perhaps a father algo applies ?
+      algo = GetAlgo();
+      if (algo == NULL)   // no more algo applying on sub-shape...
+      {
+        setAlgoState(NO_ALGO);
+      }
+      else
+      {
+        if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
+          // check if algo remains
+          if ( anHyp != algo && strcmp( anHyp->GetName(), algo->GetName()) )
+            modifiedHyp = true;
+        }
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    }
+    case MODIF_HYP: // hypothesis value may become bad
+    case ADD_FATHER_HYP: {  // new father hypothesis ?
+      algo = GetAlgo();
+      ASSERT(algo);
+      if ( algo->CheckHypothesis((*_father),_subShape, aux_ret ))
+      {
+        if (_father->IsUsedHypothesis( anHyp, this )) // new Hyp
+          modifiedHyp = true;
+      }
+      else
+        setAlgoState(MISSING_HYP);
+      break;
+    }
+    case ADD_FATHER_ALGO: {
+      algo = GetAlgo();
+      if ( algo == anHyp ) { // a new algo on father
+        if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
+          // check if algo changes
+          SMESH_HypoFilter f;
+          f.Init(   SMESH_HypoFilter::IsAlgo() );
+          f.And(    SMESH_HypoFilter::IsApplicableTo( _subShape ));
+          f.AndNot( SMESH_HypoFilter::Is( algo ));
+          const SMESH_Hypothesis* prevAlgo = _father->GetHypothesis( this, f, true );
+          if (prevAlgo &&
+              string(algo->GetName()) != string(prevAlgo->GetName()) )
+            modifiedHyp = true;
+        }
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    }
+    case REMOVE_FATHER_HYP: {
+      algo = GetAlgo();
+      ASSERT(algo);
+      if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
+        // is there the same local hyp or maybe a new father algo applied?
+        if ( !getSimilarAttached( _subShape, anHyp ) )
+          modifiedHyp = true;
+      }
+      else
+        setAlgoState(MISSING_HYP);
+      break;
+    }
+    case REMOVE_FATHER_ALGO: {
+      // IPAL21346. Edges not removed when Netgen 1d-2d is removed from a SOLID.
+      // CLEAN was not called at event REMOVE_ALGO because the algo is not applicable to SOLID.
+      algo = dynamic_cast<SMESH_Algo*> (anHyp);
+      if (!algo->NeedDiscreteBoundary())
+        algoRequiringCleaning = algo;
+      algo = GetAlgo();
+      if (algo == NULL)  // no more applying algo on father
+      {
+        setAlgoState(NO_ALGO);
+      }
+      else
+      {
+        if ( algo->CheckHypothesis((*_father),_subShape, aux_ret )) {
+          // check if algo changes
+          if ( string(algo->GetName()) != string( anHyp->GetName()) )
+            modifiedHyp = true;
+        }
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    }
+    default:
+      ASSERT(0);
+      break;
+    }
+    break;
+
+    // ----------------------------------------------------------------------
+
+  default:
+    ASSERT(0);
+    break;
+  }
+
+  // detect algorithm hiding
+  //
+  if ( ret == SMESH_Hypothesis::HYP_OK && 
+       ( event == ADD_ALGO || event == ADD_FATHER_ALGO ) && algo && 
+       algo->GetName() == anHyp->GetName() )
+  {
+    // is algo hidden?
+    SMESH_Gen* gen = _father->GetGen();
+    const std::vector< SMESH_subMesh * > & ancestors = GetAncestors();
+    for ( size_t iA = 0; ( ret == SMESH_Hypothesis::HYP_OK && iA < ancestors.size()); ++iA ) {
+      if ( SMESH_Algo* upperAlgo = ancestors[ iA ]->GetAlgo() )
+        if ( !upperAlgo->NeedDiscreteBoundary() && !upperAlgo->SupportSubmeshes())
+          ret = SMESH_Hypothesis::HYP_HIDDEN_ALGO;
+    }
+    // is algo hiding?
+    if ( ret == SMESH_Hypothesis::HYP_OK &&
+         !algo->NeedDiscreteBoundary()    &&
+         !algo->SupportSubmeshes())
+    {
+      TopoDS_Shape algoAssignedTo, otherAssignedTo;
+      gen->GetAlgo( this, &algoAssignedTo );
+      map<int, SMESH_subMesh*>::reverse_iterator i_sm = _mapDepend.rbegin();
+      for ( ; ( ret == SMESH_Hypothesis::HYP_OK && i_sm != _mapDepend.rend()) ; ++i_sm )
+        if ( gen->GetAlgo( i_sm->second, &otherAssignedTo ) &&
+             SMESH_MesherHelper::IsSubShape( /*sub=*/otherAssignedTo, /*main=*/algoAssignedTo ))
+          ret = SMESH_Hypothesis::HYP_HIDING_ALGO;
+    }
+  }
+
+  if ( _algo ) { // get an error description set by _algo->CheckHypothesis()
+    _computeError = _algo->GetComputeError();
+    _algo->InitComputeError();
+  }
+
+  bool stateChange = ( _algoState != oldAlgoState );
+
+  if ( stateChange && _algoState == HYP_OK ) // hyp becomes OK
+    algo->SetEventListener( this );
+
+  if ( event == REMOVE_ALGO || event == REMOVE_FATHER_ALGO )
+    _algo = 0;
+
+  notifyListenersOnEvent( event, ALGO_EVENT, anHyp );
+
+  if ( stateChange && oldAlgoState == HYP_OK ) { // hyp becomes KO
+    deleteOwnListeners();
+    SetIsAlwaysComputed( false );
+    if (_subShape.ShapeType() == TopAbs_VERTEX ) {
+      // restore default states
+      _algoState = HYP_OK;
+      _computeState = READY_TO_COMPUTE;
+    }
+  }
+
+  if ( algoRequiringCleaning ) {
+    // added or removed algo is all-dimensional
+    ComputeStateEngine( CLEAN );
+    cleanDependsOn( algoRequiringCleaning );
+    ComputeSubMeshStateEngine( CHECK_COMPUTE_STATE );
+  }
+
+  if ( stateChange || modifiedHyp )
+    ComputeStateEngine( MODIF_ALGO_STATE );
+
+  _realComputeCost = ( _algoState == HYP_OK ) ? computeCost() : 0;
+
+  return ret;
+}
+
+//=======================================================================
+//function : IsConform
+//purpose  : check if a conform mesh will be produced by the Algo
+//=======================================================================
+
+bool SMESH_subMesh::IsConform(const SMESH_Algo* theAlgo)
+{
+//  MESSAGE( "SMESH_subMesh::IsConform" );
+  if ( !theAlgo ) return false;
+
+  // Suppose that theAlgo is applicable to _subShape, do not check it here
+  //if ( !IsApplicableHypotesis( theAlgo )) return false;
+
+  // check only algo that doesn't NeedDiscreteBoundary(): because mesh made
+  // on a sub-shape will be ignored by theAlgo
+  if ( theAlgo->NeedDiscreteBoundary() ||
+       !theAlgo->OnlyUnaryInput() ) // all adjacent shapes will be meshed by this algo?
+    return true;
+
+  // only local algo is to be checked
+  //if ( gen->IsGlobalHypothesis( theAlgo, *_father ))
+  if ( _subShape.ShapeType() == _father->GetMeshDS()->ShapeToMesh().ShapeType() )
+    return true;
+
+  // check algo attached to adjacent shapes
+
+  // loop on one level down sub-meshes
+  TopoDS_Iterator itsub( _subShape );
+  for (; itsub.More(); itsub.Next())
+  {
+    // loop on adjacent subShapes
+    const std::vector< SMESH_subMesh * > & ancestors = GetAncestors();
+    for ( size_t iA = 0; iA < ancestors.size(); ++iA )
+    {
+      const TopoDS_Shape& adjacent = ancestors[ iA ]->GetSubShape();
+      if ( _subShape.IsSame( adjacent )) continue;
+      if ( adjacent.ShapeType() != _subShape.ShapeType())
+        break;
+
+      // check algo attached to smAdjacent
+      SMESH_Algo * algo = ancestors[ iA ]->GetAlgo();
+      if (algo &&
+          !algo->NeedDiscreteBoundary() &&
+          algo->OnlyUnaryInput())
+        return false; // NOT CONFORM MESH WILL BE PRODUCED
+    }
+  }
+
+  return true;
+}
+
+//=============================================================================
+/*!
+ *
+ */
+//=============================================================================
+
+void SMESH_subMesh::setAlgoState(algo_state state)
+{
+  _algoState = state;
+}
+
+//================================================================================
+/*!
+ * \brief Send an event to sub-meshes
+ *  \param [in] event - the event
+ *  \param [in] anHyp - an hypothesis
+ *  \param [in] exitOnFatal - to stop iteration on sub-meshes if a sub-mesh
+ *              reports a fatal result
+ *  \return SMESH_Hypothesis::Hypothesis_Status - the worst result
+ *
+ * Optional description of a problematic situation (if any) can be retrieved
+ * via GetComputeError().
+ */
+//================================================================================
+
+SMESH_Hypothesis::Hypothesis_Status
+  SMESH_subMesh::SubMeshesAlgoStateEngine(algo_event         event,
+                                          SMESH_Hypothesis * anHyp,
+                                          bool               exitOnFatal)
+{
+  SMESH_Hypothesis::Hypothesis_Status ret = SMESH_Hypothesis::HYP_OK;
+  //EAP: a wire (dim==1) should notify edges (dim==1)
+  //EAP: int dim = SMESH_Gen::GetShapeDim(_subShape);
+  //if (_subShape.ShapeType() < TopAbs_EDGE ) // wire,face etc
+  {
+    SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,false);
+    while ( smIt->more() ) {
+      SMESH_subMesh* sm = smIt->next();
+      SMESH_Hypothesis::Hypothesis_Status ret2 = sm->AlgoStateEngine(event, anHyp);
+      if ( ret2 > ret )
+      {
+        ret = ret2;
+        _computeError = sm->_computeError;
+        sm->_computeError.reset();
+        if ( exitOnFatal && SMESH_Hypothesis::IsStatusFatal( ret ))
+          break;
+      }
+    }
+  }
+  return ret;
+}
+
+//================================================================================
+/*!
+ * \brief Remove elements from sub-meshes.
+ *  \param algoRequiringCleaning - an all-dimensional algorithm whose presence
+ *         causes the cleaning.
+ */
+//================================================================================
+
+void SMESH_subMesh::cleanDependsOn( SMESH_Algo* algoRequiringCleaning/*=0*/ )
+{
+  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,
+                                                       /*complexShapeFirst=*/true);
+  if ( _father->NbNodes() == 0 )
+  {
+    while ( smIt->more() )
+      smIt->next()->ComputeStateEngine(CHECK_COMPUTE_STATE);
+  }
+  else if ( !algoRequiringCleaning || !algoRequiringCleaning->SupportSubmeshes() )
+  {
+    while ( smIt->more() )
+      smIt->next()->ComputeStateEngine(CLEAN);
+  }
+  else if ( algoRequiringCleaning && algoRequiringCleaning->SupportSubmeshes() )
+  {
+    // find sub-meshes to keep elements on
+    set< SMESH_subMesh* > smToKeep;
+    TopAbs_ShapeEnum prevShapeType = TopAbs_SHAPE;
+    bool toKeepPrevShapeType = false;
+    while ( smIt->more() )
+    {
+      SMESH_subMesh* sm = smIt->next();
+      sm->ComputeStateEngine(CHECK_COMPUTE_STATE);
+      if ( !sm->IsEmpty() )
+      {
+        const bool sameShapeType = ( prevShapeType == sm->GetSubShape().ShapeType() );
+        bool       keepSubMeshes = ( sameShapeType && toKeepPrevShapeType );
+        if ( !sameShapeType )
+        {
+          // check if the algo allows presence of global algos of dimension the algo
+          // can generate it-self;
+          // always keep a node on VERTEX, as this node can be shared by segments
+          // lying on EDGEs not shared by the VERTEX of sm, due to MergeNodes (PAL23068)
+          int  shapeDim = SMESH_Gen::GetShapeDim( sm->GetSubShape() );
+          keepSubMeshes = ( algoRequiringCleaning->NeedLowerHyps( shapeDim ) || shapeDim == 0 );
+          prevShapeType = sm->GetSubShape().ShapeType();
+          toKeepPrevShapeType = keepSubMeshes;
+        }
+        if ( !keepSubMeshes )
+        {
+          // look for a local algo used to mesh sm
+          TopoDS_Shape algoShape = SMESH_MesherHelper::GetShapeOfHypothesis
+            ( algoRequiringCleaning, _subShape, _father );
+          SMESH_HypoFilter moreLocalAlgo;
+          moreLocalAlgo.Init( SMESH_HypoFilter::IsMoreLocalThan( algoShape, *_father ));
+          moreLocalAlgo.And ( SMESH_HypoFilter::IsAlgo() );
+          bool localAlgoFound = _father->GetHypothesis( sm->_subShape, moreLocalAlgo, true );
+          keepSubMeshes = localAlgoFound;
+        }
+        // remember all sub-meshes of sm
+        if ( keepSubMeshes )
+        {
+          SMESH_subMeshIteratorPtr smIt2 = sm->getDependsOnIterator(true);
+          while ( smIt2->more() )
+            smToKeep.insert( smIt2->next() );
+        }
+      }
+    }
+    // remove elements
+    SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,true);
+    while ( smIt->more() )
+    {
+      SMESH_subMesh* sm = smIt->next();
+      if ( !smToKeep.count( sm ))
+        sm->ComputeStateEngine(CLEAN);
+    }
+  }
+}
+
+//=============================================================================
+/*!
+ *
+ */
+//=============================================================================
+
+void SMESH_subMesh::DumpAlgoState(bool isMain)
+{
+  if (isMain)
+  {
+    const map < int, SMESH_subMesh * >&subMeshes = DependsOn();
+
+    map < int, SMESH_subMesh * >::const_iterator itsub;
+    for (itsub = subMeshes.begin(); itsub != subMeshes.end(); itsub++)
+    {
+      SMESH_subMesh *sm = (*itsub).second;
+      sm->DumpAlgoState(false);
+    }
+  }
+  MESSAGE("dim = " << SMESH_Gen::GetShapeDim(_subShape) <<
+          " type of shape " << _subShape.ShapeType());
+  switch (_algoState)
+  {
+  case NO_ALGO          : MESSAGE(" AlgoState = NO_ALGO"); break;
+  case MISSING_HYP      : MESSAGE(" AlgoState = MISSING_HYP"); break;
+  case HYP_OK           : MESSAGE(" AlgoState = HYP_OK");break;
+  }
+  switch (_computeState)
+  {
+  case NOT_READY        : MESSAGE(" ComputeState = NOT_READY");break;
+  case READY_TO_COMPUTE : MESSAGE(" ComputeState = READY_TO_COMPUTE");break;
+  case COMPUTE_OK       : MESSAGE(" ComputeState = COMPUTE_OK");break;
+  case FAILED_TO_COMPUTE: MESSAGE(" ComputeState = FAILED_TO_COMPUTE");break;
+  }
+}
+
+//================================================================================
+/*!
+ * \brief Remove nodes and elements bound to submesh
+  * \param subMesh - submesh containing nodes and elements
+ */
+//================================================================================
+
+static void cleanSubMesh( SMESH_subMesh * subMesh )
+{
+  if (subMesh) {
+    if (SMESHDS_SubMesh * subMeshDS = subMesh->GetSubMeshDS()) {
+      SMESHDS_Mesh * meshDS = subMesh->GetFather()->GetMeshDS();
+      SMDS_ElemIteratorPtr ite = subMeshDS->GetElements();
+      while (ite->more()) {
+        const SMDS_MeshElement * elt = ite->next();
+        //MESSAGE( " RM elt: "<<elt->GetID()<<" ( "<<elt->NbNodes()<<" )" );
+        //meshDS->RemoveElement(elt);
+        meshDS->RemoveFreeElement(elt, 0);
+      }
+
+      SMDS_NodeIteratorPtr itn = subMeshDS->GetNodes();
+      while (itn->more()) {
+        const SMDS_MeshNode * node = itn->next();
+        //MESSAGE( " RM node: "<<node->GetID());
+        if ( node->NbInverseElements() == 0 )
+          meshDS->RemoveFreeNode(node, 0);
+        else // for StdMeshers_CompositeSegment_1D: node in one submesh, edge in another
+          meshDS->RemoveNode(node);
+      }
+      subMeshDS->Clear();
+    }
+  }
+}
+
+//=============================================================================
+/*!
+ *
+ */
+//=============================================================================
+
+bool SMESH_subMesh::ComputeStateEngine(compute_event event)
+{
+  switch ( event ) {
+  case MODIF_ALGO_STATE:
+  case COMPUTE:
+  case COMPUTE_SUBMESH:
+    //case COMPUTE_CANCELED:
+  case CLEAN:
+    //case SUBMESH_COMPUTED:
+    //case SUBMESH_RESTORED:
+    //case SUBMESH_LOADED:
+    //case MESH_ENTITY_REMOVED:
+    //case CHECK_COMPUTE_STATE:
+    _computeError.reset(); break;
+  default:;
+  }
+
+  if ( event == CLEAN )
+    _alwaysComputed = false; // Unset 'true' set by MergeNodes() (issue 0022182)
+
+  if (_subShape.ShapeType() == TopAbs_VERTEX)
+  {
+    _computeState = READY_TO_COMPUTE;
+    SMESHDS_SubMesh* smDS = GetSubMeshDS();
+    if ( smDS && smDS->NbNodes() )
+    {
+      if ( event == CLEAN ) {
+        cleanDependants();
+        cleanSubMesh( this );
+      }
+      else
+        _computeState = COMPUTE_OK;
+    }
+    else if (( event == COMPUTE || event == COMPUTE_SUBMESH )
+             && !_alwaysComputed )
+    {
+      const TopoDS_Vertex & V = TopoDS::Vertex( _subShape );
+      gp_Pnt P = BRep_Tool::Pnt(V);
+      if ( SMDS_MeshNode * n = _father->GetMeshDS()->AddNode(P.X(), P.Y(), P.Z()) ) {
+        _father->GetMeshDS()->SetNodeOnVertex(n,_Id);
+        _computeState = COMPUTE_OK;
+      }
+    }
+    if ( event == MODIF_ALGO_STATE )
+      cleanDependants();
+    return true;
+  }
+  SMESH_Gen *gen = _father->GetGen();
+  SMESH_Algo *algo = 0;
+  bool ret = true;
+  SMESH_Hypothesis::Hypothesis_Status hyp_status;
+  //algo_state oldAlgoState = (algo_state) GetAlgoState();
+
+  switch (_computeState)
+  {
+
+    // ----------------------------------------------------------------------
+
+  case NOT_READY:
+    switch (event)
+    {
+    case MODIF_ALGO_STATE:
+      algo = GetAlgo();
+      if (algo && !algo->NeedDiscreteBoundary())
+        cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
+      if ( _algoState == HYP_OK )
+        _computeState = READY_TO_COMPUTE;
+      break;
+    case COMPUTE:               // nothing to do
+    case COMPUTE_SUBMESH:
+      break;
+    case COMPUTE_CANCELED:      // nothing to do
+      break;
+    case CLEAN:
+      cleanDependants();
+      removeSubMeshElementsAndNodes();
+      break;
+    case SUBMESH_COMPUTED:      // nothing to do
+      break;
+    case SUBMESH_RESTORED:
+      ComputeSubMeshStateEngine( SUBMESH_RESTORED );
+      break;
+    case MESH_ENTITY_REMOVED:
+      break;
+    case SUBMESH_LOADED:
+      loadDependentMeshes();
+      ComputeSubMeshStateEngine( SUBMESH_LOADED );
+      //break;
+    case CHECK_COMPUTE_STATE:
+      if ( IsMeshComputed() )
+        _computeState = COMPUTE_OK;
+      break;
+    default:
+      ASSERT(0);
+      break;
+    }
+    break;
+
+    // ----------------------------------------------------------------------
+
+  case READY_TO_COMPUTE:
+    switch (event)
+    {
+    case MODIF_ALGO_STATE:
+      _computeState = NOT_READY;
+      algo = GetAlgo();
+      if (algo)
+      {
+        if (!algo->NeedDiscreteBoundary())
+          cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
+        if ( _algoState == HYP_OK )
+          _computeState = READY_TO_COMPUTE;
+      }
+      break;
+    case COMPUTE:
+    case COMPUTE_SUBMESH:
+      {
+        algo = GetAlgo();
+        ASSERT(algo);
+        ret = algo->CheckHypothesis((*_father), _subShape, hyp_status);
+        if (!ret)
+        {
+          MESSAGE("***** verify compute state *****");
+          _computeState = NOT_READY;
+          setAlgoState(MISSING_HYP);
+          break;
+        }
+        TopoDS_Shape shape = _subShape;
+        algo->SubMeshesToCompute().assign( 1, this );
+        // check submeshes needed
+        if (_father->HasShapeToMesh() ) {
+          bool subComputed = false, subFailed = false;
+          if (!algo->OnlyUnaryInput()) {
+            if ( event == COMPUTE /*&&
+                 ( algo->NeedDiscreteBoundary() || algo->SupportSubmeshes() )*/)
+              shape = getCollection( gen, algo, subComputed, subFailed, algo->SubMeshesToCompute());
+            else
+              subComputed = SubMeshesComputed( & subFailed );
+          }
+          else {
+            subComputed = SubMeshesComputed();
+          }
+          ret = ( algo->NeedDiscreteBoundary() ? subComputed :
+                  algo->SupportSubmeshes() ? !subFailed :
+                  ( !subComputed || _father->IsNotConformAllowed() ));
+          if (!ret)
+          {
+            _computeState = FAILED_TO_COMPUTE;
+            if ( !algo->NeedDiscreteBoundary() && !subFailed )
+              _computeError =
+                SMESH_ComputeError::New(COMPERR_BAD_INPUT_MESH,
+                                        "Unexpected computed sub-mesh",algo);
+            break; // goto exit
+          }
+        }
+        // Compute
+
+        // to restore cout that may be redirected by algo
+        std::streambuf* coutBuffer = std::cout.rdbuf();
+
+        //cleanDependants(); for "UseExisting_*D" algos
+        //removeSubMeshElementsAndNodes();
+        loadDependentMeshes();
+        ret = false;
+        _computeState = FAILED_TO_COMPUTE;
+        _computeError = SMESH_ComputeError::New(COMPERR_OK,"",algo);
+        try {
+          OCC_CATCH_SIGNALS;
+
+          algo->InitComputeError();
+
+          MemoryReserve aMemoryReserve;
+          SMDS_Mesh::CheckMemory();
+          Kernel_Utils::Localizer loc;
+          if ( !_father->HasShapeToMesh() ) // no shape
+          {
+            SMESH_MesherHelper helper( *_father );
+            helper.SetSubShape( shape );
+            helper.SetElementsOnShape( true );
+            ret = algo->Compute(*_father, &helper );
+          }
+          else
+          {
+            ret = algo->Compute((*_father), shape);
+          }
+          // algo can set _computeError of submesh
+          _computeError = SMESH_ComputeError::Worst( _computeError, algo->GetComputeError() );
+        }
+        catch ( ::SMESH_ComputeError& comperr ) {
+          cout << " SMESH_ComputeError caught" << endl;
+          if ( !_computeError ) _computeError = SMESH_ComputeError::New();
+          *_computeError = comperr;
+        }
+        catch ( std::bad_alloc& exc ) {
+          MESSAGE("std::bad_alloc thrown inside algo->Compute()");
+          if ( _computeError ) {
+            _computeError->myName = COMPERR_MEMORY_PB;
+            //_computeError->myComment = exc.what();
+          }
+          cleanSubMesh( this );
+          throw exc;
+        }
+        catch ( Standard_OutOfMemory& exc ) {
+          MESSAGE("Standard_OutOfMemory thrown inside algo->Compute()");
+          if ( _computeError ) {
+            _computeError->myName = COMPERR_MEMORY_PB;
+            //_computeError->myComment = exc.what();
+          }
+          cleanSubMesh( this );
+          throw std::bad_alloc();
+        }
+        catch (Standard_Failure& ex) {
+          if ( !_computeError ) _computeError = SMESH_ComputeError::New();
+          _computeError->myName    = COMPERR_OCC_EXCEPTION;
+          _computeError->myComment += ex.DynamicType()->Name();
+          if ( ex.GetMessageString() && strlen( ex.GetMessageString() )) {
+            _computeError->myComment += ": ";
+            _computeError->myComment += ex.GetMessageString();
+          }
+        }
+        catch ( SALOME_Exception& S_ex ) {
+          const int skipSalomeShift = 7; /* to skip "Salome " of
+                                            "Salome Exception" prefix returned
+                                            by SALOME_Exception::what() */
+          if ( !_computeError ) _computeError = SMESH_ComputeError::New();
+          _computeError->myName    = COMPERR_SLM_EXCEPTION;
+          _computeError->myComment = S_ex.what() + skipSalomeShift;
+        }
+        catch ( std::exception& exc ) {
+          if ( !_computeError ) _computeError = SMESH_ComputeError::New();
+          _computeError->myName    = COMPERR_STD_EXCEPTION;
+          _computeError->myComment = exc.what();
+        }
+        catch ( ... ) {
+          if ( _computeError )
+            _computeError->myName = COMPERR_EXCEPTION;
+          else
+            ret = false;
+        }
+        std::cout.rdbuf( coutBuffer ); // restore cout that could be redirected by algo
+
+        // check if an error reported on any sub-shape
+        bool isComputeErrorSet = !checkComputeError( algo, ret, shape );
+        if ( isComputeErrorSet )
+          ret = false;
+        // check if anything was built
+        TopExp_Explorer subS(shape, _subShape.ShapeType());
+        if (ret)
+        {
+          for (; ret && subS.More(); subS.Next())
+            if ( !_father->GetSubMesh( subS.Current() )->IsMeshComputed() &&
+                 ( _subShape.ShapeType() != TopAbs_EDGE ||
+                   !algo->isDegenerated( TopoDS::Edge( subS.Current() ))))
+              ret = false;
+        }
+        // Set _computeError
+        if (!ret && !isComputeErrorSet)
+        {
+          for (subS.ReInit(); subS.More(); subS.Next())
+          {
+            SMESH_subMesh* sm = _father->GetSubMesh( subS.Current() );
+            if ( !sm->IsMeshComputed() )
+            {
+              if ( !sm->_computeError )
+                sm->_computeError = SMESH_ComputeError::New();
+              if ( sm->_computeError->IsOK() )
+                sm->_computeError->myName = COMPERR_ALGO_FAILED;
+              sm->_computeState = FAILED_TO_COMPUTE;
+              sm->_computeError->myAlgo = algo;
+            }
+          }
+        }
+        if (ret && _computeError && _computeError->myName != COMPERR_WARNING )
+        {
+          _computeError.reset();
+        }
+
+        // transform errors into warnings if it is caused by mesh edition (imp 0023068)
+        if (!ret && _father->GetIsModified() )
+        {
+          for (subS.ReInit(); subS.More(); subS.Next())
+          {
+            SMESH_subMesh* sm = _father->GetSubMesh( subS.Current() );
+            if ( !sm->IsMeshComputed() && sm->_computeError )
+            {
+              // check if there is a VERTEX w/o nodes
+              // with READY_TO_COMPUTE state (after MergeNodes())
+              SMESH_subMeshIteratorPtr smIt = sm->getDependsOnIterator(false,false);
+              while ( smIt->more() )
+              {
+                SMESH_subMesh * vertSM = smIt->next();
+                if ( vertSM->_subShape.ShapeType() != TopAbs_VERTEX ) break;
+                if ( vertSM->GetComputeState() == READY_TO_COMPUTE )
+                {
+                  SMESHDS_SubMesh * ds = vertSM->GetSubMeshDS();
+                  if ( !ds || ds->NbNodes() == 0 )
+                  {
+                    sm->_computeState = READY_TO_COMPUTE;
+                    sm->_computeError->myName = COMPERR_WARNING;
+                    break;
+                  }
+                }
+              }
+            }
+          }
+        }
+
+        // send event SUBMESH_COMPUTED
+        if ( ret ) {
+          if ( !algo->NeedDiscreteBoundary() )
+            // send SUBMESH_COMPUTED to dependants of all sub-meshes of shape
+            for (subS.ReInit(); subS.More(); subS.Next())
+            {
+              SMESH_subMesh* sm = _father->GetSubMesh( subS.Current() );
+              SMESH_subMeshIteratorPtr smIt = sm->getDependsOnIterator(false,false);
+              while ( smIt->more() ) {
+                sm = smIt->next();
+                if ( sm->GetSubShape().ShapeType() == TopAbs_VERTEX )
+                  sm->updateDependantsState( SUBMESH_COMPUTED );
+                else
+                  break;
+              }
+            }
+          else
+            updateDependantsState( SUBMESH_COMPUTED );
+        }
+      }
+      break;
+    case COMPUTE_CANCELED:               // nothing to do
+      break;
+    case CLEAN:
+      cleanDependants();
+      removeSubMeshElementsAndNodes();
+      _computeState = NOT_READY;
+      algo = GetAlgo();
+      if (algo)
+      {
+        ret = algo->CheckHypothesis((*_father), _subShape, hyp_status);
+        if (ret)
+          _computeState = READY_TO_COMPUTE;
+        else
+          setAlgoState(MISSING_HYP);
+      }
+      break;
+    case SUBMESH_COMPUTED:      // nothing to do
+      break;
+    case SUBMESH_RESTORED:
+      // check if a mesh is already computed that may
+      // happen after retrieval from a file
+      ComputeStateEngine( CHECK_COMPUTE_STATE );
+      ComputeSubMeshStateEngine( SUBMESH_RESTORED );
+      algo = GetAlgo();
+      if (algo) algo->SubmeshRestored( this );
+      break;
+    case MESH_ENTITY_REMOVED:
+      break;
+    case SUBMESH_LOADED:
+      loadDependentMeshes();
+      ComputeSubMeshStateEngine( SUBMESH_LOADED );
+      //break;
+    case CHECK_COMPUTE_STATE:
+      if ( IsMeshComputed() )
+        _computeState = COMPUTE_OK;
+      else if ( _computeError && _computeError->IsKO() )
+        _computeState = FAILED_TO_COMPUTE;
+      break;
+    default:
+      ASSERT(0);
+      break;
+    }
+    break;
+
+    // ----------------------------------------------------------------------
+
+  case COMPUTE_OK:
+    switch (event)
+    {
+    case MODIF_ALGO_STATE:
+      ComputeStateEngine( CLEAN );
+      algo = GetAlgo();
+      if (algo && !algo->NeedDiscreteBoundary())
+        cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
+      break;
+    case COMPUTE:               // nothing to do
+      break;
+    case COMPUTE_CANCELED:      // nothing to do
+      break;
+    case CLEAN:
+      cleanDependants();  // clean sub-meshes, dependant on this one, with event CLEAN
+      removeSubMeshElementsAndNodes();
+      _computeState = NOT_READY;
+      if ( _algoState == HYP_OK )
+        _computeState = READY_TO_COMPUTE;
+      break;
+    case SUBMESH_COMPUTED:      // nothing to do
+      break;
+    case SUBMESH_RESTORED:
+      ComputeStateEngine( CHECK_COMPUTE_STATE );
+      ComputeSubMeshStateEngine( SUBMESH_RESTORED );
+      algo = GetAlgo();
+      if (algo) algo->SubmeshRestored( this );
+      break;
+    case MESH_ENTITY_REMOVED:
+      updateDependantsState    ( CHECK_COMPUTE_STATE );
+      ComputeStateEngine       ( CHECK_COMPUTE_STATE );
+      ComputeSubMeshStateEngine( CHECK_COMPUTE_STATE );
+      break;
+    case CHECK_COMPUTE_STATE:
+      if ( !IsMeshComputed() ) {
+        if (_algoState == HYP_OK)
+          _computeState = READY_TO_COMPUTE;
+        else
+          _computeState = NOT_READY;
+      }
+      break;
+    case SUBMESH_LOADED:
+      // already treated event, thanks to which _computeState == COMPUTE_OK
+      break;
+    default:
+      ASSERT(0);
+      break;
+    }
+    break;
+
+    // ----------------------------------------------------------------------
+
+  case FAILED_TO_COMPUTE:
+    switch (event)
+    {
+    case MODIF_ALGO_STATE:
+      if ( !IsEmpty() )
+        ComputeStateEngine( CLEAN );
+      algo = GetAlgo();
+      if (algo && !algo->NeedDiscreteBoundary())
+        cleanDependsOn( algo ); // clean sub-meshes with event CLEAN
+      if (_algoState == HYP_OK)
+        _computeState = READY_TO_COMPUTE;
+      else
+        _computeState = NOT_READY;
+      break;
+    case COMPUTE:        // nothing to do
+    case COMPUTE_SUBMESH:
+      break;
+    case COMPUTE_CANCELED:
+      {
+        algo = GetAlgo();
+        algo->CancelCompute();
+      }
+      break;
+    case CLEAN:
+      cleanDependants(); // submeshes dependent on me should be cleaned as well
+      removeSubMeshElementsAndNodes();
+      break;
+    case SUBMESH_COMPUTED:      // allow retry compute
+      if ( IsEmpty() ) // 23061
+      {
+        if (_algoState == HYP_OK)
+          _computeState = READY_TO_COMPUTE;
+        else
+          _computeState = NOT_READY;
+      }
+      break;
+    case SUBMESH_RESTORED:
+      ComputeSubMeshStateEngine( SUBMESH_RESTORED );
+      break;
+    case MESH_ENTITY_REMOVED:
+      break;
+    case CHECK_COMPUTE_STATE:
+      if ( IsMeshComputed() )
+        _computeState = COMPUTE_OK;
+      else
+        if (_algoState == HYP_OK)
+          _computeState = READY_TO_COMPUTE;
+        else
+          _computeState = NOT_READY;
+      break;
+    // case SUBMESH_LOADED:
+    //   break;
+    default:
+      ASSERT(0);
+      break;
+    }
+    break;
+
+    // ----------------------------------------------------------------------
+  default:
+    ASSERT(0);
+    break;
+  }
+
+  notifyListenersOnEvent( event, COMPUTE_EVENT );
+
+  return ret;
+}
+
+
+//=============================================================================
+/*!
+ *
+ */
+//=============================================================================
+
+bool SMESH_subMesh::Evaluate(MapShapeNbElems& aResMap)
+{
+  _computeError.reset();
+
+  bool ret = true;
+
+  if (_subShape.ShapeType() == TopAbs_VERTEX) {
+    vector<int> aVec(SMDSEntity_Last,0);
+    aVec[SMDSEntity_Node] = 1;
+    aResMap.insert(make_pair(this,aVec));
+    return ret;
+  }
+
+  //SMESH_Gen *gen = _father->GetGen();
+  SMESH_Algo *algo = 0;
+  SMESH_Hypothesis::Hypothesis_Status hyp_status;
+
+  algo = GetAlgo();
+  if( algo && !aResMap.count( this ))
+  {
+    ret = algo->CheckHypothesis((*_father), _subShape, hyp_status);
+    if (!ret) return false;
+
+    if (_father->HasShapeToMesh() && algo->NeedDiscreteBoundary() )
+    {
+      // check submeshes needed
+      bool subMeshEvaluated = true;
+      int dimToCheck = SMESH_Gen::GetShapeDim( _subShape ) - 1;
+      SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,/*complexShapeFirst=*/true);
+      while ( smIt->more() && subMeshEvaluated )
+      {
+        SMESH_subMesh* sm = smIt->next();
+        int dim = SMESH_Gen::GetShapeDim( sm->GetSubShape() );
+        if (dim < dimToCheck) break; // the rest subMeshes are all of less dimension
+        const vector<int> & nbs = aResMap[ sm ];
+        subMeshEvaluated = (std::accumulate( nbs.begin(), nbs.end(), 0 ) > 0 );
+      }
+      if ( !subMeshEvaluated )
+        return false;
+    }
+    _computeError = SMESH_ComputeError::New(COMPERR_OK,"",algo);
+
+    if ( IsMeshComputed() )
+    {
+      vector<int> & nbEntities = aResMap[ this ];
+      nbEntities.resize( SMDSEntity_Last, 0 );
+      if ( SMESHDS_SubMesh* sm = GetSubMeshDS() )
+      {
+        nbEntities[ SMDSEntity_Node ] = sm->NbNodes();
+        SMDS_ElemIteratorPtr   elemIt = sm->GetElements();
+        while ( elemIt->more() )
+          nbEntities[ elemIt->next()->GetEntityType() ]++;
+      }
+    }
+    else
+    {
+      ret = algo->Evaluate((*_father), _subShape, aResMap);
+    }
+    aResMap.insert( make_pair( this,vector<int>(0)));
+  }
+
+  return ret;
+}
+
+
+//=======================================================================
+/*!
+ * \brief Update compute_state by _computeError and send proper events to
+ * dependent submeshes
+  * \retval bool - true if _computeError is NOT set
+ */
+//=======================================================================
+
+bool SMESH_subMesh::checkComputeError(SMESH_Algo*         theAlgo,
+                                      const bool          theComputeOK,
+                                      const TopoDS_Shape& theShape)
+{
+  bool noErrors = true;
+
+  if ( !theShape.IsNull() )
+  {
+    // Check state of submeshes
+    if ( !theAlgo->NeedDiscreteBoundary())
+    {
+      SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,false);
+      while ( smIt->more() )
+        if ( !smIt->next()->checkComputeError( theAlgo, theComputeOK ))
+          noErrors = false;
+    }
+
+    // Check state of neighbours
+    if ( !theAlgo->OnlyUnaryInput() &&
+         theShape.ShapeType() == TopAbs_COMPOUND &&
+         !theShape.IsSame( _subShape ))
+    {
+      for (TopoDS_Iterator subIt( theShape ); subIt.More(); subIt.Next()) {
+        SMESH_subMesh* sm = _father->GetSubMesh( subIt.Value() );
+        if ( sm != this ) {
+          if ( !sm->checkComputeError( theAlgo, theComputeOK, sm->GetSubShape() ))
+            noErrors = false;
+          updateDependantsState( SUBMESH_COMPUTED ); // send event SUBMESH_COMPUTED
+        }
+      }
+    }
+  }
+  {
+
+    // Set my _computeState
+
+    if ( !_computeError || _computeError->IsOK() )
+    {
+      // no error description is set to this sub-mesh, check if any mesh is computed
+      _computeState = IsMeshComputed() ? COMPUTE_OK : FAILED_TO_COMPUTE;
+      if ( _computeState != COMPUTE_OK )
+      {
+        if ( _subShape.ShapeType() == TopAbs_EDGE &&
+             SMESH_Algo::isDegenerated( TopoDS::Edge( _subShape )) )
+          _computeState = COMPUTE_OK;
+        else if ( theComputeOK )
+          _computeError = SMESH_ComputeError::New(COMPERR_NO_MESH_ON_SHAPE,"",theAlgo);
+      }
+    }
+
+    if ( _computeError && !_computeError->IsOK() )
+    {
+      if ( !_computeError->myAlgo )
+        _computeError->myAlgo = theAlgo;
+
+      // Show error
+      SMESH_Comment text;
+      text << theAlgo->GetName() << " failed on sub-shape #" << _Id << " with error ";
+      if (_computeError->IsCommon() )
+        text << _computeError->CommonName();
+      else
+        text << _computeError->myName;
+      if ( _computeError->myComment.size() > 0 )
+        text << " \"" << _computeError->myComment << "\"";
+
+      INFOS( text );
+
+      _computeState = _computeError->IsKO() ? FAILED_TO_COMPUTE : COMPUTE_OK;
+
+      noErrors = false;
+    }
+  }
+  return noErrors;
+}
+
+//=======================================================================
+//function : updateSubMeshState
+//purpose  :
+//=======================================================================
+
+void SMESH_subMesh::updateSubMeshState(const compute_state theState)
+{
+  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(false,false);
+  while ( smIt->more() )
+    smIt->next()->_computeState = theState;
+}
+
+//=======================================================================
+//function : ComputeSubMeshStateEngine
+//purpose  :
+//=======================================================================
+
+void SMESH_subMesh::ComputeSubMeshStateEngine(compute_event event, const bool includeSelf)
+{
+  SMESH_subMeshIteratorPtr smIt = getDependsOnIterator(includeSelf,false);
+  while ( smIt->more() )
+    smIt->next()->ComputeStateEngine(event);
+}
+
+//=======================================================================
+//function : updateDependantsState
+//purpose  :
+//=======================================================================
+
+void SMESH_subMesh::updateDependantsState(const compute_event theEvent)
+{
+  const std::vector< SMESH_subMesh * > & ancestors = GetAncestors();
+  for ( size_t iA = 0; iA < ancestors.size(); ++iA )
+  {
+    ancestors[ iA ]->ComputeStateEngine( theEvent );
+  }
+}
+
+//=======================================================================
+//function : cleanDependants
+//purpose  : 
+//=======================================================================
+
+void SMESH_subMesh::cleanDependants()
+{
+  int dimToClean = SMESH_Gen::GetShapeDim( _subShape ) + 1;
+
+  const std::vector< SMESH_subMesh * > & ancestors = GetAncestors();
+  for ( size_t iA = 0; iA < ancestors.size(); ++iA )
+  {
+    const TopoDS_Shape& ancestor = ancestors[ iA ]->GetSubShape();
+    if ( SMESH_Gen::GetShapeDim( ancestor ) == dimToClean )
+    {
+      // PAL8021. do not go upper than SOLID, else ComputeStateEngine(CLEAN)
+      // will erase mesh on other shapes in a compound
+      if ( ancestor.ShapeType() >= TopAbs_SOLID &&
+           !ancestors[ iA ]->IsEmpty() )  // prevent infinite CLEAN via event lesteners
+        ancestors[ iA ]->ComputeStateEngine(CLEAN);
+    }
+  }
+}
+
+//=======================================================================
+//function : removeSubMeshElementsAndNodes
+//purpose  : 
+//=======================================================================
+
+void SMESH_subMesh::removeSubMeshElementsAndNodes()
+{
+  cleanSubMesh( this );
+
+  // algo may bind a submesh not to _subShape, eg 3D algo
+  // sets nodes on SHELL while _subShape may be SOLID
+
+  int dim = SMESH_Gen::GetShapeDim( _subShape );
+  int type = _subShape.ShapeType() + 1;
+  for ( ; type <= TopAbs_EDGE; type++) {
+    if ( dim == SMESH_Gen::GetShapeDim( (TopAbs_ShapeEnum) type ))
+    {
+      TopExp_Explorer exp( _subShape, (TopAbs_ShapeEnum) type );
+      for ( ; exp.More(); exp.Next() )
+        cleanSubMesh( _father->GetSubMeshContaining( exp.Current() ));
+    }
+    else
+      break;
+  }
+}
+
+//=======================================================================
+//function : getCollection
+//purpose  : return a shape containing all sub-shapes of the MainShape that can be
+//           meshed at once along with _subShape
+//=======================================================================
+
+TopoDS_Shape SMESH_subMesh::getCollection(SMESH_Gen * theGen,
+                                          SMESH_Algo* theAlgo,
+                                          bool &      theSubComputed,
+                                          bool &      theSubFailed,
+                                          std::vector<SMESH_subMesh*>& theSubs)
+{
+  theSubComputed = SubMeshesComputed( & theSubFailed );
+
+  TopoDS_Shape mainShape = _father->GetMeshDS()->ShapeToMesh();
+
+  if ( mainShape.IsSame( _subShape ))
+    return _subShape;
+
+  const bool skipAuxHyps = false;
+  list<const SMESHDS_Hypothesis*> aUsedHyp =
+    theAlgo->GetUsedHypothesis( *_father, _subShape, skipAuxHyps ); // copy
+
+  // put in a compound all shapes with the same hypothesis assigned
+  // and a good ComputeState
+
+  TopoDS_Compound aCompound;
+  BRep_Builder aBuilder;
+  aBuilder.MakeCompound( aCompound );
+
+  theSubs.clear();
+
+  SMESH_subMeshIteratorPtr smIt = _father->GetSubMesh( mainShape )->getDependsOnIterator(false);
+  while ( smIt->more() )
+  {
+    SMESH_subMesh* subMesh = smIt->next();
+    const TopoDS_Shape&  S = subMesh->_subShape;
+    if ( S.ShapeType() != this->_subShape.ShapeType() )
+      continue;
+    if ( subMesh == this )
+    {
+      aBuilder.Add( aCompound, S );
+      theSubs.push_back( subMesh );
+    }
+    else if ( subMesh->GetComputeState() == READY_TO_COMPUTE )
+    {
+      SMESH_Algo* anAlgo = subMesh->GetAlgo();
+      if (( anAlgo->IsSameName( *theAlgo )) && // same algo
+          ( anAlgo->GetUsedHypothesis( *_father, S, skipAuxHyps ) == aUsedHyp )) // same hyps
+      {
+        aBuilder.Add( aCompound, S );
+        if ( !subMesh->SubMeshesComputed() )
+          theSubComputed = false;
+        theSubs.push_back( subMesh );
+      }
+    }
+  }
+
+  return aCompound;
+}
+
+//=======================================================================
+//function : getSimilarAttached
+//purpose  : return a hypothesis attached to theShape.
+//           If theHyp is provided, similar but not same hypotheses
+//           is returned; else only applicable ones having theHypType
+//           is returned
+//=======================================================================
+
+const SMESH_Hypothesis* SMESH_subMesh::getSimilarAttached(const TopoDS_Shape&      theShape,
+                                                          const SMESH_Hypothesis * theHyp,
+                                                          const int                theHypType)
+{
+  SMESH_HypoFilter hypoKind;
+  hypoKind.Init( hypoKind.HasType( theHyp ? theHyp->GetType() : theHypType ));
+  if ( theHyp ) {
+    hypoKind.And   ( hypoKind.HasDim( theHyp->GetDim() ));
+    hypoKind.AndNot( hypoKind.Is( theHyp ));
+    if ( theHyp->IsAuxiliary() )
+      hypoKind.And( hypoKind.HasName( theHyp->GetName() ));
+    else
+      hypoKind.AndNot( hypoKind.IsAuxiliary());
+  }
+  else {
+    hypoKind.And( hypoKind.IsApplicableTo( theShape ));
+  }
+
+  return _father->GetHypothesis( theShape, hypoKind, false );
+}
+
+//=======================================================================
+//function : CheckConcurentHypothesis
+//purpose  : check if there are several applicable hypothesis attached to
+//           ancestors
+//=======================================================================
+
+SMESH_Hypothesis::Hypothesis_Status
+  SMESH_subMesh::CheckConcurentHypothesis (const int theHypType)
+{
+  MESSAGE ("SMESH_subMesh::CheckConcurentHypothesis");
+
+  // is there local hypothesis on me?
+  if ( getSimilarAttached( _subShape, 0, theHypType ) )
+    return SMESH_Hypothesis::HYP_OK;
+
+
+  TopoDS_Shape aPrevWithHyp;
+  const SMESH_Hypothesis* aPrevHyp = 0;
+  TopTools_ListIteratorOfListOfShape it( _father->GetAncestors( _subShape ));
+  for (; it.More(); it.Next())
+  {
+    const TopoDS_Shape& ancestor = it.Value();
+    const SMESH_Hypothesis* hyp = getSimilarAttached( ancestor, 0, theHypType );
+    if ( hyp )
+    {
+      if ( aPrevWithHyp.IsNull() || aPrevWithHyp.IsSame( ancestor ))
+      {
+        aPrevWithHyp = ancestor;
+        aPrevHyp     = hyp;
+      }
+      else if ( aPrevWithHyp.ShapeType() == ancestor.ShapeType() && aPrevHyp != hyp )
+        return SMESH_Hypothesis::HYP_CONCURENT;
+      else
+        return SMESH_Hypothesis::HYP_OK;
+    }
+  }
+  return SMESH_Hypothesis::HYP_OK;
+}
+
+//================================================================================
+/*!
+ * \brief Constructor of OwnListenerData
+ */
+//================================================================================
+
+SMESH_subMesh::OwnListenerData::OwnListenerData( SMESH_subMesh* sm, EventListener* el):
+  mySubMesh( sm ),
+  myMeshID( sm ? sm->GetFather()->GetId() : -1 ),
+  mySubMeshID( sm ? sm->GetId() : -1 ),
+  myListener( el )
+{
+}
+
+//================================================================================
+/*!
+ * \brief Sets an event listener and its data to a submesh
+ * \param listener - the listener to store
+ * \param data - the listener data to store
+ * \param where - the submesh to store the listener and it's data
+ * 
+ * It remembers the submesh where it puts the listener in order to delete
+ * them when HYP_OK algo_state is lost
+ * After being set, event listener is notified on each event of where submesh.
+ */
+//================================================================================
+
+void SMESH_subMesh::SetEventListener(EventListener*     listener,
+                                     EventListenerData* data,
+                                     SMESH_subMesh*     where)
+{
+  if ( listener && where ) {
+    where->setEventListener( listener, data );
+    _ownListeners.push_back( OwnListenerData( where, listener ));
+  }
+}
+
+//================================================================================
+/*!
+ * \brief Sets an event listener and its data to a submesh
+ * \param listener - the listener to store
+ * \param data - the listener data to store
+ * 
+ * After being set, event listener is notified on each event of a submesh.
+ */
+//================================================================================
+
+void SMESH_subMesh::setEventListener(EventListener*     listener,
+                                     EventListenerData* data)
+{
+  map< EventListener*, EventListenerData* >::iterator l_d =
+    _eventListeners.find( listener );
+  if ( l_d != _eventListeners.end() ) {
+    EventListenerData* curData = l_d->second;
+    if ( curData && curData != data && curData->IsDeletable() )
+      delete curData;
+    l_d->second = data;
+  }
+  else
+  {
+    for ( l_d = _eventListeners.begin(); l_d != _eventListeners.end(); ++l_d )
+      if ( listener->GetName() == l_d->first->GetName() )
+      {
+        EventListenerData* curData = l_d->second;
+        if ( curData && curData != data && curData->IsDeletable() )
+          delete curData;
+        if ( l_d->first != listener && l_d->first->IsDeletable() )
+          delete l_d->first;
+        _eventListeners.erase( l_d );
+        break;
+      }
+    _eventListeners.insert( make_pair( listener, data ));
+  }
+}
+
+//================================================================================
+/*!
+ * \brief Return an event listener data
+ * \param listener - the listener whose data is
+ * \param myOwn - if \c true, returns a listener set by this sub-mesh,
+ *        else returns a listener listening to events of this sub-mesh
+ * \retval EventListenerData* - found data, maybe NULL
+ */
+//================================================================================
+
+EventListenerData* SMESH_subMesh::GetEventListenerData(EventListener* listener,
+                                                       const bool     myOwn) const
+{
+  if ( myOwn )
+  {
+    list< OwnListenerData >::const_iterator d;
+    for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+    {
+      if ( d->myListener == listener && _father->MeshExists( d->myMeshID ))
+        return d->mySubMesh->GetEventListenerData( listener, !myOwn );
+    }
+  }
+  else
+  {
+    map< EventListener*, EventListenerData* >::const_iterator l_d =
+      _eventListeners.find( listener );
+    if ( l_d != _eventListeners.end() )
+      return l_d->second;
+  }
+  return 0;
+}
+
+//================================================================================
+/*!
+ * \brief Return an event listener data
+ * \param listenerName - the listener name
+ * \param myOwn - if \c true, returns a listener set by this sub-mesh,
+ *        else returns a listener listening to events of this sub-mesh
+ * \retval EventListenerData* - found data, maybe NULL
+ */
+//================================================================================
+
+EventListenerData* SMESH_subMesh::GetEventListenerData(const string& listenerName,
+                                                       const bool    myOwn) const
+{
+  if ( myOwn )
+  {
+    list< OwnListenerData >::const_iterator d;
+    for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+    {
+      if ( _father->MeshExists( d->myMeshID ) && listenerName == d->myListener->GetName())
+        return d->mySubMesh->GetEventListenerData( listenerName, !myOwn );
+    }
+  }
+  else
+  {
+    map< EventListener*, EventListenerData* >::const_iterator l_d = _eventListeners.begin();
+    for ( ; l_d != _eventListeners.end(); ++l_d )
+      if ( listenerName == l_d->first->GetName() )
+        return l_d->second;
+  }
+  return 0;
+}
+
+//================================================================================
+/*!
+ * \brief Notify stored event listeners on the occured event
+ * \param event - algo_event or compute_event itself
+ * \param eventType - algo_event or compute_event
+ * \param hyp - hypothesis, if eventType is algo_event
+ */
+//================================================================================
+
+void SMESH_subMesh::notifyListenersOnEvent( const int         event,
+                                            const event_type  eventType,
+                                            SMESH_Hypothesis* hyp)
+{
+  list< pair< EventListener*, EventListenerData* > > eventListeners( _eventListeners.begin(),
+                                                                     _eventListeners.end());
+  list< pair< EventListener*, EventListenerData* > >::iterator l_d = eventListeners.begin();
+  for ( ; l_d != eventListeners.end(); ++l_d )
+  {
+    std::pair< EventListener*, EventListenerData* > li_da = *l_d;
+    if ( !_eventListeners.count( li_da.first )) continue;
+
+    if ( li_da.first->myBusySM.insert( this ).second )
+    {
+      const bool isDeletable = li_da.first->IsDeletable();
+
+      li_da.first->ProcessEvent( event, eventType, this, li_da.second, hyp );
+
+      if ( !isDeletable || _eventListeners.count( li_da.first ))
+        li_da.first->myBusySM.erase( this ); // a listener is hopefully not dead
+    }
+  }
+}
+
+//================================================================================
+/*!
+ * \brief Unregister the listener and delete listener's data
+ * \param listener - the event listener
+ */
+//================================================================================
+
+void SMESH_subMesh::DeleteEventListener(EventListener* listener)
+{
+  map< EventListener*, EventListenerData* >::iterator l_d =
+    _eventListeners.find( listener );
+  if ( l_d != _eventListeners.end() && l_d->first )
+  {
+    if ( l_d->second && l_d->second->IsDeletable() )
+    {
+      delete l_d->second;
+    }
+    l_d->first->myBusySM.erase( this );
+    if ( l_d->first->IsDeletable() )
+    {
+      l_d->first->BeforeDelete( this, l_d->second );
+      delete l_d->first;
+    }
+    _eventListeners.erase( l_d );
+  }
+}
+
+//================================================================================
+/*!
+ * \brief Delete event listeners depending on algo of this submesh
+ */
+//================================================================================
+
+void SMESH_subMesh::deleteOwnListeners()
+{
+  list< OwnListenerData >::iterator d;
+  for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+  {
+    SMESH_Mesh* mesh = _father->FindMesh( d->myMeshID );
+    if ( !mesh || !mesh->GetSubMeshContaining( d->mySubMeshID ))
+      continue;
+    d->mySubMesh->DeleteEventListener( d->myListener );
+  }
+  _ownListeners.clear();
+}
+
+//=======================================================================
+//function : loadDependentMeshes
+//purpose  : loads dependent meshes on SUBMESH_LOADED event
+//=======================================================================
+
+void SMESH_subMesh::loadDependentMeshes()
+{
+  list< OwnListenerData >::iterator d;
+  for ( d = _ownListeners.begin(); d != _ownListeners.end(); ++d )
+    if ( _father != d->mySubMesh->_father )
+      d->mySubMesh->_father->Load();
+
+  // map< EventListener*, EventListenerData* >::iterator l_d = _eventListeners.begin();
+  // for ( ; l_d != _eventListeners.end(); ++l_d )
+  //   if ( l_d->second )
+  //   {
+  //     const list<SMESH_subMesh*>& smList = l_d->second->mySubMeshes;
+  //     list<SMESH_subMesh*>::const_iterator sm = smList.begin();
+  //     for ( ; sm != smList.end(); ++sm )
+  //       if ( _father != (*sm)->_father )
+  //         (*sm)->_father->Load();
+  //   }
+}
+
+//================================================================================
+/*!
+ * \brief Do something on a certain event
+ * \param event - algo_event or compute_event itself
+ * \param eventType - algo_event or compute_event
+ * \param subMesh - the submesh where the event occures
+ * \param data - listener data stored in the subMesh
+ * \param hyp - hypothesis, if eventType is algo_event
+ * 
+ * The base implementation translates CLEAN event to the subMesh
+ * stored in listener data. Also it sends SUBMESH_COMPUTED event in case of
+ * successful COMPUTE event.
+ */
+//================================================================================
+
+void SMESH_subMeshEventListener::ProcessEvent(const int          event,
+                                              const int          eventType,
+                                              SMESH_subMesh*     subMesh,
+                                              EventListenerData* data,
+                                              const SMESH_Hypothesis*  /*hyp*/)
+{
+  if ( data && !data->mySubMeshes.empty() &&
+       eventType == SMESH_subMesh::COMPUTE_EVENT)
+  {
+    ASSERT( data->mySubMeshes.front() != subMesh );
+    list<SMESH_subMesh*>::iterator smIt = data->mySubMeshes.begin();
+    list<SMESH_subMesh*>::iterator smEnd = data->mySubMeshes.end();
+    switch ( event ) {
+    case SMESH_subMesh::CLEAN:
+      for ( ; smIt != smEnd; ++ smIt)
+        (*smIt)->ComputeStateEngine( SMESH_subMesh::compute_event( event ));
+      break;
+    case SMESH_subMesh::COMPUTE:
+    case SMESH_subMesh::COMPUTE_SUBMESH:
+      if ( subMesh->GetComputeState() == SMESH_subMesh::COMPUTE_OK )
+        for ( ; smIt != smEnd; ++ smIt)
+          (*smIt)->ComputeStateEngine( SMESH_subMesh::SUBMESH_COMPUTED );
+      break;
+    default:;
+    }
+  }
+}
+
+namespace {
+
+  //================================================================================
+  /*!
+   * \brief Iterator over submeshes and optionally prepended or appended one
+   */
+  //================================================================================
+
+  struct _Iterator : public SMDS_Iterator<SMESH_subMesh*>
+  {
+    _Iterator(SMDS_Iterator<SMESH_subMesh*>* subIt,
+              SMESH_subMesh*                 prepend,
+              SMESH_subMesh*                 append): myAppend(append), myIt(subIt)
+    {
+      myCur = prepend ? prepend : myIt->more() ? myIt->next() : append;
+      if ( myCur == append ) append = 0;
+    }
+    /// Return true if and only if there are other object in this iterator
+    virtual bool more()
+    {
+      return myCur;
+    }
+    /// Return the current object and step to the next one
+    virtual SMESH_subMesh* next()
+    {
+      SMESH_subMesh* res = myCur;
+      if ( myIt->more() ) { myCur = myIt->next(); }
+      else                { myCur = myAppend; myAppend = 0; }
+      return res;
+    }
+    /// ~
+    ~_Iterator()
+    { delete myIt; }
+    ///
+    SMESH_subMesh                 *myAppend, *myCur;
+    SMDS_Iterator<SMESH_subMesh*> *myIt;
+  };
+}
+
+//================================================================================
+/*!
+ * \brief  Return iterator on the submeshes this one depends on
+  * \param includeSelf - this submesh to be returned also
+  * \param reverse - if true, complex shape submeshes go first
+ */
+//================================================================================
+
+SMESH_subMeshIteratorPtr SMESH_subMesh::getDependsOnIterator(const bool includeSelf,
+                                                             const bool reverse) const
+{
+  SMESH_subMesh *me = (SMESH_subMesh*) this;
+  SMESH_subMesh *prepend=0, *append=0;
+  if ( includeSelf ) {
+    if ( reverse ) prepend = me;
+    else            append = me;
+  }
+  typedef map < int, SMESH_subMesh * > TMap;
+  if ( reverse )
+  {
+    return SMESH_subMeshIteratorPtr
+      ( new _Iterator( new SMDS_mapReverseIterator<TMap>( me->DependsOn() ), prepend, append ));
+  }
+  {
+    return SMESH_subMeshIteratorPtr
+      ( new _Iterator( new SMDS_mapIterator<TMap>( me->DependsOn() ), prepend, append ));
+  }
+}
+
+//================================================================================
+/*!
+ * \brief Returns ancestor sub-meshes. Finds them if not yet found.
+ */
+//================================================================================
+
+const std::vector< SMESH_subMesh * > & SMESH_subMesh::GetAncestors() const
+{
+  if ( _ancestors.empty() &&
+       !_subShape.IsSame( _father->GetShapeToMesh() ))
+  {
+    const TopTools_ListOfShape& ancShapes = _father->GetAncestors( _subShape );
+
+    SMESH_subMesh* me = const_cast< SMESH_subMesh* >( this );
+    me->_ancestors.reserve( ancShapes.Extent() );
+
+    TopTools_MapOfShape map;
+   
+    for ( TopTools_ListIteratorOfListOfShape it( ancShapes ); it.More(); it.Next() )
+      if ( SMESH_subMesh* sm = _father->GetSubMeshContaining( it.Value() ))
+        if ( map.Add( it.Value() ))
+          me->_ancestors.push_back( sm );
+  }
+
+  return _ancestors;
+}
+
+//================================================================================
+/*!
+ * \brief Clears the vector of ancestor sub-meshes
+ */
+//================================================================================
+
+void SMESH_subMesh::ClearAncestors()
+{
+  _ancestors.clear();
+}
+
+//================================================================================
+/*!
+ * \brief  Find common submeshes (based on shared sub-shapes with other
+  * \param theOther submesh to check
+  * \param theSetOfCommon set of common submesh
+ */
+//================================================================================
+
+bool SMESH_subMesh::FindIntersection(const SMESH_subMesh*            theOther,
+                                     std::set<const SMESH_subMesh*>& theSetOfCommon ) const
+{
+  size_t oldNb = theSetOfCommon.size();
+
+  // check main submeshes
+  const map <int, SMESH_subMesh*>::const_iterator otherEnd = theOther->_mapDepend.end();
+  if ( theOther->_mapDepend.find(this->GetId()) != otherEnd )
+    theSetOfCommon.insert( this );
+  if ( _mapDepend.find(theOther->GetId()) != _mapDepend.end() )
+    theSetOfCommon.insert( theOther );
+
+  // check common submeshes
+  map <int, SMESH_subMesh*>::const_iterator mapIt = _mapDepend.begin();
+  for( ; mapIt != _mapDepend.end(); mapIt++ )
+    if ( theOther->_mapDepend.find((*mapIt).first) != otherEnd )
+      theSetOfCommon.insert( (*mapIt).second );
+  return oldNb < theSetOfCommon.size();
+}