IMSWeakTimer Class Reference

Inherits from NSObject
Declared in IMSWeakTimer.h

– initWithTimeInterval:target:selector:userInfo:repeats:dispatchQueue:

Creates a timer with the specified parameters and waits for a call to schedule to start ticking.

- (id)initWithTimeInterval:(NSTimeInterval)timeInterval target:(id)target selector:(SEL)selector userInfo:(id)userInfo repeats:(BOOL)repeats dispatchQueue:(dispatch_queue_t)dispatchQueue

Parameters

timeInterval

how frequently selector will be invoked on target. If the timer doens’t repeat, it will only be invoked once, approximately timeInterval millseconds from the time you call this method.
repeats

if YES, selector will be invoked on target until the IMSWeakTimer object is deallocated or until you call invalidate. If NO, it will only be invoked once.
dispatchQueue

the queue where the delegate method will be dispatched. It can be either a serial or concurrent queue.

Discussion

Creates a timer with the specified parameters and waits for a call to schedule to start ticking.

Note: It’s safe to retain the returned timer by the object that is also the target. or the provided dispatchQueue.

Declared In

IMSWeakTimer.h

+ scheduledTimerWithTimeInterval:target:selector:userInfo:repeats:dispatchQueue:

Creates an IMSWeakTimer object and schedules it to start ticking inmediately.

+ (instancetype)scheduledTimerWithTimeInterval:(NSTimeInterval)timeInterval target:(id)target selector:(SEL)selector userInfo:(id)userInfo repeats:(BOOL)repeats dispatchQueue:(dispatch_queue_t)dispatchQueue

Discussion

Creates an IMSWeakTimer object and schedules it to start ticking inmediately.

Declared In

IMSWeakTimer.h

– schedule

Starts the timer if it hadn’t been schedule yet.

- (void)schedule

Discussion

Starts the timer if it hadn’t been schedule yet.

Warning: calling this method on an already scheduled timer results in undefined behavior.

Declared In

IMSWeakTimer.h

  tolerance

  • Sets the amount of time after the scheduled fire date that the timer may fire to the given interval.
  • @discussion Setting a tolerance for a timer allows it to fire later than the scheduled fire date, improving the ability of the system to optimize for increased power savings and responsiveness. The timer may fire at any time between its scheduled fire date and the scheduled fire date plus the tolerance. The timer will not fire before the scheduled fire date. For repeating timers, the next fire date is calculated from the original fire date regardless of tolerance applied at individual fire times, to avoid drift. The default value is zero, which means no additional tolerance is applied. The system reserves the right to apply a small amount of tolerance to certain timers regardless of the value of this property. As the user of the timer, you will have the best idea of what an appropriate tolerance for a timer may be. A general rule of thumb, though, is to set the tolerance to at least 10% of the interval, for a repeating timer. Even a small amount of tolerance will have a significant positive impact on the power usage of your application. The system may put a maximum value of the tolerance.
@property (atomic, assign) NSTimeInterval tolerance

Discussion

  • Sets the amount of time after the scheduled fire date that the timer may fire to the given interval.
  • @discussion Setting a tolerance for a timer allows it to fire later than the scheduled fire date, improving the ability of the system to optimize for increased power savings and responsiveness. The timer may fire at any time between its scheduled fire date and the scheduled fire date plus the tolerance. The timer will not fire before the scheduled fire date. For repeating timers, the next fire date is calculated from the original fire date regardless of tolerance applied at individual fire times, to avoid drift. The default value is zero, which means no additional tolerance is applied. The system reserves the right to apply a small amount of tolerance to certain timers regardless of the value of this property. As the user of the timer, you will have the best idea of what an appropriate tolerance for a timer may be. A general rule of thumb, though, is to set the tolerance to at least 10% of the interval, for a repeating timer. Even a small amount of tolerance will have a significant positive impact on the power usage of your application. The system may put a maximum value of the tolerance.

Declared In

IMSWeakTimer.h

– fire

Causes the timer to be fired synchronously manually on the queue from which you call this method. You can use this method to fire a repeating timer without interrupting its regular firing schedule. If the timer is non-repeating, it is automatically invalidated after firing, even if its scheduled fire date has not arrived.

- (void)fire

Discussion

Causes the timer to be fired synchronously manually on the queue from which you call this method. You can use this method to fire a repeating timer without interrupting its regular firing schedule. If the timer is non-repeating, it is automatically invalidated after firing, even if its scheduled fire date has not arrived.

Declared In

IMSWeakTimer.h

– invalidate

You can call this method on repeatable timers in order to stop it from running and trying to call the delegate method.

- (void)invalidate

Discussion

You can call this method on repeatable timers in order to stop it from running and trying to call the delegate method.

Note: IMSWeakTimer won’t invoke the selector on target again after calling this method. You can call this method from any queue, it doesn’t have to be the queue from where you scheduled it. Since it doesn’t retain the delegate, unlike a regular NSTimer, your dealloc method will actually be called and it’s easier to place the invalidate call there, instead of figuring out a safe place to do it.

Declared In

IMSWeakTimer.h