I haven't tried that yet, but I assume that I would have to disable scrolling of the parent scroll view as soon as I know that the user will want to scroll in the child scroll view, right?
Both scroll views are scrolling horizontal.
How could I disable scrolling detection of the parent temporarily? Or is there some other way?
UIScrollView has a property called scrollEnabled, which you can set to NO to disable scrolling in your parent scroll view.
I haven't tried it yet, but you may just find that it Does The Right Thing, i.e., the inner scroll view scrolls until it can't scroll any more, at which point the outer scroll view scrolls.
I did this and it does cause the parent scrollView NOT to scroll anymore which is fine but my child scrollView which was pushed via presentModalViewController still does not respond to scroll events (e.g. scrolling up or down). I'm obviously missing something...
EDIT: Got it to work finally by using 'scrollEnabled' on the parent view. Thanks.