include/opencascade/BRepGraph_LayerIterator.hxx

0001 // Copyright (c) 2026 OPEN CASCADE SAS
0002 //
0003 // This file is part of Open CASCADE Technology software library.
0004 //
0005 // This library is free software; you can redistribute it and/or modify it under
0006 // the terms of the GNU Lesser General Public License version 2.1 as published
0007 // by the Free Software Foundation, with special exception defined in the file
0008 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0009 // distribution for complete text of the license and disclaimer of any warranty.
0010 //
0011 // Alternatively, this file may be used under the terms of Open CASCADE
0012 // commercial license or contractual agreement.
0013
0014 #ifndef _BRepGraph_LayerIterator_HeaderFile
0015 #define _BRepGraph_LayerIterator_HeaderFile
0016
0017 #include <BRepGraph_LayerRegistry.hxx>
0018 #include <NCollection_ForwardRange.hxx>
0019
0020 //! @brief Iterator over registered layers in a BRepGraph_LayerRegistry.
0021 //!
0022 //! Provides zero-allocation iteration with OCCT More()/Next()/Value() pattern
0023 //! and STL range-for via begin()/end().
0024 //!
0025 //! @code
0026 //!   // Range-for:
0027 //!   for (const occ::handle<BRepGraph_Layer>& aLayer :
0028 //!   BRepGraph_LayerIterator(aGraph.LayerRegistry()))
0029 //!     doSomething(aLayer);
0030 //!
0031 //!   // Traditional:
0032 //!   for (BRepGraph_LayerIterator anIt(aGraph.LayerRegistry()); anIt.More(); anIt.Next())
0033 //!     doSomething(anIt.Value());
0034 //! @endcode
0035 class BRepGraph_LayerIterator
0036 {
0037 public:
0038   //! Construct an iterator over all layers in the registry.
0039   explicit BRepGraph_LayerIterator(const BRepGraph_LayerRegistry& theRegistry)
0040       : myRegistry(&theRegistry),
0041         myCount(theRegistry.NbLayers()),
0042         myCurrent(0)
0043   {
0044   }
0045
0046   //! True if the iterator has a current element.
0047   [[nodiscard]] bool More() const { return myCurrent < myCount; }
0048
0049   //! Advance to the next layer.
0050   void Next() { ++myCurrent; }
0051
0052   //! Return the current layer handle.
0053   [[nodiscard]] occ::handle<BRepGraph_Layer> Value() const { return myRegistry->Layer(myCurrent); }
0054
0055   //! Return the current slot index in the registry.
0056   [[nodiscard]] uint32_t Slot() const { return myCurrent; }
0057
0058   //! Number of layers in the registry.
0059   [[nodiscard]] uint32_t NbLayers() const { return myCount; }
0060
0061   //! STL range-for support.
0062   NCollection_ForwardRangeIterator<BRepGraph_LayerIterator> begin()
0063   {
0064     return NCollection_ForwardRangeIterator<BRepGraph_LayerIterator>(this);
0065   }
0066
0067   //! Sentinel marking end of iteration.
0068   NCollection_ForwardRangeSentinel end() const { return NCollection_ForwardRangeSentinel{}; }
0069
0070 private:
0071   const BRepGraph_LayerRegistry* myRegistry;
0072   uint32_t                       myCount;
0073   uint32_t                       myCurrent;
0074 };
0075
0076 #endif // _BRepGraph_LayerIterator_HeaderFile