Use custom UITraitDefinition on iOS 17

Tusker/Preferences/Colors.swift

@@ -81,13 +81,30 @@ extension Color {
     static let appFill = Color(uiColor: .appFill)
 }
 
+@available(iOS, obsoleted: 17.0)
 private let traitsKey: String = ["Traits", "Defined", "client", "_"].reversed().joined()
+@available(iOS, obsoleted: 17.0)
 private let key = "tusker_usePureBlackDarkMode"
 
+@available(iOS 17.0, *)
+private struct PureBlackDarkModeTrait: UITraitDefinition {
+    static let defaultValue = true
+    static let affectsColorAppearance = true
+}
+
 extension UITraitCollection {
     var pureBlackDarkMode: Bool {
+        if #available(iOS 17.0, *) {
+            return self[PureBlackDarkModeTrait.self]
+        } else {
+            return obsoletePureBlackDarkMode
+        }
+    }
+    
+    @available(iOS, obsoleted: 17.0)
+    var obsoletePureBlackDarkMode: Bool {
         get {
-            // default to true to mach OS behavior
+            // default to true to match OS behavior
             (value(forKey: traitsKey) as? [String: Any])?[key] as? Bool ?? true
         }
         set {
@@ -98,7 +115,19 @@ extension UITraitCollection {
     }
     
     convenience init(pureBlackDarkMode: Bool) {
+        if #available(iOS 17.0, *) {
+            self.init(PureBlackDarkModeTrait.self, value: pureBlackDarkMode)
+        } else {
             self.init()
-        self.pureBlackDarkMode = pureBlackDarkMode
+            self.obsoletePureBlackDarkMode = pureBlackDarkMode
+        }
+    }
+}
+
+@available(iOS 17.0, *)
+extension UIMutableTraits {
+    var pureBlackDarkMode: Bool {
+        get { self[PureBlackDarkModeTrait.self] }
+        set { self[PureBlackDarkModeTrait.self] = newValue }
     }
 }

Tusker/Scenes/TuskerSceneDelegate.swift

@@ -32,6 +32,9 @@ extension TuskerSceneDelegate {
         guard let window else { return }
         window.overrideUserInterfaceStyle = Preferences.shared.theme
         window.tintColor = Preferences.shared.accentColor.color
+        if #available(iOS 17.0, *) {
+            window.traitOverrides.pureBlackDarkMode = Preferences.shared.pureBlackDarkMode
+        } else {
             let exception = catchNSException {
                 let key = ["Controller", "Presentation", "root", "_"].reversed().joined()
                 if let rootPresentationController = window.value(forKey: key) as? UIPresentationController {
@@ -42,4 +45,5 @@ extension TuskerSceneDelegate {
                 SentrySDK.capture(exception: exception)
             }
         }
+    }
 }

Tusker/Screens/Report/ReportAddStatusView.swift

@@ -76,8 +76,14 @@ private struct ScrollBackgroundModifier: ViewModifier {
                     // otherwise the pureBlackDarkMode isn't propagated, for some reason?
                     // even though it is for ReportSelectRulesView??
                     let traits: UITraitCollection = {
-                        let t = UITraitCollection(userInterfaceStyle: colorScheme == .dark ? .dark : .light)
+                        var t = UITraitCollection(userInterfaceStyle: colorScheme == .dark ? .dark : .light)
-                        t.pureBlackDarkMode = true
+                        if #available(iOS 17.0, *) {
+                            t = t.modifyingTraits({ mutableTraits in
+                                mutableTraits.pureBlackDarkMode = true
+                            })
+                        } else {
+                            t.obsoletePureBlackDarkMode = true
+                        }
                         return t
                     }()
                     Color(uiColor: .appGroupedBackground.resolvedColor(with: traits))