Added wxObjcAutoRef* classes for automatic retain/release of Objective-C objects

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@26580 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/cocoa/ObjcRef.h

@@ -0,0 +1,76 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/cocoa/ObjcRef.h
+// Purpose:     wxObjcAutoRef template class
+// Author:      David Elliott
+// Modified by: 
+// Created:     2004/03/28
+// RCS-ID:      $Id$
+// Copyright:   (c) 2004 David Elliott <dfe@cox.net>
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+/*
+wxObjcAutoRefFromAlloc: construct a reference to an object that was
+[NSObject -alloc]'ed and thus does not need a retain
+wxObjcAutoRef: construct a reference to an object that was
+either autoreleased or is retained by something else.
+*/
+
+struct objc_object;
+
+// We must do any calls to Objective-C from an Objective-C++ source file
+class wxObjcAutoRefBase
+{
+protected:
+    static struct objc_object* ObjcRetain(struct objc_object*);
+    static struct objc_object* ObjcRelease(struct objc_object*);
+};
+
+// T should be a pointer like NSObject*
+
+template <class T>
+class wxObjcAutoRefFromAlloc: wxObjcAutoRefBase
+{
+public:
+    wxObjcAutoRefFromAlloc(T p = 0)
+    :   m_ptr(p)
+    // NOTE: this is from alloc.  Do NOT retain
+    {}
+    wxObjcAutoRefFromAlloc(const wxObjcAutoRefFromAlloc& otherRef)
+    :   m_ptr(otherRef.m_ptr)
+    {   ObjcRetain(m_ptr); }
+    ~wxObjcAutoRefFromAlloc()
+    {   ObjcRelease(m_ptr); }
+    wxObjcAutoRefFromAlloc& operator=(const wxObjcAutoRefFromAlloc& otherRef)
+    {   ObjcRetain(otherRef.m_ptr);
+        ObjcRelease(m_ptr);
+        m_ptr = otherRef.m_ptr;
+        return *this;
+    }
+    operator T() const
+    {   return m_ptr; }
+    T operator->() const
+    {   return m_ptr; }
+protected:
+    T m_ptr;
+};
+
+// The only thing wxObjcAutoRef has to do is retain an initial object
+template <class T>
+class wxObjcAutoRef: public wxObjcAutoRefFromAlloc<T>
+{
+public:
+    wxObjcAutoRef(T p = 0)
+    :   wxObjcAutoRefFromAlloc<T>(p)
+    {   ObjcRetain(m_ptr); }
+    ~wxObjcAutoRef() {}
+    wxObjcAutoRef(const wxObjcAutoRef& otherRef)
+    :   wxObjcAutoRefFromAlloc<T>(otherRef)
+    {}
+    wxObjcAutoRef(const wxObjcAutoRefFromAlloc<T>& otherRef)
+    :   wxObjcAutoRefFromAlloc<T>(otherRef)
+    {}
+    wxObjcAutoRef& operator=(const wxObjcAutoRef& otherRef)
+    {   return wxObjcAutoRefFromAlloc<T>::operator=(otherRef); }
+};
+

src/cocoa/ObjcRef.mm

@@ -0,0 +1,25 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        cocoa/ObjcRef.mm
+// Purpose:     wxObjcAutoRefBase implementation
+// Author:      David Elliott
+// Modified by: 
+// Created:     2004/03/28
+// RCS-ID:      $Id$
+// Copyright:   (c) 2004 David Elliott <dfe@cox.net>
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#include "wx/cocoa/ObjcRef.h"
+
+#include <Foundation/NSObject.h>
+
+/*static*/ struct objc_object* wxObjcAutoRefBase::ObjcRetain(struct objc_object* obj)
+{
+    return [obj retain];
+}
+
+/*static*/ struct objc_object* wxObjcAutoRefBase::ObjcRelease(struct objc_object* obj)
+{
+    return [obj release];
+}
+