The callback interface for timers.
[scriptable, uuid(436a83fa-b396-11d9-bcfa-00112478d626)]
interface nsITimer : nsISupports

Constants

 nsITimer instances must be initialized by calling one of the "init" methods
 documented below.  You may also re-initialize an existing instance with new
 delay to avoid the overhead of destroying and creating a timer.  It is not
 necessary to cancel the timer in that case.


 Type of a timer that fires once only.
const short TYPE_ONE_SHOT = 0 
 After firing, a TYPE_REPEATING_SLACK timer is stopped and not restarted
 until its callback completes.  Specified timer period will be at least
 the time between when processing for last firing the callback completes
 and when the next firing occurs.

 This is the preferable repeating type for most situations.
const short TYPE_REPEATING_SLACK = 1 
 An TYPE_REPEATING_PRECISE repeating timer aims to have constant period
 between firings.  The processing time for each timer callback should not
 influence the timer period.  However, if the processing for the last
 timer firing could not be completed until just before the next firing
 occurs, then you could have two timer notification routines being
 executed in quick succession.
const short TYPE_REPEATING_PRECISE = 2

Attributes

 The nsITimerCallback object passed to initWithCallback.
readonly attribute nsITimerCallback callback 
 The opaque pointer pass to initWithFuncCallback.
[noscript] readonly attribute voidPtr closure 
 The millisecond delay of the timeout
attribute unsigned long delay 
 The timer type : one shot or repeating
attribute unsigned long type

Methods

 Cancel the timer.  This method works on all types, not just on repeating
 timers -- you might want to cancel a TYPE_ONE_SHOT timer, and even reuse
 it by re-initializing it (to avoid object destruction and creation costs
 by conserving one timer instance).
void cancel() 
 Initialize a timer that will fire after the said delay.
 A user must keep a reference to this timer till it is 
 is no longer needed or has been cancelled.

 @param aObserver   the callback object that observes the 
                    ``timer-callback'' topic with the subject being
                    the timer itself when the timer fires:

                    observe(nsISupports aSubject, => nsITimer
                            string aTopic,        => ``timer-callback''
                            wstring data          =>  null

 @param aDelay      delay in milliseconds for timer to fire
 @param aType       timer type per TYPE* consts defined above
void init(in nsIObserver aObserver, in unsigned long aDelay, in unsigned long aType) 
 Initialize a timer to fire after the given millisecond interval.
 This version takes a function to call and a closure to pass to
 that function.

 @param aFunc      nsITimerCallback interface to call when timer expires
 @param aDelay     The millisecond interval
 @param aType      Timer type per TYPE* consts defined above
void initWithCallback(in nsITimerCallback aCallback, in unsigned long aDelay, in unsigned long aType) 
 Initialize a timer to fire after the given millisecond interval.
 This version takes a function to call and a closure to pass to
 that function.

 @param aFunc      The function to invoke
 @param aClosure   An opaque pointer to pass to that function
 @param aDelay     The millisecond interval
 @param aType      Timer type per TYPE* consts defined above
[noscript] void initWithFuncCallback(in nsTimerCallbackFunc aCallback, in voidPtr aClosure, in unsigned long aDelay, in unsigned long aType)