iOS: Intercept tap gesture event from top view to bottom view

Question

In my view controller, I add a UITapGestureRecognizer to self.view. And I add a small view on top of self.view. When I tap the small view, I don't want to trigger the UITapGestureRecognizer event in self.view. Here is my code, it doesn't work.

    - (void)viewDidLoad {
    [super viewDidLoad];

    UITapGestureRecognizer *_tapOnVideoRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(toggleControlsVisible)];

    [self.view addGestureRecognizer:_tapOnVideoRecognizer];

    UIView *smallView=[[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
    smallView.backgroundColor=[UIColor redColor];
    smallView.exclusiveTouch=YES;
    smallView.userInteractionEnabled=YES;

    [self.view addSubview:smallView];
    }

    - (void)toggleControlsVisible
    {
        NSLog(@"tapped");
    }

When I tap the small view, it still triggers the tap event in self.view. Xcode logs "tapped". How to intercept the gesture event from smallView to self.view?

Answer 1

Implement UIGestureRecognizer delegate method shouldReceiveTouch like this. If touch location is inside topView, do not receive the touch.

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
    CGPoint location = [touch locationInView:self.view];

    if (CGRectContainsPoint(self.topView.frame, location)) {
        return NO;
    }
   return YES;
}