Extracted the in-app notifications from the Sample app target into its own Notifying package target.

2026-07-05 13:33:07 +02:00
parent 6bcb88c944
commit 59b0237638
8 changed files with 278 additions and 106 deletions
@@ -0,0 +1,55 @@
+import Foundation
+
+/// A transient in-app notification, posted and dismissed by a ``Notifier``.
+public struct AppNotification: Equatable, Identifiable, Sendable {
+
+    // MARK: Properties
+
+    /// The unique identifier of the notification.
+    public let id: UUID
+
+    /// The kind of the notification, driving its visual weight.
+    public let kind: Kind
+
+    /// The localized message of the notification.
+    public let message: String
+
+    /// The system symbol of the notification's icon.
+    public let symbol: String
+
+    // MARK: Initializers
+
+    /// Creates a notification of a given kind, with a localized message and a system symbol.
+    ///
+    /// - Parameters:
+    ///   - id: The unique identifier of the notification. Defaults to a newly generated identifier.
+    ///   - kind: The kind of the notification.
+    ///   - message: The localized message of the notification.
+    ///   - symbol: The system symbol of the notification's icon.
+    public init(
+        id: UUID = .init(),
+        kind: Kind,
+        message: String,
+        symbol: String
+    ) {
+        self.id = id
+        self.kind = kind
+        self.message = message
+        self.symbol = symbol
+    }
+
+}
+
+// MARK: - Enumerations
+
+extension AppNotification {
+    /// The kind of a notification, driving its visual weight.
+    public enum Kind: Sendable {
+        /// The notification reports an error.
+        case error
+        /// The notification reports an informational event.
+        case info
+        /// The notification reports a warning.
+        case warning
+    }
+}
@@ -0,0 +1,143 @@
+import SwiftUI
+
+/// The label style for the transient in-app notification banners.
+///
+/// The style renders the label's icon next to its title, over a padded, capsule Liquid Glass background. The icon is tinted with a color
+/// matching the kind of notification given at initialization — green for an informational one, yellow for a warning, and red for an
+/// error — and the title wears a medium-weight callout font.
+public struct NotificationLabelStyle: LabelStyle {
+
+    // MARK: Properties
+
+    /// The kind of notification whose matching color tints the label's icon.
+    private let kind: AppNotification.Kind
+
+    // MARK: Initializers
+
+    /// Creates a notification label style for a given kind of notification.
+    ///
+    /// - Parameter kind: The kind of notification whose matching color tints the label's icon.
+    public init(
+        kind: AppNotification.Kind
+    ) {
+        self.kind = kind
+    }
+
+    // MARK: Methods
+
+    /// Creates the styled body of the label.
+    ///
+    /// - Parameter configuration: The properties of the label being styled.
+    public func makeBody(
+        configuration: Configuration
+    ) -> some View {
+        HStack(
+            spacing: Constant.Spacing.stack
+        ) {
+            configuration.icon
+                .font(.title3)
+                .foregroundStyle(kind.imageStyle)
+
+            configuration.title
+                .font(.callout)
+                .fontWeight(.medium)
+                .foregroundStyle(.primary)
+        }
+        .padding(.vertical, Constant.Padding.vertical)
+        .padding(.horizontal, Constant.Padding.horizontal)
+        .glassEffect(
+            .regular,
+            in: .capsule
+        )
+    }
+
+}
+
+// MARK: - Styles
+
+public extension LabelStyle where Self == NotificationLabelStyle {
+
+    /// The label style for the transient in-app notification banners.
+    ///
+    /// - Parameter kind: The kind of notification whose matching color tints the label's icon.
+    /// - Returns: A notification label style for the given kind of notification.
+    static func notification(
+        kind: AppNotification.Kind
+    ) -> NotificationLabelStyle {
+        .init(kind: kind)
+    }
+
+}
+
+// MARK: - AppNotification.Kind+Properties
+
+private extension AppNotification.Kind {
+
+    /// The color that tints the icon of a notification label: green for an informational notification, yellow for a warning, and red
+    /// for an error.
+    var imageStyle: Color {
+        switch self {
+        case .error: .red
+        case .info: .green
+        case .warning: .yellow
+        }
+    }
+
+}
+
+// MARK: - Constants
+
+/// The constant values used across the label style.
+private enum Constant {
+    /// The padding constants.
+    enum Padding {
+        /// The horizontal padding between a label's content and its background.
+        static let horizontal: CGFloat = 16
+        /// The vertical padding between a label's content and its background.
+        static let vertical: CGFloat = 8
+    }
+
+    /// The spacing constants.
+    enum Spacing {
+        /// The spacing between the elements of a stack.
+        static let stack: CGFloat = 16
+    }
+}
+
+// MARK: - Previews
+
+#Preview(
+    "Notification label style"
+) {
+    VStack(
+        alignment: .leading,
+        spacing: 16
+    ) {
+        Label {
+            Text(verbatim: "Downloading the speech model for Dutch (Netherlands)…")
+        } icon: {
+            Image(systemName: "arrow.down.circle")
+        }
+        .labelStyle(.notification(
+            kind: .info
+        ))
+
+        Label {
+            Text(verbatim: "The speech model download for Dutch (Netherlands) was cancelled.")
+        } icon: {
+            Image(systemName: "xmark.circle")
+        }
+        .labelStyle(.notification(
+            kind: .warning
+        ))
+
+        Label {
+            Text(verbatim: "The speech model for German (Germany) could not be downloaded.")
+        } icon: {
+            Image(systemName: "exclamationmark.triangle")
+        }
+        .labelStyle(.notification(
+            kind: .error
+        ))
+    }
+}
@@ -0,0 +1,65 @@
+import Accessibility
+import Foundation
+import Observation
+
+/// The observable model that owns the lifecycle of the transient in-app notifications.
+///
+/// Posting a notification appends it to ``notifications``, announces its message to assistive technologies — since the visual
+/// banners are transient — and schedules its automatic dismissal a few seconds later, which is the only way a notification is
+/// dismissed.
+@MainActor
+@Observable
+public final class Notifier {
+
+    // MARK: Properties
+
+    /// The notifications currently presented, in post order.
+    public private(set) var notifications: [AppNotification] = []
+
+    /// The time a posted notification stays visible before its automatic dismissal.
+    @ObservationIgnored
+    private let delayDismissal: Duration
+
+    // MARK: Initializers
+
+    /// Creates a notifier.
+    ///
+    /// - Parameter delayDismissal: The time a posted notification stays visible before its automatic dismissal.
+    /// Defaults to four seconds.
+    public init(
+        delayDismissal: Duration = .seconds(4)
+    ) {
+        self.delayDismissal = delayDismissal
+    }
+
+    // MARK: Methods
+
+    /// Posts a notification, announcing its message to assistive technologies and scheduling its automatic dismissal.
+    ///
+    /// - Parameters:
+    ///   - kind: The kind of the notification.
+    ///   - message: The localized message of the notification.
+    ///   - symbol: The system symbol of the notification's icon.
+    public func post(
+        _ kind: AppNotification.Kind,
+        message: String,
+        symbol: String
+    ) {
+        let notification = AppNotification(
+            kind: kind,
+            message: message,
+            symbol: symbol
+        )
+
+        notifications.append(notification)
+
+        AccessibilityNotification.Announcement(message).post()
+
+        Task {
+            try? await Task.sleep(for: delayDismissal)
+
+            notifications.removeAll { $0.id == notification.id }
+        }
+    }
+
+}