Swift library for creating keyPath animations based on an offset instead of time.

ScrollableAnimation was built to mimic the normal way of animating layers with a property-based CAAnimation defined by a keyPath with the main difference being that the X axis of the animation timeline is an 'offset' instead of 'time'.

Just copy ScrollableAnimation folder to your iOS 8 project;

Create an animation controller for a particular context.

let animationController = ScrollableAnimationController()

Create an animation and add it to the layer you want to animate, passing along the animation controller.

let animatable = UIView(frame: CGRectMake(0, 0, 100, 100))
animatableSuperView.addSubview(animatable)

let rotation = ScrollableKeyframeAnimation(keyPath: "transform.rotation.z")
rotation.beginOffset = 0
rotation.distance = 600
rotation.keyOffsets = [0.0, 0.5, 1.0]
rotation.values = [0.0, Float(M_PI), 0.0]
rotation.functions = [TweenBlockEaseInQuad, TweenBlockEaseInQuad]
animatable.layer.addScrollableAnimation(rotation, forKey: "rotationAnimation", withController: animationController)

Note that instead of 'beginTime' the ScrollableAnimation has a 'beginOffset' and instead of 'duration' it has 'distance'. In this example these values refer to the contentSize of a control scrollView.

You can use any keyPath as you would in a CAPropertyAnimation and you can add multiple animations to one layer.

Finally feed the animation controller with the offset values. You can get these values from a UIScrollView, UISlider, or any other custom control.

func scrollViewDidScroll(scrollView: UIScrollView) {
     animationController.updateAnimatablesForOffset(Float(scrollView.contentOffset.y))
}

• Implement 'additive' functionality for ScrollableAnimation.

• Optimize contents-based animations with texture atlases.

The MIT License (MIT)

Copyright (c) 2014 Bruno Morgado

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

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