Merge branch 'property-manager-factories' into 'master'

add factory functions for creating PropertyManagers without restating the mesh type in C++11



See merge request !53

src/OpenMesh/Core/Utils/PropertyManager.hh

@@ -60,7 +60,23 @@ namespace OpenMesh {
  * It also defines convenience operators to access the encapsulated
  * property's value.
  *
- * Usage example:
+ * For C++11, it is recommended to use the factory functions
+ * makePropertyManagerFromNew, makePropertyManagerFromExisting,
+ * makePropertyManagerFromExistingOrNew to construct a PropertyManager, e.g.
+ *
+ * \code
+ * TriMesh mesh;
+ * auto visited = makePropertyManagerFromNew<VPropHandleT<bool>>(mesh, "visited.plugin-example.i8.informatik.rwth-aachen.de");
+ *
+ * for (auto vh : mesh.vertices()) {
+ *     if (!visited[vh]) {
+ *         visitComponent(mesh, vh, visited);
+ *     }
+ * }
+ * \endcode
+ *
+ * For C++98, it is usually more convenient to use the constructor explicitly,
+ * i.e.
  *
  * \code
  * TriMesh mesh;
@@ -107,6 +123,9 @@ class PropertyManager {
          * the property is deleted upon destruction of the PropertyManager instance). If true,
          * the instance merely acts as a convenience wrapper around an existing property with no
          * lifecycle management whatsoever.
+         *
+         * @see PropertyManager::createIfNotExists, makePropertyManagerFromNew,
+         * makePropertyManagerFromExisting, makePropertyManagerFromExistingOrNew
          */
         PropertyManager(MeshT &mesh, const char *propname, bool existing = false) : mesh_(&mesh), retain_(existing), name_(propname) {
             if (existing) {
@@ -164,15 +183,14 @@ class PropertyManager {
          * Move assignment. Transfers ownership (delete responsibility).
          */
         PropertyManager &operator=(PropertyManager &&rhs) {
-
-            deleteProperty();
-
-            mesh_ = rhs.mesh_;
-            prop_ = rhs.prop_;
-            retain_ = rhs.retain_;
-            name_ = rhs.name_;
-            rhs.retain_ = true;
-
+            if (&rhs != this) {
+                deleteProperty();
+                mesh_ = rhs.mesh_;
+                prop_ = rhs.prop_;
+                retain_ = rhs.retain_;
+                name_ = rhs.name_;
+                rhs.retain_ = true;
+            }
             return *this;
         }
 
@@ -180,6 +198,8 @@ class PropertyManager {
          * Create a property manager for the supplied property and mesh.
          * If the property doesn't exist, it is created. In any case,
          * lifecycle management is disabled.
+         *
+         * @see makePropertyManagerFromExistingOrNew
          */
         static PropertyManager createIfNotExists(MeshT &mesh, const char *propname) {
             PROPTYPE dummy_prop;
@@ -192,7 +212,7 @@ class PropertyManager {
         PropertyManager duplicate(const char *clone_name) {
             PropertyManager pm(*mesh_, clone_name, false);
             pm.mesh_->property(pm.prop_) = mesh_->property(prop_);
-            return std::move(pm);
+            return pm;
         }
 
         /**
@@ -237,6 +257,8 @@ class PropertyManager {
          * Create a property manager for the supplied property and mesh.
          * If the property doesn't exist, it is created. In any case,
          * lifecycle management is disabled.
+         *
+         * @see makePropertyManagerFromExistingOrNew
          */
         static Proxy createIfNotExists(MeshT &mesh, const char *propname) {
             PROPTYPE dummy_prop;
@@ -406,5 +428,43 @@ class PropertyManager {
         std::string name_;
 };
 
+/**
+ * Creates a new property whose lifecycle is managed by the returned
+ * PropertyManager.
+ *
+ * Intended for temporary properties. Shadows any existsing properties of
+ * matching name and type.
+ */
+template<typename PROPTYPE, typename MeshT>
+PropertyManager<PROPTYPE, MeshT> makePropertyManagerFromNew(MeshT &mesh, const char *propname) {
+    return PropertyManager<PROPTYPE, MeshT>(mesh, propname, false);
+}
+
+/**
+ * Creates a non-owning wrapper for an existing mesh property (no lifecycle
+ * management).
+ *
+ * Intended for convenient access.
+ *
+ * @pre Property with the name \p propname of matching type exists.
+ * @throws std::runtime_error if no property with the name \p propname of
+ * matching type exists.
+ */
+template<typename PROPTYPE, typename MeshT>
+PropertyManager<PROPTYPE, MeshT> makePropertyManagerFromExisting(MeshT &mesh, const char *propname) {
+    return PropertyManager<PROPTYPE, MeshT>(mesh, propname, true);
+}
+
+/**
+ * Creates a non-owning wrapper for a mesh property (no lifecycle management).
+ * If the given property does not exist, it is created.
+ *
+ * Intended for creating or accessing persistent properties.
+ */
+template<typename PROPTYPE, typename MeshT>
+PropertyManager<PROPTYPE, MeshT> makePropertyManagerFromExistingOrNew(MeshT &mesh, const char *propname) {
+    return PropertyManager<PROPTYPE, MeshT>::createIfNotExists(mesh, propname);
+}
+
 } /* namespace OpenMesh */
 #endif /* PROPERTYMANAGER_HH_ */

src/Unittests/unittests_propertymanager.cc

@@ -26,7 +26,7 @@ class OpenMeshPropertyManager : public OpenMeshBase {
 
 /*
  * ====================================================================
- * Define tests below
+ * General Tests
  * ====================================================================
  */
 
@@ -92,11 +92,112 @@ TEST_F(OpenMeshPropertyManager, set_range_bool) {
       ASSERT_TRUE(pm_f_bool[*f_it]);
 }
 
+/*
+ * ====================================================================
+ * C++11 Specific Tests
+ * ====================================================================
+ */
+#if _MSC_VER >= 1900 || __cplusplus > 199711L || defined(__GXX_EXPERIMENTAL_CXX0X__)
 
+template<typename PropHandle, typename Mesh>
+bool has_property(const Mesh& _mesh, const std::string& _name) {
+    auto dummy_handle = PropHandle{};
+    return _mesh.get_property_handle(dummy_handle, _name);
+}
 
+/*
+ * Temporary property
+ */
+TEST_F(OpenMeshPropertyManager, cpp11_temp_property) {
+    using handle_type = OpenMesh::VPropHandleT<int>;
+    const auto prop_name = "pm_v_test_property";
+    ASSERT_FALSE(has_property<handle_type>(mesh_, prop_name));
+
+    {
+        auto vprop = OpenMesh::makePropertyManagerFromNew<handle_type>(mesh_, prop_name);
+        static_cast<void>(vprop); // Unused variable
+        ASSERT_TRUE(has_property<handle_type>(mesh_, prop_name));
+    }
+
+    ASSERT_FALSE(has_property<handle_type>(mesh_, prop_name));
+}
 
+/*
+ * Two temporary properties on a mesh using the same name and type. The second
+ * (inner) one shadows the first (outer) one instead of aliasing.
+ */
+TEST_F(OpenMeshPropertyManager, cpp11_temp_property_shadowing) {
+    auto vh = mesh_.add_vertex({0,0,0}); // Dummy vertex to attach properties to
+
+    using handle_type = OpenMesh::VPropHandleT<int>;
+    const auto prop_name = "pm_v_test_property";
+
+    auto outer_prop = OpenMesh::makePropertyManagerFromNew<handle_type>(mesh_, prop_name);
+    outer_prop[vh] = 100;
+    ASSERT_EQ(100, outer_prop[vh]);
+
+    {
+        // inner_prop uses same type and name as outer_prop
+        auto inner_prop = OpenMesh::makePropertyManagerFromNew<handle_type>(mesh_, prop_name);
+        inner_prop[vh] = 200;
+        ASSERT_EQ(200, inner_prop[vh]);
+        // End of scope: inner_prop is removed from mesh_
+    }
+
+    // Ensure outer_prop still exists and its data has not been overwritten by inner_prop
+    ASSERT_TRUE(has_property<handle_type>(mesh_, prop_name));
+    ASSERT_EQ(100, outer_prop[vh]);
+}
 
+/*
+ * In sequence:
+ * - add a persistent property to a mesh
+ * - retrieve an existing property of a mesh and modify it
+ * - obtain a non-owning property handle
+ * - attempt to obtain a non-owning handle to a non-existing property (throws)
+ */
+TEST_F(OpenMeshPropertyManager, cpp11_persistent_and_non_owning_properties) {
+    auto vh = mesh_.add_vertex({0,0,0}); // Dummy vertex to attach properties to
+
+    using handle_type = OpenMesh::VPropHandleT<int>;
+    const auto prop_name = "pm_v_test_property";
+
+    ASSERT_FALSE(has_property<handle_type>(mesh_, prop_name));
+
+    {
+        auto prop = OpenMesh::makePropertyManagerFromExistingOrNew<handle_type>(mesh_, prop_name);
+        prop[vh] = 100;
+        // End of scope, property persists
+    }
+
+    ASSERT_TRUE(has_property<handle_type>(mesh_, prop_name));
+
+    {
+        // Since a property of the same name and type already exists, this refers to the existing property.
+        auto prop = OpenMesh::makePropertyManagerFromExistingOrNew<handle_type>(mesh_, prop_name);
+        ASSERT_EQ(100, prop[vh]);
+        prop[vh] = 200;
+        // End of scope, property persists
+    }
 
+    ASSERT_TRUE(has_property<handle_type>(mesh_, prop_name));
+
+    {
+        // Acquire non-owning handle to the property, knowing it exists
+        auto prop = OpenMesh::makePropertyManagerFromExisting<handle_type>(mesh_, prop_name);
+        ASSERT_EQ(200, prop[vh]);
+    }
+
+    ASSERT_TRUE(has_property<handle_type>(mesh_, prop_name));
+
+    {
+        // Attempt to acquire non-owning handle for a non-existing property
+        ASSERT_THROW(OpenMesh::makePropertyManagerFromExisting<handle_type>(mesh_, "wrong_property_name"), std::runtime_error);
+    }
+
+    ASSERT_TRUE(has_property<handle_type>(mesh_, prop_name));
+}
 
+#endif
 
 }