The guide goes over animation principles on iOS - UIKit animation, core animation, layers, controller transitions, begin/commit methods, block-based methods, implicit/explicit animations and touches bases on Apple Watch animation.

1. ANIMATIONS IN IOS
Created by Anna Dovnar

2. THERE ARE TWO WAYS TO WORK WITH
ANIMATION. THE FIRST WAY IS VIA UIKIT,
WHICH INCLUDES VIEW-BASED ANIMATIONS
AS WELL AS ANIMATED TRANSITIONS
BETWEEN CONTROLLERS. THE SECOND WAY
IS WORKING WITH CORE ANIMATION
LAYERS DIRECTLY FOR FINER-GRAINED
CONTROL.

3. UIKIT ANIMATION
• Transitions between controllers
• Transitions between views
• View property animation

4. VIEW CONTROLLER
TRANSITIONS
• CrossDissolve
• CoverVertical
• FlipHorizontal
• PartialCurl
UIVIEWCONTROLLER PROVIDES BUILT-IN
SUPPORT FOR TRANSITIONING BETWEEN
VIEW CONTROLLERS THROUGH THE
PRESENTVIEWCONTROLLER METHOD.

5. VIEW TRANSITIONS
IN ADDITION TO TRANSITIONS BETWEEN
CONTROLLERS, UIKIT ALSO SUPPORTS
ANIMATING TRANSITIONS BETWEEN VIEWS
TO SWAP ONE VIEW FOR ANOTHER.

6. VIEW PROPERTY ANIMATIONS
• Frame
• Bounds
• Center
• Alpha
• Transform
• Color

7. STARTING ANIMATIONS USING
THE BEGIN/COMMIT METHODS

8. STARTING ANIMATIONS USING
THE BLOCK-BASED METHODS
• animateWithDuration:animations:
• animateWithDuration:animations:completion:
• animateWithDuration:delay:options:animations:co
mpletion:

9. CONFIGURING THE PARAMETERS
FOR BEGIN/COMMIT ANIMATIONS
• setAnimationStartDate:
• setAnimationDelay:
• setAnimationDuration:
• setAnimationCurve:
• setAnimationRepeatCount:
• setAnimationRepeatAutoreverses:
• setAnimationDelegate:
• setAnimationWillStartSelector:
• setAnimationDidStopSelector:
• setAnimationBeginsFromCurrentState:

10. ANIMATION DELEGATE
The animationID and context parameters for both methods are the same
parameters that you passed to the beginAnimations:context: method at the
beginning of the animation block:
• animationID—An application-supplied string used to identify the
animation.
• context—An application-supplied object that you can use to pass
additional information to the delegate.
The setAnimationDidStopSelector: selector method has an additional parameter—
a Boolean value that is YES if the animation ran to completion. If the value of this
parameter is NO, the animation was either canceled or stopped prematurely by
another animation.

11. CORE ANIMATION
UIVIEW ANIMATIONS ALLOW A LOT OF CAPABILITY
AND SHOULD BE USED IF POSSIBLE DUE TO THE EASE
OF IMPLEMENTATION. HOWEVER, SOME THINGS
CANNOT BE DONE WITH UIVIEW ANIMATIONS, SUCH
AS ANIMATING ADDITIONAL PROPERTIES THAT
CANNOT BE ANIMATED WITH A VIEW, OR
INTERPOLATING ALONG A NON-LINEAR PATH. IN SUCH
CASES WHERE YOU NEED FINER CONTROL, CORE
ANIMATION CAN BE USED DIRECTLY AS WELL.

12. ANIMATION HAPPENS VIA
LAYERS
Layer animations can be either implicit or explicit

13. IMPLICIT ANIMATIONS
TO ADD AN IMPLICIT ANIMATION FOR THE
LAYER, SIMPLY WRAP PROPERTY CHANGES
IN A CATRANSACTION. THIS ALLOWS
ANIMATING PROPERTIES THAT WOULD NOT
BE ANIMATABLE WITH A VIEW ANIMATION

14. EXPLICIT ANIMATIONS
LET YOU ENCAPSULATE ANIMATIONS THAT
ARE THEN EXPLICITLY ADDED TO A LAYER.
THESE ALLOW FINER-GRAINED CONTROL
OVER ANIMATIONS

15. STOPPING AN EXPLICIT
ANIMATION WHILE IT IS RUNNING
• To remove a single animation object from the layer, call
the layer’s removeAnimationForKey: method to remove
your animation object. This method uses the key that was
passed to the addAnimation:forKey: method to identify
the animation. The key you specify must not be nil.
• To remove all animation objects from the layer, call the
layer’s removeAllAnimations method. This method
removes all ongoing animations immediately and
redraws the layer using its current state information.

16. ANIMATIONS WITH AUTO
LAYOUT
• Create outlet for constraint
• Change constraint.constant value
• Don’t forget to call layoutIfNeeded

17. ANIMATIONS IN APPLE WATCH
ANIMATION IS NOT REALLY SUPPORTED

18. TO MAKE SOMETHING APPEAR ANIMATED,
YOU HAVE TO PRE-GENERATE A TON OF
IMAGES, AND THEN CYCLE THROUGH LIKE A
FLIP-BOOK. THE ERA OF THE ANIMATED GIF
IS BACK!
[self.imgSpriteAnimation setImageNamed:@"dragon-"];
[self.imgSpriteAnimation startAnimatingWithImagesInRange:NSMakeRange(0, 60)
duration:1.0 repeatCount:0];
FOR AN EXAMPLE OF THIS, CHECK OUT
APPLE’S LISTER EXAMPLE. IN THE WATCH
APP’S GLANCE, YOU’LL SEE THERE ARE 360
IMAGES REPRESENTING A CIRCLE
ANIMATION!