First Checked In.

widget/src/mac/nsDeleteObserver.cpp

@@ -0,0 +1,74 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+#include "nsDeleteObserver.h"
+#include "nsVoidArray.h"
+
+
+//-------------------------------------------------------------------------
+//
+//-------------------------------------------------------------------------
+
+nsDeleteObserved::nsDeleteObserved(void* aObject)
+{
+	mDeleteObserverArray = nsnull;
+	mObject = (aObject ? aObject : this);
+}
+
+//-------------------------------------------------------------------------
+//
+//-------------------------------------------------------------------------
+
+nsDeleteObserved::~nsDeleteObserved()
+{
+	if (mDeleteObserverArray)
+	{
+		// notify observers of the delete
+		for (PRInt32 i = 0; i < mDeleteObserverArray->Count(); i ++)
+		{
+			nsDeleteObserver* deleteObserver = static_cast<nsDeleteObserver*>(mDeleteObserverArray->ElementAt(i));
+			if (deleteObserver)
+				deleteObserver->NotifyDelete(mObject);
+		}
+
+		delete mDeleteObserverArray;
+		mDeleteObserverArray = nsnull;
+	}
+}
+
+//-------------------------------------------------------------------------
+//
+//-------------------------------------------------------------------------
+
+void nsDeleteObserved::AddDeleteObserver(nsDeleteObserver* aDeleteObserver)
+{
+	if (! mDeleteObserverArray)
+		mDeleteObserverArray = new nsVoidArray();
+
+	if (mDeleteObserverArray)
+		mDeleteObserverArray->AppendElement(aDeleteObserver);
+}
+
+//-------------------------------------------------------------------------
+//
+//-------------------------------------------------------------------------
+
+void nsDeleteObserved::RemoveDeleteObserver(nsDeleteObserver* aDeleteObserver)
+{
+	if (mDeleteObserverArray)
+		mDeleteObserverArray->RemoveElement(aDeleteObserver);
+}

widget/src/mac/nsDeleteObserver.h

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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+#ifndef DeleteObserver_h__
+#define DeleteObserver_h__
+
+class nsVoidArray;
+
+//-------------------------------------------------------------------------
+//
+//-------------------------------------------------------------------------
+//
+// This is a small utility class which allows to notify an object
+// (the "observer") holding a reference on another object 
+// (the "observed") that the observed object has been deleted.
+//
+// As you imagine, it's reserved to cases where XPCOM refCouting doesn't fit.
+// It is used by the MacEventHandler and the Toolkit to hold references
+// on the focused widget and the the last widget hit.
+
+
+
+//-------------------------------------------------------------------------
+//
+//-------------------------------------------------------------------------
+
+class nsDeleteObserver
+{
+public:
+		virtual void	NotifyDelete(void* aDeletedObject) = 0;
+};
+
+//-------------------------------------------------------------------------
+//
+//-------------------------------------------------------------------------
+
+class nsDeleteObserved
+{
+public:
+							nsDeleteObserved(void* aObject);
+	virtual			~nsDeleteObserved();
+
+	void				AddDeleteObserver(nsDeleteObserver* aDeleteObserver);
+	void				RemoveDeleteObserver(nsDeleteObserver* aDeleteObserver);
+
+private:
+	nsVoidArray*			mDeleteObserverArray;
+	void*							mObject;
+};
+
+
+#endif //DeleteObserver_h__