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

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  30
  31 #ifndef SD_TIMER_BASED_TASK_EXECUTION_HXX
  32 #define SD_TIMER_BASED_TASK_EXECUTION_HXX
  33
  34 #include <vcl/timer.hxx>
  35
  36 #include <boost/shared_ptr.hpp>
  37
  38 namespace sd { namespace tools {
  39
  40 class AsynchronousTask;
  41
  42 /** Execute an AsynchronousTask timer based, i.e. every
  43     nMillisecondsBetweenSteps milliseconds as much steps are executed as fit
  44     into a nMaxTimePerStep millisecond intervall.
  45
  46     When a task is executed completely, i.e. HasNextStep() returns <FALSE/>,
  47     the TimerBasedTaskExecution destroys itself.  This, of course, works
  48     only if the creating instance does not hold a shared_ptr to  that object.
  49 */
  50 class TimerBasedTaskExecution
  51 {
  52 public:
  53     /** Create a new object of this class.
  54         @param rpTask
  55             The AsynchronousTask that is to be executed.
  56         @param nMillisecondsBetweenSteps
  57             Wait at least this long between the execution of steps.  Note
  58             that more than one step may be executed in succession.
  59         @param nMaxTimePerStep
  60             The maximal time for executing steps without yielding control.
  61     */
  62     static ::boost::shared_ptr<TimerBasedTaskExecution> Create (
  63         const ::boost::shared_ptr<AsynchronousTask>& rpTask,
  64         sal_uInt32 nMillisecondsBetweenSteps,
  65         sal_uInt32 nMaxTimePerStep);
  66
  67     /** Stop the execution of the task and release the shared pointer to
  68         itself so that it will eventually be destroyed.
  69     */
  70     void Release (void);
  71
  72     /** Convenience method that calls Release() on the given task.  It
  73         checks the given weak_ptr for being expired and catches bad_weak_ptr
  74         exceptions.
  75     */
  76     static void ReleaseTask (const ::boost::weak_ptr<TimerBasedTaskExecution>& rpTask);
  77
  78 private:
  79     ::boost::shared_ptr<AsynchronousTask> mpTask;
  80     Timer maTimer;
  81     /** This shared_ptr to this is used to destroy a TimerBasedTaskExecution
  82         object when its task has been executed completely.
  83     */
  84     ::boost::shared_ptr<TimerBasedTaskExecution> mpSelf;
  85     sal_uInt32 mnMaxTimePerStep;
  86
  87     TimerBasedTaskExecution (
  88         const ::boost::shared_ptr<AsynchronousTask>& rpTask,
  89         sal_uInt32 nMillisecondsBetweenSteps,
  90         sal_uInt32 nMaxTimePerStep);
  91     ~TimerBasedTaskExecution (void);
  92     void SetSelf (const ::boost::shared_ptr<TimerBasedTaskExecution>& rpSelf);
  93
  94     class Deleter;
  95     friend class Deleter;
  96
  97     DECL_LINK(TimerCallback,Timer*);
  98 };
  99
 100 } } // end of namespace ::sd::tools
 101
 102 #endif