What are shade fashions and shade areas?
A shade mannequin is a technique of describing a shade.
- RGB – Crimson+Inexperienced+Blue
- HSB – Hue+Saturation+Brightness
There are a number of different shade fashions, however if you’re coping with iOS colours you have to be aware of these two above. Normally you’ll work with the RGBA & HSBA shade fashions that are principally the identical as above prolonged with the alpha channel the place the letter A stands for that. 😉
A shade house is the set of colours which could be displayed or reproduced in a medium (whether or not saved, printed or displayed). For instance, sRGB is a selected set of intensities for pink, inexperienced and blue and defines the colours that may be reproduced by mixing these ranges of pink, inexperienced and blue.
Sufficient from the speculation, let’s do some shade magic! 💫💫💫
Find out how to work with UIColor objects utilizing RGBA and HSBA values in Swift?
Do you keep in mind the previous Paint program from old-school Home windows instances?
I’ve used Microsoft Paint so much, and I cherished it. 😅
Again then with none CS data I used to be all the time questioning in regards to the numbers between 0 and 255 that I needed to choose. In case you are working with RGB colours you normally outline your shade the identical manner, besides that in iOS the values are between 0 and 1, however that is only a totally different illustration of the fraction of 255.
So you can also make a shade with RGB codes utilizing the identical logic.
UIColor(
pink: CGFloat(128)/CGFloat(255),
inexperienced: CGFloat(128)/CGFloat(255),
blue: CGFloat(128)/CGFloat(255),
alpha: 1
)
UIColor(pink: 0.5, inexperienced: 0.5, blue: 0.5, alpha: 1)See? Fairly simple, huh? 👍
Alternatively you should utilize HSB values, virtually the identical logic applies for these values, besides that hue goes from 0 ’til 360 (due to the precise shade wheel), nonetheless saturation and brightness are measured in a “p.c like” format 0-100, so you must take into consideration these numbers when you map them to floating level values.
UIColor(hue: CGFloat(120)/CGFloat(360), saturation: 0.5, brightness: 0.5, alpha: 1)
UIColor(hue: 0.3, saturation: 0.5, brightness: 0.5, alpha: 1)Now let’s reverse the state of affairs and let me present you the way to get again these elements from an precise UIColor occasion with the assistance of an extension.
public extension UIColor {
public var rgba: (pink: CGFloat, inexperienced: CGFloat, blue: CGFloat, alpha: CGFloat) {
var r: CGFloat = 0
var g: CGFloat = 0
var b: CGFloat = 0
var a: CGFloat = 0
self.getRed(&r, inexperienced: &g, blue: &b, alpha: &a)
return (r, g, b, a)
}
public var hsba: (hue: CGFloat, saturation: CGFloat, brightness: CGFloat, alpha: CGFloat) {
var h: CGFloat = 0
var s: CGFloat = 0
var b: CGFloat = 0
var a: CGFloat = 0
self.getHue(&h, saturation: &s, brightness: &b, alpha: &a)
return (h, s, b, a)
}
}So right here it’s the way to learn the pink, inexperienced blue slash hue saturation brightness and alpha elements from a UIColor. With this little neat extension you possibly can merely get the element values and use them by means of their correct names.
UIColor.yellow.rgba.pink
UIColor.yellow.hsba.hueFind out how to convert HEX colours to RGB and vica versa for UIColor objects in Swift?
iOS developer 101 course, first questions:
- How the fuck can I create a UIColor from a hex string?
- Find out how to convert a hex shade to a UIColor?
- Find out how to use a hext string to make a UIColor?
Okay, perhaps these aren’t the primary questions, but it surely’s undoubtedly inside frequent ones. The reply is fairly easy: by means of an extension. I’ve a very nice resolution to your wants, which is able to deal with a lot of the instances like utilizing only one, 2, 3 or 6 hex values.
public extension UIColor {
public comfort init(hex: Int, alpha: CGFloat = 1.0) {
let pink = CGFloat((hex & 0xFF0000) >> 16) / 255.0
let inexperienced = CGFloat((hex & 0xFF00) >> 8) / 255.0
let blue = CGFloat((hex & 0xFF)) / 255.0
self.init(pink: pink, inexperienced: inexperienced, blue: blue, alpha: alpha)
}
public comfort init(hex string: String, alpha: CGFloat = 1.0) {
var hex = string.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()
if hex.hasPrefix("#") {
let index = hex.index(hex.startIndex, offsetBy: 1)
hex = String(hex[index...])
}
if hex.depend < 3 {
hex = "(hex)(hex)(hex)"
}
if hex.vary(of: "(^[0-9A-Fa-f]{6}$)|(^[0-9A-Fa-f]{3}$)", choices: .regularExpression) != nil {
if hex.depend == 3 {
let startIndex = hex.index(hex.startIndex, offsetBy: 1)
let endIndex = hex.index(hex.startIndex, offsetBy: 2)
let redHex = String(hex[..<startIndex])
let greenHex = String(hex[startIndex..<endIndex])
let blueHex = String(hex[endIndex...])
hex = redHex + redHex + greenHex + greenHex + blueHex + blueHex
}
let startIndex = hex.index(hex.startIndex, offsetBy: 2)
let endIndex = hex.index(hex.startIndex, offsetBy: 4)
let redHex = String(hex[..<startIndex])
let greenHex = String(hex[startIndex..<endIndex])
let blueHex = String(hex[endIndex...])
var redInt: CUnsignedInt = 0
var greenInt: CUnsignedInt = 0
var blueInt: CUnsignedInt = 0
Scanner(string: redHex).scanHexInt32(&redInt)
Scanner(string: greenHex).scanHexInt32(&greenInt)
Scanner(string: blueHex).scanHexInt32(&blueInt)
self.init(pink: CGFloat(redInt) / 255.0,
inexperienced: CGFloat(greenInt) / 255.0,
blue: CGFloat(blueInt) / 255.0,
alpha: CGFloat(alpha))
}
else {
self.init(pink: 0.0, inexperienced: 0.0, blue: 0.0, alpha: 0.0)
}
}
var hexValue: String {
var shade = self
if shade.cgColor.numberOfComponents < 4 {
let c = shade.cgColor.elements!
shade = UIColor(pink: c[0], inexperienced: c[0], blue: c[0], alpha: c[1])
}
if shade.cgColor.colorSpace!.mannequin != .rgb {
return "#FFFFFF"
}
let c = shade.cgColor.elements!
return String(format: "#%02Xpercent02Xpercent02X", Int(c[0]*255.0), Int(c[1]*255.0), Int(c[2]*255.0))
}
}Right here is how you should utilize it with a number of enter variations:
let colours = [
UIColor(hex: "#cafe00"),
UIColor(hex: "cafe00"),
UIColor(hex: "c"),
UIColor(hex: "ca"),
UIColor(hex: "caf"),
UIColor(hex: 0xcafe00),
]
let values = colours.map { $0.hexValue }
print(values) As you possibly can see I’ve tried to copy the habits of the CSS guidelines, so you should have the liberty of much less characters if a hext string is like #ffffff (you should utilize simply f, as a result of # is non-obligatory). Additionally you possibly can present integers as nicely, that is only a easy “overloaded” comfort init methodology.
Additionally .hexValue will return the string illustration of a UIColor occasion. 👏👏👏
Find out how to generate a random UIColor in Swift?
That is additionally a quite common query for newbies, I do not actually need to waste the house right here by deep clarification, arc4random() is simply doing it is job and the output is a pleasant randomly generated shade.
public extension UIColor {
public static var random: UIColor {
let max = CGFloat(UInt32.max)
let pink = CGFloat(arc4random()) / max
let inexperienced = CGFloat(arc4random()) / max
let blue = CGFloat(arc4random()) / max
return UIColor(pink: pink, inexperienced: inexperienced, blue: blue, alpha: 1.0)
}
}Find out how to create a 1×1 pixel massive UIImage object with a single stable shade in Swift?
I am utilizing this trick to set the background shade of a UIButton object. The explanation for that is state administration. In case you press the button the background picture will probably be darker, so there will probably be a visible suggestions for the person. Nonetheless by setting the background shade instantly of a UIButton occasion will not work like this, and the colour will not change in any respect on the occasion. 👆
public extension UIColor {
public var imageValue: UIImage {
let rect = CGRect(origin: .zero, dimension: CGSize(width: 1, peak: 1))
UIGraphicsBeginImageContext(rect.dimension)
let context = UIGraphicsGetCurrentContext()!
context.setFillColor(self.cgColor)
context.fill(rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}
}The snippet above will produce a 1×1 pixel picture object from the supply shade. You should utilize that anywere, however right here is my instance with a button background:
button.setBackgroundImage(UIColor.pink.imageValue, for: .regular)On-line shade palettes
You may’t discover the appropriate shade? No drawback, these hyperlinks will assist you to to decide on the correct one and to get some inspiration. Additionally if you’re searching for flat UI colours or materials design colours these are the appropriate hyperlinks the place it is best to head first.
A private factor of mine: pricey designers, please by no means ever attempt to use materials design ideas for iOS apps. Thanks. HIG
Convert colours on-line
Lastly there are some nice on-line shade converter instruments, if you’re searching for an ideal one, it is best to attempt these first.
Managing UIColors
In case your app goal is iOS 11+ you should utilize asset catalogs to arrange your shade palettes, but when you want to go beneath iOS 11, I might counsel to make use of an enum or struct with static UIColor properties. These days I am normally doing one thing like this.
class App {
struct Colour {
static var inexperienced: UIColor { return UIColor(hex: 0x4cd964) }
static var yellow: UIColor { return UIColor(hex: 0xffcc00) }
static var pink: UIColor { return UIColor(hex: 0xff3b30) }
}
}
App.Colour.yellowNormally I am grouping collectively fonts, colours and so forth inside structs, however this is only one manner of doing issues. You can too use one thing like R.swift or something that you just want.
That is it for now, I believe I’ve coated a lot of the fundamental questions on UIColor.
Be at liberty to contact me if in case you have a subject or suggestion that you just’d wish to see coated right here within the weblog. I am all the time open for brand new concepts. 😉
