ninjaprox/NVActivityIndicatorView

//
//  NVActivityIndicatorAnimationBallZigZag.swift
//  NVActivityIndicatorView
//
// The MIT License (MIT)

// Copyright (c) 2016 Vinh Nguyen

// 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.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//

#if canImport(UIKit)
import UIKit
import QuartzCore

class NVActivityIndicatorAnimationBallZigZag: NVActivityIndicatorAnimationDelegate {

    func setUpAnimation(in layer: CALayer, size: CGSize, color: UIColor) {
        let circleSize: CGFloat = size.width / 5
        let duration: CFTimeInterval = 0.7
        let deltaX = size.width / 2 - circleSize / 2
        let deltaY = size.height / 2 - circleSize / 2
        let frame = CGRect(x: (layer.bounds.size.width - circleSize) / 2, y: (layer.bounds.size.height - circleSize) / 2, width: circleSize, height: circleSize)

        // Circle 1 animation
        let animation = CAKeyframeAnimation(keyPath: "transform")

        animation.keyTimes = [0, 0.33, 0.66, 1]
        animation.timingFunction = CAMediaTimingFunction(name: .linear)
        animation.values = [
            NSValue(caTransform3D: CATransform3DMakeTranslation(0, 0, 0)),
            NSValue(caTransform3D: CATransform3DMakeTranslation(-deltaX, -deltaY, 0)),
            NSValue(caTransform3D: CATransform3DMakeTranslation(deltaX, -deltaY, 0)),
            NSValue(caTransform3D: CATransform3DMakeTranslation(0, 0, 0))
        ]
        animation.duration = duration
        animation.repeatCount = HUGE
        animation.isRemovedOnCompletion = false

        // Draw circle 1
        circleAt(frame: frame, layer: layer, size: CGSize(width: circleSize, height: circleSize), color: color, animation: animation)

        // Circle 2 animation
        animation.values = [
            NSValue(caTransform3D: CATransform3DMakeTranslation(0, 0, 0)),
            NSValue(caTransform3D: CATransform3DMakeTranslation(deltaX, deltaY, 0)),
            NSValue(caTransform3D: CATransform3DMakeTranslation(-deltaX, deltaY, 0)),
            NSValue(caTransform3D: CATransform3DMakeTranslation(0, 0, 0))
        ]

        // Draw circle 2
        circleAt(frame: frame, layer: layer, size: CGSize(width: circleSize, height: circleSize), color: color, animation: animation)
    }

    func circleAt(frame: CGRect, layer: CALayer, size: CGSize, color: UIColor, animation: CAAnimation) {
        let circle = NVActivityIndicatorShape.circle.layerWith(size: size, color: color)

        circle.frame = frame
        circle.add(animation, forKey: "animation")
        layer.addSublayer(circle)
    }
}
#endif