This project is inspired by roberthein's project BouncyLayout, I just implement it by Objective-C.

When I use OC to implement it, compare with the swift code, obviously swift is more readable and compact!

It's time to learn Swift now!

Clone or download this project, copy HWBouncyLayout.h & HWBouncyLayout.m files into your project.

Import HWBouncyLayout.h, init the layout.

- (instancetype)init;
- (instancetype)initWithStyle:(BouncyLayoutStyle)style;
- (instancetype)initWithDamping:(CGFloat)damping frequency:(CGFloat)frequency;

The param damping and frequency is UIAttachmentBehavior prop, by default:

damping = 0.7

frequency = 1.5

self.layout = [HWBouncyLayout new];
// config the layout...
self.layout.scrollDirection = UICollectionViewScrollDirectionVertical;
// init Collection wiht this layout.
self.collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:self.layout];