iOS - UILongPressGestureRecognizer

Question

In my app I want the UILongPressGestureRecognizer will send continuous messages every second until the button is released. Unfortunately there is no state like "continuous" so I need to use "began" and "ended" to control my messages. Here is my code I have so far, I get both logs on the terminal but the while loop is not stopping?

- (void)longPress:(UILongPressGestureRecognizer*)gesture {

    BOOL loop = NO;

    if (gesture.state == UIGestureRecognizerStateBegan) {
        NSLog(@"Long press detected.");
        loop = YES;
        while (loop){
            [[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:1]];
            // here I want to do my stuff every second
        }
    } else if (gesture.state == UIGestureRecognizerStateEnded) {
        NSLog(@"Long press Ended");
        loop = NO;
    }
}

Does anyone please can help?

Suggestion - use a timer. And use an instance variable instead of a local variable. — rmaddy, Feb 04 '17 at 23:16
And maybe consider subclassing UILongPressGestureRecognizer? — matt, Feb 04 '17 at 23:25

score 1 · Accepted Answer · answered Feb 04 '17 at 23:27

Its a good suggestion to use a timer (or a performSelector:withDelay: which probably conceals a timer) but, roughly:

@property(strong,nonatomic) NSTimer *timer;

- (void)longPress:(UILongPressGestureRecognizer*)gesture {
    if (gesture.state == UIGestureRecognizerStateBegan) {
        NSLog(@"started");
        self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(stillPressing:) userInfo:nil repeats:YES];
    } else if (gesture.state == UIGestureRecognizerStateEnded) {
        [self.timer invalidate];
        self.timer = nil;
        NSLog(@"ended");
    }
}

- (void)stillPressing:(NSTimer *)timer {
    NSLog(@"still pressing");
}

iOS - UILongPressGestureRecognizer

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