xpcom/glue/nsWeakReference.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
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  16  * The Original Code is the Mozilla browser.
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  20  * Portions created by the Initial Developer are Copyright (C) 1999
  21  * the Initial Developer. All Rights Reserved.
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  23  * Contributor(s):
  24  *   Scott Collins <scc@netscape.com>
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  39
  40 #ifndef nsWeakReference_h__
  41 #define nsWeakReference_h__
  42
  43 // nsWeakReference.h
  44
  45 #include "nsIWeakReference.h"
  46 #include "nsIWeakReferenceUtils.h"
  47
  48 class nsWeakReference;
  49
  50 // Set IMETHOD_VISIBILITY to empty so that the class-level NS_COM declaration
  51 // controls member method visibility.
  52 #undef  IMETHOD_VISIBILITY
  53 #define IMETHOD_VISIBILITY NS_COM_GLUE
  54
  55 class NS_COM_GLUE nsSupportsWeakReference : public nsISupportsWeakReference
  56   {
  57     public:
  58       nsSupportsWeakReference()
  59           : mProxy(0)
  60         {
  61           // nothing else to do here
  62         }
  63
  64       NS_DECL_NSISUPPORTSWEAKREFERENCE
  65
  66     protected:
  67       inline ~nsSupportsWeakReference();
  68
  69     private:
  70       friend class nsWeakReference;
  71
  72       void
  73       NoticeProxyDestruction()
  74           // ...called (only) by an |nsWeakReference| from _its_ dtor.
  75         {
  76           mProxy = 0;
  77         }
  78
  79       nsWeakReference* mProxy;
  80
  81                 protected:
  82
  83                         void ClearWeakReferences();
  84                         PRBool HasWeakReferences() const {return mProxy != 0;}
  85   };
  86
  87 #undef  IMETHOD_VISIBILITY
  88 #define IMETHOD_VISIBILITY NS_VISIBILITY_HIDDEN
  89
  90 inline
  91 nsSupportsWeakReference::~nsSupportsWeakReference()
  92   {
  93         ClearWeakReferences();
  94   }
  95
  96 #endif