xpcom/threads/nsITimer.idl

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  39
  40 #include "nsISupports.idl"
  41
  42 interface nsIObserver;
  43 interface nsIEventTarget;
  44
  45 %{C++
  46 /**
  47  * The signature of the timer callback function passed to initWithFuncCallback.
  48  * This is the function that will get called when the timer expires if the
  49  * timer is initialized via initWithFuncCallback.
  50  *
  51  * @param aTimer the timer which has expired
  52  * @param aClosure opaque parameter passed to initWithFuncCallback
  53  *
  54  * Implementers should return the following:
  55  *
  56  * @return NS_OK
  57  *
  58  */
  59 class nsITimer;
  60 typedef void (*nsTimerCallbackFunc) (nsITimer *aTimer, void *aClosure);
  61 %}
  62
  63 native nsTimerCallbackFunc(nsTimerCallbackFunc);
  64
  65 /**
  66  * The callback interface for timers.
  67  */
  68 interface nsITimer;
  69
  70 [function, scriptable, uuid(a796816d-7d47-4348-9ab8-c7aeb3216a7d)]
  71 interface nsITimerCallback : nsISupports
  72 {
  73   /**
  74    * @param aTimer the timer which has expired
  75    */
  76   void notify(in nsITimer timer);
  77 };
  78
  79
  80 /**
  81  * nsITimer instances must be initialized by calling one of the "init" methods
  82  * documented below.  You may also re-initialize (using one of the init()
  83  * methods) an existing instance to avoid the overhead of destroying and
  84  * creating a timer.  It is not necessary to cancel the timer in that case.
  85  */
  86 [scriptable, uuid(193fc37a-8aa4-4d29-aa57-1acd87c26b66)]
  87 interface nsITimer : nsISupports
  88 {
  89   /* Timer types */
  90
  91   /**
  92    * Type of a timer that fires once only.
  93    */
  94   const short TYPE_ONE_SHOT           = 0;
  95
  96   /**
  97    * After firing, a TYPE_REPEATING_SLACK timer is stopped and not restarted
  98    * until its callback completes.  Specified timer period will be at least
  99    * the time between when processing for last firing the callback completes
 100    * and when the next firing occurs.
 101    *
 102    * This is the preferable repeating type for most situations.
 103    */
 104   const short TYPE_REPEATING_SLACK    = 1;
 105
 106   /**
 107    * An TYPE_REPEATING_PRECISE repeating timer aims to have constant period
 108    * between firings.  The processing time for each timer callback should not
 109    * influence the timer period.  However, if the processing for the last
 110    * timer firing could not be completed until just before the next firing
 111    * occurs, then you could have two timer notification routines being
 112    * executed in quick succession.
 113    */
 114   const short TYPE_REPEATING_PRECISE  = 2;
 115
 116   /**
 117    * Initialize a timer that will fire after the said delay.
 118    * A user must keep a reference to this timer till it is
 119    * is no longer needed or has been cancelled.
 120    *
 121    * @param aObserver   the callback object that observes the
 122    *                    ``timer-callback'' topic with the subject being
 123    *                    the timer itself when the timer fires:
 124    *
 125    *                    observe(nsISupports aSubject, => nsITimer
 126    *                            string aTopic,        => ``timer-callback''
 127    *                            wstring data          =>  null
 128    *
 129    * @param aDelay      delay in milliseconds for timer to fire
 130    * @param aType       timer type per TYPE* consts defined above
 131    */
 132   void init(in nsIObserver aObserver, in unsigned long aDelay,
 133             in unsigned long aType);
 134
 135
 136   /**
 137    * Initialize a timer to fire after the given millisecond interval.
 138    * This version takes a function to call and a closure to pass to
 139    * that function.
 140    *
 141    * @param aFunc      The function to invoke
 142    * @param aClosure   An opaque pointer to pass to that function
 143    * @param aDelay     The millisecond interval
 144    * @param aType      Timer type per TYPE* consts defined above
 145    */
 146   [noscript] void initWithFuncCallback(in nsTimerCallbackFunc aCallback,
 147                                        in voidPtr aClosure,
 148                                        in unsigned long aDelay,
 149                                        in unsigned long aType);
 150
 151   /**
 152    * Initialize a timer to fire after the given millisecond interval.
 153    * This version takes a function to call and a closure to pass to
 154    * that function.
 155    *
 156    * @param aFunc      nsITimerCallback interface to call when timer expires
 157    * @param aDelay     The millisecond interval
 158    * @param aType      Timer type per TYPE* consts defined above
 159    */
 160   void initWithCallback(in nsITimerCallback aCallback,
 161                         in unsigned long aDelay,
 162                         in unsigned long aType);
 163
 164   /**
 165    * Cancel the timer.  This method works on all types, not just on repeating
 166    * timers -- you might want to cancel a TYPE_ONE_SHOT timer, and even reuse
 167    * it by re-initializing it (to avoid object destruction and creation costs
 168    * by conserving one timer instance).
 169    */
 170   void cancel();
 171
 172   /**
 173    * The millisecond delay of the timeout.
 174    *
 175    * NOTE: Re-setting the delay on a one-shot timer that has already fired
 176    * doesn't restart the timer. Call one of the init() methods to restart
 177    * a one-shot timer.
 178    */
 179   attribute unsigned long delay;
 180
 181   /**
 182    * The timer type - one of the above TYPE_* constants.
 183    */
 184   attribute unsigned long type;
 185
 186   /**
 187    * The opaque pointer pass to initWithFuncCallback.
 188    */
 189   [noscript] readonly attribute voidPtr closure;
 190
 191   /**
 192    * The nsITimerCallback object passed to initWithCallback.
 193    */
 194   readonly attribute nsITimerCallback callback;
 195
 196   /**
 197    * The nsIEventTarget where the callback will be dispatched. Note that this
 198    * target may only be set before the call to one of the init methods above.
 199    */
 200   attribute nsIEventTarget target;
 201 };
 202
 203 %{C++
 204 #define NS_TIMER_CONTRACTID "@mozilla.org/timer;1"
 205 #define NS_TIMER_CALLBACK_TOPIC "timer-callback"
 206 %}
 207