Created
September 25, 2020 17:54
-
-
Save snown/0224a2811a95b499a02c8413109a2395 to your computer and use it in GitHub Desktop.
an NSColor extension to convert CSS style hex string into a color and back
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
extension NSColor { | |
convenience init?(hexString: String) { | |
var hexString: String = hexString.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines) | |
if hexString.hasPrefix("#") { | |
let startIndex = hexString.index(hexString.startIndex, offsetBy: 1) | |
hexString = String(hexString[startIndex...]) | |
} | |
if hexString.count == 3 || hexString.count == 4 { | |
hexString = hexString.reduce(into: "") { (paddedHex, hexCharacter) in | |
paddedHex += "\(hexCharacter)\(hexCharacter)" | |
} | |
} | |
guard hexString.count == 6 || hexString.count == 8 else { | |
return nil | |
} | |
let scanner = Scanner(string: hexString) | |
var hexNumber: UInt64 = 0 | |
if scanner.scanHexInt64(&hexNumber) { | |
let r, g, b, a: CGFloat | |
switch hexString.count { | |
case 6: | |
r = CGFloat((hexNumber & 0xFF0000) >> 16) / 255.0 | |
g = CGFloat((hexNumber & 0x00FF00) >> 8) / 255.0 | |
b = CGFloat(hexNumber & 0x0000FF) / 255.0 | |
a = 1.0 | |
default: // count == 8 | |
r = CGFloat((hexNumber & 0xFF000000) >> 24) / 255.0 | |
g = CGFloat((hexNumber & 0x00FF0000) >> 16) / 255.0 | |
b = CGFloat((hexNumber & 0x0000FF00) >> 8) / 255.0 | |
a = CGFloat(hexNumber & 0x000000FF) / 255.0 | |
} | |
self.init(red: r, green: g, blue: b, alpha: a) | |
return | |
} | |
return nil | |
} | |
func hexString(includingAlpha: Bool = false) -> String { | |
var result = String(format: "#%02lX%02lX%02lX", lroundf(Float(redComponent) * 255), lroundf(Float(greenComponent) * 255), lroundf(Float(blueComponent) * 255)) | |
if (includingAlpha) { | |
result += String(format: "%02lX", lroundf(Float(alphaComponent) * 255)) | |
} | |
return result | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment