Question

How do I make the UIScroll view show complete views, not partial views?
(Note) I don’t want it jumping to a complete view. It needs to move naturally or at least not immediate… needs to be smooth.

thanks

Answer 1

If your views are all of a constant size and you just want left/right or up/down scrolling, set pagingEnabled on the scroll view to YES. Supposing you wanted your scroll view to be 320×480 but to show the sides of the next and previous pages (so, e.g., each thing inside the view was 280 points wide), you’d size the scroll view to be 280×480 but set masksToBounds to NO.

If you have a more complicated scheme, install a scroll view delegate and act on scrollViewDidScroll:, paying attention to contentOffset. Probably you want to implement logic like:

• add an observer on tracking; when it transitions to NO from ‘YES’ enable your logic inside scrollViewDidScroll: In there:

  • if a forced scroll is pending, cancel it
  • calculate where you’d force the scrolling to from the current position
  • schedule a scroll to there (which you’ll effect via setContentOffset:animated:) for half a second from now

You can use a non-repeating NSTimer for the scheduling aspect. The logic you’ve essentially implemented is that if the user stops adjusting the view, wait for the natural inertia to end (which you’ll detect by the 0.5 second gap since last movement), then transition smoothly to the nearest aligned position.