feat: Anhänge je Stunde, Klausur-Sitzplan mischen, Gefährdungsbeurteilungs-Assistent

Lesson bekommt dieselbe Anhang-Infrastruktur wie Documentation (Material,
Arbeitsblätter, Experimentunterlagen), samt Fix einer Sync-Lücke, die Anhang-
Dateibytes bisher nur für Documentation statt generisch übertragen hat
(IHasAttachments). Sitzplan-Tab bekommt einen "Plätze mischen"-Button für
Klausursitzpläne. Neu: mehrschrittiger Gefährdungsbeurteilungs-Assistent mit
optionalem KI-Entwurf (ai-backend/gbu.php) und PDF-Export, Format bewusst als
JSON-Anhang statt eigener Datenbank-Entität. Details und Architekturentscheidungen
in TODO.md (4.2, 7.1.5, 10.1.8).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
This commit is contained in:
2026-08-20 17:13:14 +02:00
co-authored by Claude Sonnet 5
parent 331033db5c
commit 038337997f
29 changed files with 1886 additions and 22 deletions
@@ -0,0 +1,203 @@
<Window xmlns="https://github.com/avaloniaui"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
x:Class="LehrerApp.Desktop.Views.Groups.HazardAssessmentWizardDialog"
x:DataType="vm:HazardAssessmentWizardViewModel"
Title="{Binding DialogTitle}"
Width="720" Height="720" MinWidth="600" MinHeight="480"
CanResize="True" WindowStartupLocation="CenterOwner">
<Grid RowDefinitions="Auto,Auto,*,Auto" Margin="24">
<StackPanel Grid.Row="0" Spacing="2" Margin="0,0,0,10">
<TextBlock Text="{Binding DialogTitle}" Classes="dialogtitle"/>
<TextBlock FontSize="12" Opacity="0.7">
<Run Text="{Binding StepProgressLabel}"/>
<Run Text=" · "/>
<Run Text="{Binding StepTitle}" FontWeight="SemiBold"/>
</TextBlock>
</StackPanel>
<Border Grid.Row="1" IsVisible="{Binding CanUseAi}" Background="#FFF3E0" CornerRadius="6"
Padding="10" Margin="0,0,0,10">
<Grid ColumnDefinitions="*,Auto">
<StackPanel Grid.Column="0" Spacing="2">
<TextBlock FontSize="12" TextWrapping="Wrap">
<Run Text="🤖 KI-Entwurf auf Basis von Thema und Verlaufsplan dieser Stunde." FontWeight="SemiBold"/>
<LineBreak/>
<Run Text="⚠️ Kein rechtssicheres Dokument — bitte jede Angabe (insbesondere H-/P-Sätze und Mengen) eigenverantwortlich gegen das Sicherheitsdatenblatt prüfen, bevor du die Gefährdungsbeurteilung verwendest."/>
</TextBlock>
<TextBlock Text="{Binding AiError}" Foreground="Red" FontSize="11"
IsVisible="{Binding AiError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
</StackPanel>
<Button Grid.Column="1" Content="{Binding AiButtonLabel}" Command="{Binding RequestAiDraftCommand}"
IsEnabled="{Binding !IsAiBusy}" VerticalAlignment="Top" Margin="10,0,0,0"/>
</Grid>
</Border>
<ScrollViewer Grid.Row="2">
<StackPanel Spacing="14" Margin="0,0,12,0">
<!-- Schritt 1: Basisdaten -->
<StackPanel Spacing="10" IsVisible="{Binding IsBasicsStep}">
<StackPanel Spacing="4">
<TextBlock Text="Titel *" FontSize="12" Opacity="0.7"/>
<TextBox Text="{Binding Title}" PlaceholderText="z.B. Natrium in Wasser"/>
<TextBlock Text="{Binding TitleError}" Foreground="Red" FontSize="11"
IsVisible="{Binding TitleError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
</StackPanel>
<Grid ColumnDefinitions="*,12,*,12,*">
<StackPanel Grid.Column="0" Spacing="4">
<TextBlock Text="Klassenstufe/Kurs" FontSize="12" Opacity="0.7"/>
<TextBox Text="{Binding GroupLabel}"/>
</StackPanel>
<StackPanel Grid.Column="2" Spacing="4">
<TextBlock Text="Datum" FontSize="12" Opacity="0.7"/>
<TextBox Text="{Binding DateText}" PlaceholderText="TT.MM.JJJJ"/>
</StackPanel>
<StackPanel Grid.Column="4" Spacing="4">
<TextBlock Text="Art des Versuchs" FontSize="12" Opacity="0.7"/>
<ComboBox ItemsSource="{Binding KindOptions}" SelectedItem="{Binding KindName}"
HorizontalAlignment="Stretch"/>
</StackPanel>
</Grid>
<StackPanel Spacing="4">
<TextBlock Text="Durchführung (Kurzbeschreibung)" FontSize="12" Opacity="0.7"/>
<TextBox Text="{Binding Procedure}" AcceptsReturn="True" TextWrapping="Wrap" Height="90"/>
</StackPanel>
</StackPanel>
<!-- Schritt 2: Gefahrstoffe -->
<StackPanel Spacing="10" IsVisible="{Binding IsSubstancesStep}">
<Grid ColumnDefinitions="*,Auto">
<TextBlock Grid.Column="0" Text="Verwendete Gefahrstoffe" FontSize="13" FontWeight="SemiBold"
VerticalAlignment="Center"/>
<Button Grid.Column="1" Content=" Stoff" Command="{Binding AddSubstanceCommand}"/>
</Grid>
<TextBlock Text="Noch keine Gefahrstoffe erfasst." Classes="emptyhint"
IsVisible="{Binding !HasSubstances}"/>
<ItemsControl ItemsSource="{Binding Substances}">
<ItemsControl.ItemTemplate>
<DataTemplate x:DataType="vm:HazardSubstanceEditItem">
<Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
BorderThickness="0,0,0,1" Padding="0,10">
<StackPanel Spacing="6">
<Grid ColumnDefinitions="*,140,Auto">
<TextBox Grid.Column="0" Text="{Binding Name}" PlaceholderText="Stoffname"
Margin="0,0,8,0"/>
<TextBox Grid.Column="1" Text="{Binding Amount}" PlaceholderText="Menge, z.B. ca. 2 g"
Margin="0,0,8,0"/>
<Button Grid.Column="2" Content="✕" Command="{Binding RemoveCommand}"
ToolTip.Tip="Stoff entfernen"/>
</Grid>
<ItemsControl ItemsSource="{Binding PictogramOptions}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate><WrapPanel ItemSpacing="10" LineSpacing="4"/></ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate x:DataType="vm:GhsPictogramOption">
<CheckBox Content="{Binding Label}" IsChecked="{Binding IsSelected}" FontSize="12"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<Grid ColumnDefinitions="*,12,*">
<StackPanel Grid.Column="0" Spacing="2">
<TextBlock Text="H-Sätze" FontSize="11" Opacity="0.6"/>
<TextBox Text="{Binding HStatements}" PlaceholderText="z.B. H314, H290"/>
</StackPanel>
<StackPanel Grid.Column="2" Spacing="2">
<TextBlock Text="P-Sätze" FontSize="11" Opacity="0.6"/>
<TextBox Text="{Binding PStatements}" PlaceholderText="z.B. P280, P305+P351+P338"/>
</StackPanel>
</Grid>
</StackPanel>
</Border>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
<!-- Schritt 3: Gefährdungen & Schutzmaßnahmen -->
<StackPanel Spacing="14" IsVisible="{Binding IsHazardsStep}">
<StackPanel Spacing="6">
<TextBlock Text="Identifizierte Gefährdungen" FontSize="13" FontWeight="SemiBold"/>
<ItemsControl ItemsSource="{Binding Hazards}">
<ItemsControl.ItemTemplate>
<DataTemplate x:DataType="x:String">
<Grid ColumnDefinitions="*,Auto" Margin="0,2">
<TextBlock Grid.Column="0" Text="{Binding}" VerticalAlignment="Center"/>
<Button Grid.Column="1" Content="×" FontSize="13" Padding="7,2"
Command="{Binding $parent[ItemsControl].((vm:HazardAssessmentWizardViewModel)DataContext).RemoveHazardCommand}"
CommandParameter="{Binding}"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<Grid ColumnDefinitions="*,8,Auto">
<TextBox Grid.Column="0" Text="{Binding NewHazard}" PlaceholderText="z.B. Verätzungsgefahr an Haut/Augen"/>
<Button Grid.Column="2" Content="" Command="{Binding AddHazardCommand}"/>
</Grid>
</StackPanel>
<StackPanel Spacing="6">
<TextBlock Text="Schutzmaßnahmen" FontSize="13" FontWeight="SemiBold"/>
<ItemsControl ItemsSource="{Binding ProtectiveMeasures}">
<ItemsControl.ItemTemplate>
<DataTemplate x:DataType="x:String">
<Grid ColumnDefinitions="*,Auto" Margin="0,2">
<TextBlock Grid.Column="0" Text="{Binding}" VerticalAlignment="Center"/>
<Button Grid.Column="1" Content="×" FontSize="13" Padding="7,2"
Command="{Binding $parent[ItemsControl].((vm:HazardAssessmentWizardViewModel)DataContext).RemoveProtectiveMeasureCommand}"
CommandParameter="{Binding}"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<Grid ColumnDefinitions="*,8,Auto">
<TextBox Grid.Column="0" Text="{Binding NewProtectiveMeasure}" PlaceholderText="z.B. Schutzbrille, Handschuhe, Abzug"/>
<Button Grid.Column="2" Content="" Command="{Binding AddProtectiveMeasureCommand}"/>
</Grid>
</StackPanel>
</StackPanel>
<!-- Schritt 4: Erste Hilfe & Entsorgung -->
<StackPanel Spacing="10" IsVisible="{Binding IsFirstAidStep}">
<StackPanel Spacing="4">
<TextBlock Text="Erste Hilfe" FontSize="12" Opacity="0.7"/>
<TextBox Text="{Binding FirstAid}" AcceptsReturn="True" TextWrapping="Wrap" Height="90"/>
</StackPanel>
<StackPanel Spacing="4">
<TextBlock Text="Entsorgung" FontSize="12" Opacity="0.7"/>
<TextBox Text="{Binding Disposal}" AcceptsReturn="True" TextWrapping="Wrap" Height="70"/>
</StackPanel>
<StackPanel Spacing="4">
<TextBlock Text="Weitere Hinweise" FontSize="12" Opacity="0.7"/>
<TextBox Text="{Binding Notes}" AcceptsReturn="True" TextWrapping="Wrap" Height="60"/>
</StackPanel>
</StackPanel>
<!-- Schritt 5: Zusammenfassung -->
<StackPanel Spacing="8" IsVisible="{Binding IsSummaryStep}">
<TextBlock Text="{Binding Title}" FontSize="15" FontWeight="SemiBold"/>
<TextBlock FontSize="12" Opacity="0.7">
<Run Text="{Binding GroupLabel}"/>
<Run Text=" · "/>
<Run Text="{Binding KindName}"/>
</TextBlock>
<TextBlock Text="{Binding Procedure}" TextWrapping="Wrap"/>
<TextBlock Text="{Binding Substances.Count, StringFormat='{}{0} Gefahrstoff(e) erfasst'}" FontSize="12"/>
<TextBlock Text="Alle Angaben vor dem Einsatz noch einmal gegenprüfen." FontSize="12" Opacity="0.7"
IsVisible="{Binding IsAiAssisted}"/>
</StackPanel>
</StackPanel>
</ScrollViewer>
<Grid Grid.Row="3" ColumnDefinitions="Auto,*,Auto,8,Auto,8,Auto" Margin="0,16,0,0">
<Button Grid.Column="0" Content="Abbrechen" Click="OnCancel"/>
<Button Grid.Column="2" Content="Zurück" Command="{Binding BackCommand}"
IsVisible="{Binding !IsFirstStep}"/>
<Button Grid.Column="4" Content="Weiter" Command="{Binding NextCommand}"
IsVisible="{Binding !IsLastStep}"/>
<Button Grid.Column="6" Content="Speichern" Click="OnSave" IsVisible="{Binding IsLastStep}"/>
</Grid>
</Grid>
</Window>
@@ -0,0 +1,21 @@
using Avalonia.Controls;
using Avalonia.Interactivity;
using LehrerApp.Desktop.ViewModels.Groups;
namespace LehrerApp.Desktop.Views.Groups;
public partial class HazardAssessmentWizardDialog : Window
{
public HazardAssessmentWizardDialog() => InitializeComponent();
private void OnSave(object? sender, RoutedEventArgs e)
{
if (DataContext is HazardAssessmentWizardViewModel vm)
{
vm.SaveCommand.Execute(null);
if (vm.Result is not null) Close(true);
}
}
private void OnCancel(object? sender, RoutedEventArgs e) => Close(false);
}
@@ -1,6 +1,7 @@
<Window xmlns="https://github.com/avaloniaui"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
xmlns:vms="clr-namespace:LehrerApp.Desktop.ViewModels.Students"
x:Class="LehrerApp.Desktop.Views.Groups.LessonDialog"
x:DataType="vm:LessonDialogViewModel"
Title="{Binding DialogTitle}"
@@ -139,6 +140,43 @@
<TextBox Text="{Binding Reflection}" AcceptsReturn="True" Height="56" TextWrapping="Wrap"
PlaceholderText="Nach der Stunde: was lief gut, was nicht?"/>
</StackPanel>
<Separator Margin="0,4"/>
<StackPanel Spacing="6">
<Grid ColumnDefinitions="*,Auto">
<TextBlock Grid.Column="0" Text="Anhänge (Material, Arbeitsblätter, Experiment-/Gefährdungsbeurteilung)"
FontSize="12" Opacity="0.7" VerticalAlignment="Center"/>
<StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="6">
<Button Content="🧪 Gefährdungsbeurteilung" FontSize="12" Padding="8,4" Click="OnCreateHazardAssessment"/>
<Button Content=" Datei" FontSize="12" Padding="8,4" Click="OnAddAttachment"/>
</StackPanel>
</Grid>
<ItemsControl ItemsSource="{Binding Attachments}">
<ItemsControl.ItemTemplate>
<DataTemplate x:DataType="vms:AttachmentItem">
<Grid ColumnDefinitions="*,Auto,Auto,Auto,Auto" Margin="0,2">
<TextBlock Grid.Column="0" Text="{Binding FileName}" VerticalAlignment="Center" FontSize="13"
TextTrimming="CharacterEllipsis"/>
<TextBlock Grid.Column="1" Text="{Binding SizeDisplay}" VerticalAlignment="Center"
FontSize="11" Opacity="0.5" Margin="6,0"/>
<Button Grid.Column="2" Content="Öffnen" FontSize="11" Padding="7,2" Margin="0,0,4,0"
Click="OnOpenHazardAssessment" Tag="{Binding}" IsVisible="{Binding IsHazardAssessment}"/>
<Button Grid.Column="2" Content="Speichern" FontSize="11" Padding="7,2" Margin="0,0,4,0"
Click="OnOpenAttachment" Tag="{Binding}" IsVisible="{Binding !IsHazardAssessment}"/>
<Button Grid.Column="3" Content="PDF" FontSize="11" Padding="7,2" Margin="0,0,4,0"
Click="OnPrintHazardAssessment" Tag="{Binding}"
IsVisible="{Binding IsHazardAssessment}"/>
<Button Grid.Column="4" Content="×" FontSize="13" Padding="7,2"
Command="{Binding $parent[ItemsControl].((vm:LessonDialogViewModel)DataContext).RemoveAttachmentCommand}"
CommandParameter="{Binding}"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<TextBlock Text="{Binding AttachmentError}" Foreground="Red" FontSize="11"
IsVisible="{Binding AttachmentError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
</StackPanel>
</StackPanel>
</ScrollViewer>
@@ -1,9 +1,11 @@
using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Platform.Storage;
using LehrerApp.Core.Interfaces;
using LehrerApp.Core.Models;
using LehrerApp.Desktop.Services;
using LehrerApp.Desktop.ViewModels.Groups;
using LehrerApp.Desktop.ViewModels.Students;
using Microsoft.Extensions.DependencyInjection;
namespace LehrerApp.Desktop.Views.Groups;
@@ -38,7 +40,136 @@ public partial class LessonDialog : Window
}
}
private void OnCancel(object? s, RoutedEventArgs e) => Close(false);
private void OnCancel(object? s, RoutedEventArgs e)
{
if (DataContext is LessonDialogViewModel vm) vm.DiscardUnsavedAttachments();
Close(false);
}
private async void OnAddAttachment(object? sender, RoutedEventArgs e)
{
if (DataContext is not LessonDialogViewModel vm) return;
var files = await StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
{
Title = "Anhang auswählen", AllowMultiple = false,
});
if (files.Count == 0) return;
await using var stream = await files[0].OpenReadAsync();
vm.AddAttachment(files[0].Name, stream);
}
private async void OnOpenAttachment(object? sender, RoutedEventArgs e)
{
if (DataContext is not LessonDialogViewModel vm) return;
if (sender is not Button { Tag: AttachmentItem item }) return;
using var source = vm.OpenAttachment(item);
if (source is null) return;
var file = await StorageProvider.SaveFilePickerAsync(new FilePickerSaveOptions
{
Title = "Anhang speichern unter", SuggestedFileName = item.FileName,
});
if (file is null) return;
await using var target = await file.OpenWriteAsync();
await source.CopyToAsync(target);
}
private async void OnCreateHazardAssessment(object? sender, RoutedEventArgs e)
{
if (DataContext is not LessonDialogViewModel vm) return;
var (unit, contextLesson, groupName) = BuildHazardAssessmentContext(vm);
var dialogVm = new HazardAssessmentWizardViewModel(null, groupName,
App.Services.GetRequiredService<AiPlanningService>(), App.Services.GetRequiredService<AiSettingsService>(),
unit, contextLesson);
var dialog = new HazardAssessmentWizardDialog { DataContext = dialogVm };
var ok = await dialog.ShowDialog<bool>(this);
if (!ok || dialogVm.Result is null) return;
UploadHazardAssessment(vm, dialogVm.Result);
}
private async void OnOpenHazardAssessment(object? sender, RoutedEventArgs e)
{
if (DataContext is not LessonDialogViewModel vm) return;
if (sender is not Button { Tag: AttachmentItem item }) return;
var editing = await ReadHazardAssessmentAsync(vm, item);
if (editing is null) return;
var (unit, contextLesson, _) = BuildHazardAssessmentContext(vm);
var dialogVm = new HazardAssessmentWizardViewModel(editing, editing.GroupLabel,
App.Services.GetRequiredService<AiPlanningService>(), App.Services.GetRequiredService<AiSettingsService>(),
unit, contextLesson);
var dialog = new HazardAssessmentWizardDialog { DataContext = dialogVm };
var ok = await dialog.ShowDialog<bool>(this);
if (!ok || dialogVm.Result is null) return;
vm.RemoveAttachmentCommand.Execute(item);
UploadHazardAssessment(vm, dialogVm.Result);
}
private async void OnPrintHazardAssessment(object? sender, RoutedEventArgs e)
{
var topLevel = TopLevel.GetTopLevel(this);
if (topLevel is null || DataContext is not LessonDialogViewModel vm) return;
if (sender is not Button { Tag: AttachmentItem item }) return;
var assessment = await ReadHazardAssessmentAsync(vm, item);
if (assessment is null) return;
var data = new HazardAssessmentPrintData(
assessment.Title, assessment.GroupLabel, assessment.Date?.ToString("dd.MM.yyyy") ?? "",
ExperimentKindDisplay.Label(assessment.Kind), assessment.Procedure,
assessment.Substances.Select(s => new HazardSubstancePrintRow(
s.Name, s.Amount, string.Join(", ", s.GhsPictograms.Select(GhsPictogramDisplay.Code)),
s.HStatements, s.PStatements)).ToList(),
assessment.Hazards, assessment.ProtectiveMeasures, assessment.FirstAid, assessment.Disposal,
assessment.Notes, assessment.IsAiAssisted);
var pdf = App.Services.GetRequiredService<PdfExportService>().BuildHazardAssessmentPdf(data);
await App.Services.GetRequiredService<ExportService>().SaveAsync(topLevel.StorageProvider,
ExportFile.Pdf("Gefährdungsbeurteilung als PDF speichern", $"GBU_{assessment.Title}", pdf));
}
/// Baut den Kontext für den Gefährdungsbeurteilungs-Assistenten (KI-Anfrage + Vorbelegung) aus
/// dem gerade im Dialog bearbeiteten, ggf. noch nicht gespeicherten Stand — funktioniert damit
/// auch beim Neuanlegen einer Stunde, bevor überhaupt gespeichert wurde.
private (Unit? Unit, Lesson ContextLesson, string GroupName) BuildHazardAssessmentContext(LessonDialogViewModel vm)
{
var unit = App.Services.GetRequiredService<IUnitRepository>().GetById(vm.UnitId);
var groupName = unit is null ? "" : App.Services.GetRequiredService<IGroupRepository>().GetById(unit.GroupId)?.Name ?? "";
var contextLesson = new Lesson { Topic = vm.Topic, Phases = vm.Phases.Select(p => p.ToModel()).ToList() };
return (unit, contextLesson, groupName);
}
private static async Task<HazardAssessment?> ReadHazardAssessmentAsync(LessonDialogViewModel vm, AttachmentItem item)
{
using var source = vm.OpenAttachment(item);
if (source is null) return null;
using var reader = new StreamReader(source);
var json = await reader.ReadToEndAsync();
return System.Text.Json.JsonSerializer.Deserialize<HazardAssessment>(json);
}
private static void UploadHazardAssessment(LessonDialogViewModel vm, HazardAssessment result)
{
var json = System.Text.Json.JsonSerializer.Serialize(result);
using var stream = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(json));
vm.AddAttachment(HazardAssessmentFileName(result.Title), stream);
}
private static string HazardAssessmentFileName(string title)
{
var invalid = Path.GetInvalidFileNameChars();
var safe = new string(title.Select(c => invalid.Contains(c) ? '_' : c).ToArray()).Trim();
if (safe.Length == 0) safe = "Gefaehrdungsbeurteilung";
return safe + AttachmentItem.HazardAssessmentSuffix;
}
/// KI-Unterstützung mit Fokus auf genau diese (bereits gespeicherte) Stunde, statt den Umweg
/// über die Einheiten-Übersicht nehmen zu müssen (4.5.22, Nutzer-Feedback). Die Übernahme im
@@ -99,6 +99,7 @@ public partial class PlanningTabView : UserControl
App.Services.GetRequiredService<IAlternativeLessonPathRepository>(),
App.Services.GetRequiredService<ITimetableSlotRepository>(),
App.Services.GetRequiredService<PeriodScheduleService>(),
App.Services.GetRequiredService<IAttachmentStorage>(),
unitId, groupId, vm.GroupLabel, vm.SubjectName,
materialSuggestions, shorthandHistorySuggestions, editingLesson);
@@ -51,6 +51,9 @@
<Button Grid.Column="2" Content="Löschen" Command="{Binding DeletePlanCommand}"
HorizontalAlignment="Stretch"/>
</Grid>
<Button Content="🎲 Plätze für Klausur mischen" Command="{Binding ShuffleSeatsCommand}"
HorizontalAlignment="Stretch" IsVisible="{Binding HasSelectedPlan}"
ToolTip.Tip="Legt einen neuen, unabhängigen Sitzplan mit demselben Raster an, in dem die belegten Plätze zufällig neu vertauscht sind. Der ursprüngliche Plan bleibt unverändert erhalten."/>
</StackPanel>
</Grid>
</Border>