iphone - 此时如何识别oneTap/doubleTap？

Question

我知道使用 Apple API 过滤 oneTap/doubleTap。代码如下。

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];

但是 oneTap/doubleTap checkDelayTime 感觉很长(大约 0.5 秒？)。一般来说App用户的 react 是非常快的。虽然 0.5 秒通常是很短的时间。但在移动设备环境中是很长时间的，因为用户的 react 非常重要。

说到重点，YouTubeApp 有一个非常完美的关于瞬间过滤的算法oneTap/doubleTap。 oneTap-doubleTap checkDelay 是 VeryVeryShort 完美优化。

oneTap(显示/隐藏控制栏)

doubleTap(完整/默认 videoScreenSize)

像YoutubeApp一样如何实现？关于 oneTap-doubleTap 过滤 不使用 requireGestureRecognizerToFail 选择器。关于非常短的延迟oneTap-doubleTap的区分。

我认为 YoutubeApp 没有使用 requireGestureRecognizer 选择器。

Answer 1

最简单的方法是子类化 UITapGestureRecognizer 而不是通用的 UIGestureRecognizer。

像这样:

#import <UIKit/UIGestureRecognizerSubclass.h>

#define UISHORT_TAP_MAX_DELAY 0.2
@interface UIShortTapGestureRecognizer : UITapGestureRecognizer

@end

并简单地实现:

@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