Add some syntactic sugar...

... to ease conversions between Entity and EntityRef.

smtk/model/Entity.h

@@ -62,6 +62,13 @@ public:
   ResourcePtr resource() const override;
   ManagerPtr modelResource() const;
 
+  /// Return the templated object (usually EntityRef or a subclass) that points to this component.
+  template <typename T>
+  T referenceAs() const
+  {
+    return T(this->modelResource(), this->id());
+  }
+
   bool reparent(ManagerPtr newParent);
 
   int dimension() const;

smtk/model/EntityRef.cxx

@@ -50,6 +50,16 @@ EntityRef::EntityRef(ManagerPtr mgr, const smtk::common::UUID& inEntity)
 {
 }
 
+/// Construct a entityref referencing a given \a entity residing in the given \a mgr.
+EntityRef::EntityRef(EntityPtr src)
+{
+  if (src)
+  {
+    m_manager = src->modelResource();
+    m_entity = src->id();
+  }
+}
+
 /// Change the underlying manager the entityref references.
 bool EntityRef::setManager(ManagerPtr mgr)
 {
@@ -89,6 +99,17 @@ const smtk::common::UUID& EntityRef::entity() const
   return this->m_entity;
 }
 
+/// Return the smtk::model::Entity record for this model entity.
+smtk::model::EntityPtr EntityRef::entityRecord() const
+{
+  auto mgr = this->manager();
+  if (!mgr)
+  {
+    return nullptr;
+  }
+  return mgr->findEntity(this->m_entity, true);
+}
+
 /// Return the resource component for this model entity.
 smtk::resource::ComponentPtr EntityRef::component() const
 {

smtk/model/EntityRef.h

@@ -7,8 +7,7 @@
 //  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 //  PURPOSE.  See the above copyright notice for more information.
 //=========================================================================
-#ifndef __smtk_model_EntityRef_h
-#define __smtk_model_EntityRef_h
+#pragma once
 /*! \file */
 
 #include "smtk/CoreExports.h"       // For EXPORT macro.
@@ -51,6 +50,14 @@ class MeshSet;
     : superclass(inManager, entityId)                                                              \
   {                                                                                                \
   }                                                                                                \
+  thisclass(EntityPtr src)                                                                         \
+  {                                                                                                \
+    if (src)                                                                                       \
+    {                                                                                              \
+      m_manager = src->modelResource();                                                            \
+      m_entity = src->id();                                                                        \
+    }                                                                                              \
+  }                                                                                                \
   virtual ~thisclass() {} /* Avoid warnings about non-virtual destructor */                        \
   bool isValid() const { return this->EntityRef::isValid(); }                                      \
   bool isValid(EntityPtr* entRec) const override                                                   \
@@ -94,6 +101,7 @@ public:
   SMTK_BASE_TYPE(EntityRef);
   EntityRef();
   EntityRef(ManagerPtr manager, const smtk::common::UUID& entityId);
+  EntityRef(EntityPtr src);
 
   bool setManager(ManagerPtr manager);
   ManagerPtr manager();
@@ -102,6 +110,7 @@ public:
   bool setEntity(const smtk::common::UUID& entityId);
   const smtk::common::UUID& entity() const;
 
+  smtk::model::EntityPtr entityRecord() const;
   smtk::resource::ComponentPtr component() const;
 
   int dimension() const;
@@ -415,5 +424,3 @@ EntityRef& EntityRef::removeMemberEntities(T begin, T end)
 
 } // namespace model
 } // namespace smtk
-
-#endif // __smtk_model_EntityRef_h

smtk/model/testing/cxx/unitEntityRef.cxx

@@ -210,6 +210,20 @@ void testModelMethods()
   test(m1.session() == m0.session(), "Expected sessions to match for model and its submodel.");
 }
 
+void testResourceComponentConversion()
+{
+  ManagerPtr sm = Manager::create();
+  SessionRef sess = sm->createSession("native");
+  Model m0 = sm->addModel();
+  smtk::model::EntityPtr mep = m0.entityRecord();
+  test(!!mep, "No component for Model entity-ref.");
+  test(mep->referenceAs<smtk::model::Model>() == m0, "Could not convert from component to ref.");
+  test(smtk::model::Model(mep) == m0, "Could not convert from ref to component.");
+  smtk::resource::ComponentPtr cmp = m0.component();
+  test(cmp == smtk::dynamic_pointer_cast<smtk::resource::Component>(mep),
+    "Component/Entity mismatch.");
+}
+
 int main(int argc, char* argv[])
 {
   (void)argc;
@@ -559,6 +573,7 @@ int main(int argc, char* argv[])
     testTemplatedPropertyMethods();
     testVolumeEntityRef();
     testModelMethods();
+    testResourceComponentConversion();
   }
   catch (const std::string& msg)
   {