UIColor+hexString+toHexString.swift

//  Created by Evgeny Konkin on 17.06.2019.

extension UIColor {

    static let themeExample = { () -> UIColor in
        let color = UIColor(hexString: "#7C7C7C")
        return color
    }()
    
    static let wGray = UIColor(hexString: "#7C7C7C")
    static let wDarkGray = UIColor(hexString: "#222222")
    static let wLightGray = UIColor(hexString: "#E6E6E6")

    convenience init(hexString: String, alpha: CGFloat = 1.0) {
        let hexString: String = hexString.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
        let scanner = Scanner(string: hexString)
        if (hexString.hasPrefix("#")) {
            scanner.scanLocation = 1
        }
        var color: UInt32 = 0
        scanner.scanHexInt32(&color)
        let mask = 0x000000FF
        let r = Int(color >> 16) & mask
        let g = Int(color >> 8) & mask
        let b = Int(color) & mask
        let red = CGFloat(r) / 255.0
        let green = CGFloat(g) / 255.0
        let blue = CGFloat(b) / 255.0
        self.init(red: red, green: green, blue: blue, alpha: alpha)
    }
    
    func toHexString() -> String {
        var r:CGFloat = 0
        var g:CGFloat = 0
        var b:CGFloat = 0
        var a:CGFloat = 0
        getRed(&r, green: &g, blue: &b, alpha: &a)
        let rgb:Int = (Int)(r*255)<<16 | (Int)(g*255)<<8 | (Int)(b*255)<<0
        return String(format:"#%06x", rgb)
    }
}