UIScrollView and cancel a zooming pinch gesture

Question

How do you forcibly cancel a zooming open pinch gesture on a UIScrollView, say when the user has zoomed \"sufficiently\" far to trigger a new action?

Answer 1

How's this:

-(void)handlePinchGesture:(UIPinchGestureRecognizer *)sender
{
    if (![sender isEnabled])
    {
        [sender setEnabled:YES];
    }

    if (sender.state == UIGestureRecognizerStateChanged)
    {
        if (sender.scale > 2.0)
        {
            NSLog(@"Upper bound reached");
            [sender setEnabled:NO];

        }
        else if (sender.scale < 0.75)
        {
            NSLog(@"Lower bound reached");
            [sender setEnabled:NO];
        }
    }
}

Just register this selector(handlePinchGesture:) with the gesture recognizer. This will make a sort of "one-shot" pinch handler which stops when it reaches either the upper or lower threshold.