1 files changed, 37 insertions, 0 deletions
diff --git a/xpcom/ds/nsIObserver.idl b/xpcom/ds/nsIObserver.idl
new file mode 100644
index 0000000000..773424d0a7
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+++ b/xpcom/ds/nsIObserver.idl
@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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 "nsISupports.idl"
+
+/**
+ * This interface is implemented by an object that wants
+ * to observe an event corresponding to a topic.
+ */
+
+[scriptable, function, uuid(DB242E01-E4D9-11d2-9DDE-000064657374)]
+interface nsIObserver : nsISupports {
+
+   /**
+    * Observe will be called when there is a notification for the
+    * topic |aTopic|.  This assumes that the object implementing
+    * this interface has been registered with an observer service
+    * such as the nsIObserverService.
+    *
+    * If you expect multiple topics/subjects, the impl is
+    * responsible for filtering.
+    *
+    * You should not modify, add, remove, or enumerate
+    * notifications in the implemention of observe.
+    *
+    * @param aSubject : Notification specific interface pointer.
+    * @param aTopic   : The notification topic or subject.
+    * @param aData    : Notification specific wide string.
+    *                    subject event.
+    */
+    void observe( in nsISupports aSubject,
+                  in string      aTopic,
+                  in wstring     aData );
+
+};