A basic overview of UIKit Dynamics. Demo here: https://github.com/rob-brown/Demos

1. UIKit Dynamics
Robert Brown
Twitter: @robby_brown
ADN: @robert_brown

2. What is UIKit Dynamics?
A composable, reusable, declarative, real-world
inspired animation and interaction system.

3. What is UIKit Dynamics?
Based on real-world interactions
Gravity
Collisions
Attachments
Snap
Forces
Weight

4. Limitations
It is possible to create behaviors that can’t be satisfied
Not completely accurate physics
Does not replace Core Animation, UIView animations,
or motion effects
Only supports 2D transforms

5. UIGravityBehavior
Gravity is a simple vector
Default is (0, 1) meaning straight down
Default constant is 1000 px/sec2

6. UICollisionBehavior
Views can collide with boundaries and other views
Views can collide conditionally with other views
Callbacks for when collisions begin and end
(UICollisionBehaviorDelegate)
Collisions have a CPU cost

7. UIAttachmentBehavior
Acts like a rope, string, or spring
Damping is customizable
Has a length and two anchor points
Attachments are invisible

8. UISnapBehavior
Locks position and angle
Can use damping

9. UIPushBehavior
Simple force vector
1 UIKit Newton accelerates a (100,100) view by 100
px/sec2

10. UIDynamicItemBehavior
friction
resistance
angularResistance
elasticity
density
allowsRotation

11. Composing Behaviors
Effect
Combination
Bounce
Gravity + collision
Drag and snap
Attachment then snap
Lock screen
Gravity + Collision +
Attachment + Push
Magnet
Multiple push

12. Demo

13. Questions?

14. Want to Learn More?
WWDC 2013 Session 206
WWDC 2013 Session 221
UIKit Dynamics Catalog Sample