.. _program_listing_file_MRML_vtkMRMLLayerDMNodeReferenceObserver.h:

Program Listing for File vtkMRMLLayerDMNodeReferenceObserver.h
==============================================================

|exhale_lsh| :ref:`Return to documentation for file <file_MRML_vtkMRMLLayerDMNodeReferenceObserver.h>` (``MRML/vtkMRMLLayerDMNodeReferenceObserver.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   
   // LayerDM includes
   #include "vtkSlicerLayerDMModuleMRMLExport.h"
   
   // VTK includes
   #include <vtkObject.h>
   #include <vtkSmartPointer.h>
   #include <vtkWeakPointer.h>
   
   // STL includes
   #include <functional>
   #include <map>
   #include <set>
   
   class vtkMRMLNode;
   class vtkMRMLLayerDMObjectEventObserver;
   class vtkMRMLScene;
   
   class VTK_SLICER_LAYERDM_MODULE_MRML_EXPORT vtkMRMLLayerDMNodeReferenceObserver : public vtkObject
   {
   public:
     using RefT = std::tuple<vtkWeakPointer<vtkMRMLNode>, std::string>;
   
     enum Event
     {
       ReferenceAddedEvent = 0,
       ReferenceRemovedEvent
     };
   
     static vtkMRMLLayerDMNodeReferenceObserver* New();
   
     std::set<RefT> GetNodeToReferences(vtkMRMLNode* node) const;
     std::set<RefT> GetNodeFromReferences(vtkMRMLNode* node) const;
   
     int GetReferenceToSize() const;
     int GetReferenceFromSize() const;
     int GetNumberOfNodes() const;
   
     using CallBackT = std::function<void(vtkMRMLNode*, vtkMRMLNode*, const std::string&, int eventType)>;
     void SetReferenceModifiedCallBack(const CallBackT& modifiedCallback);
   
     void SetScene(vtkMRMLScene* scene);
   
   protected:
     vtkMRMLLayerDMNodeReferenceObserver();
     ~vtkMRMLLayerDMNodeReferenceObserver() override = default;
   
   private:
     vtkMRMLLayerDMNodeReferenceObserver(const vtkMRMLLayerDMNodeReferenceObserver&);
     void operator=(const vtkMRMLLayerDMNodeReferenceObserver&);
   
     void UpdateFromScene();
     void OnNodeRemoved(vtkMRMLNode* node);
     void OnNodeAdded(vtkMRMLNode* node);
     void OnReferenceAdded(vtkMRMLNode* fromNode, vtkMRMLNode* toNode, const std::string& role);
     void OnReferenceRemoved(vtkMRMLNode* fromNode, vtkMRMLNode* toNode, const std::string& role);
     void RemoveOutdatedReferences(vtkMRMLNode* fromNode);
     void OnReferenceModified(vtkMRMLNode* fromNode, vtkMRMLNode* toNode, const std::string& role);
   
     static std::set<RefT> GetNodeReferencesFromScene(vtkMRMLNode* node);
     void TriggerReferenceAdded(vtkMRMLNode* fromNode, vtkMRMLNode* toNode, const std::string& role) const;
     void TriggerReferenceRemoved(vtkMRMLNode* fromNode, vtkMRMLNode* toNode, const std::string& role) const;
     static void TriggerCallback(const CallBackT& callback, vtkMRMLNode* fromNode, vtkMRMLNode* toNode, const std::string& role, int eventType);
   
     vtkWeakPointer<vtkMRMLScene> m_scene{};
     vtkSmartPointer<vtkMRMLLayerDMObjectEventObserver> m_obs{};
     std::map<vtkSmartPointer<vtkMRMLNode>, std::set<RefT>> m_refTo{};
     std::map<vtkSmartPointer<vtkMRMLNode>, std::set<RefT>> m_refFrom{};
     std::set<vtkSmartPointer<vtkMRMLNode>> m_nodes{};
   
     CallBackT m_onRefModified{};
   };