Objective-C : Endless UIScrollView without pagingEnabled

Question

In my iPhone app there is a scrollview pagingEnabled=NO which can contain up to 200 subviews (150 x 150) and the challenge is to do lazy loading and simulate endless scrolling (without bouncing) in horizontal directions.

Is there a solution or an alternative for this request?

Answer 1

Lazy loading of a scroll view is demonstrated in one of Apple's sample code projects: PageControl.

To fake endless scrolling what I'd suggest is to make your scroll view very wide to begin with, wider than an average person would scroll in one set of scrolling behaviors. Then in your delegate methods -scrollViewDidEndScrollingAnimation:, -scrollViewDidEndDragging:willDecelerate: and -scrollViewDidEndDecelerating:, one or more of which will be called after the user is done scrolling, reposition your content to exist in the center of the scroll view and update your contentOffset point without animating.

For that to work visually you would need to also disable the horizontal scroller. You'll also need to consider how to determine what view to draw at a particular contentOffset with this method since you won't be able to just divide the contentOffset.x by the scroll view's bounds anymore to find out where you are.