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diff --git a/include/vcl/task.hxx b/include/vcl/task.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_VCL_TASK_HXX
+#define INCLUDED_VCL_TASK_HXX
+
+#include <vcl/dllapi.h>
+
+struct ImplSchedulerData;
+
+enum class TaskPriority
+{
+    HIGHEST,       ///< These events should run very fast!
+    DEFAULT,       ///< Default priority used, e.g. the default timer priority
+    // Input from the OS event queue is processed before HIGH_IDLE tasks.
+    HIGH_IDLE,     ///< Important idle events to be run before processing drawing events
+    RESIZE,        ///< Resize runs before repaint, so we won't paint twice
+    REPAINT,       ///< All repaint events should go in here
+    POST_PAINT,    ///< Everything running directly after painting
+    DEFAULT_IDLE,  ///< Default idle priority
+    LOWEST         ///< Low, very idle cleanup tasks
+};
+
+#define PRIO_COUNT (static_cast<int>(TaskPriority::LOWEST) + 1)
+
+class VCL_DLLPUBLIC Task
+{
+    friend class Scheduler;
+    friend struct ImplSchedulerData;
+
+    ImplSchedulerData *mpSchedulerData; ///< Pointer to the element in scheduler list
+    const char        *mpDebugName;     ///< Useful for debugging
+    TaskPriority       mePriority;      ///< Task priority
+    bool               mbActive;        ///< Currently in the scheduler
+    bool               mbStatic;        ///< Is a static object
+
+protected:
+    static void StartTimer( sal_uInt64 nMS );
+
+    const ImplSchedulerData* GetSchedulerData() const { return mpSchedulerData; }
+
+    virtual void SetDeletionFlags();
+
+    /**
+     * How long (in MS) until the Task is ready to be dispatched?
+     *
+     * Simply return Scheduler::ImmediateTimeoutMs if you're ready, like an
+     * Idle. If you have to return Scheduler::InfiniteTimeoutMs, you probably
+     * need another mechanism to wake up the Scheduler or rely on other
+     * Tasks to be scheduled, or simply use a polling Timer.
+     *
+     * @param nTimeNow the current time
+     * @return the sleep time of the Task to become ready
+     */
+    virtual sal_uInt64 UpdateMinPeriod( sal_uInt64 nTimeNow ) const = 0;
+
+public:
+    Task( const char *pDebugName );
+    Task( const Task& rTask );
+    virtual ~Task() COVERITY_NOEXCEPT_FALSE;
+    Task& operator=( const Task& rTask );
+
+    void            SetPriority(TaskPriority ePriority);
+    TaskPriority    GetPriority() const { return mePriority; }
+
+    const char     *GetDebugName() const { return mpDebugName; }
+
+    // Call handler
+    virtual void    Invoke() = 0;
+
+    /**
+     * Schedules the task for execution
+     *
+     * If the timer is already active, it's reset!
+     * Check with Task::IsActive() to prevent reset.
+     *
+     * If you unset bStartTimer, the Task must call Task::StartTimer(...) to be correctly scheduled!
+     * Otherwise it might just be picked up when the Scheduler runs the next time.
+     *
+     * @param bStartTimer if false, don't schedule the Task by calling Task::StartTimer(0).
+     */
+    virtual void Start(bool bStartTimer = true);
+    void            Stop();
+
+    bool            IsActive() const { return mbActive; }
+
+    /**
+     * This function must be called for static tasks, so the Task destructor
+     * ignores the scheduler mutex, as it may not be available anymore.
+     * The cleanup is still correct, as it has already happened in
+     * DeInitScheduler call well before the static destructor calls.
+     */
+    void            SetStatic() { mbStatic = true; }
+    bool            IsStatic() const { return mbStatic; }
+};
+
+#endif // INCLUDED_VCL_TASK_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */