Objective-C: Flip the pages through different time intervals [closed] - ios

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There are 10 pages that I want to turn at different time intervals. I need to create 10 timers for flip? Or can I make an array intervals and to insert them to the timer? Сan I do it in a simpler way?

Answer 1

There are a lot of ways to do this. Here's one:
This is possibly a good solution if your intervals are irregular and far apart. If they are more evenly spaced (e.g. first is two seconds, next is four seconds) then you could simplify this design. But, I'm assuming that you just want to be able to pass in an array of intervals and then let the code take care of it all.
For this implementation, we're going to need an instance variable to hold an array of timers. Use a property if you prefer them to instance variables.
#implementation ViewController {
NSArray *_multipleTimerInstances;
}
Then some code to handle the timings.
- (void)multipleTimers:(NSArray *)durations {
// Get rid of any timers that have already been created.
[self mulitpleTimerStopAll];
NSMutableArray *newTimers = [NSMutableArray new];
// Create the new timers.
[durations enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
// Each element of the durations array specifies the flip interval in seconds.
double duration = [(NSNumber *)obj doubleValue];
// Schedule it.
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:duration
target:self
selector:#selector(multipleTimersFlip:)
userInfo:[NSNumber numberWithInteger:idx]
repeats:YES];
// Keep a reference to the new timer so we can invalidate it later, if we want.
[newTimers addObject:timer];
}];
// We now have a new list of timers.
_multipleTimerInstances = [newTimers copy];
}
- (void)multipleTimersFlip:(NSTimer *)timer {
NSInteger index = [timer.userInfo integerValue];
// The integer index corresponds to the index of the timer in the array passed
// to the multipleTimers method.
NSLog(#"Flip page for timer with index: %ld", (long)index);
}
- (void)mulitpleTimerStopAll {
// Get rid of any timers that have already been created.
for (NSTimer *timer in _multipleTimerInstances) [timer invalidate];
// And nil out the array, they're gone.
_multipleTimerInstances = nil;
}
Then you can invoke the timers like this:
[self multipleTimers:#[ #5.0, #10.0, #7.5 ]];
That's going to call back the multipleTimersFlip method every 5, 7.5, and 10 seconds.
Remember to call multipleTimersStopAll to stop all this going on when you don't need it.