[Core] Introduce WriteAccessor move constructor

Sofa/framework/Core/src/sofa/core/objectmodel/Data.h

@@ -409,14 +409,27 @@ class WriteAccessor< core::objectmodel::Data<T> > : public WriteAccessor<T>
 
 protected:
     data_container_type& data;
+    bool m_moved = false;
 
     /// @internal used by WriteOnlyAccessor
     WriteAccessor( container_type* c, data_container_type& d) : Inherit(*c), data(d) {}
 
 public:
+    WriteAccessor(WriteAccessor&& other) noexcept : Inherit(std::move(other)), data(other.data)
+    {
+        other.m_moved = true;
+    }
+
     WriteAccessor(data_container_type& d) : Inherit(*d.beginEdit()), data(d) {}
     WriteAccessor(data_container_type* d) : Inherit(*d->beginEdit()), data(*d) {}
-    ~WriteAccessor() { data.endEdit(); }
+
+    ~WriteAccessor()
+    {
+        if (!m_moved)
+        {
+            data.endEdit();
+        }
+    }
 };
 
 

Sofa/framework/Core/test/CMakeLists.txt

@@ -3,8 +3,8 @@ cmake_minimum_required(VERSION 3.22)
 project(Sofa.Core_test)
 
 set(SOURCE_FILES
-    accessor/ReadAccessor.cpp
-    accessor/WriteAccessor.cpp
+    accessor/ReadAccessor_test.cpp
+    accessor/WriteAccessor_test.cpp
     collision/NarrowPhaseDetection_test.cpp
     loader/MeshLoader_test.cpp
     objectmodel/AspectPool_test.cpp

Sofa/framework/Core/test/accessor/WriteAccessor.cpp → Sofa/framework/Core/test/accessor/WriteAccessor_test.cpp

@@ -22,6 +22,7 @@
 #include <gtest/gtest.h>
 
 #include <sofa/core/objectmodel/Data.h>
+#include <sofa/core/objectmodel/DataCallback.h>
 #include <sofa/type/vector.h>
 
 namespace sofa
@@ -79,5 +80,74 @@ TEST(WriteAccessor, VectorTypes)
     EXPECT_FLOAT_EQ(vector.getValue()[3], 6.f);
 }
 
+TEST(WriteAccessor, MoveConstructor)
+{
+    Data<float> floatValue { 12.f };
+    int initialCounter = floatValue.getCounter();
+
+    {
+        sofa::helper::WriteAccessor floatAccessor(floatValue);
+        EXPECT_EQ(floatValue.getCounter(), initialCounter + 1);
+        EXPECT_FLOAT_EQ(floatAccessor.ref(), 12.f);
+
+        sofa::helper::WriteAccessor floatAccessorMoved(std::move(floatAccessor));
+        EXPECT_EQ(floatValue.getCounter(), initialCounter + 1);
+        EXPECT_FLOAT_EQ(floatAccessorMoved.ref(), 12.f);
+
+        // Even if we moved from it, we can still call ref() and wref()
+        // but it is not recommended as it doesn't hold the responsibility of endEdit anymore.
+        EXPECT_FLOAT_EQ(floatAccessor.ref(), 12.f);
+
+        floatAccessorMoved.wref() = 14.f;
+        EXPECT_FLOAT_EQ(floatValue.getValue(), 14.f);
+    }
+
+    Data<float> data { 1.f };
+    int endEditCount = 0;
+    sofa::core::objectmodel::DataCallback cb;
+    cb.addInput(&data);
+    cb.addCallback([&endEditCount](){
+        endEditCount++;
+    });
+
+    {
+        sofa::helper::WriteAccessor acc1(data);
+        EXPECT_EQ(endEditCount, 0); // beginEdit doesn't trigger callback
+        {
+            sofa::helper::WriteAccessor acc2(std::move(acc1));
+            EXPECT_EQ(endEditCount, 0);
+        }
+        // acc2 out of scope, endEdit called
+        EXPECT_EQ(endEditCount, 1);
+    }
+    // acc1 out of scope, if move constructor worked correctly, endEdit should NOT be called again.
+    EXPECT_EQ(endEditCount, 1);
+}
+
+TEST(WriteAccessor, MoveConstructorVector)
+{
+    Data<sofa::type::vector<float>> vector { sofa::type::vector<float> { 0.f, 1.f, 2.f, 3.f, 4.f} };
+    int endEditCount = 0;
+    sofa::core::objectmodel::DataCallback cb;
+    cb.addInput(&vector);
+    cb.addCallback([&endEditCount](){
+        endEditCount++;
+    });
+
+    {
+        sofa::helper::WriteAccessor acc1(vector);
+        EXPECT_EQ(acc1.size(), 5);
+        {
+            sofa::helper::WriteAccessor acc2(std::move(acc1));
+            EXPECT_EQ(acc2.size(), 5);
+            EXPECT_EQ(acc1.size(), 5); // Still valid but no longer responsible for endEdit
+            acc2[0] = 10.f;
+        }
+        EXPECT_EQ(endEditCount, 1);
+    }
+    EXPECT_EQ(endEditCount, 1);
+    EXPECT_FLOAT_EQ(vector.getValue()[0], 10.f);
+}
+
 
 }

Sofa/framework/Helper/test/CMakeLists.txt

@@ -13,8 +13,8 @@ set(SOURCE_FILES
     StringUtils_test.cpp
     TagFactory_test.cpp
     Utils_test.cpp
-    accessor/ReadAccessor.cpp
-    accessor/WriteAccessor.cpp
+    accessor/ReadAccessor_test.cpp
+    accessor/WriteAccessor_test.cpp
     io/MeshOBJ_test.cpp
     io/STBImage_test.cpp
     io/XspLoader_test.cpp