ColorExtensions is a Swift Package Manager package for iOS/tvOS (10.0 and above) and watchOS (5.0 and above) providing a variety of useful extensions to UIColor, with nearly 90% test coverage. In fact, here's a complete list of all the functions and extra types that are made available by this package:
extension UIColor {
public enum ColorSpaceError: Error {
case incompatibleColorSpace
}
public struct RGBAComponents: Equatable {
public let red: CGFloat
public let green: CGFloat
public let blue: CGFloat
public let alpha: CGFloat
}
public struct HSBAComponents: Equatable {
public let hue: CGFloat
public let saturation: CGFloat
public let brightness: CGFloat
public let alpha: CGFloat
}
public struct WhiteAlphaComponents: Equatable {
public let white: CGFloat
public let alpha: CGFloat
}
// MARK: - HEX
/// Creates an instance of UIColor in the RGB color space, given its
/// hexadecimal representation (which does include alpha).
///
public convenience init(hexValueRGBA: UInt32)
/// Creates an instance of UIColor in the RGB color space, given its
/// hexadecimal representation (which does not include alpha), if valid.
///
public convenience init?(hexValueRGB: UInt32, alpha: CGFloat = 1.0)
/// Creates an instance of UIColor in the RGB color space, given its
/// hexadecimal string representation (which does include alpha).
///
public convenience init?(hexStringRGBA: String)
/// Creates an instance of UIColor in the RGB color space, given its
/// hexadecimal string representation (which does not include alpha), if
/// valid.
///
public convenience init?(hexStringRGB: String, alpha: CGFloat = 1.0)
/// Returns the hexadecimal representation of self, as a string, without
/// including the alpha value, if self is represented internally in a
/// RGB-compatible color scheme, or the error value
/// ColorSpaceError.incompatibleColorSpace if not.
///
public func hexStringRGB() -> Result<String, ColorSpaceError>
/// Returns the hexadecimal representation of self, as a string, including
/// the alpha value, if self is represented internally in a RGB-compatible
/// color scheme, or the error value ColorSpaceError.incompatibleColorSpace
/// if not.
///
public func hexStringRGBA() -> Result<String, ColorSpaceError>
// MARK: - Display P3
/// Returns a new instance of UIColor in the Display P3 color space, with
/// random values for its color coordinates (red, green, blue), but with
/// its opacity (alpha) set to the argument passed in (whose default value
/// is 1).
///
public static func randomDisplayP3(alpha: CGFloat = 1) -> UIColor
/// Returns a new instance of UIColor in the Display P3 color space, with
/// random values for all of its color coordinates (red, green, blue,
/// alpha).
///
public static func randomDisplayP3A() -> UIColor
/// Returns a new instance of UIColor in the Display P3 color space, with
/// random values for its color coordinates (red, green, blue), but with
/// its opacity (alpha) set to the argument passed in (whose default value
/// is 1), and using a particular random number generator.
///
public static func randomDisplayP3 <RNG: RandomNumberGenerator> (
alpha: CGFloat = 1,
using rng: inout RNG
) -> UIColor
/// Returns a new instance of UIColor in the Display P3 color space, with
/// random values for all of its color coordinates (red, green, blue,
/// alpha), using a particular random number generator.
///
public static func randomDisplayP3A <RNG: RandomNumberGenerator> (
using rng: inout RNG
) -> UIColor
// MARK: - RGBA
/// Returns a new instance of UIColor in the RGB color space, with random
/// values for its color coordinates (red, green, blue), but with its
/// opacity (alpha) set to the argument passed in (whose default value is
/// 1).
///
public static func randomRGB(alpha: CGFloat = 1) -> UIColor
/// Returns a new instance of UIColor in the RGB color space, with random
/// values for all of its color coordinates (red, green, blue, alpha).
///
public static func randomRGBA() -> UIColor
/// Returns a new instance of UIColor in the RGB color space, with random
/// values for its color coordinates (red, green, blue), but with its
/// opacity (alpha) set to the argument passed in (whose default value is
/// 1), and using a particular random number generator.
///
public static func randomRGB <RNG: RandomNumberGenerator> (
alpha: CGFloat = 1,
using rng: inout RNG
) -> UIColor
/// Returns a new instance of UIColor in the RGB color space, with random
/// values for all of its color coordinates (red, green, blue, alpha),
/// using a particular random number generator.
///
public static func randomRGBA <RNG: RandomNumberGenerator> (
using rng: inout RNG
) -> UIColor
/// Returns the RGBA components of self, if self is represented internally
/// in a RGB-compatible color scheme, or the error value
/// ColorSpaceError.incompatibleColorSpace if not.
///
public func rgbaComponents() -> Result<RGBAComponents, ColorSpaceError>
// MARK: - HSBA
/// Returns a new instance of UIColor in the HSB color space, with random
/// values for its color coordinates (hue, saturation, brightness), but
/// with its opacity (alpha) set to the argument passed in (whose default
/// value is 1).
///
public static func randomHSB(alpha: CGFloat = 1) -> UIColor
/// Returns a new instance of UIColor in the HSB color space, with random
/// values for all of its color coordinates (hue, saturation, brightness,
/// alpha).
///
public static func randomHSBA() -> UIColor
/// Returns a new instance of UIColor in the HSB color space, with random
/// values for its color coordinates (hue, saturation, brightness), but
/// with its opacity (alpha) set to the argument passed in (whose default
/// value is 1), and using a particular random number generator.
///
public static func randomHSB <RNG: RandomNumberGenerator> (
alpha: CGFloat = 1,
using rng: inout RNG
) -> UIColor
/// Returns a new instance of UIColor in the HSB color space, with random
/// values for all of its color coordinates (hue, saturation, brightness,
/// alpha), using a particular random number generator.
///
public static func randomHSBA <RNG: RandomNumberGenerator> (
using rng: inout RNG
) -> UIColor
/// Returns the HSBA components of self, if self is represented internally
/// in a HSB-compatible color scheme, or the error value
/// ColorSpaceError.incompatibleColorSpace if not.
///
public func hsbaComponents() -> Result<HSBAComponents, ColorSpaceError>
// MARK: - White, Alpha
/// Returns a new instance of UIColor in the Grayscale color space, with
/// random values for its white color coordinate, but with its opacity
/// (alpha) set to the argument passed in (whose default value is 1).
///
public static func randomWhite(alpha: CGFloat = 1) -> UIColor
/// Returns a new instance of UIColor in the Grayscale color space, with
/// random values for both of its color coordinates (white, alpha).
///
public static func randomWhiteAndAlpha() -> UIColor
/// Returns a new instance of UIColor in the Grayscale color space, with
/// random values for its white color coordinate, but with its opacity
/// (alpha) set to the argument passed in (whose default value is 1), and
/// using a particular random number generator.
///
public static func randomWhite <RNG: RandomNumberGenerator> (
alpha: CGFloat = 1,
using rng: inout RNG
) -> UIColor
/// Returns a new instance of UIColor in the Grayscale color space, with
/// random values for both of its color coordinates (white, alpha), using a
/// particular random number generator.
///
public static func randomWhiteAndAlpha <RNG: RandomNumberGenerator> (
using rng: inout RNG
) -> UIColor
/// Returns the white and alpha components of self, if self is represented
/// internally in a Grayscale-compatible color scheme, or the error value
/// ColorSpaceError.incompatibleColorSpace if not.
///
public func whiteAlphaComponents() -> Result<WhiteAlphaComponents, ColorSpaceError>
// MARK: - Luminance
/// Returns an approximate value for the luminance of an RGB color.
///
/// See http://gamedev.stackexchange.com/questions/38536/given-a-rgb-color-x-how-to-find-the-most-contrasting-color-y
///
public static func quadraticLuma(red: CGFloat, green: CGFloat, blue: CGFloat) -> CGFloat
/// Returns an approximate value for the luminance of an RGB color.
///
/// See http://gamedev.stackexchange.com/questions/38536/given-a-rgb-color-x-how-to-find-the-most-contrasting-color-y
///
public func quadraticLuma() -> Result<CGFloat, ColorSpaceError>
// MARK: - Contrast
/// Returns a color that contrasts well with self.
///
/// See http://gamedev.stackexchange.com/questions/38536/given-a-rgb-color-x-how-to-find-the-most-contrasting-color-y
///
/// - Parameters:
///
/// - continuous: when true, the resulting color is some shade of gray
/// ranging from white to black; when false, the resulting color is either
/// white or black, depending on a luminance threshold. The default
/// behaviour is to result in a continuous shade of gray.
///
/// - threshold: ignored when continuous is set to true, otherwise used to
/// decide whether the resulting color is white or black. The result is
/// black when self has a luminance larger than this threshold, else the
/// result if white. The default threshold value is 0.2.
///
/// - sameAlpha: when true, the resulting color has the same alpha
/// component as self, otherwise it has alpha equal to 1. The default is
/// false so the resulting color has alpha equal to 1.
///
/// - Returns: a color that contrasts well with self.
///
public func contrastingColor(
continuous: Bool = true,
threshold: CGFloat = 0.2,
sameAlpha: Bool = false
) -> Result<UIColor, ColorSpaceError>
}ColorExtensions is provided only as a Swift Package Manager package, because I'm moving away from CocoaPods and Carthage, and can be easily installed directly from Xcode.
ColorExtensions is available under the MIT license. See the LICENSE file for more info.