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-rw-r--r--xpcom/ds/nsObserverList.h93
1 files changed, 93 insertions, 0 deletions
diff --git a/xpcom/ds/nsObserverList.h b/xpcom/ds/nsObserverList.h
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+++ b/xpcom/ds/nsObserverList.h
@@ -0,0 +1,93 @@
+/* -*- 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/. */
+
+#ifndef nsObserverList_h___
+#define nsObserverList_h___
+
+#include "nsISupports.h"
+#include "nsTArray.h"
+#include "nsCOMPtr.h"
+#include "nsCOMArray.h"
+#include "nsIObserver.h"
+#include "nsIWeakReference.h"
+#include "nsHashKeys.h"
+#include "nsISimpleEnumerator.h"
+#include "mozilla/Attributes.h"
+
+struct ObserverRef
+{
+ ObserverRef(const ObserverRef& aO) : isWeakRef(aO.isWeakRef), ref(aO.ref) {}
+ explicit ObserverRef(nsIObserver* aObserver) : isWeakRef(false), ref(aObserver) {}
+ explicit ObserverRef(nsIWeakReference* aWeak) : isWeakRef(true), ref(aWeak) {}
+
+ bool isWeakRef;
+ nsCOMPtr<nsISupports> ref;
+
+ nsIObserver* asObserver()
+ {
+ NS_ASSERTION(!isWeakRef, "Isn't a strong ref.");
+ return static_cast<nsIObserver*>((nsISupports*)ref);
+ }
+
+ nsIWeakReference* asWeak()
+ {
+ NS_ASSERTION(isWeakRef, "Isn't a weak ref.");
+ return static_cast<nsIWeakReference*>((nsISupports*)ref);
+ }
+
+ bool operator==(nsISupports* aRhs) const { return ref == aRhs; }
+};
+
+class nsObserverList : public nsCharPtrHashKey
+{
+ friend class nsObserverService;
+
+public:
+ explicit nsObserverList(const char* aKey) : nsCharPtrHashKey(aKey)
+ {
+ MOZ_COUNT_CTOR(nsObserverList);
+ }
+
+ ~nsObserverList()
+ {
+ MOZ_COUNT_DTOR(nsObserverList);
+ }
+
+ MOZ_MUST_USE nsresult AddObserver(nsIObserver* aObserver, bool aOwnsWeak);
+ MOZ_MUST_USE nsresult RemoveObserver(nsIObserver* aObserver);
+
+ void NotifyObservers(nsISupports* aSubject,
+ const char* aTopic,
+ const char16_t* aSomeData);
+ void GetObserverList(nsISimpleEnumerator** aEnumerator);
+
+ // Fill an array with the observers of this category.
+ // The array is filled in last-added-first order.
+ void FillObserverArray(nsCOMArray<nsIObserver>& aArray);
+
+ // Like FillObserverArray(), but only for strongly held observers.
+ void AppendStrongObservers(nsCOMArray<nsIObserver>& aArray);
+
+private:
+ nsTArray<ObserverRef> mObservers;
+};
+
+class nsObserverEnumerator final : public nsISimpleEnumerator
+{
+public:
+ NS_DECL_ISUPPORTS
+ NS_DECL_NSISIMPLEENUMERATOR
+
+ explicit nsObserverEnumerator(nsObserverList* aObserverList);
+
+private:
+ ~nsObserverEnumerator() {}
+
+ int32_t mIndex; // Counts up from 0
+ nsCOMArray<nsIObserver> mObservers;
+};
+
+#endif /* nsObserverList_h___ */