🌈 Color darken/lighten modifiers

Flowductive · Feb 3, 2022 · 2606265 · 2606265
1 parent 09f2c10
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diff --git a/Sources/ShinySwiftUI/Extensions/SwiftUI/Color.swift b/Sources/ShinySwiftUI/Extensions/SwiftUI/Color.swift
@@ -10,6 +10,8 @@ import SwiftUI
 @available(macOS 11.0, iOS 13.0, *)
 public extension Color {
 
+  // MARK: - Public Methods
+
   /**
    Sets the opacity of the color.
 
@@ -20,3 +22,86 @@ public extension Color {
     return self.opacity(Double(level.rawValue))
   }
 }
+
+@available(macOS 11.0, iOS 14.0, *)
+public extension Color {
+
+  // MARK: - Public Methods
+
+  /**
+   Makes the color lighter.
+
+   - parameter amount: The amount to lighten. Use `0.0` for no lightness and `1.0` for white.
+   */
+  func lighter(by amount: CGFloat = 0.2) -> Self { Self(_Color(self).lighter(by: amount)) }
+
+  /**
+   Makes the color darker.
+
+   - parameter amount: The amount to darken. Use `0.0` for no darkness and `1.0` for black.
+   */
+  func darker(by amount: CGFloat = 0.2) -> Self { Self(_Color(self).darker(by: amount)) }
+}
+
+#if os(iOS)
+
+fileprivate typealias _Color = UIColor
+fileprivate extension UIColor {
+
+  func mix(with color: UIColor, amount: CGFloat) -> Self {
+    var red1: CGFloat = 0
+    var green1: CGFloat = 0
+    var blue1: CGFloat = 0
+    var alpha1: CGFloat = 0
+
+    var red2: CGFloat = 0
+    var green2: CGFloat = 0
+    var blue2: CGFloat = 0
+    var alpha2: CGFloat = 0
+
+    getRed(&red1, green: &green1, blue: &blue1, alpha: &alpha1)
+    color.getRed(&red2, green: &green2, blue: &blue2, alpha: &alpha2)
+
+    return Self(
+      red: red1 * CGFloat(1.0 - amount) + red2 * amount,
+      green: green1 * CGFloat(1.0 - amount) + green2 * amount,
+      blue: blue1 * CGFloat(1.0 - amount) + blue2 * amount,
+      alpha: alpha1
+    )
+  }
+
+  func lighter(by amount: CGFloat = 0.2) -> Self { mix(with: .white, amount: amount) }
+  func darker(by amount: CGFloat = 0.2) -> Self { mix(with: .black, amount: amount) }
+}
+
+#elseif os(macOS)
+
+fileprivate typealias _Color = NSColor
+fileprivate extension NSColor {
+  func mix(with color: NSColor, amount: CGFloat) -> Self {
+    var red1: CGFloat = 0
+    var green1: CGFloat = 0
+    var blue1: CGFloat = 0
+    var alpha1: CGFloat = 0
+
+    var red2: CGFloat = 0
+    var green2: CGFloat = 0
+    var blue2: CGFloat = 0
+    var alpha2: CGFloat = 0
+
+    getRed(&red1, green: &green1, blue: &blue1, alpha: &alpha1)
+    color.getRed(&red2, green: &green2, blue: &blue2, alpha: &alpha2)
+
+    return Self(
+      red: red1 * CGFloat(1.0 - amount) + red2 * amount,
+      green: green1 * CGFloat(1.0 - amount) + green2 * amount,
+      blue: blue1 * CGFloat(1.0 - amount) + blue2 * amount,
+      alpha: alpha1
+    )
+  }
+
+  func lighter(by amount: CGFloat = 0.2) -> Self { mix(with: .white, amount: amount) }
+  func darker(by amount: CGFloat = 0.2) -> Self { mix(with: .black, amount: amount) }
+}
+
+#endif
diff --git a/Sources/ShinySwiftUI/Extensions/UIKit/UIDevice.swift b/Sources/ShinySwiftUI/Extensions/UIKit/UIDevice.swift
@@ -5,6 +5,7 @@
 //  Created by Ben Myers on 2/3/22.
 //
 
+#if os(iOS)
 import UIKit
 
 public extension UIDevice {
@@ -20,3 +21,5 @@ public extension UIDevice {
       }
   }
 }
+
+#endif