NSTimer countdown tick

Question

Please excuse my english, I'm not very fluent.

I have an application with 10 workouts, and i would like to give to each workout an amount of time, for ex : 1st workout : 30 seconds 2nd workout : 40 seconds

But for now, i only managed to give each workout the same amount of seconds for all workout..

This is what i used to work this :

#define EXERCISELENGTH 30
#define EXERCISELENGTH1 40
#define RESTLENGTH 10

- (void)tick
{
if (self.inCountdown && (countdown == 0)) {
    self.inCountdown = NO;
    self.inExercise = YES;
    countdown = EXERCISELENGTH;
    [self workoutUI];
    [self updateUI];
    workoutIndex++;
}

if (self.inExercise && (countdown == 0)) {
    self.inExercise = NO;
    self.inRest = YES;
    countdown = RESTLENGTH;
    [self restUI];
    [self updateUI];
}
if (self.inRest && (countdown == 0)) {
    self.inRest = NO;
    self.inExercise = YES;
    countdown = EXERCISELENGTH;
    [self workoutUI];
    [self updateUI];
    workoutIndex++;
    if (workoutIndex == 10) {
        [self doneUI];
        [self.timer invalidate];
        return;
    }
}
[self updateUI];
countdown--;
}

Any help would be appreciated.

Thank you

No, i want to run timer for 30 seconds for the first workout, then 10 seconds for rest, than 40 seconds for the second workout ect... — daviddev38, Sep 17 '15 at 14:21

score 0 · Answer 1 · edited May 23 '17 at 12:29

0

you have many options:

If you want to call a workout method every 30 seconds, you use this:

  [NSTimer scheduledTimerWithTimeInterval:30.0
                                     target:self
                                   selector:@selector(workoutMethod)
                                   userInfo:nil
                                    repeats:YES];

If you want to call the workout method after 30 seconds, you use this:

 [self performSelector:@selector(workoutMethod) withObject:nil afterDelay:30.0];

If you want to start a countdown timer after you start the workout method, you use this example : CountDown Timer ios tutorial?

edited May 23 '17 at 12:29

Community

1
1

answered Sep 17 '15 at 14:35

Teja Nandamuri

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I have already done that.. what i want to do is give each workout a specific amount of time. – daviddev38 Sep 17 '15 at 14:50
Well, Im confsed. What do you mean by giving each workout a specific amount of time? HOw is it different than running a count down timer after the workout starts ? – Teja Nandamuri Sep 17 '15 at 14:54
this is what happens with my current code : Workout 1 : 30 seconds Workout 2 : 30 seconds Workout 3 : 30 seconds But what i want to do is : Workout 1 : 20 seconds Workout 2 : 30 seconds Workout 3 : 40 seconds. – daviddev38 Sep 17 '15 at 14:57

score 0 · Answer 2 · answered Sep 17 '15 at 17:42

If you want a countdown timer, you should set up a repeating NSTimer that triggers an action that updates the display every second or so. However, that action should calculate the time remaining using the system time. So, your code should:

get the current time and calculate the expected finish time according to the desired time period (20 sec, 30 sec, etc.)
start a repeating timer with a 1 sec interval

Your timer's action should:

get the current system time
compare to the expected finish time
update the display
invalidate itself if it has reached the finish time

What you don't want to do is to rely on the timer to trigger at exactly 1 second intervals. NSTimer's resolution is such that each 'tick' can be off by as much as 0.1 sec, which means that 30 ticks could be off by up to 3 seconds. Using the system time, e.g. CACurrentMediaTime(), will provide a much more accurate clock and avoid accumulation of error.

NSTimer countdown tick

2 Answers2