1 : /* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : /* ***** BEGIN LICENSE BLOCK *****
3 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 : *
5 : * The contents of this file are subject to the Mozilla Public License Version
6 : * 1.1 (the "License"); you may not use this file except in compliance with
7 : * the License. You may obtain a copy of the License at
8 : * http://www.mozilla.org/MPL/
9 : *
10 : * Software distributed under the License is distributed on an "AS IS" basis,
11 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 : * for the specific language governing rights and limitations under the
13 : * License.
14 : *
15 : * The Original Code is mozilla.org code.
16 : *
17 : * The Initial Developer of the Original Code is
18 : * Netscape Communications Corporation.
19 : * Portions created by the Initial Developer are Copyright (C) 1998
20 : * the Initial Developer. All Rights Reserved.
21 : *
22 : * Contributor(s):
23 : * Scott Collins <scc@mozilla.org> (Original Author)
24 : *
25 : * Alternatively, the contents of this file may be used under the terms of
26 : * either of the GNU General Public License Version 2 or later (the "GPL"),
27 : * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
28 : * in which case the provisions of the GPL or the LGPL are applicable instead
29 : * of those above. If you wish to allow use of your version of this file only
30 : * under the terms of either the GPL or the LGPL, and not to allow others to
31 : * use your version of this file under the terms of the MPL, indicate your
32 : * decision by deleting the provisions above and replace them with the notice
33 : * and other provisions required by the GPL or the LGPL. If you do not delete
34 : * the provisions above, a recipient may use your version of this file under
35 : * the terms of any one of the MPL, the GPL or the LGPL.
36 : *
37 : * ***** END LICENSE BLOCK ***** */
38 :
39 : #ifndef nsIWeakReferenceUtils_h__
40 : #define nsIWeakReferenceUtils_h__
41 :
42 : #ifndef nsCOMPtr_h__
43 : #include "nsCOMPtr.h"
44 : #endif
45 :
46 : #include "nsIWeakReference.h"
47 :
48 : typedef nsCOMPtr<nsIWeakReference> nsWeakPtr;
49 :
50 : /**
51 : *
52 : */
53 :
54 : // a type-safe shortcut for calling the |QueryReferent()| member function
55 : // T must inherit from nsIWeakReference, but the cast may be ambiguous.
56 : template <class T, class DestinationType>
57 : inline
58 : nsresult
59 521481 : CallQueryReferent( T* aSource, DestinationType** aDestination )
60 : {
61 521481 : NS_PRECONDITION(aSource, "null parameter");
62 521481 : NS_PRECONDITION(aDestination, "null parameter");
63 :
64 : return aSource->QueryReferent(NS_GET_TEMPLATE_IID(DestinationType),
65 521481 : reinterpret_cast<void**>(aDestination));
66 : }
67 :
68 :
69 : class NS_COM_GLUE nsQueryReferent : public nsCOMPtr_helper
70 : {
71 : public:
72 61803 : nsQueryReferent( nsIWeakReference* aWeakPtr, nsresult* error )
73 : : mWeakPtr(aWeakPtr),
74 61803 : mErrorPtr(error)
75 : {
76 : // nothing else to do here
77 61803 : }
78 :
79 : virtual nsresult NS_FASTCALL operator()( const nsIID& aIID, void** ) const;
80 :
81 : private:
82 : nsIWeakReference* mWeakPtr;
83 : nsresult* mErrorPtr;
84 : };
85 :
86 : inline
87 : const nsQueryReferent
88 61803 : do_QueryReferent( nsIWeakReference* aRawPtr, nsresult* error = 0 )
89 : {
90 61803 : return nsQueryReferent(aRawPtr, error);
91 : }
92 :
93 :
94 : /**
95 : * Deprecated, use |do_GetWeakReference| instead.
96 : */
97 : extern NS_COM_GLUE
98 : nsIWeakReference*
99 : NS_GetWeakReference( nsISupports* , nsresult* aResult=0 );
100 :
101 : /**
102 : * |do_GetWeakReference| is a convenience function that bundles up all the work needed
103 : * to get a weak reference to an arbitrary object, i.e., the |QueryInterface|, test, and
104 : * call through to |GetWeakReference|, and put it into your |nsCOMPtr|.
105 : * It is specifically designed to cooperate with |nsCOMPtr| (or |nsWeakPtr|) like so:
106 : * |nsWeakPtr myWeakPtr = do_GetWeakReference(aPtr);|.
107 : */
108 : inline
109 : already_AddRefed<nsIWeakReference>
110 108279 : do_GetWeakReference( nsISupports* aRawPtr, nsresult* error = 0 )
111 : {
112 108279 : return NS_GetWeakReference(aRawPtr, error);
113 : }
114 :
115 : inline
116 : void
117 : do_GetWeakReference( nsIWeakReference* aRawPtr, nsresult* error = 0 )
118 : {
119 : // This signature exists solely to _stop_ you from doing a bad thing.
120 : // Saying |do_GetWeakReference()| on a weak reference itself,
121 : // is very likely to be a programmer error.
122 : }
123 :
124 : template <class T>
125 : inline
126 : void
127 : do_GetWeakReference( already_AddRefed<T>& )
128 : {
129 : // This signature exists solely to _stop_ you from doing the bad thing.
130 : // Saying |do_GetWeakReference()| on a pointer that is not otherwise owned by
131 : // someone else is an automatic leak. See <http://bugzilla.mozilla.org/show_bug.cgi?id=8221>.
132 : }
133 :
134 : template <class T>
135 : inline
136 : void
137 : do_GetWeakReference( already_AddRefed<T>&, nsresult* )
138 : {
139 : // This signature exists solely to _stop_ you from doing the bad thing.
140 : // Saying |do_GetWeakReference()| on a pointer that is not otherwise owned by
141 : // someone else is an automatic leak. See <http://bugzilla.mozilla.org/show_bug.cgi?id=8221>.
142 : }
143 :
144 : #endif
|