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@designerGenes
Last active December 16, 2016 23:33
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A custom activity indicator because regular activity indicators are no good
import UIKit
protocol ActivityIndicatorType {
func startAnimating()
func stopAnimating()
var isAnimating: Bool { get set }
}
class CustomActivityIndicator: UIView, ActivityIndicatorType {
// MARK: - properties
private var numberOfBars: Int = 3
var color: UIColor = UIColor.green
var duration: Double = 0.35
var maskLayers = [CAShapeLayer]()
var isAnimating: Bool = false
// MARK: - methods
override func draw(_ rect: CGRect) {
UIGraphicsGetCurrentContext()?.clear(rect)
layer.backgroundColor = UIColor.clear.cgColor
let individualWidth = frame.width / CGFloat(numberOfBars)
for z in 0..<numberOfBars {
let newLayer = CAShapeLayer()
newLayer.anchorPoint = CGPoint(x: 0, y: 1)
newLayer.path = UIBezierPath(rect:
CGRect(
x: CGFloat(z) * individualWidth,
y: 0,
width: individualWidth - 0.5,
height: frame.height)).cgPath
newLayer.fillColor = color.cgColor
layer.addSublayer(newLayer)
let maskLayer = CAShapeLayer()
maskLayer.path = UIBezierPath(roundedRect: CGRect(
x: CGFloat(z) * individualWidth,
y: 0,
width: individualWidth - 1,
height: frame.height * 2),
byRoundingCorners: [.topLeft, .topRight ],
cornerRadii: CGSize(width: 1 , height: 2)).cgPath
maskLayer.anchorPoint = CGPoint(x: 0, y: 0)
maskLayer.position = CGPoint(x: maskLayer.position.x, y: frame.height + 2)
newLayer.mask = maskLayer
maskLayers.append(maskLayer)
}
}
func startAnimating() {
isAnimating = true
layer.opacity = 1 // implicit animation
for (z, maskLayer) in maskLayers.enumerated() {
var differential: CGFloat = 0
if maskLayers.count > 2 {
let middleIndex = Int(floor(Double(maskLayers.count) / 2))
let fixedDelta = middleIndex - abs(middleIndex - z)
differential += (frame.height * 0.15) * CGFloat(fixedDelta)
}
let motionAnimation = CABasicAnimation(keyPath: "position.y")
motionAnimation.byValue = max(-frame.height, (-(frame.height / 2) - differential))
let colorAnimation = CABasicAnimation(keyPath: "fillColor")
colorAnimation.fromValue = color.withAlphaComponent(0.65).cgColor
colorAnimation.toValue = color.cgColor
for animation in [motionAnimation, colorAnimation] {
animation.speed = 1 - (Float(z) * 0.1)
animation.autoreverses = true
animation.duration = duration
animation.repeatCount = .infinity
animation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseIn)
}
maskLayer.add(colorAnimation, forKey: "fillColor")
maskLayer.add(motionAnimation, forKey: "position.y")
}
}
func stopAnimating() {
isAnimating = false
layer.opacity = 0 // implicit animation
for maskLayer in maskLayers {
maskLayer.removeAllAnimations()
}
}
convenience init(size: CGSize, withBars bars: Int, withDuration duration: Double, withColor color: UIColor) {
self.init(frame: CGRect(origin: CGPoint.zero, size: size))
numberOfBars = bars
self.duration = duration
self.color = color
self.isOpaque = false
layer.opacity = 0
}
}
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