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diff --git a/slideshow/source/inc/interruptabledelayevent.hxx b/slideshow/source/inc/interruptabledelayevent.hxx
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+++ b/slideshow/source/inc/interruptabledelayevent.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_INTERRUPTABLEDELAYEVENT_HXX
+#define INCLUDED_SLIDESHOW_SOURCE_INC_INTERRUPTABLEDELAYEVENT_HXX
+
+#include "delayevent.hxx"
+
+namespace slideshow
+{
+    namespace internal
+    {
+        /** Event, which delays calling passed Event's fire() method
+            the given amount of time.
+
+            This is actually a facade around the passed event object,
+            that passes on all calls to that object, and the sole
+            contribution of itself is the delay.
+        */
+        class DelayFacade : public Event
+        {
+        public:
+            DelayFacade( const EventSharedPtr&  rEvent,
+                         double                 nTimeout    ) :
+                Event("DelayFacade"),
+                mpEvent( rEvent ),
+                mnTimeout( nTimeout )
+            {
+            }
+
+            virtual bool fire() override
+            {
+                if( mpEvent && isCharged() )
+                {
+                    // pass on directly - we're supposed to be called
+                    // from EventQueue here, anyway - and if not,
+                    // we're only keeping that incorrect transitively.
+                    return mpEvent->fire();
+                }
+
+                return false;
+            }
+
+            virtual bool isCharged() const override
+            {
+                // pass on to wrappee - this ensures that we return
+                // false on isCharged(), even if the other event has
+                // been fired outside our own fire() method
+                return mpEvent && mpEvent->isCharged();
+            }
+
+            virtual double getActivationTime( double nCurrentTime ) const override
+            {
+                // enforce _our_ timeout to our clients (this
+                // overrides any timeout possibly set at the wrappee!)
+                return nCurrentTime + mnTimeout;
+            }
+
+            virtual void dispose() override
+            {
+                mpEvent.reset();
+            }
+
+        private:
+            EventSharedPtr  mpEvent;
+            double          mnTimeout;
+        };
+
+        /// Return value for makeInterruptableDelay()
+        struct InterruptableEventPair
+        {
+            /** This member contains a pointer to the timeout
+                event. When enqueued, this event will fire the
+                requested action only after the specified timeout.
+             */
+            EventSharedPtr  mpTimeoutEvent;
+
+            /** This member contains a pointer to the interruption
+                event. When enqueued, this event will fire
+                immediately, interrupting a potentially waiting
+                timeout event.
+             */
+            EventSharedPtr  mpImmediateEvent;
+        };
+
+        /** Generate an interruptable delay event.
+
+            This function generates a pair of events, that are
+            especially tailored to achieve the following behaviour: By
+            default, the given functor is called after the specified
+            timeout (after insertion of the event into the EventQueue,
+            of course). But optionally, when the interruption event
+            InterruptableEventPair::mpImmediateEvent is fired, the
+            given functor is called <em>at once</em>, and the delay is
+            ignored (that means, the given functor is guaranteed to be
+            called at utmost once, and never twice. Furthermore, it is
+            ensured that both events return false on isCharged(), once
+            anyone of them has been fired already).
+
+            @param rFunctor
+            Functor to call when the event fires.
+
+            @param nTimeout
+            Timeout in seconds, to wait until functor is called.
+
+            @returns a pair of events, where the first one waits the
+            specified amount of time, and the other fires the given
+            functor immediately.
+         */
+        template< typename Functor > InterruptableEventPair makeInterruptableDelay( const Functor&  rFunctor,
+                                                                                    double          nTimeout    )
+        {
+            InterruptableEventPair aRes;
+
+            aRes.mpImmediateEvent = makeEvent( rFunctor, "makeInterruptableDelay");
+            aRes.mpTimeoutEvent = std::make_shared<DelayFacade>( aRes.mpImmediateEvent,
+                                                        nTimeout );
+
+            return aRes;
+        }
+    }
+}
+
+#endif // INCLUDED_SLIDESHOW_SOURCE_INC_INTERRUPTABLEDELAYEVENT_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */