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

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  19
  20 #ifndef INCLUDED_SD_SOURCE_UI_INC_TOOLS_TIMERBASEDTASKEXECUTION_HXX
  21 #define INCLUDED_SD_SOURCE_UI_INC_TOOLS_TIMERBASEDTASKEXECUTION_HXX
  22
  23 #include <vcl/timer.hxx>
  24
  25 #include <boost/shared_ptr.hpp>
  26
  27 namespace sd { namespace tools {
  28
  29 class AsynchronousTask;
  30
  31 /** Execute an AsynchronousTask timer based, i.e. every
  32     nMillisecondsBetweenSteps milliseconds as much steps are executed as fit
  33     into a nMaxTimePerStep millisecond intervall.
  34
  35     When a task is executed completely, i.e. HasNextStep() returns <FALSE/>,
  36     the TimerBasedTaskExecution destroys itself.  This, of course, works
  37     only if the creating instance does not hold a shared_ptr to  that object.
  38 */
  39 class TimerBasedTaskExecution
  40 {
  41 public:
  42     /** Create a new object of this class.
  43         @param rpTask
  44             The AsynchronousTask that is to be executed.
  45         @param nMillisecondsBetweenSteps
  46             Wait at least this long between the execution of steps.  Note
  47             that more than one step may be executed in succession.
  48         @param nMaxTimePerStep
  49             The maximal time for executing steps without yielding control.
  50     */
  51     static ::boost::shared_ptr<TimerBasedTaskExecution> Create (
  52         const ::boost::shared_ptr<AsynchronousTask>& rpTask,
  53         sal_uInt32 nMillisecondsBetweenSteps,
  54         sal_uInt32 nMaxTimePerStep);
  55
  56     /** Stop the execution of the task and release the shared pointer to
  57         itself so that it will eventually be destroyed.
  58     */
  59     void Release();
  60
  61     /** Convenience method that calls Release() on the given task.  It
  62         checks the given weak_ptr for being expired and catches bad_weak_ptr
  63         exceptions.
  64     */
  65     static void ReleaseTask (const ::boost::weak_ptr<TimerBasedTaskExecution>& rpTask);
  66
  67 private:
  68     ::boost::shared_ptr<AsynchronousTask> mpTask;
  69     Timer maTimer;
  70     /** This shared_ptr to this is used to destroy a TimerBasedTaskExecution
  71         object when its task has been executed completely.
  72     */
  73     ::boost::shared_ptr<TimerBasedTaskExecution> mpSelf;
  74     sal_uInt32 mnMaxTimePerStep;
  75
  76     TimerBasedTaskExecution (
  77         const ::boost::shared_ptr<AsynchronousTask>& rpTask,
  78         sal_uInt32 nMillisecondsBetweenSteps,
  79         sal_uInt32 nMaxTimePerStep);
  80     ~TimerBasedTaskExecution();
  81     void SetSelf (const ::boost::shared_ptr<TimerBasedTaskExecution>& rpSelf);
  82
  83     class Deleter;
  84     friend class Deleter;
  85
  86     DECL_LINK_TYPED(TimerCallback, Timer *, void);
  87 };
  88
  89 } } // end of namespace ::sd::tools
  90
  91 #endif
  92
  93 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */