読み込みに使えそうなアニメーション2 〜Windows10風〜 #Swift

開発環境

XCode8.1
Swift3

Windows10のアップデート中のアニメーションを見てて、なんとなく作ってみた。

元にしたサンプルはクックパッドの開発ブログにあるやつ。
心地よいアニメーションを求めて
CAReplicatorLayerはここで初めて知った。

        // CAReplicatorLayerを生成、追加
        let replicatorLayer = CAReplicatorLayer()
        replicatorLayer.frame = view.bounds
        view.layer.addSublayer(replicatorLayer)

        let circle = Circlelayer()
        circle.frame = CGRect(x: self.view.frame.midX-40, y: self.view.frame.midY - 80, width: 80, height: 80)
        replicatorLayer.addSublayer(circle)
        circle.setNeedsDisplay()

        let animation = CAKeyframeAnimation(keyPath: "position")
        animation.fillMode = kCAFillModeForwards
        animation.isRemovedOnCompletion = false
        animation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)

        let x : CGFloat = self.view.frame.size.width/2
        let y : CGFloat = self.view.frame.size.height/2
        let radius : CGFloat = 100.0

        let cyclePath : CGMutablePath = CGMutablePath()
        cyclePath.addArc(center: CGPoint(x:x, y:y), radius: radius, startAngle: CGFloat(M_PI*(3/2)), endAngle: CGFloat(-M_PI*(1/2)), clockwise: false)

        animation.path = cyclePath

        let blinkAnimation = CAKeyframeAnimation(keyPath: "opacity")
        blinkAnimation.fillMode = kCAFillModeForwards
        blinkAnimation.isRemovedOnCompletion = false
        blinkAnimation.values = [1, 0, 1, 1, 1]

        let group = CAAnimationGroup()
        group.animations = [animation, blinkAnimation]
        group.duration = 5
        group.repeatCount = .infinity

        circle.add(group, forKey: nil)

        replicatorLayer.instanceCount = 6
        replicatorLayer.instanceDelay = 0.1
        let angle = (2.0*M_PI)/30
        replicatorLayer.instanceTransform = CATransform3DMakeRotation(-CGFloat(angle), 0.0, 0.0, 1.0);