feat(mac): menu bar item with the running lecture

App/StudyAppApp.swift

@@ -18,6 +18,7 @@ struct StudyAppApp: App {
     @State private var examsViewModel: ExamsViewModel
     @State private var updater = AppUpdater()
     @AppStorage(ViewPreferences.appearanceKey) private var appearance = AppAppearance.standard
+    @AppStorage(ViewPreferences.showsMenuBarItemKey) private var showsMenuBarItem = true
 
     init() {
         do {
@@ -126,6 +127,29 @@ struct StudyAppApp: App {
             BackupCommands(viewModel: backupViewModel)
         }
 
+        MenuBarExtra(isInserted: menuBarItemInserted) {
+            MenuBarContent(
+                summary: menuBarSummary,
+                onOpenLecture: { moduleID in
+                    Self.bringToFront()
+                    navigation.show(module: moduleID, section: .slides, intent: .resumeSlides)
+                },
+                onReviewCards: {
+                    Self.bringToFront()
+                    // Starts with the module that has the most due cards, like „Lernen starten“ on Today.
+                    if let moduleID = todayViewModel.dueCounts.max(by: { $0.value < $1.value })?.key {
+                        navigation.show(module: moduleID, section: .flashcards)
+                    }
+                },
+                onOpenApp: { Self.bringToFront() }
+            )
+            .tint(Theme.accent)
+            .preferredColorScheme(appearance.colorScheme)
+        } label: {
+            MenuBarLabel(summary: menuBarSummary)
+        }
+        .menuBarExtraStyle(.window)
+
         Settings {
             SettingsView(
                 settings: container.preferences,
@@ -160,6 +184,29 @@ struct StudyAppApp: App {
         await notificationsViewModel.refresh()
     }
 
+    /// Keeps the menu bar item out of the unit test host: on CI runners its status item
+    /// blocks the launch, so the test runner never connects.
+    private var menuBarItemInserted: Binding<Bool> {
+        Binding(
+            get: { showsMenuBarItem && !Self.isRunningAsTestHost },
+            set: { showsMenuBarItem = $0 }
+        )
+    }
+
+    private static var isRunningAsTestHost: Bool {
+        ProcessInfo.processInfo.environment["XCTestConfigurationFilePath"] != nil
+    }
+
+    private var menuBarSummary: MenuBarSummary {
+        MenuBarSummary(calendar: calendarViewModel, dueCards: todayViewModel.totalDue)
+    }
+
+    /// Shows the main window, e.g. after a click in the menu bar.
+    private static func bringToFront() {
+        NSApplication.shared.activate()
+        NSApplication.shared.windows.first { $0.canBecomeMain }?.makeKeyAndOrderFront(nil)
+    }
+
     /// Opens what a clicked notification refers to.
     private static func open(_ target: NotificationTarget, navigation: AppNavigation) {
         NSApplication.shared.activate()

Presentation/MenuBar/MenuBarContent.swift

@@ -0,0 +1,73 @@
+import AppKit
+import SwiftUI
+
+/// The menu bar item's label: an icon, plus the remaining minutes while a lecture runs.
+struct MenuBarLabel: View {
+    let summary: MenuBarSummary
+
+    var body: some View {
+        if summary.title.isEmpty {
+            Image(systemName: "graduationcap")
+        } else {
+            Label(summary.title, systemImage: "record.circle")
+                .labelStyle(.titleAndIcon)
+        }
+    }
+}
+
+/// The window that opens from the menu bar item.
+struct MenuBarContent: View {
+    let summary: MenuBarSummary
+    let onOpenLecture: (UUID) -> Void
+    let onReviewCards: () -> Void
+    let onOpenApp: () -> Void
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            if let lecture = summary.lecture {
+                lectureSection(lecture)
+            } else {
+                Label("Heute keine Vorlesung mehr", systemImage: "calendar")
+                    .foregroundStyle(Theme.textSecondary)
+            }
+            Divider()
+            Button(action: onReviewCards) {
+                Label(
+                    summary.dueCards == 0 ? "Keine Karten fällig" : "\(summary.dueCards) Karten wiederholen",
+                    systemImage: "rectangle.stack"
+                )
+            }
+            .buttonStyle(.plain)
+            .disabled(summary.dueCards == 0)
+            Divider()
+            HStack {
+                Button("StudyApp öffnen", action: onOpenApp)
+                Spacer()
+                Button("Beenden") { NSApplication.shared.terminate(nil) }
+            }
+            .buttonStyle(.link)
+        }
+        .padding(14)
+        .frame(width: 280)
+    }
+
+    private func lectureSection(_ lecture: MenuBarSummary.Lecture) -> some View {
+        VStack(alignment: .leading, spacing: 6) {
+            Text(lecture.isLive ? "Läuft gerade" : "Als Nächstes")
+                .font(Theme.Typography.overline)
+                .textCase(.uppercase)
+                .foregroundStyle(lecture.isLive ? Theme.live : Theme.textSecondary)
+            Text(lecture.moduleName)
+                .font(Theme.Typography.headline)
+            Text([lecture.timeText, lecture.location].filter { !$0.isEmpty }.joined(separator: " · "))
+                .font(Theme.Typography.small)
+                .foregroundStyle(Theme.textSecondary)
+            if lecture.isLive {
+                SlimProgressBar(progress: lecture.progress, tint: Theme.live)
+            }
+            Button("Folien öffnen") { onOpenLecture(lecture.moduleID) }
+                .buttonStyle(.borderedProminent)
+                .controlSize(.small)
+        }
+    }
+}

Presentation/MenuBar/MenuBarSummary.swift

@@ -0,0 +1,61 @@
+import Foundation
+
+/// What the menu bar item shows: the running lecture with remaining time, otherwise the next one,
+/// and the due flashcards. Pure, so it is easy to test.
+struct MenuBarSummary: Equatable {
+    struct Lecture: Equatable {
+        let moduleID: UUID
+        let moduleName: String
+        let location: String
+        let isLive: Bool
+        /// „noch 38 Min.“ or „um 14:15“.
+        let timeText: String
+        let progress: Double
+    }
+
+    let lecture: Lecture?
+    let dueCards: Int
+
+    /// Short text next to the menu bar icon; empty when nothing is going on.
+    var title: String {
+        guard let lecture, lecture.isLive else { return "" }
+        return lecture.timeText.replacingOccurrences(of: "noch ", with: "")
+    }
+
+    init(lecture: Lecture?, dueCards: Int) {
+        self.lecture = lecture
+        self.dueCards = dueCards
+    }
+
+    @MainActor
+    init(calendar: StudyCalendarViewModel, dueCards: Int) {
+        let now = calendar.referenceDate
+        let event = calendar.currentLecture ?? calendar.nextLecture
+        if let event, let module = calendar.module(for: event) {
+            let isLive = event.startDate <= now
+            let timeText = isLive
+                ? "noch \(max(Int(event.endDate.timeIntervalSince(now) / 60), 0)) Min."
+                : Self.startText(event.startDate, now: now)
+            lecture = Lecture(
+                moduleID: module.id,
+                moduleName: module.name,
+                location: event.location,
+                isLive: isLive,
+                timeText: timeText,
+                progress: isLive ? calendar.progress(of: event) : 0
+            )
+        } else {
+            lecture = nil
+        }
+        self.dueCards = dueCards
+    }
+
+    static func startText(_ start: Date, now: Date, calendar: Calendar = .current) -> String {
+        let time = start.formatted(date: .omitted, time: .shortened)
+        if calendar.isDate(start, inSameDayAs: now) { return "um \(time)" }
+        if let tomorrow = calendar.date(byAdding: .day, value: 1, to: now), calendar.isDate(start, inSameDayAs: tomorrow) {
+            return "morgen \(time)"
+        }
+        return start.formatted(.dateTime.weekday(.abbreviated).hour().minute())
+    }
+}

Presentation/Settings/GeneralSettingsPane.swift

@@ -6,6 +6,7 @@ struct GeneralSettingsPane: View {
 
     @AppStorage(ViewPreferences.appearanceKey) private var appearance = AppAppearance.standard
     @AppStorage(ViewPreferences.noteFontSizeKey) private var noteFontSize = NoteFontSize.standard
+    @AppStorage(ViewPreferences.showsMenuBarItemKey) private var showsMenuBarItem = true
     @State private var autoOpenLecture = true
     @State private var leadMinutes = 10
 
@@ -18,6 +19,7 @@ struct GeneralSettingsPane: View {
                     }
                 }
                 .pickerStyle(.segmented)
+                Toggle("In der Menüleiste anzeigen (laufende Vorlesung, fällige Karten)", isOn: $showsMenuBarItem)
                 LabeledContent("Schriftgröße der Notizen") {
                     HStack(spacing: 10) {
                         Slider(value: $noteFontSize, in: NoteFontSize.range, step: NoteFontSize.step)

Presentation/Settings/SettingsPane.swift

@@ -37,7 +37,7 @@ enum SettingsPane: String, CaseIterable, Identifiable {
     /// content taller than this scrolls, so the window never outgrows a laptop display.
     var preferredHeight: CGFloat {
         switch self {
-        case .general: 340
+        case .general: 370
         case .schedule: 260
         case .studIP: 400
         case .notifications: 290

Presentation/Settings/ViewPreferences.swift

@@ -36,6 +36,8 @@ enum ViewPreferences {
     static let slideReaderShowsNotesKey = "slideReader.showsNotes"
     /// Last opened pane of the settings window.
     static let settingsPaneKey = "settings.selectedPane"
+    /// Show the StudyApp item in the menu bar.
+    static let showsMenuBarItemKey = "menuBar.isShown"
 }
 
 /// Schriftgröße für Notizen (Editor und Vorschau), einstellbar über ⌘+ / ⌘−.

StudyAppTests/MenuBarTests.swift

@@ -0,0 +1,29 @@
+import Foundation
+import Testing
+@testable import StudyApp
+
+@MainActor
+struct MenuBarSummaryTests {
+    private func lecture(live: Bool, time: String) -> MenuBarSummary.Lecture {
+        MenuBarSummary.Lecture(
+            moduleID: UUID(), moduleName: "Analysis I", location: "HS 1", isLive: live, timeText: time, progress: 0.5
+        )
+    }
+
+    @Test func titleShowsRemainingMinutesOnlyWhileALectureRuns() {
+        #expect(MenuBarSummary(lecture: lecture(live: true, time: "noch 38 Min."), dueCards: 3).title == "38 Min.")
+        #expect(MenuBarSummary(lecture: lecture(live: false, time: "um 14:15"), dueCards: 3).title.isEmpty)
+        #expect(MenuBarSummary(lecture: nil, dueCards: 0).title.isEmpty)
+    }
+
+    @Test func startTextSaysTodayTomorrowOrWeekday() throws {
+        var calendar = Calendar(identifier: .gregorian)
+        calendar.timeZone = try #require(TimeZone(identifier: "Europe/Berlin"))
+        let now = try #require(calendar.date(from: DateComponents(year: 2026, month: 10, day: 28, hour: 9)))
+        let later = try #require(calendar.date(from: DateComponents(year: 2026, month: 10, day: 28, hour: 14, minute: 15)))
+        let tomorrow = try #require(calendar.date(from: DateComponents(year: 2026, month: 10, day: 29, hour: 8)))
+
+        #expect(MenuBarSummary.startText(later, now: now, calendar: calendar).hasPrefix("um "))
+        #expect(MenuBarSummary.startText(tomorrow, now: now, calendar: calendar).hasPrefix("morgen "))
+    }
+}

docs/FEATURES.md

@@ -69,6 +69,12 @@ Code: `Presentation/Grades/`, `Domain/UseCases/GradeUseCases.swift`, `Domain/Ent
 
 Code: `Presentation/StudIP/`, `Domain/UseCases/StudIPUseCases.swift`, `Data/StudIP/` · Details: [STUDIP.md](STUDIP.md)
 
+## Menu bar
+
+The menu bar item shows the remaining minutes while a lecture runs. Its window lists the running or next lecture (with „Folien öffnen“) and the due flashcards, and opens the main window. It can be hidden in Settings → Allgemein.
+
+Code: `Presentation/MenuBar/`
+
 ## Updates and settings
 
 - Automatic updates through Sparkle („Nach Updates suchen …“ in the app menu). See [RELEASING.md](RELEASING.md).