Question

I have a UIScrollview with paging enabled. There are 3 views (pages) inside this scroll view. There’s a tap gesture on the parent view of the scrollview that shows and hides a navigation bar at the top.

The Problem:
In one of the pages I want to add buttons. But the problem is that whenever i tap these buttons, the show/hide navigation bar method is also fired. What is the best way to pass the touch only to these buttons and not the the parent view of the scrollview?

Answer 1

NJones is on the right track, but I think there are some problems with his answer.

I assume that you want to pass through touches on any button in your scroll view. In your gesture recognizer’s delegate, implement gestureRecognizer:shouldReceiveTouch: like this:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)recognizer shouldReceiveTouch:(UITouch *)touch {

    UIView *gestureView = recognizer.view;
    // gestureView is the view that the recognizer is attached to - should be the scroll view

    CGPoint point = [touch locationInView:gestureView];
    UIView *touchedView = [gestureView hitTest:point withEvent:nil];
    // touchedView is the deepest descendant of gestureView that contains point

    // Block the recognizer if touchedView is a UIButton, or a descendant of a UIButton
    while (touchedView && touchedView != gestureView) {
        if ([touchedView isKindOfClass:[UIButton class]])
            return NO;
        touchedView = touchedView.superview;
    }
    return YES;
}