The document discusses Core Animation for iPhone. It describes how every view is layer-backed and layers take responsibility during animation. It explains different animation types like implicit, explicit and keyframe animation. Implicit animation involves telling a view to animate and changing its properties between beginAnimations and commitAnimations calls. Explicit animation allows specifying animations for each layer property by creating a CABasicAnimation. The document also covers view transitions using CATransition, describing its different types, subtypes, timing functions and applying a transition animation to a view's layer.

1. Core Animation
for iPhone
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2. What’s that?
Transforming smoothly an object’s visual
representation over time
Import QuartzCore.framework in your project
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3. CALayer
• Every view is layer-backed
• A cached copy of UIView’s appearance
• Takes responsibility during animation
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4. CALayer
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5. Layer geometry
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6. Layer transformations
You can use matrix transformations
It is a CGFloat 4x4 matrix
trasform and sublayerTransform
Function Use
CATranform3DMakeTranslation Returns a transform that translates by '(tx, ty, tz)'. t' = [1 0 0 0; 0 1 0 0; 0 0 1 0; tx ty tz 1].
CATranform3DTranslate Translate 't' by '(tx, ty, tz)' and return the result: * t' = translate(tx, ty, tz) * t.
CATranform3DMakeScale Returns a transform that scales by `(sx, sy, sz)': * t' = [sx 0 0 0; 0 sy 0 0; 0 0 sz 0; 0 0 0 1].
CATranform3DScale Scale 't' by '(sx, sy, sz)' and return the result: * t' = scale(sx, sy, sz) * t.
Returns a transform that rotates by 'angle' radians about the vector '(x, y, z)'. If the vector has
CATranform3DMakeRotation
length zero the identity transform is returned.
Rotate 't' by 'angle' radians about the vector '(x, y, z)' and return the result. t' = rotation(angle, x,
CATranform3DRotate
y, z) * t.
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7. Animation types
• Implicit animation
• Explicit animation
• Key-frame animation
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8. Implicit animations
• The simplest type of animation
• Tell UIView that it should animate and change its
properties
The animation starts when commitAnimations is sent
[UIView beginAnimations:nil context:nil];
// your code here
[UIVIew commitAnimations];
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9. Implicit animations
Defined in UIView + beginAnimations:context:
+ commitAnimations
+ setAnimationStartDate:
+ setAnimationsEnabled:
+ setAnimationDelegate:
+ setAnimationWillStartSelector:
+ setAnimationDidStopSelector:
+ setAnimationDuration:
+ setAnimationDelay:
+ setAnimationCurve:
+ setAnimationRepeatCount:
+ setAnimationRepeatAutoreverses:
+ setAnimationBeginsFromCurrentState:
+ setAnimationTransition:forView:cache:
+ areAnimationsEnabled
All the properties change concurrently
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10. Explicit animations
• Basic Animations: CABasicAnimation
• You can specify the animation for each layer property
• Create an animation with
+animationWithKeyPath:
• Apply the animation sending
addAnimation:forKey
• Stop the animation sending:
removeAnimationForKey:
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11. Objects
CAAnimation <CAMediaTiming>
CAAnimationGroup
CATransition
CAPropertyAnimation
CABasicAnimation CAKeyframeAnimation
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12. CAMediaTimingFunction
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13. View Transitions
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14. What is it?
• Special kind of animation
#import <QuartzCore/CAAnimation.h>
CATransition *aTransition = [CATransition animation];
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15. Animation type
aTransition.type = kCATransitionMoveIn;
Animation type Description
kCATransitionFade Fade from one view to the next
kCATransitionPush Push the old view out, bringing the new one in
kCATransitionReveal Move the old view out revealing the new one
kCATransitionMoveIn Move the new view in over the old one
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16. Animation subtype
aTransition.subtype = kCATransitionFromLeft;
Animation subtype Description
kCATransitionFromTop New views slides from top
kCATransitionFromBottom New views slides from bottom
kCATransitionFromRight New views slides from right
kCATransitionFromLeft New views slides from left
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17. Timing and duration
aTransition.timingFunction = UIViewAnimationCurveEaseIn;
Timing Description
UIViewAnimationCurveEaseInOut Animation is slow at the beginning and the end
UIViewAnimationCurveEaseIn Animation speed increase at the beginning
UIViewAnimationCurveEaseOut Animation speed decrease at the end
UIViewAnimationCurveLinear Uniform speed
aTransition.duration = 0.5; // seconds
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18. Animate a view
[self.view.superview.layer addAnimation:myTransition forKey:nil];
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