Merge "(Partial Update) Mark as not rendered if the node is transparent or culled...

[platform/core/uifw/dali-core.git] / dali / internal / common / owner-pointer.h

diff --git a/dali/internal/common/owner-pointer.h b/dali/internal/common/owner-pointer.h
index 5ce648f..28fe69e 100644 (file)
--- a/dali/internal/common/owner-pointer.h
+++ b/dali/internal/common/owner-pointer.h
@@ -1,8 +1,8 @@
-#ifndef __DALI_INTERNAL_OWNER_POINTER_H__
-#define __DALI_INTERNAL_OWNER_POINTER_H__
+#ifndef DALI_INTERNAL_OWNER_POINTER_H
+#define DALI_INTERNAL_OWNER_POINTER_H
 
 /*
- * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2021 Samsung Electronics Co., Ltd.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,27 +18,25 @@
  *
  */
 
-// EXTERNAL INCLUDES
-#include <cstddef>    // NULL
-
 // INTERNAL INCLUDES
 #include <dali/public-api/common/dali-common.h>
 
 namespace Dali
 {
-
 namespace Internal
 {
-
-template < typename T >
+template<typename T>
 class OwnerPointer
 {
 public:
   /**
    * Default constructor. Creates an OwnerPointer that does not own any object.
+   * @note This does not protect against two different OwnerPointers pointing to the same object.
+   *       Both OwnerPointers will try to release the memory of the same object in that case which
+   *       could lead to a crash.
    */
   OwnerPointer()
-  : mObject(NULL)
+  : mObject(nullptr)
   {
   }
 
@@ -46,7 +44,7 @@ public:
    * Constructor. Creates an OwnerPointer that owns the object.
    * @param[in] object A pointer to a heap allocated object.
    */
-  OwnerPointer( T* object )
+  OwnerPointer(T* object)
   : mObject(object)
   {
   }
@@ -55,22 +53,34 @@ public:
    * Copy constructor. Passes the ownership of a pointer to another.
    * @param[in] other The pointer that gives away the ownership.
    */
-  OwnerPointer( OwnerPointer& other )
-  : mObject(NULL)
+  OwnerPointer(const OwnerPointer& other)
+  : OwnerPointer(static_cast<OwnerPointer&&>(const_cast<OwnerPointer&>(other))) // Remove constness & cast to rvalue to use the move constructor
+  {
+    // other needs to be const for compiler to pick up this as copy constructor;
+    // though we are using this as move as there can only be one owner
+  }
+
+  /**
+   * Move constructor. Passes the ownership of a pointer to another.
+   * @param[in] other The pointer that gives away the ownership.
+   */
+  OwnerPointer(OwnerPointer&& other)
+  : mObject(nullptr)
   {
-    Swap( other );
+    Swap(other);
   }
 
   /**
    * Assignment operator. Passes the ownership of a pointer to another.
    * @param[in] other The pointer that gives away the ownership.
    */
-  OwnerPointer& operator=( OwnerPointer& other )
+  OwnerPointer& operator=(OwnerPointer& other)
   {
-    if( this != &other )    // no self-assignment
+    if(this != &other) // no self-assignment
     {
-      // Creation of temportaty object to prevent premature deletion of object
-      OwnerPointer(other).Swap(*this);
+      delete mObject;
+      mObject       = other.mObject;
+      other.mObject = nullptr;
     }
 
     // return self
@@ -78,13 +88,23 @@ public:
   }
 
   /**
+   * Move assignment operator. Passes the ownership of a pointer to another.
+   * @param[in] other The pointer that gives away the ownership.
+   */
+  OwnerPointer& operator=(OwnerPointer&& other)
+  {
+    // Reuse operator=
+    return operator=(other);
+  }
+
+  /**
    * Assignment operator. Takes the ownership of the object.
    * If it owns an object already, it will be deleted.
    * @param[in] pointer A pointer to a heap allocated object.
    */
-  OwnerPointer& operator=( T* pointer )
+  OwnerPointer& operator=(T* pointer)
   {
-    if( mObject != pointer )
+    if(mObject != pointer)
     {
       Reset();
       mObject = pointer;
@@ -107,7 +127,7 @@ public:
    */
   T& operator*()
   {
-    DALI_ASSERT_DEBUG( mObject != NULL );
+    DALI_ASSERT_DEBUG(mObject);
 
     return *mObject;
   }
@@ -118,10 +138,10 @@ public:
    */
   T& operator*() const
   {
-    DALI_ASSERT_DEBUG( mObject != NULL );
+    DALI_ASSERT_DEBUG(mObject);
 
     // Pointer semantics: A const pointer does not mean const data.
-    return const_cast< T& >( *mObject );
+    return const_cast<T&>(*mObject);
   }
 
   /**
@@ -140,16 +160,16 @@ public:
   T* operator->() const
   {
     // Pointer semantics: A const pointer does not mean const data.
-    return const_cast< T* >( mObject );
+    return const_cast<T*>(mObject);
   }
 
   /**
    * Compare with a raw pointer.
    * @return true if the raw pointer matches the one owned by this object.
    */
-  bool operator==( const T* pointer )
+  bool operator==(const T* pointer)
   {
-    return ( mObject == pointer );
+    return (mObject == pointer);
   }
 
   /**
@@ -157,11 +177,8 @@ public:
    */
   void Reset()
   {
-    if ( mObject != NULL )
-    {
-      delete mObject;
-      mObject = NULL;
-    }
+    delete mObject;
+    mObject = nullptr;
   }
 
   /**
@@ -170,8 +187,8 @@ public:
    */
   T* Release()
   {
-    T* tmp = mObject;
-    mObject = NULL;
+    T* tmp  = mObject;
+    mObject = nullptr;
     return tmp;
   }
 
@@ -186,37 +203,30 @@ public:
 
   /**
    * Swap owned objects
+   * @param[in] other The pointer to swap the owned objects with.
    */
-  void Swap( OwnerPointer& other )
+  void Swap(OwnerPointer& other)
   {
-    T* tmp = mObject;
-    mObject = other.mObject;
-    other.mObject = tmp;
+    if(this != &other)
+    {
+      T* tmp        = mObject;
+      mObject       = other.mObject;
+      other.mObject = tmp;
+    }
   }
 
-  // Handle comparisons - This is a variation of the safe bool idiom
+  // Handle comparisons
 
   /**
-   * Pointer-to-member type. Objects can be implicitly converted to this for validity checks.
-   */
-  typedef void (OwnerPointer::*BooleanType)() const;
-
-  /**
-   * Converts an object handle to a BooleanType.
+   * Converts an object handle to a bool.
    * This is useful for checking whether the handle is NULL.
    */
-  operator BooleanType() const
+  explicit operator bool() const
   {
-    return (mObject != NULL) ? &OwnerPointer::ThisIsSaferThanReturningVoidStar : NULL;
+    return mObject != nullptr;
   }
 
 private:
-
-  /**
-   * Used by the safe bool idiom.
-   */
-  void ThisIsSaferThanReturningVoidStar() const {}
-
   // data
   T* mObject; ///< Raw pointer to the object
 };
@@ -225,4 +235,4 @@ private:
 
 } // namespace Dali
 
-#endif //__DALI_INTERNAL_OWNER_POINTER_H__
+#endif // DALI_INTERNAL_OWNER_POINTER_H