Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Swift 4: Convert CSS color names and RGB hex values to UIColor. UIColor from hex 3, 4, 6, and 8 characters in length with or without # prefix. UIColor to hex. UIColor extension that creates immutable UIColor instances from hexadecimal and CSS color name strings (e.g. ff0, #f00, ff0000, ff0000ff, Pink, aZure, CLEAR, nil). Conversely, you can obta…
//
// UIColor.swift
// previously Color+HexAndCSSColorNames.swift
//
// Created by Norman Basham on 12/8/15.
// Copyright ©2018 Black Labs. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
import UIKit
public extension UIColor {
/**
Creates an immuatble UIColor instance specified by a hex string, CSS color name, or nil.
- parameter hexString: A case insensitive String? representing a hex or CSS value e.g.
- **"abc"**
- **"abc7"**
- **"#abc7"**
- **"00FFFF"**
- **"#00FFFF"**
- **"00FFFF77"**
- **"Orange", "Azure", "Tomato"** Modern browsers support 140 color names (<http://www.w3schools.com/cssref/css_colornames.asp>)
- **"Clear"** [UIColor clearColor]
- **"Transparent"** [UIColor clearColor]
- **nil** [UIColor clearColor]
- **empty string** [UIColor clearColor]
*/
public convenience init(hex: String?) {
let normalizedHexString: String = UIColor.normalize(hex)
var c: CUnsignedInt = 0
Scanner(string: normalizedHexString).scanHexInt32(&c)
self.init(red:UIColorMasks.redValue(c), green:UIColorMasks.greenValue(c), blue:UIColorMasks.blueValue(c), alpha:UIColorMasks.alphaValue(c))
}
/**
Returns a hex equivalent of this UIColor.
- Parameter includeAlpha: Optional parameter to include the alpha hex.
color.hexDescription() -> "ff0000"
color.hexDescription(true) -> "ff0000aa"
- Returns: A new string with `String` with the color's hexidecimal value.
*/
public func hexDescription(_ includeAlpha: Bool = false) -> String {
guard self.cgColor.numberOfComponents == 4 else {
return "Color not RGB."
}
let a = self.cgColor.components!.map { Int($0 * CGFloat(255)) }
let color = String.init(format: "%02x%02x%02x", a[0], a[1], a[2])
if includeAlpha {
let alpha = String.init(format: "%02x", a[3])
return "\(color)\(alpha)"
}
return color
}
fileprivate enum UIColorMasks: CUnsignedInt {
case redMask = 0xff000000
case greenMask = 0x00ff0000
case blueMask = 0x0000ff00
case alphaMask = 0x000000ff
static func redValue(_ value: CUnsignedInt) -> CGFloat {
return CGFloat((value & redMask.rawValue) >> 24) / 255.0
}
static func greenValue(_ value: CUnsignedInt) -> CGFloat {
return CGFloat((value & greenMask.rawValue) >> 16) / 255.0
}
static func blueValue(_ value: CUnsignedInt) -> CGFloat {
return CGFloat((value & blueMask.rawValue) >> 8) / 255.0
}
static func alphaValue(_ value: CUnsignedInt) -> CGFloat {
return CGFloat(value & alphaMask.rawValue) / 255.0
}
}
fileprivate static func normalize(_ hex: String?) -> String {
guard var hexString = hex else {
return "00000000"
}
if let cssColor = cssToHexDictionairy[hexString.uppercased()] {
return cssColor.count == 8 ? cssColor : cssColor + "ff"
}
if hexString.hasPrefix("#") {
hexString = String(hexString.dropFirst())
}
if hexString.count == 3 || hexString.count == 4 {
hexString = hexString.map { "\($0)\($0)" } .joined()
}
let hasAlpha = hexString.count > 7
if !hasAlpha {
hexString += "ff"
}
return hexString
}
/**
All modern browsers support the following 140 color names (see http://www.w3schools.com/cssref/css_colornames.asp)
*/
fileprivate static func hexFromCssName(_ cssName: String) -> String {
let key = cssName.uppercased()
if let hex = cssToHexDictionairy[key] {
return hex
}
return cssName
}
fileprivate static let cssToHexDictionairy: [String: String] = [
"CLEAR": "00000000",
"TRANSPARENT": "00000000",
"": "00000000",
"ALICEBLUE": "F0F8FF",
"ANTIQUEWHITE": "FAEBD7",
"AQUA": "00FFFF",
"AQUAMARINE": "7FFFD4",
"AZURE": "F0FFFF",
"BEIGE": "F5F5DC",
"BISQUE": "FFE4C4",
"BLACK": "000000",
"BLANCHEDALMOND": "FFEBCD",
"BLUE": "0000FF",
"BLUEVIOLET": "8A2BE2",
"BROWN": "A52A2A",
"BURLYWOOD": "DEB887",
"CADETBLUE": "5F9EA0",
"CHARTREUSE": "7FFF00",
"CHOCOLATE": "D2691E",
"CORAL": "FF7F50",
"CORNFLOWERBLUE": "6495ED",
"CORNSILK": "FFF8DC",
"CRIMSON": "DC143C",
"CYAN": "00FFFF",
"DARKBLUE": "00008B",
"DARKCYAN": "008B8B",
"DARKGOLDENROD": "B8860B",
"DARKGRAY": "A9A9A9",
"DARKGREY": "A9A9A9",
"DARKGREEN": "006400",
"DARKKHAKI": "BDB76B",
"DARKMAGENTA": "8B008B",
"DARKOLIVEGREEN": "556B2F",
"DARKORANGE": "FF8C00",
"DARKORCHID": "9932CC",
"DARKRED": "8B0000",
"DARKSALMON": "E9967A",
"DARKSEAGREEN": "8FBC8F",
"DARKSLATEBLUE": "483D8B",
"DARKSLATEGRAY": "2F4F4F",
"DARKSLATEGREY": "2F4F4F",
"DARKTURQUOISE": "00CED1",
"DARKVIOLET": "9400D3",
"DEEPPINK": "FF1493",
"DEEPSKYBLUE": "00BFFF",
"DIMGRAY": "696969",
"DIMGREY": "696969",
"DODGERBLUE": "1E90FF",
"FIREBRICK": "B22222",
"FLORALWHITE": "FFFAF0",
"FORESTGREEN": "228B22",
"FUCHSIA": "FF00FF",
"GAINSBORO": "DCDCDC",
"GHOSTWHITE": "F8F8FF",
"GOLD": "FFD700",
"GOLDENROD": "DAA520",
"GRAY": "808080",
"GREY": "808080",
"GREEN": "008000",
"GREENYELLOW": "ADFF2F",
"HONEYDEW": "F0FFF0",
"HOTPINK": "FF69B4",
"INDIANRED": "CD5C5C",
"INDIGO": "4B0082",
"IVORY": "FFFFF0",
"KHAKI": "F0E68C",
"LAVENDER": "E6E6FA",
"LAVENDERBLUSH": "FFF0F5",
"LAWNGREEN": "7CFC00",
"LEMONCHIFFON": "FFFACD",
"LIGHTBLUE": "ADD8E6",
"LIGHTCORAL": "F08080",
"LIGHTCYAN": "E0FFFF",
"LIGHTGOLDENRODYELLOW": "FAFAD2",
"LIGHTGRAY": "D3D3D3",
"LIGHTGREY": "D3D3D3",
"LIGHTGREEN": "90EE90",
"LIGHTPINK": "FFB6C1",
"LIGHTSALMON": "FFA07A",
"LIGHTSEAGREEN": "20B2AA",
"LIGHTSKYBLUE": "87CEFA",
"LIGHTSLATEGRAY": "778899",
"LIGHTSLATEGREY": "778899",
"LIGHTSTEELBLUE": "B0C4DE",
"LIGHTYELLOW": "FFFFE0",
"LIME": "00FF00",
"LIMEGREEN": "32CD32",
"LINEN": "FAF0E6",
"MAGENTA": "FF00FF",
"MAROON": "800000",
"MEDIUMAQUAMARINE": "66CDAA",
"MEDIUMBLUE": "0000CD",
"MEDIUMORCHID": "BA55D3",
"MEDIUMPURPLE": "9370DB",
"MEDIUMSEAGREEN": "3CB371",
"MEDIUMSLATEBLUE": "7B68EE",
"MEDIUMSPRINGGREEN": "00FA9A",
"MEDIUMTURQUOISE": "48D1CC",
"MEDIUMVIOLETRED": "C71585",
"MIDNIGHTBLUE": "191970",
"MINTCREAM": "F5FFFA",
"MISTYROSE": "FFE4E1",
"MOCCASIN": "FFE4B5",
"NAVAJOWHITE": "FFDEAD",
"NAVY": "000080",
"OLDLACE": "FDF5E6",
"OLIVE": "808000",
"OLIVEDRAB": "6B8E23",
"ORANGE": "FFA500",
"ORANGERED": "FF4500",
"ORCHID": "DA70D6",
"PALEGOLDENROD": "EEE8AA",
"PALEGREEN": "98FB98",
"PALETURQUOISE": "AFEEEE",
"PALEVIOLETRED": "DB7093",
"PAPAYAWHIP": "FFEFD5",
"PEACHPUFF": "FFDAB9",
"PERU": "CD853F",
"PINK": "FFC0CB",
"PLUM": "DDA0DD",
"POWDERBLUE": "B0E0E6",
"PURPLE": "800080",
"RED": "FF0000",
"ROSYBROWN": "BC8F8F",
"ROYALBLUE": "4169E1",
"SADDLEBROWN": "8B4513",
"SALMON": "FA8072",
"SANDYBROWN": "F4A460",
"SEAGREEN": "2E8B57",
"SEASHELL": "FFF5EE",
"SIENNA": "A0522D",
"SILVER": "C0C0C0",
"SKYBLUE": "87CEEB",
"SLATEBLUE": "6A5ACD",
"SLATEGRAY": "708090",
"SLATEGREY": "708090",
"SNOW": "FFFAFA",
"SPRINGGREEN": "00FF7F",
"STEELBLUE": "4682B4",
"TAN": "D2B48C",
"TEAL": "008080",
"THISTLE": "D8BFD8",
"TOMATO": "FF6347",
"TURQUOISE": "40E0D0",
"VIOLET": "EE82EE",
"WHEAT": "F5DEB3",
"WHITE": "FFFFFF",
"WHITESMOKE": "F5F5F5",
"YELLOW": "FFFF00",
"YELLOWGREEN": "9ACD32"
]
}
@nbasham

This comment has been minimized.

Copy link
Owner Author

commented Dec 9, 2015

gist

@smehta

This comment has been minimized.

Copy link

commented Dec 9, 2015

Nice. I always wanted this whenever I deal with UI Color.

@osmely

This comment has been minimized.

Copy link

commented Mar 2, 2017

WOW

@jakubknejzlik

This comment has been minimized.

Copy link

commented May 4, 2017

I've updated this gist according to swiftlint rules. You can find it here https://gist.github.com/jakubknejzlik/ba4ff55263c760fe5d3cabddb2b915fb

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.