Proper collectionView page scrolling with flicks handled

gistfile1.m

    - (CGFloat)pageWidth {
        return self.itemSize.width + self.minimumLineSpacing;
    }
    
    - (CGPoint)targetContentOffsetForProposedContentOffset:(CGPoint)proposedContentOffset withScrollingVelocity:(CGPoint)velocity {
        
        if (self.paginationEnabled) {
            CGFloat rawPageValue = self.collectionView.contentOffset.x / self.pageWidth;
            CGFloat currentPage = (velocity.x > 0.0) ? floor(rawPageValue) : ceil(rawPageValue);
            CGFloat nextPage = (velocity.x > 0.0) ? ceil(rawPageValue) : floor(rawPageValue);
    
            BOOL pannedLessThanAPage = fabs(1 + currentPage - rawPageValue) > 0.5;
            BOOL flicked = fabs(velocity.x) > [self flickVelocity];
            if (pannedLessThanAPage && flicked) {
                proposedContentOffset.x = nextPage * self.pageWidth;
            } else {
                proposedContentOffset.x = round(rawPageValue) * self.pageWidth;
            }
            
            return proposedContentOffset;
        }
        
        return proposedContentOffset;
    }
    
    - (CGFloat)flickVelocity {
        return 0.3;
    }