I'd just add scroll's gesture recognizers to this custom view
@implementation CustomView
- (void)overridePinchForScroll:(UIScrollView *)scroll
{
[self addGestureRecognizer:scroll.panGestureRecognizer];
[self addGestureRecognizer:scroll.pinchGestureRecognizer];
}
@end
Note.
You should add both pan and pinch gesture recognizers, because if you only add a pinch recognizer, it'll throw an error:
Ignoring call to [UIPanGestureRecognizer setTranslation:inView:] since gesture recognizer is not active.
And, of course, thus you'll still be able to drag zoomed content.