xpcom/ds/nsObserverList.cpp

branch
TOR_BUG_3246
changeset 7
129ffea94266
equal deleted inserted replaced
-1:000000000000 0:473d4d21fdf5
1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6 #include "nsObserverList.h"
7
8 #include "nsAutoPtr.h"
9 #include "nsCOMArray.h"
10 #include "nsISimpleEnumerator.h"
11 #include "xpcpublic.h"
12
13 nsresult
14 nsObserverList::AddObserver(nsIObserver* anObserver, bool ownsWeak)
15 {
16 NS_ASSERTION(anObserver, "Null input");
17
18 if (!ownsWeak) {
19 ObserverRef* o = mObservers.AppendElement(anObserver);
20 if (!o)
21 return NS_ERROR_OUT_OF_MEMORY;
22
23 return NS_OK;
24 }
25
26 nsCOMPtr<nsIWeakReference> weak = do_GetWeakReference(anObserver);
27 if (!weak)
28 return NS_NOINTERFACE;
29
30 ObserverRef *o = mObservers.AppendElement(weak);
31 if (!o)
32 return NS_ERROR_OUT_OF_MEMORY;
33
34 return NS_OK;
35 }
36
37 nsresult
38 nsObserverList::RemoveObserver(nsIObserver* anObserver)
39 {
40 NS_ASSERTION(anObserver, "Null input");
41
42 if (mObservers.RemoveElement(static_cast<nsISupports*>(anObserver)))
43 return NS_OK;
44
45 nsCOMPtr<nsIWeakReference> observerRef = do_GetWeakReference(anObserver);
46 if (!observerRef)
47 return NS_ERROR_FAILURE;
48
49 if (!mObservers.RemoveElement(observerRef))
50 return NS_ERROR_FAILURE;
51
52 return NS_OK;
53 }
54
55 nsresult
56 nsObserverList::GetObserverList(nsISimpleEnumerator** anEnumerator)
57 {
58 nsRefPtr<nsObserverEnumerator> e(new nsObserverEnumerator(this));
59 e.forget(anEnumerator);
60 return NS_OK;
61 }
62
63 void
64 nsObserverList::FillObserverArray(nsCOMArray<nsIObserver> &aArray)
65 {
66 aArray.SetCapacity(mObservers.Length());
67
68 nsTArray<ObserverRef> observers(mObservers);
69
70 for (int32_t i = observers.Length() - 1; i >= 0; --i) {
71 if (observers[i].isWeakRef) {
72 nsCOMPtr<nsIObserver> o(do_QueryReferent(observers[i].asWeak()));
73 if (o) {
74 aArray.AppendObject(o);
75 }
76 else {
77 // the object has gone away, remove the weakref
78 mObservers.RemoveElement(observers[i].asWeak());
79 }
80 }
81 else {
82 aArray.AppendObject(observers[i].asObserver());
83 }
84 }
85 }
86
87 void
88 nsObserverList::NotifyObservers(nsISupports *aSubject,
89 const char *aTopic,
90 const char16_t *someData)
91 {
92 nsCOMArray<nsIObserver> observers;
93 FillObserverArray(observers);
94
95 for (int32_t i = 0; i < observers.Count(); ++i) {
96 observers[i]->Observe(aSubject, aTopic, someData);
97 }
98 }
99
100 void
101 nsObserverList::UnmarkGrayStrongObservers()
102 {
103 for (uint32_t i = 0; i < mObservers.Length(); ++i) {
104 if (!mObservers[i].isWeakRef) {
105 xpc_TryUnmarkWrappedGrayObject(mObservers[i].asObserver());
106 }
107 }
108 }
109
110 NS_IMPL_ISUPPORTS(nsObserverEnumerator, nsISimpleEnumerator)
111
112 nsObserverEnumerator::nsObserverEnumerator(nsObserverList* aObserverList)
113 : mIndex(0)
114 {
115 aObserverList->FillObserverArray(mObservers);
116 }
117
118 NS_IMETHODIMP
119 nsObserverEnumerator::HasMoreElements(bool *aResult)
120 {
121 *aResult = (mIndex < mObservers.Count());
122 return NS_OK;
123 }
124
125 NS_IMETHODIMP
126 nsObserverEnumerator::GetNext(nsISupports* *aResult)
127 {
128 if (mIndex == mObservers.Count()) {
129 NS_ERROR("Enumerating after HasMoreElements returned false.");
130 return NS_ERROR_UNEXPECTED;
131 }
132
133 NS_ADDREF(*aResult = mObservers[mIndex]);
134 ++mIndex;
135 return NS_OK;
136 }

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