Question

In UITableView, you can tap and hold on a table cell and cancels the tap and continue on with scrolling if you move your finger. How can this done with UIScrollView with a subview? I am able to make it so you can scroll and you can tap on the subview, but am having issue with the latter behavior – make scrollview continue to scroll if you move your finger while tapping and holding.

Answer 1

I assume you are using a UITapGestureRecognizer on the subview. The scroll view uses a UIPanGestureRecognizer for scrolling. You simply need to tell the tap recognizer not to recognize unless the pan recognizer fails.

If you are targetting iOS 5, this is very easy:

[self.tapRecognizer requireGestureRecognizerToFail:self.scrollView.panGestureRecognizer];

If you are targetting an older version of iOS, older versions of UIScrollView don’t have the panGestureRecognizer property. Instead you have to search through the scroll view’s gestureRecognizers array:

for (UIGestureRecognizer *recognizer in self.scrollView.gestureRecognizers) {
    if ([recognizer isKindOfClass:[UIPanGestureRecognizer class]])
        [self.tapRecognizer requireGestureRecognizerToFail:recognizer];
}