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CABasicAnimation Class Reference

Overview

CABasicAnimation provides basic, single-keyframe animation capabilities for a layer property. You create an instance of CABasicAnimation using the inherited animationWithKeyPath: method, specifying the key path of the property to be animated in the render tree.

Setting Interpolation Values

The fromValue, byValue and toValue properties define the values being interpolated between. All are optional, and no more than two should be non-nil. The object type should match the type of the property being animated.

The interpolation values are used as follows:

• Both fromValue and toValue are non-nil. Interpolates between fromValue and toValue.

• fromValue and byValue are non-nil. Interpolates between fromValue and (fromValue + byValue).

• byValue and toValue are non-nil. Interpolates between (toValue - byValue) and toValue.

• fromValue is non-nil. Interpolates between fromValue and the current presentation value of the property.

• toValue is non-nil. Interpolates between the current value of keyPath in the target layer’s presentation layer and toValue.

• byValue is non-nil. Interpolates between the current value of keyPath in the target layer’s presentation layer and that value plus byValue.

• All properties are nil. Interpolates between the previous value of keyPath in the target layer’s presentation layer and the current value of keyPath in the target layer’s presentation layer.

Tasks

Interpolation Values

•   fromValue  property
•   toValue  property
•   byValue  property

Properties

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

byValue

Defines the value the receiver uses to perform relative interpolation.

@property(retain) id byValue

Discussion

See “Setting Interpolation Values” for details on how byValue interacts with the other interpolation values.

Availability

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

Declared In

CAAnimation.h

fromValue

Defines the value the receiver uses to start interpolation.

@property(retain) id fromValue

Discussion

See “Setting Interpolation Values” for details on how fromValue interacts with the other interpolation values.

Availability

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

Declared In

CAAnimation.h

toValue

Defines the value the receiver uses to end interpolation.

@property(retain) id toValue

Discussion

See “Setting Interpolation Values” for details on how toValue interacts with the other interpolation values.

Availability

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

Declared In

CAAnimation.h

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