[1660792 ] wxObject::Dec/IncRef and wxObjectDataPtr

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44521 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/object.h

@@ -392,14 +392,83 @@ class WXDLLIMPEXP_BASE wxObjectRefData
 
 public:
     wxObjectRefData() : m_count(1) { }
-    virtual ~wxObjectRefData() { }
 
     int GetRefCount() const { return m_count; }
 
+    void IncRef() { m_count++; }
+    void DecRef();
+
+protected:
+    // this object should never be destroyed directly but only as a
+    // result of a DecRef() call:
+    virtual ~wxObjectRefData() { }
+
 private:
+    // our refcount:
     int m_count;
 };
 
+// ----------------------------------------------------------------------------
+// wxObjectDataPtr: helper class to avoid memleaks because of missing calls
+//                  to wxObjectRefData::DecRef
+// ----------------------------------------------------------------------------
+
+template <class T>
+class wxObjectDataPtr
+{
+public:
+    typedef T element_type;
+
+    wxEXPLICIT wxObjectDataPtr(T *ptr = NULL) : m_ptr(ptr) {}
+
+    // copy ctor
+    wxObjectDataPtr(const wxObjectDataPtr<T> &tocopy) 
+        : m_ptr(tocopy.m_ptr)
+    { 
+        if (m_ptr)
+            m_ptr->IncRef(); 
+    }
+
+    ~wxObjectDataPtr() 
+    { 
+        if (m_ptr) 
+            m_ptr->DecRef(); 
+    }
+
+    T *get() const { return m_ptr; }
+    T *operator->() const { return get(); }
+
+    void reset(T *ptr)
+    {
+        if (m_ptr)
+            m_ptr->DecRef();
+        m_ptr = ptr;
+    }
+
+    wxObjectDataPtr& operator=(const wxObjectDataPtr &tocopy)
+    { 
+        if (m_ptr) 
+            m_ptr->DecRef(); 
+        m_ptr = tocopy.m_ptr; 
+        if (m_ptr)
+            m_ptr->IncRef(); 
+        return *this;
+    }
+
+    wxObjectDataPtr& operator=(T *ptr)
+    { 
+        if (m_ptr) 
+            m_ptr->DecRef(); 
+        m_ptr = ptr; 
+        if (m_ptr)
+            m_ptr->IncRef(); 
+        return *this;
+    }
+
+private:
+    T *m_ptr;
+};
+
 // ----------------------------------------------------------------------------
 // wxObject: the root class of wxWidgets object hierarchy
 // ----------------------------------------------------------------------------
@@ -520,7 +589,8 @@ public:
 #ifdef _MSC_VER
         return (wxClassInfo*) m_classInfo;
 #else
-        return wx_const_cast(wxClassInfo *, m_classInfo);
+        wxDynamicClassInfo *nonconst = wx_const_cast(wxDynamicClassInfo *, m_classInfo);
+        return wx_static_cast(wxClassInfo *, nonconst);
 #endif
     }