FuctionalViewStyleExperiments1

FuctionalViewStyleExperiments1.swift

//: Playground - noun: a place where people can play

import UIKit
import XCPlayground
import PlaygroundSupport


let viewController = UIViewController()
viewController.view.backgroundColor = .white

let view = UIView()
view.backgroundColor = .orange

view.frame = CGRect(x: 100, y: 100, width: 100, height: 100)
viewController.view.addSubview(view)

PlaygroundPage.current.liveView = viewController




typealias Style = (UIView) -> UIView // (UIView) -> Void でもいけそう（composeを変えれば）

func cornerRadius(_ radius: CGFloat) -> Style {
    return { view in
        view.layer.cornerRadius = radius
        return view
    }
}

/*
 // un-curried version
 func unCurriedCornerRadius(radius: CGFloat, view: UIView) {
    view.layer.cornerRadius = radius
 }
 unCurriedCornerRadius(radius: 10, view: view)
 */

func borderWidth(_ width: CGFloat) -> Style {
    return { view in
        view.layer.borderWidth = width
        return view
    }
}

func borderColor(_ color: CGColor) -> Style {
    return { view in
        view.layer.borderColor = color
        return view
    }
}

// compose functions
// borderColor(UIColor.blue.cgColor)(borderWidth(10.0)(cornerRadius(radius: 10.0)(view)))


func compose(style style1: @escaping Style, with style2: @escaping Style) -> Style {
    return { view in
        return style2(style1(view))
    }
}

func compose2(_ styles: Style...) -> Style {
    return { view in
        var composedView: UIView = view
        for style in styles {
            composedView = style(composedView)
        }
        return composedView
    }
}

//let someBorder = compose(style: borderWidth(10.0), with: borderColor(UIColor.blue.cgColor))
//compose(
//    style: someBorder,
//    with: cornerRadius(10.0)
//    )(view)

//compose2(borderWidth(10.0), borderColor(UIColor.blue.cgColor), cornerRadius(10.0))(view)

infix operator >>>
func >>>(style1: @escaping Style, style2: @escaping Style) -> Style {
    return { view in
        return style2(style1(view))
    }
}

let finalStyle = (borderWidth(10.0) >>> borderColor(UIColor.blue.cgColor))
    >>> cornerRadius(10.0)
finalStyle(view)