include/vcl/task.hxx

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  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 .
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  19
  20 #ifndef INCLUDED_VCL_TASK_HXX
  21 #define INCLUDED_VCL_TASK_HXX
  22
  23 #include <vcl/dllapi.h>
  24
  25 struct ImplSchedulerData;
  26
  27 enum class TaskPriority
  28 {
  29     HIGHEST,       ///< These events should run very fast!
  30     DEFAULT,       ///< Default priority used, e.g. the default timer priority
  31     // Input from the OS event queue is processed before HIGH_IDLE tasks.
  32     HIGH_IDLE,     ///< Important idle events to be run before processing drawing events
  33     RESIZE,        ///< Resize runs before repaint, so we won't paint twice
  34     REPAINT,       ///< All repaint events should go in here
  35     POST_PAINT,    ///< Everything running directly after painting
  36     DEFAULT_IDLE,  ///< Default idle priority
  37     LOWEST,        ///< Low, very idle cleanup tasks
  38     TOOLKIT_DEBUG  ///< Do not use. Solely for IdleTask::waitUntilIdleDispatched
  39 };
  40
  41 #define PRIO_COUNT (static_cast<int>(TaskPriority::TOOLKIT_DEBUG) + 1)
  42
  43 class VCL_DLLPUBLIC Task
  44 {
  45     friend class Scheduler;
  46     friend struct ImplSchedulerData;
  47
  48     ImplSchedulerData *mpSchedulerData; ///< Pointer to the element in scheduler list
  49     const char        *mpDebugName;     ///< Useful for debugging
  50     TaskPriority       mePriority;      ///< Task priority
  51     bool               mbActive;        ///< Currently in the scheduler
  52     bool               mbStatic;        ///< Is a static object
  53
  54 protected:
  55     static void StartTimer( sal_uInt64 nMS );
  56
  57     const ImplSchedulerData* GetSchedulerData() const { return mpSchedulerData; }
  58
  59     virtual void SetDeletionFlags();
  60
  61     /**
  62      * How long (in MS) until the Task is ready to be dispatched?
  63      *
  64      * Simply return Scheduler::ImmediateTimeoutMs if you're ready, like an
  65      * Idle. If you have to return Scheduler::InfiniteTimeoutMs, you probably
  66      * need another mechanism to wake up the Scheduler or rely on other
  67      * Tasks to be scheduled, or simply use a polling Timer.
  68      *
  69      * @param nTimeNow the current time
  70      * @return the sleep time of the Task to become ready
  71      */
  72     virtual sal_uInt64 UpdateMinPeriod( sal_uInt64 nTimeNow ) const = 0;
  73
  74 public:
  75     Task( const char *pDebugName );
  76     Task( const Task& rTask );
  77     virtual ~Task() COVERITY_NOEXCEPT_FALSE;
  78     Task& operator=( const Task& rTask );
  79
  80     void            SetPriority(TaskPriority ePriority);
  81     TaskPriority    GetPriority() const { return mePriority; }
  82
  83     const char     *GetDebugName() const { return mpDebugName; }
  84
  85     // Call handler
  86     virtual void    Invoke() = 0;
  87
  88     /**
  89      * Schedules the task for execution
  90      *
  91      * If the timer is already active, it's reset!
  92      * Check with Task::IsActive() to prevent reset.
  93      *
  94      * If you unset bStartTimer, the Task must call Task::StartTimer(...) to be correctly scheduled!
  95      * Otherwise it might just be picked up when the Scheduler runs the next time.
  96      *
  97      * @param bStartTimer if false, don't schedule the Task by calling Task::StartTimer(0).
  98      */
  99     virtual void Start(bool bStartTimer = true);
 100     void            Stop();
 101
 102     bool            IsActive() const { return mbActive; }
 103
 104     /**
 105      * This function must be called for static tasks, so the Task destructor
 106      * ignores the scheduler mutex, as it may not be available anymore.
 107      * The cleanup is still correct, as it has already happened in
 108      * DeInitScheduler call well before the static destructor calls.
 109      */
 110     void            SetStatic() { mbStatic = true; }
 111     bool            IsStatic() const { return mbStatic; }
 112 };
 113
 114 #endif // INCLUDED_VCL_TASK_HXX
 115
 116 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */