Implementing Engaging UI on iOS

Custom UIViewController transitions

• Create and Initialize new UIViewController

• Set transitioningDelegate to be self

• Set modalPresentationStyle to be UIModalPresentationCustom

• Call - presentViewController:animated:completion:

• In this UIViewController, conforms to UIViewControllerTransitioningDelegate

• Implement - (id <UIViewControllerAnimatedTransitioning>) animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source delegate method. In this method, we could totally customize the return object which conforms to UIViewControllerAnimatedTransitioning. This delegate method give custom transition when trying to present a new UIViewController.

• Implement - (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed, In this method, we could also totally customize the return object which conforms to UIViewControllerAnimatedTransitioning. This delegate method give custom transition when trying to dismiss a presented UIViewController.

• Create a custom subclass of NSObject conforms to UIViewControllerAnimatedTransitioning, override several required methods, then magic happens.

App-wide appearance

UIAppearance is very useful Protocol in iOS system. Developer could use this protocol to customize all the UIView or UIControl in one action. Example is like: [[UIButton appearance] setTintColor:[UIColor redColor]]

Resizable and template images

- [UIImage resizableImageWithCapInsets:]

UIKit Dynamics

The basics:

animator = [[UIDynamicAnimator alloc] initWithReferenceView:self.view];

gravityBehavior = [[UIGravityBehavior alloc] initWithItems:@[itemToAnimate]];

[animator addBehavior:gravityBehavior];