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diff --git a/slideshow/source/inc/viewupdate.hxx b/slideshow/source/inc/viewupdate.hxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * 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/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#ifndef INCLUDED_SLIDESHOW_SOURCE_INC_VIEWUPDATE_HXX
+#define INCLUDED_SLIDESHOW_SOURCE_INC_VIEWUPDATE_HXX
+
+#include "disposable.hxx"
+#include <memory>
+
+/* Definition of ViewUpdate interface */
+
+namespace slideshow::internal
+    {
+        /** Interface for something that can perform view updates.
+
+            Use this interface for objects that perform view updates
+            from time to time, e.g. slide content. Availability of
+            updates can be queried, and subsequently performed.
+         */
+        class ViewUpdate : public Disposable
+        {
+        public:
+            /** Perform the update action on all views
+
+                @return true, if the update was performed
+                successfully, false otherwise.
+             */
+            virtual bool update() = 0;
+
+            /** Query whether updates are pending
+
+                @return true, if updates are pending. Calling update()
+                subsequently will perform the pending update then.
+             */
+            virtual bool needsUpdate() const = 0;
+        };
+
+        typedef ::std::shared_ptr< ViewUpdate > ViewUpdateSharedPtr;
+
+}
+
+#endif // INCLUDED_SLIDESHOW_SOURCE_INC_VIEWUPDATE_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */