Merge branch 'main' of https://git.science-teaching.de/admin/LehrerApp

LehrerApp.Core/Models/Participation.cs

@@ -60,6 +60,11 @@ public enum AttendanceStatus
     OtherSchoolEvent,
     // Hinten angefügt, damit die numerischen Werte bereits gespeicherter LiteDB-Einträge stabil bleiben.
     Present,
+    Late,
+    SignificantlyLate,
+    LeftDuringClass,
+    LearningIsland,
+    Suspended,
 }
 
 /// <summary>

LehrerApp.Core/Models/SeatingPlan.cs

@@ -12,6 +12,16 @@ public class SeatingPlan
     public string Room { get; set; } = "";
     public int Rows { get; set; } = 4;
     public int Columns { get; set; } = 4;
+    /// <summary>
+    /// Zeigt die Tafel unterhalb des Sitzrasters an. Der Standardwert <c>false</c>
+    /// erhält für bestehende Pläne die bisherige Darstellung oberhalb des Rasters.
+    /// </summary>
+    public bool IsBoardAtBottom { get; set; }
+    /// <summary>
+    /// Zusätzlicher horizontaler Abstand nach jeder Spalte, in Pixeln. Der Eintrag mit Index 0
+    /// liegt zwischen der ersten und zweiten Spalte. Fehlende Einträge bedeuten keinen Abstand.
+    /// </summary>
+    public List<double> ColumnGapWidths { get; set; } = [];
     public List<SeatAssignment> Assignments { get; set; } = [];
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
     public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;

LehrerApp.Core/Services/AttendanceBalanceService.cs

@@ -25,10 +25,13 @@ public class AttendanceBalanceService
             .Select(e => e.Status!.Value)
             .ToList();
 
-        var present      = relevant.Count(s => s == AttendanceStatus.Present);
+        var present      = relevant.Count(s => s is AttendanceStatus.Present
+            or AttendanceStatus.Late or AttendanceStatus.SignificantlyLate);
         var excused      = relevant.Count(s => s == AttendanceStatus.Excused);
-        var unexcused    = relevant.Count(s => s is AttendanceStatus.Unexcused or AttendanceStatus.Truant);
+        var unexcused    = relevant.Count(s => s is AttendanceStatus.Unexcused
-        var schoolEvent  = relevant.Count(s => s == AttendanceStatus.OtherSchoolEvent);
+            or AttendanceStatus.Truant or AttendanceStatus.LeftDuringClass);
+        var schoolEvent  = relevant.Count(s => s is AttendanceStatus.OtherSchoolEvent
+            or AttendanceStatus.LearningIsland or AttendanceStatus.Suspended);
         var pending      = relevant.Count(s => s == AttendanceStatus.ExcusePending);
         var total        = relevant.Count;
 

LehrerApp.Data.Tests/RepositoryTests.cs

@@ -267,6 +267,8 @@ public sealed class RepositoryTests
         repo.Save(new SeatingPlan
         {
             GroupId = group.Id, Name = "Standard", Room = "Physik", Rows = 2, Columns = 3,
+            IsBoardAtBottom = true,
+            ColumnGapWidths = [0, 90],
             Assignments = [new SeatAssignment { Row = 1, Column = 2, StudentId = ben.Id }],
         });
 
@@ -274,7 +276,9 @@ public sealed class RepositoryTests
 
         Assert.Equal(2, plans.Count);
         Assert.Contains(plans, p => p.Room == "B204" && p.Assignments.Single().StudentId == anna.Id);
-        Assert.Contains(plans, p => p.Room == "Physik" && p.Assignments.Single().StudentId == ben.Id);
+        Assert.Contains(plans, p => p.Room == "Physik" && p.IsBoardAtBottom
+                                               && p.ColumnGapWidths.SequenceEqual([0, 90])
+                                               && p.Assignments.Single().StudentId == ben.Id);
     }
 
     [Fact]

LehrerApp.Data/Repositories/AllRepositories.cs

@@ -107,6 +107,7 @@ public class SeatingPlanRepository(LiteDbContext db) : ISeatingPlanRepository
         plan.Name = plan.Name?.Trim() ?? "";
         plan.Room = plan.Room?.Trim() ?? "";
         plan.Assignments ??= [];
+        plan.ColumnGapWidths ??= [];
         if (plan.Name.Length == 0)
             throw new ArgumentException("Der Name des Sitzplans darf nicht leer sein.");
         if (plan.Rows is < 1 or > 10 || plan.Columns is < 1 or > 10)
@@ -114,6 +115,12 @@ public class SeatingPlanRepository(LiteDbContext db) : ISeatingPlanRepository
         if (db.Groups.FindById(plan.GroupId) is null)
             throw new InvalidOperationException("Die zugehörige Lerngruppe existiert nicht.");
 
+        plan.ColumnGapWidths = Enumerable.Range(0, Math.Max(0, plan.Columns - 1))
+            .Select(i => i < plan.ColumnGapWidths.Count && double.IsFinite(plan.ColumnGapWidths[i])
+                ? Math.Clamp(plan.ColumnGapWidths[i], 0, 300)
+                : 0)
+            .ToList();
+
         var duplicateName = db.SeatingPlans.Find(p => p.GroupId == plan.GroupId)
             .FirstOrDefault(p => p.Id != plan.Id
                 && string.Equals(p.Name, plan.Name, StringComparison.OrdinalIgnoreCase)

LehrerApp.Desktop.Tests/ParticipationSessionEditingTests.cs

@@ -0,0 +1,62 @@
+using LehrerApp.Core.Models;
+using LehrerApp.Desktop.ViewModels.Groups;
+using Xunit;
+
+namespace LehrerApp.Desktop.Tests;
+
+public sealed class ParticipationSessionEditingTests
+{
+    [Fact]
+    public void Bearbeitungsdialog_AendertBestehendeSessionOhneVerknuepfungenZuErsetzen()
+    {
+        var session = new ParticipationSession
+        {
+            GroupId = Guid.NewGuid(),
+            Date = new DateOnly(2026, 8, 19),
+            Comment = "Sitzplan",
+            LessonId = Guid.NewGuid(),
+            CompetencyCodes = ["K1"],
+        };
+        var vm = new AddSessionDialogViewModel(session)
+        {
+            DateText = "20.08.2026",
+            Comment = "Elektrische Stromkreise",
+        };
+
+        vm.SaveCommand.Execute(null);
+
+        Assert.Same(session, vm.Result);
+        Assert.Equal(new DateOnly(2026, 8, 20), session.Date);
+        Assert.Equal("Elektrische Stromkreise", session.Comment);
+        Assert.NotNull(session.LessonId);
+        Assert.Equal(["K1"], session.CompetencyCodes);
+    }
+
+    [Fact]
+    public async Task BearbeitenBefehl_SpeichertSessionUndAktualisiertAnzeige()
+    {
+        var group = new LearningGroup { Name = "8a", SchoolYear = "2026/27" };
+        var session = new ParticipationSession
+        {
+            GroupId = group.Id,
+            Date = new DateOnly(2026, 8, 19),
+            Comment = "Sitzplan",
+        };
+        var sessions = new FakeSessions([session]);
+        var vm = new ParticipationTabViewModel(
+            sessions, new FakeEntries(), new FakeAspects(), new FakeStudents([]),
+            new FakeMemberships([]), new FakeGroups([group]), new FakeCompetencyDomains());
+        vm.OnEditSession = existing =>
+        {
+            existing.Comment = "Nachbesprechung Elektrizität";
+            return Task.FromResult<ParticipationSession?>(existing);
+        };
+        vm.Initialize(group.Id, group.SchoolYear);
+
+        await vm.EditSessionCommand.ExecuteAsync(null);
+
+        Assert.Equal(session.Id, vm.SelectedSession?.Id);
+        Assert.Equal("Nachbesprechung Elektrizität", sessions.GetById(session.Id)?.Comment);
+        Assert.Contains("Nachbesprechung Elektrizität", vm.SelectedSessionDisplay);
+    }
+}

LehrerApp.Desktop.Tests/QuickInputViewModelTests.cs

@@ -6,6 +6,24 @@ namespace LehrerApp.Desktop.Tests;
 
 public sealed class QuickInputViewModelTests
 {
+    [Theory]
+    [InlineData(AttendanceStatus.Late, false, "Verspätet", "V")]
+    [InlineData(AttendanceStatus.SignificantlyLate, false, "Erheblich verspätet", "V!")]
+    [InlineData(AttendanceStatus.LeftDuringClass, true, "Während des Unterrichts abgängig", "A")]
+    [InlineData(AttendanceStatus.LearningIsland, true, "Lerninsel", "L")]
+    [InlineData(AttendanceStatus.Suspended, true, "Suspendiert", "S")]
+    public void ZusaetzlicheAnwesenheitsstatus_HabenAnzeigeUndPassendeAbwesenheitswertung(
+        AttendanceStatus status, bool isAbsent, string label, string symbol)
+    {
+        var row = new ParticipationStudentRow(Guid.NewGuid(), "Anna",
+            new ParticipationEntry { Attendance = status }, [], []);
+
+        Assert.Equal(isAbsent, row.IsAbsent);
+        Assert.Equal(label, row.AttendanceTooltip);
+        Assert.Equal(symbol, row.AttendanceLabel);
+        Assert.False(string.IsNullOrWhiteSpace(AttendanceDisplay.Color(status)));
+    }
+
     [Fact]
     public void ZurueckZuVorherigemSchueler_ZeigtBereitsGesetzteBewertung()
     {

LehrerApp.Desktop.Tests/SeatingPlanViewModelTests.cs

@@ -1,11 +1,41 @@
 using LehrerApp.Core.Models;
 using LehrerApp.Desktop.ViewModels.Groups;
+using LehrerApp.Desktop.Views.Groups;
 using Xunit;
 
 namespace LehrerApp.Desktop.Tests;
 
 public sealed class SeatingPlanViewModelTests
 {
+    [Fact]
+    public void TafelpositionWirdAusPlanGeladenUndBeimBearbeitenGespeichert()
+    {
+        var groupId = Guid.NewGuid();
+        var plan = new SeatingPlan
+        {
+            GroupId = groupId,
+            Name = "Standard",
+            Rows = 1,
+            Columns = 1,
+            IsBoardAtBottom = true,
+        };
+        var plans = new FakeSeatingPlans([plan]);
+        var tabVm = new SeatingPlanTabViewModel(
+            plans, new FakeStudents([]), new FakeMemberships([]),
+            new FakeSessions([]), new FakeEntries(), new FakeAspects());
+
+        tabVm.Initialize(groupId, isReadOnly: false);
+
+        Assert.True(tabVm.IsBoardAtBottom);
+        Assert.False(tabVm.IsBoardAtTop);
+
+        var dialogVm = tabVm.CreateDialogViewModel(plan);
+        dialogVm.IsBoardAtBottom = false;
+        dialogVm.SaveCommand.Execute(null);
+
+        Assert.False(plans.GetById(plan.Id)!.IsBoardAtBottom);
+    }
+
     [Fact]
     public void AuswahlEinesBereitsZugeordnetenSchuelers_VerschiebtIhnAufDenNeuenPlatz()
     {
@@ -27,6 +57,7 @@ public sealed class SeatingPlanViewModelTests
         var vm = new SeatingPlanTabViewModel(plans, students, memberships,
             new FakeSessions([]), new FakeEntries(), new FakeAspects());
         vm.Initialize(groupId, isReadOnly: false);
+        vm.IsEditMode = true;
 
         vm.Seats[1].SelectedOption = vm.StudentOptions.Single(o => o.StudentId == student.Id);
 
@@ -75,6 +106,7 @@ public sealed class SeatingPlanViewModelTests
         var vm = new SeatingPlanTabViewModel(plans, students, memberships,
             new FakeSessions([]), new FakeEntries(), new FakeAspects());
         vm.Initialize(groupId, isReadOnly: false);
+        vm.IsEditMode = true;
 
         vm.MoveSeat(vm.Seats[0], vm.Seats[1]);
 
@@ -83,6 +115,78 @@ public sealed class SeatingPlanViewModelTests
         Assert.Equal(2, plans.GetById(plan.Id)!.Assignments.Count);
     }
 
+    [Fact]
+    public void Ansichtsmodus_VerhindertVerschiebenUndBlendetBearbeitungsbefehleAus()
+    {
+        var groupId = Guid.NewGuid();
+        var student = new Student { FirstName = "Anna", LastName = "A" };
+        var plan = new SeatingPlan
+        {
+            GroupId = groupId, Name = "Standard", Rows = 1, Columns = 2,
+            Assignments = [new SeatAssignment { Row = 0, Column = 0, StudentId = student.Id }],
+        };
+        var vm = new SeatingPlanTabViewModel(
+            new FakeSeatingPlans([plan]), new FakeStudents([student]),
+            new FakeMemberships([new GroupMembership { GroupId = groupId, StudentId = student.Id }]),
+            new FakeSessions([]), new FakeEntries(), new FakeAspects());
+        vm.Initialize(groupId, isReadOnly: false);
+
+        vm.MoveSeat(vm.Seats[0], vm.Seats[1]);
+
+        Assert.False(vm.IsEditMode);
+        Assert.False(vm.CanEditLayout);
+        Assert.False(vm.EditPlanCommand.CanExecute(null));
+        Assert.Equal(student.Id, vm.Seats[0].SelectedOption.StudentId);
+        Assert.Null(vm.Seats[1].SelectedOption.StudentId);
+
+        vm.IsEditMode = true;
+
+        Assert.True(vm.CanEditLayout);
+        Assert.True(vm.EditPlanCommand.CanExecute(null));
+        Assert.All(vm.Seats, seat => Assert.True(seat.CanEdit));
+    }
+
+    [Fact]
+    public void Tischabstaende_WerdenBeimBearbeitenProSpaltengrenzeGespeichert()
+    {
+        var groupId = Guid.NewGuid();
+        var plan = new SeatingPlan
+        {
+            GroupId = groupId, Name = "Standard", Rows = 2, Columns = 4,
+            ColumnGapWidths = [0, 80, 20],
+        };
+        var plans = new FakeSeatingPlans([plan]);
+        var vm = new SeatingPlanDialogViewModel(plans, groupId, plan);
+
+        Assert.Equal([0m, 80m, 20m], vm.ColumnGaps.Select(g => g.Width));
+        vm.ColumnGaps[0].Width = 40;
+        vm.SaveCommand.Execute(null);
+
+        Assert.Equal([40d, 80d, 20d], plans.GetById(plan.Id)!.ColumnGapWidths);
+    }
+
+    [Fact]
+    public void SitzplanPanel_FuegtAbstandNurAnKonfigurierterSpaltengrenzeEin()
+    {
+        var panel = new SeatingPlanPanel
+        {
+            Columns = 3,
+            ColumnGapWidths = [0, 70],
+        };
+        for (var i = 0; i < 6; i++)
+            panel.Children.Add(new Avalonia.Controls.Border { Width = 100, Height = 50 });
+
+        panel.Measure(Avalonia.Size.Infinity);
+        panel.Arrange(new Avalonia.Rect(panel.DesiredSize));
+
+        Assert.Equal(370, panel.DesiredSize.Width);
+        Assert.Equal(100, panel.DesiredSize.Height);
+        Assert.Equal(0, panel.Children[0].Bounds.X);
+        Assert.Equal(100, panel.Children[1].Bounds.X);
+        Assert.Equal(270, panel.Children[2].Bounds.X);
+        Assert.Equal(270, panel.Children[5].Bounds.X);
+    }
+
     [Fact]
     public void SitzplatzBewertung_ErstelltHeutigeSitzungUndSpeichertAlleDreiBereiche()
     {

LehrerApp.Desktop/ViewModels/Groups/ParticipationViewModels.cs

@@ -48,6 +48,7 @@ public partial class ParticipationTabViewModel : ObservableObject
     public ObservableCollection<CompetencyTagGroup>        CompetencyTagGroups { get; } = [];
 
     public Func<Task<ParticipationSession?>>? OnAddSession   { get; set; }
+    public Func<ParticipationSession, Task<ParticipationSession?>>? OnEditSession { get; set; }
     public Func<ParticipationTabViewModel, Task>? OnQuickInput { get; set; }
     public Func<ParticipationTabViewModel, Task>? OnStatusQuickInput { get; set; }
     public Func<ParticipationTabViewModel, Task>? OnComputeGrade { get; set; }
@@ -118,6 +119,7 @@ public partial class ParticipationTabViewModel : ObservableObject
     partial void OnSelectedSessionChanged(ParticipationSessionItem? value)
     {
         OnPropertyChanged(nameof(SelectedSessionDisplay));
+        EditSessionCommand.NotifyCanExecuteChanged();
         if (value is null)
         {
             StudentRows.Clear();
@@ -265,6 +267,23 @@ public partial class ParticipationTabViewModel : ObservableObject
         SelectedSession = Sessions.FirstOrDefault(s => s.Id == session.Id);
     }
 
+    [RelayCommand(CanExecute = nameof(CanEditSession))]
+    private async Task EditSession()
+    {
+        if (SelectedSession is null || OnEditSession is null) return;
+        var session = _sessions.GetById(SelectedSession.Id);
+        if (session is null) return;
+        var edited = await OnEditSession(session);
+        if (edited is null) return;
+        edited.GroupId = _groupId;
+        _sessions.Save(edited);
+        LoadSessions();
+    }
+
+    private bool CanEditSession() => !IsReadOnly && SelectedSession is not null;
+
+    partial void OnIsReadOnlyChanged(bool value) => EditSessionCommand.NotifyCanExecuteChanged();
+
     [RelayCommand(CanExecute = nameof(CanQuickInput))]
     private async Task QuickInput()
     {
@@ -363,7 +382,10 @@ public partial class ParticipationStudentRow : ObservableObject
     public string AttendanceTooltip => AttendanceDisplay.Label(Attendance);
     /// Abwesend im Sinne der Mitarbeitsbewertung: eine Bewertung ergibt für diese Stunde keinen
     /// Sinn, unabhängig davon, ob die Abwesenheit entschuldigt ist oder noch geklärt werden muss.
-    public bool IsAbsent => Attendance is not null and not AttendanceStatus.Present;
+    public bool IsAbsent => Attendance is not null
+        and not AttendanceStatus.Present
+        and not AttendanceStatus.Late
+        and not AttendanceStatus.SignificantlyLate;
     public string HomeworkSymbol => HomeworkDisplay.Symbol(Homework);
     public string HomeworkTooltip => HomeworkDisplay.Label(Homework);
 
@@ -538,6 +560,11 @@ public static class AttendanceDisplay
         AttendanceStatus.Unexcused      => "Krank, unentschuldigt",
         AttendanceStatus.Truant         => "Geschwänzt",
         AttendanceStatus.OtherSchoolEvent => "Andere Schulveranstaltung",
+        AttendanceStatus.Late           => "Verspätet",
+        AttendanceStatus.SignificantlyLate => "Erheblich verspätet",
+        AttendanceStatus.LeftDuringClass => "Während des Unterrichts abgängig",
+        AttendanceStatus.LearningIsland => "Lerninsel",
+        AttendanceStatus.Suspended      => "Suspendiert",
         _                                => "Anwesend",
     };
 
@@ -550,6 +577,11 @@ public static class AttendanceDisplay
         AttendanceStatus.Unexcused      => "!",
         AttendanceStatus.Truant         => "✕",
         AttendanceStatus.OtherSchoolEvent => "◇",
+        AttendanceStatus.Late           => "V",
+        AttendanceStatus.SignificantlyLate => "V!",
+        AttendanceStatus.LeftDuringClass => "A",
+        AttendanceStatus.LearningIsland => "L",
+        AttendanceStatus.Suspended      => "S",
         _                                => "",
     };
 
@@ -561,6 +593,11 @@ public static class AttendanceDisplay
         AttendanceStatus.Unexcused        => "#D96C00",
         AttendanceStatus.Truant           => "#D64545",
         AttendanceStatus.OtherSchoolEvent => "#5277C3",
+        AttendanceStatus.Late             => "#D98200",
+        AttendanceStatus.SignificantlyLate => "#D96C00",
+        AttendanceStatus.LeftDuringClass  => "#D64545",
+        AttendanceStatus.LearningIsland   => "#5277C3",
+        AttendanceStatus.Suspended        => "#6B6576",
         _                                 => "",
     };
 }
@@ -698,12 +735,26 @@ public class ParticipationSessionItem
 
 public partial class AddSessionDialogViewModel : ObservableObject
 {
+    private readonly ParticipationSession? _editingSession;
+
     [ObservableProperty] private DateOnly _date = DateOnly.FromDateTime(DateTime.Today);
     [ObservableProperty] private string   _comment = "";
     [ObservableProperty] private string   _dateText = DateOnly.FromDateTime(DateTime.Today).ToString("dd.MM.yyyy");
     [ObservableProperty] private string   _dateTextError = "";
 
     public ParticipationSession? Result { get; private set; }
+    public bool IsEditing => _editingSession is not null;
+    public string DialogTitle => IsEditing ? "Bewertungszeitpunkt bearbeiten" : "Bewertungszeitpunkt anlegen";
+    public string SaveButtonText => IsEditing ? "Speichern" : "Anlegen";
+
+    public AddSessionDialogViewModel(ParticipationSession? editingSession = null)
+    {
+        _editingSession = editingSession;
+        if (editingSession is null) return;
+        Date = editingSession.Date;
+        DateText = editingSession.Date.ToString("dd.MM.yyyy");
+        Comment = editingSession.Comment ?? "";
+    }
 
     [RelayCommand]
     private void Save()
@@ -715,7 +766,10 @@ public partial class AddSessionDialogViewModel : ObservableObject
             return;
         }
         DateTextError = "";
-        Result = new ParticipationSession { Date = date, Comment = Comment.Trim() };
+        var session = _editingSession ?? new ParticipationSession();
+        session.Date = date;
+        session.Comment = Comment.Trim();
+        Result = session;
     }
 }
 

LehrerApp.Desktop/ViewModels/Groups/SeatingPlanViewModels.cs

@@ -24,6 +24,10 @@ public partial class SeatingPlanTabViewModel : ObservableObject
     [ObservableProperty] private string _planTitle = "";
     [ObservableProperty] private string _planSubtitle = "";
     [ObservableProperty] private string _assignmentSummary = "";
+    [ObservableProperty] private bool _isBoardAtTop = true;
+    [ObservableProperty] private bool _isBoardAtBottom;
+    [ObservableProperty] private IReadOnlyList<double> _columnGapWidths = [];
+    [ObservableProperty] private bool _isEditMode;
 
     public ObservableCollection<SeatingPlanSummary> Plans { get; } = [];
     public ObservableCollection<SeatCellViewModel> Seats { get; } = [];
@@ -33,6 +37,7 @@ public partial class SeatingPlanTabViewModel : ObservableObject
     public bool HasPlans => Plans.Count > 0;
     public bool HasSelectedPlan => _currentPlan is not null;
     public bool IsEditable => !_isReadOnly;
+    public bool CanEditLayout => IsEditable && IsEditMode;
     public Func<SeatingPlan?, Task<SeatingPlan?>>? OnEditPlan { get; set; }
     public Func<SeatingPlanSummary, Task<bool>>? OnConfirmDelete { get; set; }
     public Func<SeatAssessmentViewModel, Task>? OnAssessStudent { get; set; }
@@ -57,6 +62,7 @@ public partial class SeatingPlanTabViewModel : ObservableObject
     {
         _groupId = groupId;
         _isReadOnly = isReadOnly;
+        IsEditMode = false;
         LoadStudentOptions();
         ReloadPlans();
         OnPropertyChanged(nameof(IsEditable));
@@ -102,6 +108,9 @@ public partial class SeatingPlanTabViewModel : ObservableObject
             PlanTitle = "";
             PlanSubtitle = "";
             AssignmentSummary = "";
+            IsBoardAtTop = true;
+            IsBoardAtBottom = false;
+            ColumnGapWidths = [];
         }
         else
         {
@@ -110,6 +119,12 @@ public partial class SeatingPlanTabViewModel : ObservableObject
             PlanSubtitle = string.IsNullOrWhiteSpace(plan.Room)
                 ? $"{plan.Rows} × {plan.Columns} Plätze"
                 : $"Raum {plan.Room} · {plan.Rows} × {plan.Columns} Plätze";
+            IsBoardAtBottom = plan.IsBoardAtBottom;
+            IsBoardAtTop = !plan.IsBoardAtBottom;
+            var savedGapWidths = plan.ColumnGapWidths ?? [];
+            ColumnGapWidths = Enumerable.Range(0, Math.Max(0, plan.Columns - 1))
+                .Select(i => i < savedGapWidths.Count ? savedGapWidths[i] : 0)
+                .ToArray();
             for (var row = 0; row < plan.Rows; row++)
             for (var column = 0; column < plan.Columns; column++)
             {
@@ -118,7 +133,7 @@ public partial class SeatingPlanTabViewModel : ObservableObject
                     ? StudentSeatOption.Empty
                     : StudentOptions.FirstOrDefault(o => o.StudentId == assignment.StudentId)
                       ?? StudentSeatOption.Empty;
-                Seats.Add(new SeatCellViewModel(row, column, StudentOptions, option, OnSeatChanged, IsEditable));
+                Seats.Add(new SeatCellViewModel(row, column, StudentOptions, option, OnSeatChanged, CanEditLayout));
             }
             UpdateAssignmentSummary();
         }
@@ -128,7 +143,7 @@ public partial class SeatingPlanTabViewModel : ObservableObject
 
     private void OnSeatChanged(SeatCellViewModel changed)
     {
-        if (_currentPlan is null || !IsEditable) return;
+        if (_currentPlan is null || !CanEditLayout) return;
         if (changed.SelectedOption.StudentId is Guid studentId)
         {
             foreach (var other in Seats.Where(s => s != changed && s.SelectedOption.StudentId == studentId))
@@ -152,7 +167,7 @@ public partial class SeatingPlanTabViewModel : ObservableObject
 
     public void MoveSeat(SeatCellViewModel source, SeatCellViewModel target)
     {
-        if (!IsEditable || source == target || !source.SelectedOption.StudentId.HasValue) return;
+        if (!CanEditLayout || source == target || !source.SelectedOption.StudentId.HasValue) return;
         var targetOption = target.SelectedOption;
         target.SetSelectionSilently(source.SelectedOption);
         source.SetSelectionSilently(targetOption);
@@ -161,7 +176,7 @@ public partial class SeatingPlanTabViewModel : ObservableObject
 
     public void AssignStudent(StudentSeatOption student, SeatCellViewModel target)
     {
-        if (!IsEditable || !student.StudentId.HasValue) return;
+        if (!CanEditLayout || !student.StudentId.HasValue) return;
         foreach (var other in Seats.Where(s => s != target && s.SelectedOption.StudentId == student.StudentId))
             other.SetSelectionSilently(StudentSeatOption.Empty);
         target.SetSelectionSilently(student);
@@ -170,7 +185,7 @@ public partial class SeatingPlanTabViewModel : ObservableObject
 
     public void ClearSeat(SeatCellViewModel seat)
     {
-        if (!IsEditable || !seat.SelectedOption.StudentId.HasValue) return;
+        if (!CanEditLayout || !seat.SelectedOption.StudentId.HasValue) return;
         seat.SetSelectionSilently(StudentSeatOption.Empty);
         SaveSeatAssignments();
     }
@@ -223,8 +238,15 @@ public partial class SeatingPlanTabViewModel : ObservableObject
         ReloadPlans();
     }
 
-    private bool CanEdit() => IsEditable;
+    partial void OnIsEditModeChanged(bool value)
-    private bool CanEditSelected() => IsEditable && _currentPlan is not null;
+    {
+        OnPropertyChanged(nameof(CanEditLayout));
+        foreach (var seat in Seats) seat.CanEdit = CanEditLayout;
+        NotifyCommands();
+    }
+
+    private bool CanEdit() => IsEditable && (IsEditMode || !HasPlans);
+    private bool CanEditSelected() => CanEditLayout && _currentPlan is not null;
 
     private void NotifyCommands()
     {
@@ -264,7 +286,7 @@ public partial class SeatCellViewModel : ObservableObject
     public int Column { get; }
     public string PositionLabel => $"Reihe {Row + 1} · Platz {Column + 1}";
     public ObservableCollection<StudentSeatOption> Options { get; }
-    public bool CanEdit { get; }
+    [ObservableProperty] private bool _canEdit;
     public bool IsOccupied => SelectedOption.StudentId.HasValue;
     public string StudentName => IsOccupied ? SelectedOption.DisplayName : "Freier Platz";
 
@@ -276,7 +298,7 @@ public partial class SeatCellViewModel : ObservableObject
         Options = options;
         _selectedOption = selectedOption;
         _onChanged = onChanged;
-        CanEdit = canEdit;
+        _canEdit = canEdit;
     }
 
     partial void OnSelectedOptionChanged(StudentSeatOption value)
@@ -363,6 +385,11 @@ public partial class SeatAssessmentViewModel : ObservableObject
         AttendanceChoices.Add(new("◇", "Schulveranstaltung", "Strg+7", AttendanceStatus.OtherSchoolEvent, SetAttendance));
         AttendanceChoices.Add(new("✕", "Geschwänzt", "Strg+9", AttendanceStatus.Truant, SetAttendance));
         AttendanceChoices.Add(new("!", "Unentschuldigt", "Strg+0", AttendanceStatus.Unexcused, SetAttendance));
+        AttendanceChoices.Add(new("V", "Verspätet", "", AttendanceStatus.Late, SetAttendance));
+        AttendanceChoices.Add(new("V!", "Erheblich verspätet", "", AttendanceStatus.SignificantlyLate, SetAttendance));
+        AttendanceChoices.Add(new("A", "Im Unterricht abgängig", "", AttendanceStatus.LeftDuringClass, SetAttendance));
+        AttendanceChoices.Add(new("L", "Lerninsel", "", AttendanceStatus.LearningIsland, SetAttendance));
+        AttendanceChoices.Add(new("S", "Suspendiert", "", AttendanceStatus.Suspended, SetAttendance));
         AttendanceChoices.Add(new("·", "Nicht kontrolliert", "Strg+X", null, SetAttendance));
     }
 
@@ -579,10 +606,12 @@ public partial class SeatingPlanDialogViewModel : ObservableObject
     [ObservableProperty] private string _room = "";
     [ObservableProperty] private decimal _rows = 4;
     [ObservableProperty] private decimal _columns = 4;
+    [ObservableProperty] private bool _isBoardAtBottom;
     [ObservableProperty] private string _nameError = "";
     [ObservableProperty] private string _layoutError = "";
 
     public SeatingPlan? Result { get; private set; }
+    public ObservableCollection<ColumnGapEditor> ColumnGaps { get; } = [];
     public string DialogTitle => _editingPlan is null ? "Neuen Sitzplan anlegen" : "Sitzplan bearbeiten";
     public string SaveButtonText => _editingPlan is null ? "Anlegen" : "Speichern";
 
@@ -591,11 +620,26 @@ public partial class SeatingPlanDialogViewModel : ObservableObject
         _plans = plans;
         _groupId = groupId;
         _editingPlan = editingPlan;
+        RebuildColumnGaps(decimal.ToInt32(Columns));
         if (editingPlan is null) return;
         Name = editingPlan.Name ?? "";
         Room = editingPlan.Room ?? "";
         Rows = editingPlan.Rows;
         Columns = editingPlan.Columns;
+        IsBoardAtBottom = editingPlan.IsBoardAtBottom;
+        var savedGapWidths = editingPlan.ColumnGapWidths ?? [];
+        for (var i = 0; i < ColumnGaps.Count && i < savedGapWidths.Count; i++)
+            ColumnGaps[i].Width = (decimal)savedGapWidths[i];
+    }
+
+    partial void OnColumnsChanged(decimal value) => RebuildColumnGaps(decimal.ToInt32(value));
+
+    private void RebuildColumnGaps(int columns)
+    {
+        var previous = ColumnGaps.ToDictionary(g => g.AfterColumn, g => g.Width);
+        ColumnGaps.Clear();
+        for (var afterColumn = 1; afterColumn < columns; afterColumn++)
+            ColumnGaps.Add(new ColumnGapEditor(afterColumn, previous.GetValueOrDefault(afterColumn)));
     }
 
     [RelayCommand]
@@ -621,6 +665,8 @@ public partial class SeatingPlanDialogViewModel : ObservableObject
         plan.Room = Room?.Trim() ?? "";
         plan.Rows = decimal.ToInt32(Rows);
         plan.Columns = decimal.ToInt32(Columns);
+        plan.IsBoardAtBottom = IsBoardAtBottom;
+        plan.ColumnGapWidths = ColumnGaps.Select(g => decimal.ToDouble(g.Width)).ToList();
         try
         {
             _plans.Save(plan);
@@ -632,3 +678,10 @@ public partial class SeatingPlanDialogViewModel : ObservableObject
         }
     }
 }
+
+public partial class ColumnGapEditor(int afterColumn, decimal width) : ObservableObject
+{
+    public int AfterColumn { get; } = afterColumn;
+    public string Label => $"Nach Platz {AfterColumn}";
+    [ObservableProperty] private decimal _width = width;
+}

LehrerApp.Desktop/Views/Groups/AddSessionDialog.axaml

@@ -3,13 +3,13 @@
         xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
         x:Class="LehrerApp.Desktop.Views.Groups.AddSessionDialog"
         x:DataType="vm:AddSessionDialogViewModel"
-        Title="Bewertungszeitpunkt anlegen"
+        Title="{Binding DialogTitle}"
         Width="380" SizeToContent="Height"
         CanResize="False" WindowStartupLocation="CenterOwner">
 
   <Grid RowDefinitions="*,Auto" Margin="24">
     <StackPanel Grid.Row="0" Spacing="14">
-      <TextBlock Text="Neuer Bewertungszeitpunkt" Classes="dialogtitle"/>
+      <TextBlock Text="{Binding DialogTitle}" Classes="dialogtitle"/>
 
       <StackPanel Spacing="4">
         <TextBlock Text="Datum *" FontSize="12" Opacity="0.7"/>
@@ -20,13 +20,14 @@
 
       <StackPanel Spacing="4">
         <TextBlock Text="Kommentar (optional)" FontSize="12" Opacity="0.7"/>
-        <TextBox Text="{Binding Comment}" PlaceholderText="z. B. Stunde 12 – Säure-Base-Reaktion"/>
+        <TextBox Text="{Binding Comment}" PlaceholderText="z. B. Stunde 12 – Säure-Base-Reaktion"
+                 x:Name="CommentBox"/>
       </StackPanel>
     </StackPanel>
 
     <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,20,0,0">
       <Button Grid.Column="0" Content="Abbrechen"  HorizontalAlignment="Stretch" Click="OnCancel"/>
-      <Button Grid.Column="2" Content="Anlegen"    HorizontalAlignment="Stretch" Click="OnSave"/>
+      <Button Grid.Column="2" Content="{Binding SaveButtonText}" HorizontalAlignment="Stretch" Click="OnSave"/>
     </Grid>
   </Grid>
 </Window>

LehrerApp.Desktop/Views/Groups/AddSessionDialog.axaml.cs

@@ -11,8 +11,17 @@ public partial class AddSessionDialog : Window
     protected override void OnOpened(EventArgs e)
     {
         base.OnOpened(e);
+        if (DataContext is AddSessionDialogViewModel { IsEditing: true })
+        {
+            var commentBox = this.FindControl<TextBox>("CommentBox");
+            commentBox?.Focus();
+            commentBox?.SelectAll();
+        }
+        else
+        {
             this.FindControl<TextBox>("DateBox")?.Focus();
         }
+    }
 
     private void OnSave(object? s, RoutedEventArgs e)
     {

LehrerApp.Desktop/Views/Groups/AttendanceHomeworkQuickInputDialog.axaml

@@ -28,7 +28,7 @@
     <Grid Grid.Row="2" RowDefinitions="Auto,Auto" ColumnDefinitions="*,Auto" Margin="0,12,0,0">
       <StackPanel Grid.Row="0" Grid.Column="0" Spacing="3">
         <TextBlock FontSize="10" Opacity="0.55" TextWrapping="Wrap"
-                   Text="Anwesenheit: 1 anwesend · 2 Entschuldigung offen · 5 krank/entschuldigt · 7 andere Schulveranstaltung · 9 geschwänzt · 0 unentschuldigt · X nicht kontrolliert"/>
+                   Text="Anwesenheit: 1 anwesend · 2 Entschuldigung offen · 5 krank/entschuldigt · 7 andere Schulveranstaltung · 9 geschwänzt · 0 unentschuldigt · X nicht kontrolliert · seltene Status per Klick im Menü"/>
         <TextBlock FontSize="10" Opacity="0.55" TextWrapping="Wrap"
                    Text="Hausaufgaben mit Alt/⌥: 1 gemacht  ·  3 teilweise/Rest offen · 4 Rest nachgereicht · 5 Rest nicht nachgereicht  ·  7 nicht gemacht/offen · 8 vollständig nachgereicht  ·  0 endgültig nicht nachgereicht  ·  X keine aufgegeben"/>
         <TextBlock FontSize="10" Opacity="0.55"

LehrerApp.Desktop/Views/Groups/AttendanceHomeworkQuickInputDialog.axaml.cs

@@ -67,6 +67,13 @@ public partial class AttendanceHomeworkQuickInputDialog : Window
             AddAttendanceItem(flyout, row, "[7]  ◇  Andere Schulveranstaltung", AttendanceStatus.OtherSchoolEvent);
             AddAttendanceItem(flyout, row, "[9]  ✕  Geschwänzt", AttendanceStatus.Truant);
             AddAttendanceItem(flyout, row, "[0]  !  Unentschuldigt", AttendanceStatus.Unexcused);
+            flyout.Items.Add(new Separator());
+            AddAttendanceItem(flyout, row, "V   Verspätet", AttendanceStatus.Late);
+            AddAttendanceItem(flyout, row, "V!  Erheblich verspätet", AttendanceStatus.SignificantlyLate);
+            AddAttendanceItem(flyout, row, "A   Während des Unterrichts abgängig", AttendanceStatus.LeftDuringClass);
+            AddAttendanceItem(flyout, row, "L   Lerninsel", AttendanceStatus.LearningIsland);
+            AddAttendanceItem(flyout, row, "S   Suspendiert", AttendanceStatus.Suspended);
+            flyout.Items.Add(new Separator());
             AddAttendanceItem(flyout, row, "[X]  ·  Nicht kontrolliert", null);
             button.Flyout = flyout;
 

LehrerApp.Desktop/Views/Groups/ParticipationTabView.axaml

@@ -53,13 +53,16 @@
                    Text="{Binding SelectedSessionDisplay}"
                    FontSize="13" FontWeight="SemiBold"
                    VerticalAlignment="Center"/>
-        <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="6"
+        <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="6">
-                    IsVisible="{Binding HasCompetencyCatalog}">
+          <Button Content="✎ Sitzung bearbeiten" Command="{Binding EditSessionCommand}"
+                  IsVisible="{Binding !IsReadOnly}" FontSize="11" Padding="8,3"/>
           <ToggleButton Content="◇ Kompetenzen"
                         IsChecked="{Binding CompetencyTagsVisible}"
+                        IsVisible="{Binding HasCompetencyCatalog}"
                         FontSize="11" Padding="8,3"/>
           <ToggleButton Content="◈ Schüler-Bewertungen"
                         IsChecked="{Binding StudentCompetencyRatingsVisible}"
+                        IsVisible="{Binding HasCompetencyCatalog}"
                         FontSize="11" Padding="8,3"/>
         </StackPanel>
       </Grid>

LehrerApp.Desktop/Views/Groups/ParticipationTabView.axaml.cs

@@ -23,6 +23,7 @@ public partial class ParticipationTabView : UserControl
         {
             _vm = vm;
             vm.OnAddSession = ShowAddSessionDialog;
+            vm.OnEditSession = ShowEditSessionDialog;
             vm.OnQuickInput = ShowQuickInputDialog;
             vm.OnStatusQuickInput = ShowStatusQuickInputDialog;
             vm.OnComputeGrade = ShowComputeGradeDialog;
@@ -283,6 +284,17 @@ public partial class ParticipationTabView : UserControl
         return ok ? vm.Result : null;
     }
 
+    private async Task<LehrerApp.Core.Models.ParticipationSession?> ShowEditSessionDialog(
+        LehrerApp.Core.Models.ParticipationSession session)
+    {
+        var vm = new AddSessionDialogViewModel(session);
+        var dialog = new AddSessionDialog { DataContext = vm };
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null) return null;
+        var ok = await dialog.ShowDialog<bool>(owner);
+        return ok ? vm.Result : null;
+    }
+
     private async Task ShowQuickInputDialog(ParticipationTabViewModel tabVm)
     {
         if (tabVm.StudentRows.Count == 0) return;

LehrerApp.Desktop/Views/Groups/SeatingPlanDialog.axaml

@@ -3,9 +3,10 @@
         xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
         x:Class="LehrerApp.Desktop.Views.Groups.SeatingPlanDialog"
         x:DataType="vm:SeatingPlanDialogViewModel"
-        Title="{Binding DialogTitle}" Width="480" Height="470"
+        Title="{Binding DialogTitle}" Width="620" Height="680" MinHeight="560"
-        CanResize="False" WindowStartupLocation="CenterOwner">
+        CanResize="True" WindowStartupLocation="CenterOwner">
   <Grid RowDefinitions="*,Auto" Margin="24">
+    <ScrollViewer>
     <StackPanel Spacing="16">
       <StackPanel Spacing="3">
         <TextBlock Text="{Binding DialogTitle}" Classes="dialogtitle"/>
@@ -40,12 +41,39 @@
       <TextBlock Text="{Binding LayoutError}" Foreground="Red" FontSize="11"
                  IsVisible="{Binding LayoutError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
 
+      <StackPanel Spacing="4">
+        <TextBlock Text="Tafelposition" FontSize="12" Opacity="0.7"/>
+        <CheckBox Content="Tafel unterhalb der Sitzplätze anzeigen"
+                  IsChecked="{Binding IsBoardAtBottom}"/>
+      </StackPanel>
+
+      <StackPanel Spacing="7">
+        <TextBlock Text="Abstände zwischen den Tischen" FontSize="12" Opacity="0.7"/>
+        <TextBlock Text="Breite 0 bedeutet: kein zusätzlicher Abstand. So lassen sich z. B. Tischgruppen und Mittelgänge abbilden."
+                   FontSize="11" Opacity="0.55" TextWrapping="Wrap"/>
+        <ItemsControl ItemsSource="{Binding ColumnGaps}">
+          <ItemsControl.ItemsPanel>
+            <ItemsPanelTemplate><WrapPanel/></ItemsPanelTemplate>
+          </ItemsControl.ItemsPanel>
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:ColumnGapEditor">
+              <StackPanel Width="125" Margin="0,0,10,8" Spacing="3">
+                <TextBlock Text="{Binding Label}" FontSize="11" Opacity="0.65"/>
+                <NumericUpDown Value="{Binding Width}" Minimum="0" Maximum="300"
+                               Increment="10" FormatString="0 px"/>
+              </StackPanel>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+      </StackPanel>
+
       <Border Background="{DynamicResource SystemControlBackgroundChromeMediumLowBrush}"
               CornerRadius="6" Padding="12">
         <TextBlock Text="Beim Verkleinern des Rasters entfallen Zuordnungen außerhalb der neuen Größe."
                    FontSize="12" Opacity="0.7" TextWrapping="Wrap"/>
       </Border>
     </StackPanel>
+    </ScrollViewer>
 
     <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,20,0,0">
       <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>

LehrerApp.Desktop/Views/Groups/SeatingPlanPanel.cs

@@ -0,0 +1,77 @@
+using Avalonia;
+using Avalonia.Controls;
+
+namespace LehrerApp.Desktop.Views.Groups;
+
+/// <summary>
+/// Ordnet Sitzplätze in einem Raster an und fügt zwischen ausgewählten Spalten zusätzliche
+/// transparente Breite ein. Anders als ein UniformGrid kann der Abstand je Spaltengrenze variieren.
+/// </summary>
+public sealed class SeatingPlanPanel : Panel
+{
+    public static readonly StyledProperty<int> ColumnsProperty =
+        AvaloniaProperty.Register<SeatingPlanPanel, int>(nameof(Columns), 1);
+
+    public static readonly StyledProperty<IReadOnlyList<double>> ColumnGapWidthsProperty =
+        AvaloniaProperty.Register<SeatingPlanPanel, IReadOnlyList<double>>(
+            nameof(ColumnGapWidths), Array.Empty<double>());
+
+    public int Columns
+    {
+        get => GetValue(ColumnsProperty);
+        set => SetValue(ColumnsProperty, value);
+    }
+
+    public IReadOnlyList<double> ColumnGapWidths
+    {
+        get => GetValue(ColumnGapWidthsProperty);
+        set => SetValue(ColumnGapWidthsProperty, value);
+    }
+
+    static SeatingPlanPanel() =>
+        AffectsMeasure<SeatingPlanPanel>(ColumnsProperty, ColumnGapWidthsProperty);
+
+    protected override Size MeasureOverride(Size availableSize)
+    {
+        foreach (var child in Children)
+            child.Measure(Size.Infinity);
+
+        if (Children.Count == 0) return default;
+        var columns = Math.Max(1, Columns);
+        var rows = (int)Math.Ceiling((double)Children.Count / columns);
+        var cellWidth = Children.Max(child => child.DesiredSize.Width);
+        var cellHeight = Children.Max(child => child.DesiredSize.Height);
+        return new Size(cellWidth * columns + GapWidth(columns), cellHeight * rows);
+    }
+
+    protected override Size ArrangeOverride(Size finalSize)
+    {
+        if (Children.Count == 0) return finalSize;
+        var columns = Math.Max(1, Columns);
+        var cellWidth = Children.Max(child => child.DesiredSize.Width);
+        var cellHeight = Children.Max(child => child.DesiredSize.Height);
+
+        for (var index = 0; index < Children.Count; index++)
+        {
+            var column = index % columns;
+            var row = index / columns;
+            var child = Children[index];
+            var x = column * cellWidth + GapWidthBefore(column);
+            var childX = x + Math.Max(0, (cellWidth - child.DesiredSize.Width) / 2);
+            var childY = row * cellHeight + Math.Max(0, (cellHeight - child.DesiredSize.Height) / 2);
+            child.Arrange(new Rect(childX, childY, child.DesiredSize.Width, child.DesiredSize.Height));
+        }
+
+        return finalSize;
+    }
+
+    private double GapWidth(int columns) =>
+        Enumerable.Range(0, Math.Max(0, columns - 1)).Sum(GapAt);
+
+    private double GapWidthBefore(int column) =>
+        Enumerable.Range(0, Math.Max(0, column)).Sum(GapAt);
+
+    private double GapAt(int index) => index < ColumnGapWidths.Count
+        ? Math.Clamp(ColumnGapWidths[index], 0, 300)
+        : 0;
+}

LehrerApp.Desktop/Views/Groups/SeatingPlanTabView.axaml

@@ -1,6 +1,7 @@
 <UserControl xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+             xmlns:groups="clr-namespace:LehrerApp.Desktop.Views.Groups"
              x:Class="LehrerApp.Desktop.Views.Groups.SeatingPlanTabView"
              x:DataType="vm:SeatingPlanTabViewModel">
   <UserControl.Styles>
@@ -37,7 +38,7 @@
             </DataTemplate>
           </ListBox.ItemTemplate>
         </ListBox>
-        <StackPanel Grid.Row="2" Spacing="8" Margin="0,12,0,0">
+        <StackPanel Grid.Row="2" Spacing="8" Margin="0,12,0,0" IsVisible="{Binding IsEditMode}">
           <Button Content="＋ Sitzplan" Command="{Binding AddPlanCommand}" HorizontalAlignment="Stretch"/>
           <Grid ColumnDefinitions="*,8,*" IsVisible="{Binding HasSelectedPlan}">
             <Button Grid.Column="0" Content="Bearbeiten" Command="{Binding EditPlanCommand}"
@@ -60,30 +61,41 @@
                 HorizontalAlignment="Center"/>
       </StackPanel>
 
-      <Grid RowDefinitions="Auto,*" IsVisible="{Binding HasSelectedPlan}" Margin="24">
+      <Grid RowDefinitions="Auto,*" ColumnDefinitions="*,Auto" IsVisible="{Binding HasSelectedPlan}" Margin="24">
-        <Grid Grid.Row="0" ColumnDefinitions="*,Auto" Margin="0,0,0,18">
+        <Grid Grid.Row="0" Grid.ColumnSpan="2" ColumnDefinitions="*,Auto" Margin="0,0,0,18">
           <StackPanel Spacing="3">
             <TextBlock Text="{Binding PlanTitle}" FontSize="22" FontWeight="SemiBold"/>
             <TextBlock Text="{Binding PlanSubtitle}" Opacity="0.65"/>
           </StackPanel>
-          <StackPanel Grid.Column="1" VerticalAlignment="Bottom">
+          <StackPanel Grid.Column="1" VerticalAlignment="Bottom" Spacing="4">
+            <ToggleSwitch Content="Bearbeitungsmodus" IsChecked="{Binding IsEditMode}"
+                          IsVisible="{Binding IsEditable}" HorizontalAlignment="Right"/>
             <TextBlock Text="{Binding AssignmentSummary}" HorizontalAlignment="Right" FontSize="12" Opacity="0.6"/>
             <TextBlock Text="Ziehen: Platz ändern · Klicken: bewerten" HorizontalAlignment="Right"
-                       FontSize="11" Opacity="0.5"/>
+                       FontSize="11" Opacity="0.5" IsVisible="{Binding IsEditMode}"/>
+            <TextBlock Text="Klicken: bewerten" HorizontalAlignment="Right"
+                       FontSize="11" Opacity="0.5" IsVisible="{Binding IsEditMode, Converter={x:Static BoolConverters.Not}}"/>
           </StackPanel>
         </Grid>
 
-        <ScrollViewer Grid.Row="1" HorizontalScrollBarVisibility="Auto"
+        <ScrollViewer x:Name="RoomScrollViewer" Grid.Row="1" Grid.Column="0"
-                      VerticalScrollBarVisibility="Auto">
+                      Margin="0,0,16,0"
+                      HorizontalScrollBarVisibility="Auto"
+                      VerticalScrollBarVisibility="Auto"
+                      DragDrop.AllowDrop="True"
+                      DragDrop.DragOver="OnRoomDragOver"
+                      DragDrop.DragLeave="OnRoomDragLeave">
           <StackPanel Spacing="14" HorizontalAlignment="Center">
             <Border Background="{DynamicResource SystemControlBackgroundChromeMediumLowBrush}"
-                    CornerRadius="6" Padding="36,8" HorizontalAlignment="Center">
+                    CornerRadius="6" Padding="36,8" HorizontalAlignment="Center"
+                    IsVisible="{Binding IsBoardAtTop}">
               <TextBlock Text="Tafel / Vorderseite" FontWeight="SemiBold" Opacity="0.75"/>
             </Border>
             <ItemsControl ItemsSource="{Binding Seats}" HorizontalAlignment="Center">
               <ItemsControl.ItemsPanel>
                 <ItemsPanelTemplate>
-                  <UniformGrid Columns="{Binding PlanColumns}"/>
+                  <groups:SeatingPlanPanel Columns="{Binding PlanColumns}"
+                                           ColumnGapWidths="{Binding ColumnGapWidths}"/>
                 </ItemsPanelTemplate>
               </ItemsControl.ItemsPanel>
               <ItemsControl.ItemTemplate>
@@ -104,7 +116,7 @@
                     <StackPanel Spacing="5">
                       <Grid ColumnDefinitions="*,Auto">
                         <TextBlock Text="{Binding PositionLabel}" FontSize="10" Opacity="0.5"/>
-                        <TextBlock Grid.Column="1" Text="⠿" Opacity="0.45" IsVisible="{Binding IsOccupied}"/>
+                        <TextBlock Grid.Column="1" Text="⠿" Opacity="0.45" IsVisible="{Binding CanEdit}"/>
                       </Grid>
                       <TextBlock Text="{Binding StudentName}" FontWeight="SemiBold" FontSize="13"
                                  HorizontalAlignment="Center" VerticalAlignment="Center"/>
@@ -113,38 +125,52 @@
                 </DataTemplate>
               </ItemsControl.ItemTemplate>
             </ItemsControl>
+            <Border Background="{DynamicResource SystemControlBackgroundChromeMediumLowBrush}"
+                    CornerRadius="6" Padding="36,8" HorizontalAlignment="Center"
+                    IsVisible="{Binding IsBoardAtBottom}">
+              <TextBlock Text="Tafel / Vorderseite" FontWeight="SemiBold" Opacity="0.75"/>
+            </Border>
+          </StackPanel>
+        </ScrollViewer>
 
-            <Border DragDrop.AllowDrop="True" DragDrop.DragOver="OnUnassignedDragOver"
+        <!-- Die Schülerliste hat einen eigenen Scrollbereich und bleibt dadurch auch bei
+             großen Räumen neben den aktuell sichtbaren Sitzplätzen erreichbar. -->
+        <Border Grid.Row="1" Grid.Column="1"
+                Width="220" IsVisible="{Binding IsEditMode}"
+                DragDrop.AllowDrop="True" DragDrop.DragOver="OnUnassignedDragOver"
                 DragDrop.Drop="OnUnassignedDrop"
                 BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
-                    BorderThickness="1" CornerRadius="7" Padding="12" Margin="5,8">
+                BorderThickness="1" CornerRadius="7" Padding="12">
-              <StackPanel Spacing="8">
+          <Grid RowDefinitions="Auto,Auto,*">
-                <TextBlock Text="NICHT ZUGEORDNET" FontSize="10" FontWeight="Bold" Opacity="0.5"/>
+            <TextBlock Grid.Row="0" Text="NICHT ZUGEORDNET" FontSize="10"
-                <TextBlock Text="Schüler hierher ziehen, um einen Platz zu leeren."
+                       FontWeight="Bold" Opacity="0.5"/>
-                           FontSize="11" Opacity="0.5"/>
+            <TextBlock Grid.Row="1" Margin="0,5,0,10"
+                       Text="Schüler auf einen Platz ziehen. Belegte Plätze hierher ziehen, um sie zu leeren."
+                       TextWrapping="Wrap" FontSize="11" Opacity="0.5"/>
+            <ScrollViewer Grid.Row="2" VerticalScrollBarVisibility="Auto"
+                          HorizontalScrollBarVisibility="Disabled">
+              <StackPanel Spacing="6">
                 <ItemsControl ItemsSource="{Binding UnassignedStudents}">
-                  <ItemsControl.ItemsPanel>
-                    <ItemsPanelTemplate><WrapPanel/></ItemsPanelTemplate>
-                  </ItemsControl.ItemsPanel>
                   <ItemsControl.ItemTemplate>
                     <DataTemplate x:DataType="vm:StudentSeatOption">
                       <Border Background="{DynamicResource SystemAccentColorLight2}" CornerRadius="5"
-                              Padding="9,5" Margin="0,0,6,6"
+                              Padding="9,7"
                               PointerPressed="OnDragSourcePressed"
                               PointerMoved="OnDragSourceMoved"
                               PointerReleased="OnDragSourceReleased">
-                        <TextBlock Text="{Binding DisplayName}" FontSize="12"/>
+                        <TextBlock Text="{Binding DisplayName}" FontSize="12" TextTrimming="CharacterEllipsis"/>
                       </Border>
                     </DataTemplate>
                   </ItemsControl.ItemTemplate>
                 </ItemsControl>
                 <TextBlock Text="Alle Schüler sind zugeordnet." Classes="emptyhint"
+                           TextWrapping="Wrap"
                            IsVisible="{Binding !UnassignedStudents.Count}"/>
               </StackPanel>
-            </Border>
-          </StackPanel>
             </ScrollViewer>
           </Grid>
+        </Border>
+      </Grid>
     </Grid>
   </Grid>
 </UserControl>

LehrerApp.Desktop/Views/Groups/SeatingPlanTabView.axaml.cs

@@ -10,6 +10,9 @@ namespace LehrerApp.Desktop.Views.Groups;
 
 public partial class SeatingPlanTabView : UserControl
 {
+    private const double AutoScrollEdgeSize = 72;
+    private const double AutoScrollStep = 14;
+
     private object? _dragCandidate;
     private PointerPressedEventArgs? _dragTrigger;
     private Avalonia.Point _pressPosition;
@@ -18,8 +21,15 @@ public partial class SeatingPlanTabView : UserControl
     private SeatCellViewModel? _pendingDropTarget;
     private bool _pendingClearSeat;
     private DateTime _ignoreTapUntil;
+    private readonly DispatcherTimer _autoScrollTimer;
+    private Avalonia.Vector _autoScrollDirection;
 
-    public SeatingPlanTabView() => InitializeComponent();
+    public SeatingPlanTabView()
+    {
+        InitializeComponent();
+        _autoScrollTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(30) };
+        _autoScrollTimer.Tick += OnAutoScrollTick;
+    }
 
     protected override void OnDataContextChanged(EventArgs e)
     {
@@ -38,7 +48,7 @@ public partial class SeatingPlanTabView : UserControl
             !e.GetCurrentPoint(control).Properties.IsLeftButtonPressed) return;
         var candidate = control.DataContext;
         if (candidate is SeatCellViewModel { IsOccupied: false } or null) return;
-        if (DataContext is not SeatingPlanTabViewModel { IsEditable: true }) return;
+        if (DataContext is not SeatingPlanTabViewModel { CanEditLayout: true }) return;
         _dragCandidate = candidate;
         _dragTrigger = e;
         _pressPosition = e.GetPosition(this);
@@ -69,6 +79,7 @@ public partial class SeatingPlanTabView : UserControl
         _draggedStudent = null;
         _pendingDropTarget = null;
         _pendingClearSeat = false;
+        StopAutoScroll();
         _ignoreTapUntil = DateTime.UtcNow.AddMilliseconds(250);
 
         // Never mutate an ItemsControl while Avalonia is still processing its native
@@ -107,6 +118,7 @@ public partial class SeatingPlanTabView : UserControl
 
     private void OnSeatDrop(object? sender, DragEventArgs e)
     {
+        StopAutoScroll();
         if (sender is not Border { DataContext: SeatCellViewModel target }) return;
         target.IsDropTarget = false;
         if (!CanDropOn(target))
@@ -120,7 +132,7 @@ public partial class SeatingPlanTabView : UserControl
     }
 
     private bool CanDropOn(SeatCellViewModel target) =>
-        DataContext is SeatingPlanTabViewModel { IsEditable: true }
+        DataContext is SeatingPlanTabViewModel { CanEditLayout: true }
         && ((_draggedSeat is not null && _draggedSeat != target) || _draggedStudent?.StudentId is not null);
 
     private void OnUnassignedDragOver(object? sender, DragEventArgs e) =>
@@ -128,6 +140,7 @@ public partial class SeatingPlanTabView : UserControl
 
     private void OnUnassignedDrop(object? sender, DragEventArgs e)
     {
+        StopAutoScroll();
         if (_draggedSeat is not null)
         {
             _pendingDropTarget = null;
@@ -136,6 +149,50 @@ public partial class SeatingPlanTabView : UserControl
         }
     }
 
+    private void OnRoomDragOver(object? sender, DragEventArgs e)
+    {
+        if (_draggedSeat is null && _draggedStudent is null)
+        {
+            StopAutoScroll();
+            return;
+        }
+
+        var position = e.GetPosition(RoomScrollViewer);
+        _autoScrollDirection = new Avalonia.Vector(
+            GetAutoScrollDirection(position.X, RoomScrollViewer.Bounds.Width),
+            GetAutoScrollDirection(position.Y, RoomScrollViewer.Bounds.Height));
+
+        if (_autoScrollDirection == default)
+            StopAutoScroll();
+        else if (!_autoScrollTimer.IsEnabled)
+            _autoScrollTimer.Start();
+    }
+
+    private void OnRoomDragLeave(object? sender, DragEventArgs e) => StopAutoScroll();
+
+    private void OnAutoScrollTick(object? sender, EventArgs e)
+    {
+        var maxX = Math.Max(0, RoomScrollViewer.Extent.Width - RoomScrollViewer.Viewport.Width);
+        var maxY = Math.Max(0, RoomScrollViewer.Extent.Height - RoomScrollViewer.Viewport.Height);
+        var offset = RoomScrollViewer.Offset;
+        RoomScrollViewer.Offset = new Avalonia.Vector(
+            Math.Clamp(offset.X + _autoScrollDirection.X * AutoScrollStep, 0, maxX),
+            Math.Clamp(offset.Y + _autoScrollDirection.Y * AutoScrollStep, 0, maxY));
+    }
+
+    private static double GetAutoScrollDirection(double position, double viewportSize)
+    {
+        if (position < AutoScrollEdgeSize) return -1;
+        if (position > viewportSize - AutoScrollEdgeSize) return 1;
+        return 0;
+    }
+
+    private void StopAutoScroll()
+    {
+        _autoScrollDirection = default;
+        _autoScrollTimer.Stop();
+    }
+
     private async void OnSeatTapped(object? sender, TappedEventArgs e)
     {
         if (DateTime.UtcNow < _ignoreTapUntil || sender is not Border { DataContext: SeatCellViewModel seat }

LehrerApp.Tests/AttendanceBalanceServiceTests.cs

@@ -22,16 +22,22 @@ public sealed class AttendanceBalanceServiceTests
             (new DateOnly(2025, 9, 5), AttendanceStatus.Truant),
             (new DateOnly(2025, 9, 6), AttendanceStatus.OtherSchoolEvent),
             (new DateOnly(2025, 9, 7), AttendanceStatus.ExcusePending),
+            (new DateOnly(2025, 9, 8), AttendanceStatus.Late),
+            (new DateOnly(2025, 9, 9), AttendanceStatus.SignificantlyLate),
+            (new DateOnly(2025, 9, 10), AttendanceStatus.LeftDuringClass),
+            (new DateOnly(2025, 9, 11), AttendanceStatus.LearningIsland),
+            (new DateOnly(2025, 9, 12), AttendanceStatus.Suspended),
         };
 
         var balance = _service.Calculate(entries, From, To);
 
-        Assert.Equal(7, balance.TotalChecked);
+        Assert.Equal(12, balance.TotalChecked);
-        Assert.Equal(2, balance.Present);
+        Assert.Equal(4, balance.Present);
         Assert.Equal(1, balance.Excused);
-        Assert.Equal(2, balance.Unexcused); // Unexcused + Truant
+        Assert.Equal(3, balance.Unexcused); // Unexcused + Truant + im Unterricht abgängig
-        Assert.Equal(1, balance.SchoolEvent);
+        Assert.Equal(3, balance.SchoolEvent); // Schulveranstaltung + Lerninsel + Suspendierung
         Assert.Equal(1, balance.ExcusePending);
+        Assert.Equal(41.7, balance.AbsenceRatePercent);
     }
 
     [Fact]