Xcode 9 • Swift 4 or later extension UIColor { convenience init?(hexaRGB: String, alpha: CGFloat = 1) { var chars = Array(hexaRGB.hasPrefix(“#”) ? hexaRGB.dropFirst() : hexaRGB[…]) switch chars.count { case 3: chars = chars.flatMap { [$0, $0] } case 6: break default: return nil } self.init(red: .init(strtoul(String(chars[0…1]), nil, 16)) / 255, green: .init(strtoul(String(chars[2…3]), nil, 16)) … Read more
W3C has the following: http://www.w3.org/WAI/ER/WD-AERT/#color-contrast If you’re only doing black or white text, use the color brightness calculation above. If it is below 125, use white text. If it is 125 or above, use black text. edit 1: bias towards black text. 🙂 edit 2: The formula to use is ((Red value * 299) + … Read more
In iOS 5 you could use: CGFloat red = 0.0, green = 0.0, blue = 0.0, alpha =0.0; [multipliedColor getRed:&red green:&green blue:&blue alpha:&alpha];
UIColor(named: “myColor”) Source: WWDC 2017 Session 237 —— What’s New in MapKit Caveat: Your project’s Deployment Target needs to be set to iOS 11.0.
UIColor has a method which gives you the RGB components (-getRed:green:blue:alpha:) which works great on iOS 7 or higher. On iOS 6 and earlier, this method will fail and return NO if the color is not in an RGB color space (as it will for [UIColor grayColor].) For iOS 6 and earlier, the only way … Read more
You’re going to need a function to produce random CGFloats in the range 0 to 1: extension CGFloat { static func random() -> CGFloat { return CGFloat(arc4random()) / CGFloat(UInt32.max) } } Then you can use this to create a random colour: extension UIColor { static func random() -> UIColor { return UIColor( red: .random(), green: … Read more
You can convert UIColor to CIColor and then extract the color components from it as follow: Update: Xcode 8.3.2 • Swift 3.1 extension UIColor { var coreImageColor: CIColor { return CIColor(color: self) } var components: (red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat) { let coreImageColor = self.coreImageColor return (coreImageColor.red, coreImageColor.green, coreImageColor.blue, coreImageColor.alpha) } } … Read more
Objective-C: UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)]; CAGradientLayer *gradient = [CAGradientLayer layer]; gradient.frame = view.bounds; gradient.colors = @[(id)[UIColor whiteColor].CGColor, (id)[UIColor blackColor].CGColor]; [view.layer insertSublayer:gradient atIndex:0]; Swift: let view = UIView(frame: CGRect(x: 0, y: 0, width: 320, height: 50)) let gradient = CAGradientLayer() gradient.frame = view.bounds gradient.colors = [UIColor.white.cgColor, UIColor.black.cgColor] view.layer.insertSublayer(gradient, at: 0) Info: … Read more
On iOS 7 you can set the tintColor of the UITextView. It affects the link color as well as the cursor line and the selected text color. iOS 7 also added a new property to UITextView called linkTextAttributes which would appear to let you fully control the link style.
Have you tried [myColor isEqual:someOtherColor] ?