1 files changed, 89 insertions, 0 deletions
diff --git a/sd/source/ui/inc/tools/TimerBasedTaskExecution.hxx b/sd/source/ui/inc/tools/TimerBasedTaskExecution.hxx
new file mode 100644
index 000000000..bbff549f1
--- /dev/null
+++ b/sd/source/ui/inc/tools/TimerBasedTaskExecution.hxx
@@ -0,0 +1,89 @@
+/* -*- 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 .
+ */
+
+#pragma once
+
+#include <vcl/timer.hxx>
+
+#include <memory>
+
+namespace sd::tools {
+
+class AsynchronousTask;
+
+/** Execute an AsynchronousTask timer based, i.e. every
+    nMillisecondsBetweenSteps milliseconds as much steps are executed as fit
+    into a nMaxTimePerStep millisecond interval.
+
+    When a task is executed completely, i.e. HasNextStep() returns <FALSE/>,
+    the TimerBasedTaskExecution destroys itself.  This, of course, works
+    only if the creating instance does not hold a shared_ptr to  that object.
+*/
+class TimerBasedTaskExecution
+{
+public:
+    /** Create a new object of this class.
+        @param rpTask
+            The AsynchronousTask that is to be executed.
+        @param nMillisecondsBetweenSteps
+            Wait at least this long between the execution of steps.  Note
+            that more than one step may be executed in succession.
+        @param nMaxTimePerStep
+            The maximal time for executing steps without yielding control.
+    */
+    static std::shared_ptr<TimerBasedTaskExecution> Create (
+        const std::shared_ptr<AsynchronousTask>& rpTask,
+        sal_uInt32 nMillisecondsBetweenSteps,
+        sal_uInt32 nMaxTimePerStep);
+
+    /** Stop the execution of the task and release the shared pointer to
+        itself so that it will eventually be destroyed.
+    */
+    void Release();
+
+    /** Convenience method that calls Release() on the given task.  It
+        checks the given weak_ptr for being expired and catches bad_weak_ptr
+        exceptions.
+    */
+    static void ReleaseTask (const std::weak_ptr<TimerBasedTaskExecution>& rpTask);
+
+private:
+    std::shared_ptr<AsynchronousTask> mpTask;
+    Timer maTimer;
+    /** This shared_ptr to this is used to destroy a TimerBasedTaskExecution
+        object when its task has been executed completely.
+    */
+    std::shared_ptr<TimerBasedTaskExecution> mpSelf;
+    sal_uInt32 mnMaxTimePerStep;
+
+    TimerBasedTaskExecution (
+        const std::shared_ptr<AsynchronousTask>& rpTask,
+        sal_uInt32 nMillisecondsBetweenSteps,
+        sal_uInt32 nMaxTimePerStep);
+    ~TimerBasedTaskExecution();
+
+    class Deleter;
+    friend class Deleter;
+
+    DECL_LINK(TimerCallback, Timer *, void);
+};
+
+} // end of namespace ::sd::tools
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */