KCCScrollViewContext provides additional UIScrollView state and expands upon UIScrollViewDelegate. It’s simple to add and works with existing messaging from UIScrollViewDelegate and its extended protocols. It features:
- accessors like isScrolling, isAnimating, and current scrolling direction (UIRectEdge)
- accessors to contentOffset values during scrolling events (scrollingBeganOffset , expectedScrollingEndOffset, scrollingEndedOffset)
- additional delegate callbacks with content offsets for ‘will scroll’ (calculated) and ‘did scroll’ (actual),
- additional delegate callbacks for ‘will scroll’ and ‘did scroll’ events with content edge detection (UIRectEdge) and scrollview bounce events.
- completion block handlers for UIScrollView’s built in animated methods (setContentOffset:animated: / scrollRectToVisible:animated:)
- additional zooming callbacks when the user initiates zooming at and past the minimum or maximum zoom scale.
- UIScrollViewDelegate and its extended protocols (UITableViewDelegate and so on) methods are forwarded to the original delegate (such as UITableViewController).
How to use:
- (void)viewDidLoad {
[super viewDidLoad];
self.scrollContext = [[KCCScrollViewContext alloc]initWithScrollView:self.tableView andDelegate:self];
}
Respond to events:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// handle row selection as usual
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
// handle UIScrollView messages as usual
}
- (void)scrollViewWillScroll:(KCCScrollViewContext *)context toOffset:(CGPoint)offset {
// do something
}
- (void)scrollViewDidBounce:(KCCScrollViewContext *)context fromEdge:(UIRectEdge)edge {
// do something
}
Brief explanation at : http://00steveng.github.io/KCCScrollViewContext