Gravity
Gravity is arguably the easiest UIDynamicItem to implement as well as one of the most practical. Apple makes heavy use of the gravity item in iOS 7, and a user does not need to go further than the lock screen to interact with gravity. Dragging up on the camera icon from the iOS 7 lock screen and releasing it under the halfway point will drop the home screen back into place using UIGravityBehavior. This functionality, even prior to iOS 7, was often cloned and implemented by hand using timers and animations.
The following will set up a gravity effect on frogImageView that is a subview of self.view. First a new UIDynamicAnimator is created for the enclosing view that the animated view will appear in, in this example self.view. A new UIGravityBehavior ...
Get iOS Components and Frameworks: Understanding the Advanced Features of the iOS SDK now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
