iphone - How to recognize oneTap/doubleTap at moment?

Question

I Know filtering oneTap/doubleTap using a Apple API. code are follows.

UITapGestureRecognizer *doubleTapGestureRecognizer = [[UITapGestureRecognizer alloc]
                        initWithTarget:self action:@selector(handleDoubleTap:)];
doubleTapGestureRecognizer.numberOfTapsRequired = 2;


[self addGestureRecognizer:doubleTapGestureRecognizer];


UITapGestureRecognizer *singleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
singleTapGestureRecognizer.numberOfTapsRequired = 1;

**[singleTapGestureRecognizer requireGestureRecognizerToFail: doubleTapGestureRecognizer];**

[self addGestureRecognizer:singleTapGestureRecognizer];

but oneTap/doubleTap checkDelayTime is feeling a so Long (About 0.5sec?). Generally App Users of the reaction is very fast. Although 0.5 seconds is typically short-time. but In Mobile Device Environment is long-time, because users react is very important.

Speaking to the point, YouTubeApp have a very Perfectly algorithm about filtering at a moment oneTap/doubleTap. oneTap-doubleTap checkDelay is VeryVeryShort Perfectly Optimization.

oneTap(show/hidden controlBar)

doubleTap(full/default videoScreenSize)

How to implement like YoutubeApp? about oneTap-doubleTap filtering Not Using a requireGestureRecognizerToFail Selector. about very short delay oneTap-doubleTap distinguishing.

I think YoutubeApp is Not Use a requireGestureRecognizer Selector.

Answer 1

The easiest way to do this is to subclass UITapGestureRecognizer and not a general UIGestureRecognizer.

Like this:

#import <UIKit/UIGestureRecognizerSubclass.h>

#define UISHORT_TAP_MAX_DELAY 0.2
@interface UIShortTapGestureRecognizer : UITapGestureRecognizer

@end

And simply implement:

@implementation UIShortTapGestureRecognizer

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [super touchesBegan:touches withEvent:event];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(UISHORT_TAP_MAX_DELAY * NSEC_PER_SEC)), dispatch_get_main_queue(), ^
    {
        // Enough time has passed and the gesture was not recognized -> It has failed.
        if  (self.state != UIGestureRecognizerStateRecognized)
        {
            self.state = UIGestureRecognizerStateFailed;
        }
    });
}
@end