prevent touchdown IBAction event from firing when UITapGestureRecognizer fires on double tap

Question

I have two IBActions applied to a button one of which fires on touchdown and down and the other on touch up, however I also have a tap gesture applied to the button that fires on a double tap.

I've applied NSLog to see whats happening and the result is that both the touchdown and double tap fire when I double tap (fortunately the touch up doesn't fire) which makes sense - but how do i prevent the touch down firing when I double tap?

Code example

//fired on touch down 
-(IBAction)touchdown:(id)sender
{
    NSLog(@"touching down.");
}

//fired on touch up
-(IBAction)touchup:(id)sender
{   
    NSLog(@"taking off.");
}

//fired on double click
-(IBAction)boost:(UITapGestureRecognizer *)sender
{
    NSLog(@"goodbye.");
}

Please provide sample code so we can help you in a better way — Nirav Gadhiya, Oct 16 '13 at 07:14
I think this http://stackoverflow.com/questions/6587453/filtering-single-and-double-taps can help you — KIDdAe, Oct 16 '13 at 07:33
I've added my example code these are all linked to buttons and gestures within the storyboard. — user2885214, Oct 16 '13 at 07:48
You need to implement this method, - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch — karthika, Oct 16 '13 at 08:47
@karthika would you be able to edit the code above to show how this would be implemented?thanks. — user2885214, Oct 16 '13 at 09:29

score 0 · Answer 1 · answered Oct 16 '13 at 09:59

Import the delegate, <UIGestureRecognizerDelegate>

I think you done this in viewDidLoad Method,

UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(boost:)];
tapGestureRecognizer.delegate = self;
tapGestureRecognizer.numberOfTapsRequired = 2;
[self.button addGestureRecognizer:tapGestureRecognizer];

You need to implement this delegate method, based on your touch down coordinates,

  -(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
    {
        CGPoint coords = [touch locationInView:self.button];
        NSLog(@"Coords: %g, %g", coords.x, coords.y);
        if (coords.y < 21 && coords.y > 25)
           return NO;
        else
           return YES;
    }

prevent touchdown IBAction event from firing when UITapGestureRecognizer fires on double tap

1 Answers1