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CAPropertyAnimation Class Reference

Overview

CAPropertyAnimation is an abstract subclass of CAAnimation for creating animations that manipulate the value of layer properties. The property is specified using a key path that is relative to the layer using the animation.

Tasks

Animated Key Path

•   keyPath  property

Property Value Calculation Behavior

•   cumulative  property
• – isCumulative
•   additive  property
• – isAdditive

Creating an Animation

• + animationWithKeyPath:

Properties

For more about Objective-C properties, see “Properties” in The Objective-C 2.0 Programming Language.

additive

Determines if the value specified by the animation is added to the current render tree value to produce the new render tree value.

@property BOOL additive

Discussion

If YES, the value specified by the animation will be added to the current render tree value of the property to produce the new render tree value. The addition function is type-dependent, e.g. for affine transforms the two matrices are concatenated. The default is NO.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CAAnimation.h

cumulative

Determines if the value of the property is the value at the end of the previous repeat cycle, plus the value of the current repeat cycle.

@property BOOL cumulative

Discussion

If YES, then the value of the property is the value at the end of the previous repeat cycle, plus the value of the current repeat cycle. If NO, the value of the property is simply the value calculated for the current repeat cycle. The default is NO.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CAAnimation.h

keyPath

Specifies the key path the receiver animates.

@property(copy) NSString *keyPath

Discussion

The key path is relative to the layer the receiver is attached to.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CAAnimation.h

Class Methods

animationWithKeyPath:

Creates and returns an CAPropertyAnimation instance for the specified key path.

+ (id)animationWithKeyPath:(NSString *)keyPath

Parameters

keyPath

The key path of the property to be animated.

Return Value

A new instance of CAPropertyAnimation with the key path set to keyPath.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CAAnimation.h

Instance Methods

isAdditive

A synthesized accessor for the additive property.

- (BOOL)isAdditive

See Also

•   @property additive

isCumulative

A synthesized accessor for the cumulative property.

- (BOOL)isCumulative

See Also

•   @property cumulative

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