include/wx/cocoa/ObjcRef.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/cocoa/ObjcRef.h
   3 // Purpose:     wxObjcAutoRef template class
   4 // Author:      David Elliott
   5 // Modified by:
   6 // Created:     2004/03/28
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2004 David Elliott <dfe@cox.net>
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_COCOA_OBJCREF_H__
  13 #define _WX_COCOA_OBJCREF_H__
  14 /*
  15 wxObjcAutoRefFromAlloc: construct a reference to an object that was
  16 [NSObject -alloc]'ed and thus does not need a retain
  17 wxObjcAutoRef: construct a reference to an object that was
  18 either autoreleased or is retained by something else.
  19 */
  20
  21 struct objc_object;
  22
  23 // We must do any calls to Objective-C from an Objective-C++ source file
  24 class wxObjcAutoRefBase
  25 {
  26 protected:
  27     static struct objc_object* ObjcRetain(struct objc_object*);
  28     static void ObjcRelease(struct objc_object*);
  29 };
  30
  31 // T should be a pointer like NSObject*
  32
  33 template <class T>
  34 class wxObjcAutoRefFromAlloc: wxObjcAutoRefBase
  35 {
  36 public:
  37     wxObjcAutoRefFromAlloc(T p = 0)
  38     :   m_ptr(p)
  39     // NOTE: this is from alloc.  Do NOT retain
  40     {}
  41     wxObjcAutoRefFromAlloc(const wxObjcAutoRefFromAlloc& otherRef)
  42     :   m_ptr(otherRef.m_ptr)
  43     {   ObjcRetain(m_ptr); }
  44     ~wxObjcAutoRefFromAlloc()
  45     {   ObjcRelease(m_ptr); }
  46     wxObjcAutoRefFromAlloc& operator=(const wxObjcAutoRefFromAlloc& otherRef)
  47     {   ObjcRetain(otherRef.m_ptr);
  48         ObjcRelease(m_ptr);
  49         m_ptr = otherRef.m_ptr;
  50         return *this;
  51     }
  52     operator T() const
  53     {   return m_ptr; }
  54     T operator->() const
  55     {   return m_ptr; }
  56 protected:
  57     T m_ptr;
  58 };
  59
  60 // The only thing wxObjcAutoRef has to do is retain an initial object
  61 template <class T>
  62 class wxObjcAutoRef: public wxObjcAutoRefFromAlloc<T>
  63 {
  64 public:
  65     wxObjcAutoRef(T p = 0)
  66     :   wxObjcAutoRefFromAlloc<T>(p)
  67     {   ObjcRetain(m_ptr); }
  68     ~wxObjcAutoRef() {}
  69     wxObjcAutoRef(const wxObjcAutoRef& otherRef)
  70     :   wxObjcAutoRefFromAlloc<T>(otherRef)
  71     {}
  72     wxObjcAutoRef(const wxObjcAutoRefFromAlloc<T>& otherRef)
  73     :   wxObjcAutoRefFromAlloc<T>(otherRef)
  74     {}
  75     wxObjcAutoRef& operator=(const wxObjcAutoRef& otherRef)
  76     {   return wxObjcAutoRefFromAlloc<T>::operator=(otherRef); }
  77 };
  78
  79 #endif //ndef _WX_COCOA_OBJCREF_H__