Policies/Library Code Policy/Shared D-Pointer Example - Revision history

Mck182: Add note about QScopedPointer for d-pointers

2013-01-07T08:14:24Z

Add note about QScopedPointer for d-pointers

Ogoffart: s/QScopePointer/QScopedPointer/ (and few miner fixes)

2012-02-17T13:00:10Z

s/QScopePointer/QScopedPointer/ (and few miner fixes)

Ogoffart: /* The .cpp file */ Use smart pointer

2012-02-17T12:57:32Z

‎The .cpp file: Use smart pointer

Ogoffart: /* The header file, with Q_DECLARE_PRIVATE */ Use smart pointer

2012-02-17T12:56:23Z

‎The header file, with Q_DECLARE_PRIVATE: Use smart pointer

Ogoffart: /* The header file, without Q_DECLARE_PRIVATE */ Use smart pointer

2012-02-17T12:54:37Z

‎The header file, without Q_DECLARE_PRIVATE: Use smart pointer

ORBAT: Changed all `tags to tags to fix syntax highlighting problems`


2011-06-28T10:03:55Z
Changed all <code> tags to <source> tags to fix syntax highlighting problems

				
				
				
				
			
			← Older revision
			Revision as of 10:03, 28 June 2011
			
Line 2:
Line 2:
    
  == The header file, without Q_DECLARE_PRIVATE ==   == The header file, without Q_DECLARE_PRIVATE ==
− <code cppqt> + <source lang="cpp-qt">
  class KFooBasePrivate;   class KFooBasePrivate;
  class KFooBase : public QObject   class KFooBase : public QObject
Line 36:
Line 36:
       { return reinterpret_cast<KFooDerivedPrivate *>(d_ptr); }        { return reinterpret_cast<KFooDerivedPrivate *>(d_ptr); }
  };   };
− </code> + </source>
    
  == The header file, with Q_DECLARE_PRIVATE ==   == The header file, with Q_DECLARE_PRIVATE ==
− <code cppqt> + <source lang="cpp-qt">
  class KFooBasePrivate;   class KFooBasePrivate;
  class KFooBase : public QObject   class KFooBase : public QObject
Line 67:
Line 67:
       Q_DECLARE_PRIVATE(KFooDerived)        Q_DECLARE_PRIVATE(KFooDerived)
  };   };
− </code> + </source>
    
  == The .cpp file ==   == The .cpp file ==
− <code cppqt> + <source lang="cpp-qt">
  /*** KFooBase ***/   /*** KFooBase ***/
  class KFooBasePrivate   class KFooBasePrivate
Line 154:
Line 154:
       return d->someInteger + d->anotherInteger;        return d->someInteger + d->anotherInteger;
  }   }
− </code> + </source>



Tampakrap: Oops I didn't mean to submit...
2009-03-12T15:36:03Z
Oops I didn't mean to submit...

				
				
				
				
			
			← Older revision
			Revision as of 15:36, 12 March 2009
			
Line 155:
Line 155:
  }   }
  </code>   </code>
−  
− How is a copy constructor done for such an object?  



Tampakrap at 15:28, 12 March 2009
2009-03-12T15:28:02Z


				
				
				
				
			
			← Older revision
			Revision as of 15:28, 12 March 2009
			
Line 155:
Line 155:
  }   }
  </code>   </code>
  + 
  + How is a copy constructor done for such an object?



Frinring: access to anotherInteger helps with example
2008-10-23T23:37:46Z
access to anotherInteger helps with example

				
				
				
				
			
			← Older revision
			Revision as of 23:37, 23 October 2008
			
Line 24:
Line 24:
  public:   public:
       KFooDerived(QObject *parent);        KFooDerived(QObject *parent);
  +     void setAnotherInteger(int i);
  +     int anotherInteger() const;
       int sumOfIntegers() const;        int sumOfIntegers() const;
  protected:   protected:
Line 57:
Line 59:
  public:   public:
       KFooDerived(QObject *parent);        KFooDerived(QObject *parent);
  +     void setAnotherInteger(int i);
  +     int anotherInteger() const;
       int sumOfIntegers() const;        int sumOfIntegers() const;
  protected:   protected:





Frinring: no need to use d_func() in const functions
2008-10-23T23:35:43Z
no need to use d_func() in const functions

				
				
				
				
			
			← Older revision
			Revision as of 23:35, 23 October 2008
			
Line 93:
Line 93:
  {   {
       Q_D(KFooBase);        Q_D(KFooBase);
  + 
       d->someInteger = i;        d->someInteger = i;
  }   }
Line 98:
Line 99:
  int KFooBase::someInteger() const   int KFooBase::someInteger() const
  {   {
−      // because of 'const' use d_func here instead of Q_D +      // in const functions add 'const' to the class name
−      return d_func()->someInteger; +      Q_D(const KFooBase);
  +  
  +     return d->someInteger;
  }   }
    
Line 123:
Line 126:
  {   {
       /* no need to delete the d-pointer! */        /* no need to delete the d-pointer! */
  + }
  + 
  + void KFooDerived::setAnotherInteger(int i)
  + {
  +     Q_D(KFooDerived);
  + 
  +     d->anotherInteger = i;
  + }
  + 
  + int KFooDerived::anotherInteger() const
  + {
  +     // in const functions add 'const' to the class name
  +     Q_D(const KFooDerived);
  + 
  +     return d->anotherInteger;
  }   }
    
  int KFooDerived::sumOfIntegers() const   int KFooDerived::sumOfIntegers() const
  {   {
−      return d_func()->someInteger + d_func()->anotherInteger; +      // in const functions add 'const' to the class name
  +     Q_D(const KFooDerived);
  +  
  +     return d->someInteger + d->anotherInteger;
  }   }
  </code>   </code>

← Older revision		Revision as of 08:14, 7 January 2013
Line 1:		Line 1:
−	The following example illustrates the [[Policies/Library_Code_Policy#Shared D-Pointers\|shared d-pointer]] concept. The class presented here derives from QObject to illustrate parameter-passing in the constructor; it is not necessary to be like that in your code.	+	The following example illustrates the [[Policies/Library_Code_Policy#Shared D-Pointers\|shared d-pointer]] concept. The class presented here derives from QObject to illustrate parameter-passing in the constructor; it is not necessary to be like that in your code. This example puts your d-pointer into {{qt\|QScopedPointer}} which will handle proper deleting of the d-pointer once the main object is destroyed. Be sure to delete the d-pointer properly when not using {{qt\|QScopedPointer}}, otherwise your d_ptr will leak.

	== The header file, without Q_DECLARE_PRIVATE ==		== The header file, without Q_DECLARE_PRIVATE ==

@@ Line 12: / Line 12: @@
      int someInteger() const;
 protected:
-     const QScopePointer<KFooBasePrivate> d_ptr;
+     const QScopedPointer<KFooBasePrivate> d_ptr;
      KFooBase(KFooBasePrivate &dd, QObject *parent);
 private:
@@ Line 50: / Line 50: @@
      int someInteger() const;
 protected:
-     const QScopePointer<KFooBasePrivate>  d_ptr;
+     const QScopedPointer<KFooBasePrivate> d_ptr;
      KFooBase(KFooBasePrivate &dd, QObject *parent);
 private:
@@ Line 91: / Line 91: @@
+}
 KFooBase::~KFooBase()
+{
@@ Line 125: / Line 126: @@
 KFooDerived::KFooDerived(KFooDerivedPrivate &dd, QObject *parent)
      : KFooBase(dd, parent)
+{
+}

@@ Line 93: / Line 93: @@
 KFooBase::~KFooBase()
+{
+}
@@ Line 131: / Line 130: @@
 KFooDerived::~KFooDerived()
+{
+}

@@ Line 46: / Line 46: @@
 public:
      KFooBase(QObject *parent);
      void setSomeInteger(int i);
      int someInteger() const;
 protected:
-     KFooBasePrivate * const d_ptr;
+     const QScopePointer<KFooBasePrivate>  d_ptr;
      KFooBase(KFooBasePrivate &dd, QObject *parent);
 private:

@@ Line 8: / Line 8: @@
 public:
      KFooBase(QObject *parent);
      void setSomeInteger(int i);
      int someInteger() const;
 protected:
-     KFooBasePrivate * const d_ptr;
+     const QScopePointer<KFooBasePrivate> d_ptr;
      KFooBase(KFooBasePrivate &dd, QObject *parent);
 private:
@@ Line 32: / Line 33: @@
      friend class KFooDerivedPrivate;
      inline KFooDerivedPrivate *d_func()
-     { return reinterpret_cast<KFooDerivedPrivate *>(d_ptr); }
+     { return reinterpret_cast<KFooDerivedPrivate *>(d_ptr.data()); }
      inline const KFooDerivedPrivate *d_func() const
-     { return reinterpret_cast<KFooDerivedPrivate *>(d_ptr); }
+     { return reinterpret_cast<KFooDerivedPrivate *>(d_ptr.data()); }
 };
 </source>

← Older revision		Revision as of 15:36, 12 March 2009
Line 155:		Line 155:
	}		}
	</code>		</code>
−
−	~~How is a copy constructor done for such an object?~~

← Older revision		Revision as of 15:28, 12 March 2009
Line 155:		Line 155:
	}		}
	</code>		</code>
		+
		+	How is a copy constructor done for such an object?

Policies/Library Code Policy/Shared D-Pointer Example - Revision history

Mck182: Add note about QScopedPointer for d-pointers

Ogoffart: s/QScopePointer/QScopedPointer/ (and few miner fixes)

Ogoffart: /* The .cpp file */ Use smart pointer

Ogoffart: /* The header file, with Q_DECLARE_PRIVATE */ Use smart pointer

Ogoffart: /* The header file, without Q_DECLARE_PRIVATE */ Use smart pointer

ORBAT: Changed all tags to tags to fix syntax highlighting problems

Tampakrap: Oops I didn't mean to submit...

Tampakrap at 15:28, 12 March 2009

Frinring: access to anotherInteger helps with example

Frinring: no need to use d_func() in const functions

ORBAT: Changed all `tags to tags to fix syntax highlighting problems`