Question

I am currently making a application using NSTimer as base for recording time. However, in the event that the player used a hint or forfeit on the current question, I would like to have a penalty of increasing time to the on-going NSTimer.

The question I have is, is it possible to add in more value to the on-going NSTimer?
e.g The timer is at 0:23:41.2, and the user press hint/forfeit. I want to have a function that add, lets say 10min. How do I make a function such that the timer will become 0:33:41.2 when the player press hint/forfeit?

I tried finding on google and SO on articles related to NSTimer and came across this SO thread which might be useful. How to value for NSTimer

Instead of elapse time as shown in the thread, I think I could swap it with a variable like below. (But if the example I shown below is not feasible, please enlighten me. I really want to make this game a successful one)

-(BOOL)hintButtonPressed

.

-(void) timerFireMethod:(NSTimer *) theTimer {

        if (hintButtonPressed == true) {
            // do something to increase value
            [theTimer invalidate];
        } 
}

Answer 1

Even though I would not use a NSTimer for a countdown, there is an easy way to add time to its fireDate:

[_timer setFireDate:[[_timer fireDate] dateByAddingTimeInterval:600]];

This would add 10 minutes (600 seconds) to my _timer.

And the best solution for your example would be to create an action-method for the button and check in that action-method whether the user already got a time bonus.

Of course you can modify the fireDate in the fire method but it won’t fire again with my codeline.