feat: handle denied camera and microphone permissions (#1)

CLAUDE.md

@@ -24,4 +24,5 @@ A native macOS app that shows video from a capture device (camera / capture card
 - Settings live in `UserDefaults` (keys: `video`, `audio`, `autostart`, `autostartName`, `keepAwake`, `startFull`, `onTop`, `gravity`, `format.<id>`).
 - Add new strings through `NSLocalizedString` and to both `Localizable.strings` files.
 - Run `make check` before committing. Version is in `Config/Info.plist`; build number = commit count.
-- Commits: small, one per feature, with a `Co-Authored-By` line.
+- Work on a feature branch (`feature/<topic>`, `fix/<topic>`) and open a PR with `gh pr create`; do not commit straight to `main`.
+- Commits follow [Conventional Commits](https://www.conventionalcommits.org), in English: `feat:`, `fix:`, `docs:`, `refactor:`, `build:`, `chore:` (optional scope, e.g. `feat(menu):`), imperative subject under ~72 chars. Small, one per change, with a `Co-Authored-By` line.

Resources/en.lproj/Localizable.strings

@@ -23,3 +23,6 @@
 "Autostart" = "Autostart";
 "(not connected)" = "(not connected)";
 "About Second Display" = "About Second Display";
+"Camera access denied" = "Camera access denied";
+"Allow camera access for Second Display in System Settings > Privacy & Security > Camera, then launch it again." = "Allow camera access for Second Display in System Settings > Privacy & Security > Camera, then launch it again.";
+"Microphone access denied. Enable it in System Settings." = "Microphone access denied. Enable it in System Settings.";

Resources/pl.lproj/Localizable.strings

@@ -23,3 +23,6 @@
 "Autostart" = "Autostart";
 "(not connected)" = "(niepodłączone)";
 "About Second Display" = "O programie Second Display";
+"Camera access denied" = "Brak dostępu do kamery";
+"Allow camera access for Second Display in System Settings > Privacy & Security > Camera, then launch it again." = "Zezwól Second Display na dostęp do kamery w Ustawieniach systemowych > Prywatność i ochrona > Kamera i uruchom aplikację ponownie.";
+"Microphone access denied. Enable it in System Settings." = "Brak dostępu do mikrofonu. Włącz go w Ustawieniach systemowych.";

Sources/App.swift

@@ -21,6 +21,13 @@ final class App: NSObject, NSApplicationDelegate {
             other.activate(); return NSApp.terminate(nil)
         }
         guard !videoDevices().isEmpty else { return quitNoDevices() }
+        AVCaptureDevice.requestAccess(for: .video) { granted in
+            DispatchQueue.main.async { granted ? self.start() : self.quitCameraDenied() }
+        }
+    }
+
+    // runs once camera access is granted
+    private func start() {
         window = NSWindow(contentRect: NSRect(x: 0, y: 0, width: 960, height: 540),
                           styleMask: [.titled, .closable, .miniaturizable, .resizable],
                           backing: .buffered, defer: false)
@@ -50,10 +57,8 @@ final class App: NSObject, NSApplicationDelegate {
 
         observeDevices()
 
-        AVCaptureDevice.requestAccess(for: .video) { _ in
-            AVCaptureDevice.requestAccess(for: .audio) { _ in
-                DispatchQueue.main.async { self.restore() }
-            }
+        AVCaptureDevice.requestAccess(for: .audio) { _ in
+            DispatchQueue.main.async { self.restore() }
         }
     }
 

Sources/Capture.swift

@@ -16,16 +16,26 @@ extension App {
         }
     }
 
-    func quitNoDevices() {
+    func quitWithError(_ title: String, _ info: String) {
         let alert = NSAlert()
         alert.alertStyle = .warning
-        alert.messageText = NSLocalizedString("No capture devices found", comment: "")
-        alert.informativeText = NSLocalizedString("Connect a camera or capture card and launch Second Display again.", comment: "")
+        alert.messageText = title
+        alert.informativeText = info
         alert.addButton(withTitle: "OK")
         NSApp.activate()
         alert.runModal()
         NSApp.terminate(nil)
     }
+    func quitNoDevices() {
+        quitWithError(NSLocalizedString("No capture devices found", comment: ""),
+                      NSLocalizedString("Connect a camera or capture card and launch Second Display again.", comment: ""))
+    }
+    func quitCameraDenied() {
+        quitWithError(NSLocalizedString("Camera access denied", comment: ""),
+                      NSLocalizedString("Allow camera access for Second Display in System Settings > Privacy & Security > Camera, then launch it again.", comment: ""))
+    }
+    // .notDetermined is not blocked: the prompt is still to come
+    var micBlocked: Bool { [.denied, .restricted].contains(AVCaptureDevice.authorizationStatus(for: .audio)) }
 
     // MARK: devices
     func videoDevices() -> [AVCaptureDevice] {
@@ -43,7 +53,7 @@ extension App {
             let preferred = [autostartID, defaults.string(forKey: "video")].compactMap { id in devices.first { $0.uniqueID == id } }
             if let d = preferred.first ?? devices.first { setVideo(d) }
         }
-        if audioInput == nil, let id = defaults.string(forKey: "audio"), let d = audioDevices().first(where: { $0.uniqueID == id }) {
+        if audioInput == nil, !micBlocked, let id = defaults.string(forKey: "audio"), let d = audioDevices().first(where: { $0.uniqueID == id }) {
             setAudio(d)
         }  // default: audio off until chosen
         if !session.isRunning { session.startRunning() }

Sources/Menu.swift

@@ -48,12 +48,17 @@ extension App: NSMenuDelegate {
             }
         } else if menu === audioMenu {
             menu.removeAllItems()
-            let off = NSMenuItem(title: NSLocalizedString("Off", comment: ""), action: #selector(pickAudio(_:)), keyEquivalent: "")
+            let pick = micBlocked ? nil : #selector(pickAudio(_:))  // no action = greyed out
+            if micBlocked {
+                menu.addItem(header(NSLocalizedString("Microphone access denied. Enable it in System Settings.", comment: "")))
+                menu.addItem(.separator())
+            }
+            let off = NSMenuItem(title: NSLocalizedString("Off", comment: ""), action: pick, keyEquivalent: "")
             off.target = self; off.state = audioInput == nil ? .on : .off
             menu.addItem(off)
             menu.addItem(.separator())
             for d in audioDevices() {
-                let it = NSMenuItem(title: d.localizedName, action: #selector(pickAudio(_:)), keyEquivalent: "")
+                let it = NSMenuItem(title: d.localizedName, action: pick, keyEquivalent: "")
                 it.target = self; it.representedObject = d
                 it.state = d.uniqueID == audioInput?.device.uniqueID ? .on : .off
                 menu.addItem(it)