Implement RedactionReasons

Author: Kyle-Ye

Sources/OpenSwiftUICore/Data/EnvironmentKeys/RedactionReasons.swift

@@ -3,16 +3,111 @@
 //  OpenSwiftUICore
 //
 //  Audited for 6.5.4
-//  Status: WIP
+//  Status: Blocked by Image
 //  ID: 18671928047E57F039DC339288B6FAFB (SwiftUICore)
 
+// MARK: - RedactionReasons
+
+/// The reasons to apply a redaction to data displayed on screen.
+@available(OpenSwiftUI_v2_0, *)
+public struct RedactionReasons: OptionSet, Sendable {
+    public let rawValue: Int
+
+    public init(rawValue: Int) {
+        self.rawValue = rawValue
+    }
+
+    /// Displayed data should appear as generic placeholders.
+    ///
+    /// Text and images will be automatically masked to appear as
+    /// generic placeholders, though maintaining their original size and shape.
+    /// Use this to create a placeholder UI without directly exposing
+    /// placeholder data to users.
+    public static let placeholder: RedactionReasons = .init(rawValue: 1 << 0)
+
+    /// Displayed data should be obscured to protect private information.
+    ///
+    /// Views marked with `privacySensitive` will be automatically redacted
+    /// using a standard styling. To apply a custom treatment the redaction
+    /// reason can be read out of the environment.
+    ///
+    ///     struct BankingContentView: View {
+    ///         @Environment(\.redactionReasons) var redactionReasons
+    ///
+    ///         var body: some View {
+    ///             if redactionReasons.contains(.privacy) {
+    ///                 FullAppCover()
+    ///             } else {
+    ///                 AppContent()
+    ///             }
+    ///         }
+    ///     }
+    @available(OpenSwiftUI_v3_0, *)
+    public static let privacy: RedactionReasons = .init(rawValue: 1 << 1)
+
+    /// Displayed data should appear as invalidated and pending a new update.
+    ///
+    /// Views marked with `invalidatableContent` will be automatically
+    /// redacted with a standard styling indicating the content is invalidated
+    /// and new content will be available soon.
+    @available(OpenSwiftUI_v5_0, *)
+    public static let invalidated: RedactionReasons = .init(rawValue: 1 << 2)
+
+    @_spi(Private)
+    @available(OpenSwiftUI_v6_0, *)
+    public static let screencaptureProhibited: RedactionReasons = .init(rawValue: 1 << 3)
+}
+
+// MARK: - View + redacted
+
+@available(OpenSwiftUI_v2_0, *)
+extension View {
+
+    /// Adds a reason to apply a redaction to this view hierarchy.
+    ///
+    /// Adding a redaction is an additive process: any redaction
+    /// provided will be added to the reasons provided by the parent.
+    nonisolated public func redacted(reason: RedactionReasons) -> some View {
+        transformEnvironment(\.redactionReasons) {
+            $0.insert(reason)
+        }
+    }
+
+    /// Removes any reason to apply a redaction to this view hierarchy.
+    nonisolated public func unredacted() -> some View {
+        environment(\.redactionReasons, [])
+    }
+}
+
 // MARK: - EnvironmentValues + RedactionReasons
 
-// TODO
+private struct RedactionReasonsKey: EnvironmentKey {
+    static let defaultValue: RedactionReasons = []
+}
+
 private struct ShouldRedactContentKey: DerivedEnvironmentKey {
     static func value(in environment: EnvironmentValues) -> Bool {
-        // redaction
-        false
+        let redactionReasons = environment.redactionReasons
+        if redactionReasons.contains(.placeholder) {
+            return true
+        } else if redactionReasons.contains(.privacy) {
+            return environment.sensitiveContent
+        } else {
+            return false
+        }
+    }
+}
+
+private struct UnredactSymbolImage: EnvironmentKey {
+    static let defaultValue: Bool = false
+}
+
+private struct ShouldRedactSymbolImagesKey: DerivedEnvironmentKey {
+    static func value(in environment: EnvironmentValues) -> Bool {
+        guard environment.shouldRedactContent else {
+            return false
+        }
+        return !environment.unredactSymbolImage
     }
 }
 
@@ -21,3 +116,41 @@ extension EnvironmentValues {
         self[ShouldRedactContentKey.self]
     }
 }
+
+@_spi(Private)
+@available(OpenSwiftUI_v6_0, *)
+extension EnvironmentValues {
+
+    public var unredactSymbolImage: Bool {
+        get { self[UnredactSymbolImage.self] }
+        set { self[UnredactSymbolImage.self] = newValue }
+    }
+
+    package var shouldRedactSymbolImages: Bool {
+        self[ShouldRedactSymbolImagesKey.self]
+    }
+}
+
+@available(OpenSwiftUI_v2_0, *)
+extension EnvironmentValues {
+
+    /// The current redaction reasons applied to the view hierarchy.
+    public var redactionReasons: RedactionReasons {
+        get { self[RedactionReasonsKey.self] }
+        set { self[RedactionReasonsKey.self] = newValue }
+    }
+}
+
+// MARK: - Image + redacted [TODO]
+
+extension GraphicsImage {
+    package mutating func redact(in environment: EnvironmentValues) {
+        _openSwiftUIUnimplementedFailure()
+    }
+}
+
+extension Image {
+    package static let redacted: Image = {
+        _openSwiftUIUnimplementedFailure()
+    }()
+}

Sources/OpenSwiftUICore/Data/EnvironmentKeys/SensitiveContent.swift

@@ -0,0 +1,18 @@
+//
+//  SensitiveContent.swift
+//  OpenSwiftUICore
+//
+//  Audited for 6.5.4
+//  Status: WIP
+//  ID: 7799685610985DBA9248562F2E4D5E6E (SwiftUICore?)
+
+private struct SensitiveContentKey: EnvironmentKey {
+    static let defaultValue: Bool = false
+}
+
+extension EnvironmentValues {
+    package var sensitiveContent: Bool {
+        get { self[SensitiveContentKey.self] }
+        set { self[SensitiveContentKey.self] = newValue }
+    }
+}