UIButton subview of a gesture recognizer

Question

I have a UIView with two gesture recognizers. Both recognize tap with two fingers: one for the upper half of the screen, the other for the bottom of the screen. In that UIView, I have 4 buttons that cover the entire screen (each button is a quarter of the screen).

I'm using the gesture recognizer to detect when the user presses 2 buttons at the same time, and I still want to recognize the normal touches on the buttons.

I've setup everything, and it works fine. However, when pressing with just one finger the shadow on the button appears on Touch Up, and not on Touch Down. And it feels weird. I've tried to change delaysTouchesBegan with no success.

Is there a way to have both behaviours? Detect the touches with two fingers, but have a "normal behaviour" when there's only one finger? Otherwise, can I force the pressed state of a UIbutton?

Here's how I setup my gestures :

-(void)initGestureRecognition{
    handClapTapGestureRecognizer = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handClapDetected:)];
    handClapTapGestureRecognizer.numberOfTouchesRequired = 2;
    handClapTapGestureRecognizer.numberOfTapsRequired = 1;
    handClapTapGestureRecognizer.cancelsTouchesInView = YES;
    [self.gestureRecognitionView addGestureRecognizer:handClapTapGestureRecognizer];
    handClapTapGestureRecognizer.delegate = self;


    jumpTapGestureRecognizer = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(jumpDetected:)];
    jumpTapGestureRecognizer.numberOfTouchesRequired = 2;
    jumpTapGestureRecognizer.numberOfTapsRequired = 1;
    jumpTapGestureRecognizer.cancelsTouchesInView = YES;
    [self.gestureRecognitionView addGestureRecognizer:jumpTapGestureRecognizer];
    jumpTapGestureRecognizer.delegate = self;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{

    return NO;
}


- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
    if ([gestureRecognizer isEqual:handClapTapGestureRecognizer] && [touch locationInView:self.view].y > self.view.frame.size.height/2)
        return NO;
    if ([gestureRecognizer isEqual:jumpTapGestureRecognizer] && [touch locationInView:self.view].y < self.view.frame.size.height/2)
        return NO;

    return YES;
}

I know my problem is similar to that one : UIButton inside a view that has a UITapGestureRecognizer but the difference is that in my case, the behaviour is ok, and I'm just trying to get the shadow on the button on Touch DOwn, rather than on Touch Up.

Thanks

Guy Kogus Guy Kogus · Accepted Answer · 2013-09-24T10:25:56

Could you manually set [button setHighlighted:YES] when the tap gesture is first recognized and its location matches that of the button's, and then to NO when the gesture ends?

UIButton subview of a gesture recognizer

1 Answers