import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

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;
+}