Get scroll direction from ScrollViiew.

ScrollDirection.m

typedef enum ScrollDirection {
    ScrollDirectionNone,
    ScrollDirectionRight,
    ScrollDirectionLeft,
    ScrollDirectionUp,
    ScrollDirectionDown
} ScrollDirection;

@property ScrollDirection lastScrollDirection;
@property (nonatomic, assign) CGFloat lastContentOffset;

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    self.lastScrollDirection =  [self getScrollDirection:scrollView];
}

- (ScrollDirection)getScrollDirection:(UIScrollView *)scrollView {
    ScrollDirection scrollDirection;
    if (self.lastContentOffset > scrollView.contentOffset.x)
        scrollDirection = ScrollDirectionRight;
    else if (self.lastContentOffset < scrollView.contentOffset.x)
        scrollDirection = ScrollDirectionLeft;
    self.lastContentOffset = scrollView.contentOffset.x;
    return scrollDirection;
}