Add: Lunar Support

DynamicIsland/DynamicIslandApp.swift

@@ -159,6 +159,9 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         windowSizeUpdateWorkItem?.cancel()
         NotificationCenter.default.removeObserver(self)
         extensionXPCServiceHost.stop()
+
+        // Restore Lunar's native OSD if integration was active
+        LunarManager.shared.appWillTerminate()
     }
     
     @objc func onScreenLocked(_: Notification) {
@@ -416,6 +419,9 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         // Setup BetterDisplay integration
         BetterDisplayManager.shared.configure(coordinator: coordinator)
 
+        // Setup Lunar integration
+        LunarManager.shared.configure(coordinator: coordinator)
+        
         // Setup ScreenRecording Manager
         if Defaults[.enableScreenRecordingDetection] {
             ScreenRecordingManager.shared.startMonitoring()

DynamicIsland/components/Settings/SettingsView.swift

@@ -740,6 +740,7 @@ struct SettingsView: View {
             SettingsSearchEntry(tab: .hudAndOSD, title: "Material", keywords: ["material", "frosted", "liquid", "glass", "solid", "osd"], highlightID: SettingsTab.hudAndOSD.highlightID(for: "Material")),
             SettingsSearchEntry(tab: .hudAndOSD, title: "Icon & Progress Color", keywords: ["color", "icon", "white", "black", "gray", "osd"], highlightID: SettingsTab.hudAndOSD.highlightID(for: "Icon & Progress Color")),
             SettingsSearchEntry(tab: .hudAndOSD, title: "BetterDisplay integration", keywords: ["betterdisplay", "external", "display", "brightness", "integration", "third party"], highlightID: SettingsTab.hudAndOSD.highlightID(for: "BetterDisplay integration")),
+            SettingsSearchEntry(tab: .hudAndOSD, title: "Lunar integration", keywords: ["lunar", "ddc", "external", "display", "brightness", "contrast", "integration", "third party"], highlightID: SettingsTab.hudAndOSD.highlightID(for: "Lunar integration")),
 
             // Media
             SettingsSearchEntry(tab: .media, title: "Music Source", keywords: ["media source", "controller"], highlightID: SettingsTab.media.highlightID(for: "Music Source")),
@@ -1495,6 +1496,7 @@ private struct HUDAndOSDSettingsView: View {
     @Default(.enableBrightnessHUD) var enableBrightnessHUD
     @Default(.enableKeyboardBacklightHUD) var enableKeyboardBacklightHUD
     @Default(.enableBetterDisplayIntegration) var enableBetterDisplayIntegration
+    @Default(.enableLunarIntegration) var enableLunarIntegration
     @Default(.verticalHUDShowValue) var verticalHUDShowValue
     @Default(.verticalHUDInteractive) var verticalHUDInteractive
     @Default(.verticalHUDHeight) var verticalHUDHeight
@@ -1730,7 +1732,7 @@ private struct HUDAndOSDSettingsView: View {
                 }
             case .vertical:
                 Form {
-                    if !accessibilityPermission.isAuthorized && !enableBetterDisplayIntegration {
+                    if !accessibilityPermission.isAuthorized && !enableBetterDisplayIntegration && !enableLunarIntegration {
                         Section {
                             SettingsPermissionCallout(
                                 message: "Accessibility permission is needed to intercept system controls for the Vertical HUD.",
@@ -1746,13 +1748,13 @@ private struct HUDAndOSDSettingsView: View {
                         }
                     }
 
-                    if accessibilityPermission.isAuthorized || enableBetterDisplayIntegration {
+                    if accessibilityPermission.isAuthorized || enableBetterDisplayIntegration || enableLunarIntegration {
                         Section {
                             Toggle("Volume HUD", isOn: $enableVolumeHUD)
                             Toggle("Brightness HUD", isOn: $enableBrightnessHUD)
                             Toggle("Keyboard Backlight HUD", isOn: $enableKeyboardBacklightHUD)
-                                .disabled(enableBetterDisplayIntegration)
-                                .help(enableBetterDisplayIntegration ? "Disabled while BetterDisplay integration is active — BetterDisplay uses Cmd+Brightness keys for its own controls." : "")
+                                .disabled(enableBetterDisplayIntegration || enableLunarIntegration)
+                                .help((enableBetterDisplayIntegration || enableLunarIntegration) ? "Disabled while external display integration is active — brightness keys are handled by the external app." : "")
                         } header: {
                             Text("Controls")
                         } footer: {
@@ -1847,7 +1849,7 @@ private struct HUDAndOSDSettingsView: View {
 
             case .circular:
                 Form {
-                    if !accessibilityPermission.isAuthorized && !enableBetterDisplayIntegration {
+                    if !accessibilityPermission.isAuthorized && !enableBetterDisplayIntegration && !enableLunarIntegration {
                         Section {
                             SettingsPermissionCallout(
                                 message: "Accessibility permission is needed to intercept system controls for the Circular HUD.",
@@ -1863,13 +1865,13 @@ private struct HUDAndOSDSettingsView: View {
                         }
                     }
 
-                    if accessibilityPermission.isAuthorized || enableBetterDisplayIntegration {
+                    if accessibilityPermission.isAuthorized || enableBetterDisplayIntegration || enableLunarIntegration {
                         Section {
                             Toggle("Volume HUD", isOn: $enableVolumeHUD)
                             Toggle("Brightness HUD", isOn: $enableBrightnessHUD)
                             Toggle("Keyboard Backlight HUD", isOn: $enableKeyboardBacklightHUD)
-                                .disabled(enableBetterDisplayIntegration)
-                                .help(enableBetterDisplayIntegration ? "Disabled while BetterDisplay integration is active — BetterDisplay uses Cmd+Brightness keys for its own controls." : "")
+                                .disabled(enableBetterDisplayIntegration || enableLunarIntegration)
+                                .help((enableBetterDisplayIntegration || enableLunarIntegration) ? "Disabled while external display integration is active — brightness keys are handled by the external app." : "")
                         } header: {
                             Text("Controls")
                         } footer: {
@@ -1909,8 +1911,8 @@ private struct HUDAndOSDSettingsView: View {
                 }
             }
 
-            // BetterDisplay Integration (shared across all HUD variants)
-            BetterDisplayIntegrationSection()
+            // Third-party display integrations (shared across all HUD variants)
+            ExternalDisplayIntegrationsSection()
         }
         .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .top)
         .background(paneBackgroundColor)
@@ -1924,93 +1926,175 @@ private struct HUDAndOSDSettingsView: View {
     }
 }
 
-// MARK: - BetterDisplay Integration Settings Section
+// MARK: - External Display Integrations Settings Section
 
-private struct BetterDisplayIntegrationSection: View {
+private struct ExternalDisplayIntegrationsSection: View {
     @Default(.enableBetterDisplayIntegration) var enableBetterDisplayIntegration
+    @Default(.enableLunarIntegration) var enableLunarIntegration
     @ObservedObject private var betterDisplayManager = BetterDisplayManager.shared
+    @ObservedObject private var lunarManager = LunarManager.shared
+
+    @State private var isBetterDisplayExpanded = false
+    @State private var isLunarExpanded = false
 
     private func highlightID(_ title: String) -> String {
         SettingsTab.hudAndOSD.highlightID(for: title)
     }
 
-    private var statusText: String {
-        if betterDisplayManager.isRunning {
-            return "Running"
-        } else if betterDisplayManager.isDetected {
-            return "Not running"
-        } else {
-            return "Not detected"
-        }
+    // MARK: BetterDisplay helpers
+
+    private var bdStatusText: String {
+        if betterDisplayManager.isRunning { return "Running" }
+        if betterDisplayManager.isDetected { return "Not running" }
+        return "Not detected"
     }
 
-    private var statusColor: Color {
-        if betterDisplayManager.isRunning {
-            return .green
-        } else if betterDisplayManager.isDetected {
-            return .orange
-        } else {
-            return .secondary
-        }
+    private var bdStatusColor: Color {
+        if betterDisplayManager.isRunning { return .green }
+        if betterDisplayManager.isDetected { return .orange }
+        return .secondary
+    }
+
+    // MARK: Lunar helpers
+
+    private var lunarStatusText: String {
+        if lunarManager.isConnected { return "Connected" }
+        if lunarManager.isRunning { return "Running" }
+        if lunarManager.isDetected { return "Not running" }
+        return "Not detected"
+    }
+
+    private var lunarStatusColor: Color {
+        if lunarManager.isConnected { return .green }
+        if lunarManager.isRunning { return .orange }
+        if lunarManager.isDetected { return .orange }
+        return .secondary
     }
 
     var body: some View {
         Form {
+            // MARK: - BetterDisplay
+
             Section {
-                HStack {
-                    VStack(alignment: .leading, spacing: 2) {
+                DisclosureGroup(isExpanded: $isBetterDisplayExpanded) {
+                    HStack {
+                        VStack(alignment: .leading, spacing: 2) {
+                            Text(bdStatusText)
+                                .font(.caption)
+                                .foregroundStyle(bdStatusColor)
+                        }
+                        Spacer()
+                        Toggle("", isOn: $enableBetterDisplayIntegration)
+                            .toggleStyle(.switch)
+                            .labelsHidden()
+                            .disabled(!betterDisplayManager.isDetected)
+                    }
+                    .settingsHighlight(id: highlightID("BetterDisplay integration"))
+
+                    if !betterDisplayManager.isDetected {
+                        Text("Install [BetterDisplay](https://betterdisplay.pro) to control external display brightness and volume through Atoll's HUD.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    } else if !betterDisplayManager.isRunning {
+                        Text("BetterDisplay is installed but not currently running. Launch BetterDisplay to enable integration.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    } else if enableBetterDisplayIntegration {
+                        Text("BetterDisplay OSD events will be routed through Atoll's active HUD style. Make sure BetterDisplay's OSD integration is enabled in its Settings › Application › Integration.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    } else {
+                        Text("Enable to route BetterDisplay's brightness and volume changes through Atoll's HUD instead of the system OSD.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    }
+
+                    if betterDisplayManager.isDetected {
+                        Button {
+                            betterDisplayManager.refreshDetectionStatus()
+                        } label: {
+                            Label("Refresh detection", systemImage: "arrow.clockwise")
+                                .font(.caption)
+                        }
+                        .buttonStyle(.link)
+                    }
+                } label: {
+                    HStack(spacing: 6) {
+                        Image(systemName: "display.2")
                         Text("BetterDisplay")
                             .font(.system(size: 13, weight: .medium))
-                        Text(statusText)
-                            .font(.caption)
-                            .foregroundStyle(statusColor)
                     }
-
-                    Spacer()
-
-                    Toggle("", isOn: $enableBetterDisplayIntegration)
-                        .toggleStyle(.switch)
-                        .labelsHidden()
-                        .disabled(!betterDisplayManager.isDetected)
-                }
-                .settingsHighlight(id: highlightID("BetterDisplay integration"))
-
-                if !betterDisplayManager.isDetected {
-                    Text("Install [BetterDisplay](https://betterdisplay.pro) to control external display brightness and volume through Atoll's HUD.")
-                        .font(.caption)
-                        .foregroundStyle(.secondary)
-                } else if !betterDisplayManager.isRunning {
-                    Text("BetterDisplay is installed but not currently running. Launch BetterDisplay to enable integration.")
-                        .font(.caption)
-                        .foregroundStyle(.secondary)
-                } else if enableBetterDisplayIntegration {
-                    Text("BetterDisplay OSD events will be routed through Atoll's active HUD style. Make sure BetterDisplay's OSD integration is enabled in its Settings › Application › Integration.")
-                        .font(.caption)
-                        .foregroundStyle(.secondary)
-                } else {
-                    Text("Enable to route BetterDisplay's brightness and volume changes through Atoll's HUD instead of the system OSD.")
-                        .font(.caption)
-                        .foregroundStyle(.secondary)
-                }
-
-                if betterDisplayManager.isDetected {
-                    Button {
-                        betterDisplayManager.refreshDetectionStatus()
-                    } label: {
-                        Label("Refresh detection", systemImage: "arrow.clockwise")
-                            .font(.caption)
-                    }
-                    .buttonStyle(.link)
-                }
-            } header: {
-                HStack(spacing: 6) {
-                    Image(systemName: "display.2")
-                    Text("BetterDisplay Integration")
                 }
             } footer: {
-                Text("When enabled, Atoll listens for OSD notifications from BetterDisplay and displays them using your selected HUD style above. This works alongside the existing media key interception — BetterDisplay handles external display controls while Atoll provides the visual feedback.")
-                    .foregroundStyle(.secondary)
-                    .font(.caption)
+                if isBetterDisplayExpanded {
+                    Text("When enabled, Atoll listens for OSD notifications from BetterDisplay and displays them using your selected HUD style above.")
+                        .foregroundStyle(.secondary)
+                        .font(.caption)
+                }
+            }
+
+            // MARK: - Lunar
+
+            Section {
+                DisclosureGroup(isExpanded: $isLunarExpanded) {
+                    HStack {
+                        VStack(alignment: .leading, spacing: 2) {
+                            Text(lunarStatusText)
+                                .font(.caption)
+                                .foregroundStyle(lunarStatusColor)
+                        }
+                        Spacer()
+                        Toggle("", isOn: $enableLunarIntegration)
+                            .toggleStyle(.switch)
+                            .labelsHidden()
+                            .disabled(!lunarManager.isDetected)
+                    }
+                    .settingsHighlight(id: highlightID("Lunar integration"))
+
+                    if !lunarManager.isDetected {
+                        Text("Install [Lunar](https://lunar.fyi) to control external display brightness, contrast, and volume through Atoll's HUD via DDC.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    } else if !lunarManager.isRunning {
+                        Text("Lunar is installed but not currently running. Launch Lunar to enable integration.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    } else if lunarManager.isConnected && enableLunarIntegration {
+                        Text("Connected to Lunar's DDC socket. Brightness, contrast, and volume adjustments will be shown through Atoll's HUD.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    } else if enableLunarIntegration {
+                        Text("Lunar is running but the socket connection is not yet established. It will connect automatically.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    } else {
+                        Text("Enable to route Lunar's DDC brightness, contrast, and volume changes through Atoll's HUD.")
+                            .font(.caption)
+                            .foregroundStyle(.secondary)
+                    }
+
+                    if lunarManager.isDetected {
+                        Button {
+                            lunarManager.refreshDetectionStatus()
+                        } label: {
+                            Label("Refresh detection", systemImage: "arrow.clockwise")
+                                .font(.caption)
+                        }
+                        .buttonStyle(.link)
+                    }
+                } label: {
+                    HStack(spacing: 6) {
+                        Image(systemName: "moon.fill")
+                        Text("Lunar")
+                            .font(.system(size: 13, weight: .medium))
+                    }
+                }
+            } footer: {
+                if isLunarExpanded {
+                    Text("When enabled, Atoll connects to Lunar's TCP socket and displays DDC brightness, contrast, and volume events using your selected HUD style above.")
+                        .foregroundStyle(.secondary)
+                        .font(.caption)
+                }
             }
         }
     }
@@ -2158,6 +2242,7 @@ struct HUD: View {
     @Default(.enableBrightnessHUD) var enableBrightnessHUD
     @Default(.enableKeyboardBacklightHUD) var enableKeyboardBacklightHUD
     @Default(.enableBetterDisplayIntegration) var enableBetterDisplayIntegration
+    @Default(.enableLunarIntegration) var enableLunarIntegration
     @Default(.systemHUDSensitivity) var systemHUDSensitivity
     @ObservedObject var coordinator = DynamicIslandViewCoordinator.shared
     @ObservedObject private var accessibilityPermission = AccessibilityPermissionStore.shared
@@ -2176,7 +2261,7 @@ struct HUD: View {
     
     var body: some View {
         Form {
-            if !hasAccessibilityPermission && !enableBetterDisplayIntegration {
+            if !hasAccessibilityPermission && !enableBetterDisplayIntegration && !enableLunarIntegration {
                 Section {
                     SettingsPermissionCallout(
                         message: "Accessibility permission lets Dynamic Island replace the native volume, brightness, and keyboard HUDs.",
@@ -2190,13 +2275,13 @@ struct HUD: View {
 
 
             
-            if enableSystemHUD && !Defaults[.enableCustomOSD] && (hasAccessibilityPermission || enableBetterDisplayIntegration) {
+            if enableSystemHUD && !Defaults[.enableCustomOSD] && (hasAccessibilityPermission || enableBetterDisplayIntegration || enableLunarIntegration) {
                 Section {
                     Toggle("Volume HUD", isOn: $enableVolumeHUD)
                     Toggle("Brightness HUD", isOn: $enableBrightnessHUD)
                     Toggle("Keyboard Backlight HUD", isOn: $enableKeyboardBacklightHUD)
-                        .disabled(enableBetterDisplayIntegration)
-                        .help(enableBetterDisplayIntegration ? "Disabled while BetterDisplay integration is active \u{2014} BetterDisplay uses Cmd+Brightness keys for its own controls." : "")
+                        .disabled(enableBetterDisplayIntegration || enableLunarIntegration)
+                        .help((enableBetterDisplayIntegration || enableLunarIntegration) ? "Disabled while external display integration is active \u{2014} brightness keys are handled by the external app." : "")
                 } header: {
                     Text("Controls")
                 } footer: {
@@ -6909,6 +6994,7 @@ struct CustomOSDSettings: View {
     @Default(.enableOSDBrightness) var enableOSDBrightness
     @Default(.enableOSDKeyboardBacklight) var enableOSDKeyboardBacklight
     @Default(.enableBetterDisplayIntegration) var enableBetterDisplayIntegration
+    @Default(.enableLunarIntegration) var enableLunarIntegration
     @Default(.osdMaterial) var osdMaterial
     @Default(.osdLiquidGlassCustomizationMode) var osdLiquidGlassCustomizationMode
     @Default(.osdLiquidGlassVariant) var osdLiquidGlassVariant
@@ -6951,7 +7037,7 @@ struct CustomOSDSettings: View {
     
     var body: some View {
         Form {
-            if !hasAccessibilityPermission && !enableBetterDisplayIntegration {
+            if !hasAccessibilityPermission && !enableBetterDisplayIntegration && !enableLunarIntegration {
                 Section {
                     SettingsPermissionCallout(
                         message: "Accessibility permission is needed to intercept system controls for the Custom OSD.",
@@ -6963,7 +7049,7 @@ struct CustomOSDSettings: View {
                 }
             }
 
-            if hasAccessibilityPermission || enableBetterDisplayIntegration {
+            if hasAccessibilityPermission || enableBetterDisplayIntegration || enableLunarIntegration {
                 Section {
                     Toggle("Volume OSD", isOn: $enableOSDVolume)
                         .settingsHighlight(id: highlightID("Volume OSD"))
@@ -6971,8 +7057,8 @@ struct CustomOSDSettings: View {
                         .settingsHighlight(id: highlightID("Brightness OSD"))
                     Toggle("Keyboard Backlight OSD", isOn: $enableOSDKeyboardBacklight)
                         .settingsHighlight(id: highlightID("Keyboard Backlight OSD"))
-                        .disabled(enableBetterDisplayIntegration)
-                        .help(enableBetterDisplayIntegration ? "Disabled while BetterDisplay integration is active \u{2014} BetterDisplay uses Cmd+Brightness keys for its own controls." : "")
+                        .disabled(enableBetterDisplayIntegration || enableLunarIntegration)
+                        .help((enableBetterDisplayIntegration || enableLunarIntegration) ? "Disabled while external display integration is active \u{2014} brightness keys are handled by the external app." : "")
                 } header: {
                     Text("Controls")
                 } footer: {

DynamicIsland/managers/LunarManager.swift

@@ -0,0 +1,505 @@
+/*
+ * Atoll (DynamicIsland)
+ * Copyright (C) 2024-2026 Atoll Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+@preconcurrency import Foundation
+import AppKit
+import Combine
+import Defaults
+import Network
+
+// MARK: - Lunar Display Data Model
+
+/// Matches the JSON structure streamed by Lunar's socket listener.
+struct LunarDisplayData: Codable {
+    var brightness: Float?
+    var contrast: Float?
+    var volume: Float?
+    var mute: Bool?
+    var nits: Float?
+    var display: Int
+}
+
+// MARK: - Lunar Control Category
+
+enum LunarControlCategory {
+    case brightness
+    case contrast
+    case volume
+}
+
+// MARK: - Lunar Manager
+
+/// Manages integration with the Lunar app (fyi.lunar.Lunar).
+///
+/// Responsibilities:
+/// - Detect whether Lunar is installed and running
+/// - Observe app launch / termination to connect / disconnect automatically
+/// - Connect to Lunar's TCP socket on localhost:23803 and listen for DDC changes
+/// - Route brightness / contrast / volume events to Atoll's HUD pipeline
+@MainActor
+final class LunarManager: ObservableObject {
+    static let shared = LunarManager()
+
+    /// Bundle identifier of the Lunar app.
+    nonisolated static let bundleID = "fyi.lunar.Lunar"
+
+    /// UserDefaults suite used by Lunar to store its API key.
+    private static let lunarDomain = "fyi.lunar.Lunar"
+    private static let apiKeyKey = "apiKey"
+
+    // MARK: Published state
+
+    /// Whether Lunar is currently detected (installed) on this machine.
+    @Published private(set) var isDetected: Bool = false
+
+    /// Whether Lunar is currently running.
+    @Published private(set) var isRunning: Bool = false
+
+    /// Whether the TCP socket connection to Lunar is active.
+    @Published private(set) var isConnected: Bool = false
+
+    // MARK: Private
+
+    private var connection: NWConnection?
+    private var workspaceLaunchObserver: NSObjectProtocol?
+    private var workspaceTermObserver: NSObjectProtocol?
+    private var cancellables = Set<AnyCancellable>()
+    private weak var coordinator: DynamicIslandViewCoordinator?
+
+    /// Reconnection back-off state.
+    private var reconnectTask: Task<Void, Never>?
+    private var reconnectAttempts: Int = 0
+    private static let maxReconnectAttempts = 5
+    private static let baseReconnectDelay: UInt64 = 2_000_000_000 // 2 seconds
+
+    private init() {
+        isDetected = Self.checkInstallation()
+        isRunning = Self.checkRunning()
+        setupWorkspaceObservers()
+        setupSettingsObserver()
+    }
+
+    // MARK: - Public API
+
+    /// Configure with the view coordinator for HUD dispatch.
+    func configure(coordinator: DynamicIslandViewCoordinator) {
+        self.coordinator = coordinator
+
+        if Defaults[.enableLunarIntegration] && isRunning {
+            connectToLunar()
+        }
+    }
+
+    /// Called when Atoll is about to quit so Lunar's native OSD is restored.
+    func appWillTerminate() {
+        setLunarHideOSD(false)
+    }
+
+    /// Refresh detection status (e.g. after manual check from Settings).
+    func refreshDetectionStatus() {
+        let wasRunning = isRunning
+        isDetected = Self.checkInstallation()
+        isRunning = Self.checkRunning()
+        if wasRunning && !isRunning {
+            disconnect()
+        } else if !wasRunning && isRunning && Defaults[.enableLunarIntegration] {
+            connectToLunar()
+        }
+    }
+
+    // MARK: - Detection
+
+    /// Check if Lunar is installed by looking for its bundle ID.
+    nonisolated static func checkInstallation() -> Bool {
+        if NSWorkspace.shared.runningApplications.contains(where: { $0.bundleIdentifier == bundleID }) {
+            return true
+        }
+        if let url = NSWorkspace.shared.urlForApplication(withBundleIdentifier: bundleID) {
+            return FileManager.default.fileExists(atPath: url.path)
+        }
+        return false
+    }
+
+    /// Check if Lunar is currently running.
+    nonisolated static func checkRunning() -> Bool {
+        NSWorkspace.shared.runningApplications.contains(where: { $0.bundleIdentifier == bundleID })
+    }
+
+    // MARK: - Socket Connection
+
+    private func connectToLunar() {
+        guard connection == nil else { return }
+        guard let apiKey = Self.retrieveAPIKey() else {
+            NSLog("⚠️ Lunar: failed to retrieve API key from UserDefaults suite '\(Self.lunarDomain)'")
+            return
+        }
+
+        setLunarHideOSD(true)
+
+        let host = NWEndpoint.Host("localhost")
+        let port = NWEndpoint.Port(23803)
+        let conn = NWConnection(host: host, port: port, using: .tcp)
+
+        conn.stateUpdateHandler = { [weak self] state in
+            Task { @MainActor in
+                self?.handleConnectionState(state, apiKey: apiKey)
+            }
+        }
+
+        connection = conn
+        conn.start(queue: DispatchQueue.global(qos: .utility))
+        NSLog("🌙 Lunar: connecting to socket on \(host):\(port)…")
+    }
+
+    private func disconnect() {
+        reconnectTask?.cancel()
+        reconnectTask = nil
+        reconnectAttempts = 0
+
+        if let conn = connection {
+            conn.stateUpdateHandler = nil
+            conn.cancel()
+            connection = nil
+        }
+        isConnected = false
+        setLunarHideOSD(false)
+        NSLog("⏹ Lunar: socket disconnected")
+    }
+
+    private func handleConnectionState(_ state: NWConnection.State, apiKey: String) {
+        switch state {
+        case .ready:
+            isConnected = true
+            reconnectAttempts = 0
+            NSLog("🌙 Lunar: connected to socket")
+            sendListenCommand(apiKey: apiKey)
+            receiveMessages()
+
+        case .failed(let error):
+            NSLog("🌙 Lunar: connection failed — \(error.localizedDescription)")
+            isConnected = false
+            connection?.cancel()
+            connection = nil
+            scheduleReconnect()
+
+        case .cancelled:
+            isConnected = false
+
+        case .waiting(let error):
+            NSLog("🌙 Lunar: connection waiting — \(error.localizedDescription)")
+
+        default:
+            break
+        }
+    }
+
+    /// Send Lunar's listen command with the API key.
+    private func sendListenCommand(apiKey: String) {
+        guard let conn = connection else { return }
+
+        let separator = String(UnicodeScalar(0x01))
+        let message = [apiKey, "listen", "--json", "--only-user-adjustments"]
+            .joined(separator: separator)
+
+        guard let data = message.data(using: .utf8) else {
+            NSLog("⚠️ Lunar: failed to encode listen command")
+            return
+        }
+
+        conn.send(content: data, completion: .contentProcessed { error in
+            if let error {
+                NSLog("⚠️ Lunar: failed to send listen command — \(error.localizedDescription)")
+            } else {
+                NSLog("🌙 Lunar: listen command sent")
+            }
+        })
+    }
+
+    /// Receive JSON messages from Lunar's socket in a loop.
+    private func receiveMessages() {
+        guard let conn = connection else { return }
+
+        conn.receive(minimumIncompleteLength: 1, maximumLength: 4096) { [weak self] data, _, isComplete, error in
+            if let data, !data.isEmpty {
+                Task { @MainActor in
+                    self?.handleReceivedData(data)
+                }
+            }
+
+            if isComplete {
+                NSLog("🌙 Lunar: stream ended")
+                Task { @MainActor in
+                    self?.isConnected = false
+                    self?.connection?.cancel()
+                    self?.connection = nil
+                    self?.scheduleReconnect()
+                }
+            } else if let error {
+                NSLog("⚠️ Lunar: receive error — \(error.localizedDescription)")
+                Task { @MainActor in
+                    self?.isConnected = false
+                    self?.connection?.cancel()
+                    self?.connection = nil
+                    self?.scheduleReconnect()
+                }
+            } else {
+                // Continue reading
+                Task { @MainActor in
+                    self?.receiveMessages()
+                }
+            }
+        }
+    }
+
+    private func handleReceivedData(_ data: Data) {
+        guard Defaults[.enableLunarIntegration], isRunning else { return }
+
+        do {
+            let displayData = try JSONDecoder().decode(LunarDisplayData.self, from: data)
+            NSLog("🌙 Lunar: display=\(displayData.display) brightness=\(displayData.brightness ?? -1) contrast=\(displayData.contrast ?? -1) volume=\(displayData.volume ?? -1) mute=\(displayData.mute.map(String.init) ?? "nil")")
+            routeToHUD(displayData)
+        } catch {
+            // Lunar may send multi-line JSON or partial data; try splitting by newlines
+            let rawString = String(data: data, encoding: .utf8) ?? ""
+            let lines = rawString.components(separatedBy: .newlines).filter { !$0.isEmpty }
+            for line in lines {
+                guard let lineData = line.data(using: .utf8) else { continue }
+                if let displayData = try? JSONDecoder().decode(LunarDisplayData.self, from: lineData) {
+                    NSLog("🌙 Lunar: display=\(displayData.display) brightness=\(displayData.brightness ?? -1) contrast=\(displayData.contrast ?? -1) volume=\(displayData.volume ?? -1)")
+                    routeToHUD(displayData)
+                }
+            }
+        }
+    }
+
+    // MARK: - HUD Routing
+
+    private func routeToHUD(_ data: LunarDisplayData) {
+        let targetScreen = resolveScreen(for: data.display)
+        let isExternal = isExternalDisplay(data.display)
+
+        // Nits-only events are informational (no user-facing HUD needed).
+        let hasActionableChange = data.brightness != nil || data.contrast != nil || data.volume != nil || data.mute != nil
+        guard hasActionableChange else { return }
+
+        // Brightness — values arrive in 0…1 range from Lunar
+        if let brightness = data.brightness {
+            let value = CGFloat(brightness)
+            let icon = isExternal ? "display" : ""
+            dispatchBrightnessHUD(value: value, icon: icon, onScreen: targetScreen)
+        }
+
+        // Contrast — show as brightness-style HUD with a contrast icon
+        if let contrast = data.contrast {
+            let value = CGFloat(contrast)
+            dispatchBrightnessHUD(value: value, icon: "circle.righthalf.filled", onScreen: targetScreen)
+        }
+
+        // Volume
+        if let volume = data.volume {
+            let value = CGFloat(volume)
+            let isMuted = data.mute ?? false
+            dispatchVolumeHUD(value: value, isMuted: isMuted, onScreen: targetScreen)
+        } else if let mute = data.mute {
+            // Mute toggle without a volume value
+            dispatchVolumeHUD(value: mute ? 0 : 1, isMuted: mute, onScreen: targetScreen)
+        }
+    }
+
+    // MARK: - HUD Dispatch (mirrors BetterDisplayManager / SystemChangesObserver logic)
+
+    private func dispatchVolumeHUD(value: CGFloat, isMuted: Bool, onScreen targetScreen: NSScreen? = nil) {
+        if HUDSuppressionCoordinator.shared.shouldSuppressVolumeHUD { return }
+
+        if Defaults[.enableCircularHUD] {
+            CircularHUDWindowManager.shared.show(type: .volume, value: value, onScreen: targetScreen)
+            return
+        }
+        if Defaults[.enableVerticalHUD] {
+            VerticalHUDWindowManager.shared.show(type: .volume, value: value, icon: "", onScreen: targetScreen)
+            return
+        }
+        if Defaults[.enableCustomOSD] && Defaults[.enableOSDVolume] {
+            CustomOSDWindowManager.shared.showVolume(value: value, onScreen: targetScreen)
+        }
+        if Defaults[.enableSystemHUD] && !Defaults[.enableCustomOSD] && !Defaults[.enableVerticalHUD] && !Defaults[.enableCircularHUD] {
+            coordinator?.toggleSneakPeek(
+                status: true,
+                type: .volume,
+                value: value,
+                icon: ""
+            )
+        }
+    }
+
+    private func dispatchBrightnessHUD(value: CGFloat, icon: String = "", onScreen targetScreen: NSScreen? = nil) {
+        if Defaults[.enableCircularHUD] {
+            CircularHUDWindowManager.shared.show(type: .brightness, value: value, icon: icon, onScreen: targetScreen)
+            return
+        }
+        if Defaults[.enableVerticalHUD] {
+            VerticalHUDWindowManager.shared.show(type: .brightness, value: value, icon: icon, onScreen: targetScreen)
+            return
+        }
+        if Defaults[.enableCustomOSD] && Defaults[.enableOSDBrightness] {
+            CustomOSDWindowManager.shared.showBrightness(value: value, icon: icon, onScreen: targetScreen)
+        }
+        if Defaults[.enableSystemHUD] && !Defaults[.enableCustomOSD] && !Defaults[.enableVerticalHUD] && !Defaults[.enableCircularHUD] {
+            coordinator?.toggleSneakPeek(
+                status: true,
+                type: .brightness,
+                value: value,
+                icon: icon
+            )
+        }
+    }
+
+    // MARK: - Helpers
+
+    /// Retrieve the Lunar API key from its UserDefaults suite.
+    nonisolated private static func retrieveAPIKey() -> String? {
+        UserDefaults(suiteName: lunarDomain)?.string(forKey: apiKeyKey)
+    }
+
+    /// Resolve a Lunar display ID (CGDirectDisplayID) to the matching NSScreen.
+    private func resolveScreen(for displayID: Int) -> NSScreen? {
+        let target = UInt32(displayID)
+        return NSScreen.screens.first { screen in
+            guard let num = screen.deviceDescription[NSDeviceDescriptionKey("NSScreenNumber")] as? NSNumber else { return false }
+            return num.uint32Value == target
+        }
+    }
+
+    /// Whether the given displayID refers to an external (non-built-in) display.
+    private func isExternalDisplay(_ displayID: Int) -> Bool {
+        CGDisplayIsBuiltin(UInt32(displayID)) == 0
+    }
+
+    // MARK: - Reconnection
+
+    private func scheduleReconnect() {
+        guard Defaults[.enableLunarIntegration], isRunning else { return }
+        guard reconnectAttempts < Self.maxReconnectAttempts else {
+            NSLog("🌙 Lunar: max reconnect attempts reached, giving up")
+            return
+        }
+
+        reconnectTask?.cancel()
+        let attempt = reconnectAttempts
+        reconnectAttempts += 1
+
+        let delay = Self.baseReconnectDelay * UInt64(1 << min(attempt, 3)) // exponential back-off, max 16s
+
+        reconnectTask = Task { @MainActor in
+            try? await Task.sleep(nanoseconds: delay)
+            guard !Task.isCancelled, self.isRunning, Defaults[.enableLunarIntegration] else { return }
+            NSLog("🌙 Lunar: reconnect attempt \(attempt + 1)/\(Self.maxReconnectAttempts)")
+            self.connectToLunar()
+        }
+    }
+
+    // MARK: - Workspace Observers (detect Lunar launch / quit)
+
+    private func setupWorkspaceObservers() {
+        let lunarBundleID = Self.bundleID
+
+        workspaceLaunchObserver = NSWorkspace.shared.notificationCenter.addObserver(
+            forName: NSWorkspace.didLaunchApplicationNotification,
+            object: nil,
+            queue: .main
+        ) { [weak self] notification in
+            guard let app = notification.userInfo?[NSWorkspace.applicationUserInfoKey] as? NSRunningApplication,
+                  app.bundleIdentifier == lunarBundleID
+            else { return }
+            Task { @MainActor in
+                NSLog("🟢 Lunar launched (pid: \(app.processIdentifier))")
+                self?.isDetected = true
+                self?.isRunning = true
+                self?.reconnectAttempts = 0
+                if Defaults[.enableLunarIntegration] {
+                    // Give Lunar a moment to start its socket server
+                    try? await Task.sleep(nanoseconds: 1_500_000_000)
+                    self?.connectToLunar()
+                }
+            }
+        }
+
+        workspaceTermObserver = NSWorkspace.shared.notificationCenter.addObserver(
+            forName: NSWorkspace.didTerminateApplicationNotification,
+            object: nil,
+            queue: .main
+        ) { [weak self] notification in
+            guard let app = notification.userInfo?[NSWorkspace.applicationUserInfoKey] as? NSRunningApplication,
+                  app.bundleIdentifier == lunarBundleID
+            else { return }
+            Task { @MainActor in
+                NSLog("🔴 Lunar terminated (pid: \(app.processIdentifier))")
+                self?.isRunning = false
+                self?.disconnect()
+            }
+        }
+    }
+
+    // MARK: - Settings Observer
+
+    private func setupSettingsObserver() {
+        Defaults.publisher(.enableLunarIntegration, options: [])
+            .sink { [weak self] change in
+                Task { @MainActor in
+                    guard let self else { return }
+                    if change.newValue && self.isRunning {
+                        self.connectToLunar()
+                    } else {
+                        self.disconnect()
+                    }
+                }
+            }
+            .store(in: &cancellables)
+    }
+
+    deinit {
+        // Restore Lunar's native OSD synchronously on teardown
+        LunarManager.writeLunarDefault(hideOSD: false)
+        connection?.cancel()
+        reconnectTask?.cancel()
+        if let workspaceLaunchObserver {
+            NSWorkspace.shared.notificationCenter.removeObserver(workspaceLaunchObserver)
+        }
+        if let workspaceTermObserver {
+            NSWorkspace.shared.notificationCenter.removeObserver(workspaceTermObserver)
+        }
+        cancellables.removeAll()
+    }
+
+    // MARK: - Lunar OSD Suppression
+
+    /// Tell Lunar to hide (or show) its own native OSD by writing to its UserDefaults.
+    private func setLunarHideOSD(_ hide: Bool) {
+        Self.writeLunarDefault(hideOSD: hide)
+    }
+
+    /// Synchronous, nonisolated helper so it can also be called from `deinit`.
+    nonisolated private static func writeLunarDefault(hideOSD hide: Bool) {
+        guard let defaults = UserDefaults(suiteName: lunarDomain) else {
+            NSLog("⚠️ Lunar: unable to open UserDefaults suite '\(lunarDomain)' to set hideOSD")
+            return
+        }
+        defaults.set(hide, forKey: "hideOSD")
+        NSLog("🌙 Lunar: hideOSD set to \(hide)")
+    }
+}

DynamicIsland/managers/SystemHUDManager.swift

@@ -188,6 +188,14 @@ class SystemHUDManager {
                 await self.startSystemObserver()
             }
         }.store(in: &cancellables)
+
+        // When Lunar integration toggled, restart observer to update brightness key interception
+        Defaults.publisher(.enableLunarIntegration, options: []).sink { [weak self] _ in
+            guard let self = self, self.isSetupComplete else { return }
+            Task { @MainActor in
+                await self.startSystemObserver()
+            }
+        }.store(in: &cancellables)
     }
     
     private var cancellables = Set<AnyCancellable>()
@@ -240,9 +248,9 @@ class SystemHUDManager {
             keyboardBacklightEnabled = Defaults[.enableKeyboardBacklightHUD]
         }
 
-        // When BetterDisplay integration is on, stop intercepting brightness and
-        // Cmd+Brightness keys so BetterDisplay receives them and sends OSD notifications.
-        if Defaults[.enableBetterDisplayIntegration] {
+        // When BetterDisplay or Lunar integration is on, stop intercepting brightness and
+        // Cmd+Brightness keys so the external app receives them and sends DDC/OSD events.
+        if Defaults[.enableBetterDisplayIntegration] || Defaults[.enableLunarIntegration] {
             brightnessEnabled = false
             keyboardBacklightEnabled = false
         }

DynamicIsland/models/Constants.swift

@@ -1030,6 +1030,9 @@ extension Defaults.Keys {
     // MARK: BetterDisplay Integration
     static let enableBetterDisplayIntegration = Key<Bool>("enableBetterDisplayIntegration", default: false)
 
+    // MARK: Lunar Integration
+    static let enableLunarIntegration = Key<Bool>("enableLunarIntegration", default: false)
+    
     static let hasSeenOSDAlphaWarning = Key<Bool>("hasSeenOSDAlphaWarning", default: false)
     static let enableOSDVolume = Key<Bool>("enableOSDVolume", default: true)
     static let enableOSDBrightness = Key<Bool>("enableOSDBrightness", default: true)