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-rw-r--r--xpcom/ds/nsObserverList.cpp142
1 files changed, 142 insertions, 0 deletions
diff --git a/xpcom/ds/nsObserverList.cpp b/xpcom/ds/nsObserverList.cpp
new file mode 100644
index 000000000..fef8831b8
--- /dev/null
+++ b/xpcom/ds/nsObserverList.cpp
@@ -0,0 +1,142 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsObserverList.h"
+
+#include "nsAutoPtr.h"
+#include "nsCOMArray.h"
+#include "nsISimpleEnumerator.h"
+#include "xpcpublic.h"
+
+nsresult
+nsObserverList::AddObserver(nsIObserver* anObserver, bool ownsWeak)
+{
+ NS_ASSERTION(anObserver, "Null input");
+
+ if (!ownsWeak) {
+ ObserverRef* o = mObservers.AppendElement(anObserver);
+ if (!o) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ return NS_OK;
+ }
+
+ nsCOMPtr<nsIWeakReference> weak = do_GetWeakReference(anObserver);
+ if (!weak) {
+ return NS_NOINTERFACE;
+ }
+
+ ObserverRef* o = mObservers.AppendElement(weak);
+ if (!o) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ return NS_OK;
+}
+
+nsresult
+nsObserverList::RemoveObserver(nsIObserver* anObserver)
+{
+ NS_ASSERTION(anObserver, "Null input");
+
+ if (mObservers.RemoveElement(static_cast<nsISupports*>(anObserver))) {
+ return NS_OK;
+ }
+
+ nsCOMPtr<nsIWeakReference> observerRef = do_GetWeakReference(anObserver);
+ if (!observerRef) {
+ return NS_ERROR_FAILURE;
+ }
+
+ if (!mObservers.RemoveElement(observerRef)) {
+ return NS_ERROR_FAILURE;
+ }
+
+ return NS_OK;
+}
+
+void
+nsObserverList::GetObserverList(nsISimpleEnumerator** anEnumerator)
+{
+ RefPtr<nsObserverEnumerator> e(new nsObserverEnumerator(this));
+ e.forget(anEnumerator);
+}
+
+void
+nsObserverList::FillObserverArray(nsCOMArray<nsIObserver>& aArray)
+{
+ aArray.SetCapacity(mObservers.Length());
+
+ nsTArray<ObserverRef> observers(mObservers);
+
+ for (int32_t i = observers.Length() - 1; i >= 0; --i) {
+ if (observers[i].isWeakRef) {
+ nsCOMPtr<nsIObserver> o(do_QueryReferent(observers[i].asWeak()));
+ if (o) {
+ aArray.AppendObject(o);
+ } else {
+ // the object has gone away, remove the weakref
+ mObservers.RemoveElement(observers[i].asWeak());
+ }
+ } else {
+ aArray.AppendObject(observers[i].asObserver());
+ }
+ }
+}
+
+void
+nsObserverList::AppendStrongObservers(nsCOMArray<nsIObserver>& aArray)
+{
+ aArray.SetCapacity(aArray.Length() + mObservers.Length());
+
+ for (int32_t i = mObservers.Length() - 1; i >= 0; --i) {
+ if (!mObservers[i].isWeakRef) {
+ aArray.AppendObject(mObservers[i].asObserver());
+ }
+ }
+}
+
+void
+nsObserverList::NotifyObservers(nsISupports* aSubject,
+ const char* aTopic,
+ const char16_t* someData)
+{
+ nsCOMArray<nsIObserver> observers;
+ FillObserverArray(observers);
+
+ for (int32_t i = 0; i < observers.Count(); ++i) {
+ observers[i]->Observe(aSubject, aTopic, someData);
+ }
+}
+
+NS_IMPL_ISUPPORTS(nsObserverEnumerator, nsISimpleEnumerator)
+
+nsObserverEnumerator::nsObserverEnumerator(nsObserverList* aObserverList)
+ : mIndex(0)
+{
+ aObserverList->FillObserverArray(mObservers);
+}
+
+NS_IMETHODIMP
+nsObserverEnumerator::HasMoreElements(bool* aResult)
+{
+ *aResult = (mIndex < mObservers.Count());
+ return NS_OK;
+}
+
+NS_IMETHODIMP
+nsObserverEnumerator::GetNext(nsISupports** aResult)
+{
+ if (mIndex == mObservers.Count()) {
+ NS_ERROR("Enumerating after HasMoreElements returned false.");
+ return NS_ERROR_UNEXPECTED;
+ }
+
+ NS_ADDREF(*aResult = mObservers[mIndex]);
+ ++mIndex;
+ return NS_OK;
+}