ライブラリのリファクタリング実践 ref: http://qiita.com/shoheiyokoyama/items/3405b85205dad77f1b01

file0.swift

public class SYButton: UIButton {
...

file1.swift

public final class SYButton: UIButton {
...

file10.swift

struct AnimationDefaultColor {
    static let border     = UIColor(red: 54/255, green: 215/255, blue: 183/255, alpha: 1)
    static let background = UIColor(red: 248/255, green: 148/255, blue: 6/255, alpha: 1)
    static let text       = UIColor(red: 214/255, green: 69/255, blue: 65/255, alpha: 1)
    static let ripple     = UIColor(red: 171/255, green: 183/255, blue: 183/255, alpha: 1)
}


private var animationBorderColor = AnimationDefaultColor.border

//必要に応じてアクセスコントロールをprivateにする
private struct AnimationConstants {
        static let borderWidth: CGFloat = 1
        static let defaultDuration: CFTimeInterval = 1.5
        static let rippleDiameterRatio: CGFloat = 0.7
        ...
}

private var animationDuration: CFTimeInterval = AnimationConstants.defaultDuration

file11.swift

let borderColorAnimtion = CABasicAnimation(keyPath: "borderColor")

let backgroundColorAnimtion = CABasicAnimation(keyPath: "backgroundColor")

file12.swift

extension CABasicAnimation {
    convenience init(type: AnimationKeyType) {
        self.init(keyPath: type.rawValue)
    }
}

enum AnimationType: String {
        case borderColor
        case backgroundColor
        ..


//使用時
let borderColorAnimtion = CABasicAnimation(type: .borderColor)

let backgroundColorAnimtion = CABasicAnimation(type: .backgroundColor)

file13.swift

private func setTextLayer() {
        guard let font = titleLabel?.font, text = currentTitle else {
            return
        }

        var attributes = [String: AnyObject]()
        attributes[NSFontAttributeName] = font

        let size  = text.sizeWithAttributes(attributes)
        let x     = ( self.frame.width - size.width ) / 2
        let y     = ( self.frame.height - size.height ) / 2
        let frame = CGRect(origin: CGPoint(x: x, y: y), size: CGSize(width: size.width, height: size.height + layer.borderWidth))

        textLayer.font            = font
        textLayer.string          = text
        textLayer.fontSize        = font.pointSize
        textLayer.foregroundColor = textColor.CGColor
        textLayer.contentsScale   = UIScreen.mainScreen().scale
        textLayer.frame           = frame
        textLayer.alignmentMode   = kCAAlignmentCenter
    }

file14.swift

protocol TextConvertible {
    var textLayer: CATextLayer { get set }

    func configureTextLayer(text: String?, font: UIFont?, textColor: UIColor)
}

extension TextConvertible where Self: UIView {
    func configureTextLayer(text: String?, font: UIFont?, textColor: UIColor) {
        guard let text = text, font = font else { return }

        var attributes = [String: AnyObject]()
        attributes[NSFontAttributeName] = font

        let size  = text.sizeWithAttributes(attributes)
        let x     = ( self.frame.width - size.width ) / 2
        let y     = ( self.frame.height - size.height ) / 2
        let frame = CGRect(x: x, y: y, width: size.width, height: size.height + layer.borderWidth)

        textLayer.font            = font
        textLayer.string          = text
        textLayer.fontSize        = font.pointSize
        textLayer.foregroundColor = textColor.CGColor
        textLayer.contentsScale   = UIScreen.mainScreen().scale
        textLayer.frame           = frame
        textLayer.alignmentMode   = kCAAlignmentCenter
    }
}

//使用時
class SYButton: UIButton, TextConvertible {
...

func resetTextLayer() {
configureTextLayer(currentTitle, font: titleLabel?.font, textColor: textColor)
...

file15.swift

class SYLayer {
...

// CALayerを管理する処理
func setLayer() {
...

func resizeLayer() {
...

// アニメーションの処理
func startAnimation() {
...

func stopAnimation() {
...

file16.swift

// CALayerを管理するクラス Animator protocolに準拠
class SYLayer: Animator {
...

func setLayer() {
...

func resizeLayer() {
...


// アニメーションを管理するprotocol
protocol Animatable {
..

extension Animatable {

func startAnimation() {
..

func stopAnimation() {
...


//使用時
class SYLabel {
..

let layer = SYLayer(self.layer)
layer.startAnimation()

file2.swift

switch animationType {
case .border:
    syLayer.animationType = .border
case .borderWithShadow:
    syLayer.animationType = .borderWithShadow
case .background:
    syLayer.animationType = .background
case .ripple:
    syLayer.animationType = .ripple
case .text:
    syLayer.animationType = .text
}

file3.swift

syLayer.animationType = {
            switch animationType {
            case .border:
                return .border
            case .borderWithShadow:
                return .borderWithShadow
            case .background:
                return .background
            case .ripple:
                return .ripple
            case .text:
                return .text
            }
}()

file4.swift

// MARK: - Private Methods -

private extension SYButton {

    private func setup() {
    ...

file5.swift

// MARK: - UITableViewDataSource -

extension UIViewController: UITableViewDataSource {
...

// MARK: - UITableViewDelegate -

extension UIViewController: UITableViewDelegate {

file6.swift

let rect = CGRectMake(0, 0, 100, 100)
let point = CGPointMake(0, 0)
let size = CGSizeMake(100, 100)

let height = CGRectGetHeight(frame)
let width = CGRectGetWidth(frame)

file7.swift

let rect = CGRect(x: 0, y: 0, width: 100, height: 100)
let size = CGSize(width: 100, height: 100)
let point = CGPoint(x: 0, y: 0)

let height = frame.height
let width = frame.width

file8.swift

let frame = CGRect(x: 0, y: 0, width: 100, height: 100)
let maxX = frame.maxX
let maxY = frame.maxY

let rect = CGRect.zero
let size = CGSize.zero
let point = CGPoint.zero

file9.swift

private var animationBorderColor = UIColor(red: 54/255, green: 215/255, blue: 183/255, alpha: 1)
private var animationDuration: CFTimeInterval = 1.5