sd/source/ui/inc/tools/TimerBasedTaskExecution.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
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   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <vcl/timer.hxx>
  23
  24 #include <memory>
  25
  26 namespace sd::tools {
  27
  28 class AsynchronousTask;
  29
  30 /** Execute an AsynchronousTask timer based, i.e. every
  31     nMillisecondsBetweenSteps milliseconds as much steps are executed as fit
  32     into a nMaxTimePerStep millisecond interval.
  33
  34     When a task is executed completely, i.e. HasNextStep() returns <FALSE/>,
  35     the TimerBasedTaskExecution destroys itself.  This, of course, works
  36     only if the creating instance does not hold a shared_ptr to  that object.
  37 */
  38 class TimerBasedTaskExecution
  39 {
  40 public:
  41     /** Create a new object of this class.
  42         @param rpTask
  43             The AsynchronousTask that is to be executed.
  44         @param nMillisecondsBetweenSteps
  45             Wait at least this long between the execution of steps.  Note
  46             that more than one step may be executed in succession.
  47         @param nMaxTimePerStep
  48             The maximal time for executing steps without yielding control.
  49     */
  50     static std::shared_ptr<TimerBasedTaskExecution> Create (
  51         const std::shared_ptr<AsynchronousTask>& rpTask,
  52         sal_uInt32 nMillisecondsBetweenSteps,
  53         sal_uInt32 nMaxTimePerStep);
  54
  55     /** Stop the execution of the task and release the shared pointer to
  56         itself so that it will eventually be destroyed.
  57     */
  58     void Release();
  59
  60     /** Convenience method that calls Release() on the given task.  It
  61         checks the given weak_ptr for being expired and catches bad_weak_ptr
  62         exceptions.
  63     */
  64     static void ReleaseTask (const std::weak_ptr<TimerBasedTaskExecution>& rpTask);
  65
  66 private:
  67     std::shared_ptr<AsynchronousTask> mpTask;
  68     Timer maTimer;
  69     /** This shared_ptr to this is used to destroy a TimerBasedTaskExecution
  70         object when its task has been executed completely.
  71     */
  72     std::shared_ptr<TimerBasedTaskExecution> mpSelf;
  73     sal_uInt32 mnMaxTimePerStep;
  74
  75     TimerBasedTaskExecution (
  76         std::shared_ptr<AsynchronousTask> pTask,
  77         sal_uInt32 nMillisecondsBetweenSteps,
  78         sal_uInt32 nMaxTimePerStep);
  79     ~TimerBasedTaskExecution();
  80
  81     class Deleter;
  82     friend class Deleter;
  83
  84     DECL_LINK(TimerCallback, Timer *, void);
  85 };
  86
  87 } // end of namespace ::sd::tools
  88
  89 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */