Changed cost page to view affected flats together with the name.

ucalc/Controls/Converters.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.Linq;
 using System.Windows;
 using System.Windows.Data;
 using UCalc.Models;
@@ -149,6 +150,36 @@ namespace UCalc.Controls
         }
     }
 
+    public class CostToAffectedConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            var cost = (CostProperty) value;
+
+            if (cost == null)
+            {
+                return "";
+            }
+
+            if (cost.AffectsAll.Value)
+            {
+                return "Betrifft: Alle Wohnungen";
+            }
+
+            if (cost.AffectedFlats.Count == 0)
+            {
+                return "Betrifft: Niemanden";
+            }
+
+            return $"Betrifft: {string.Join(", ", cost.AffectedFlats.Select(flat => flat.Name.Value))}";
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new InvalidOperationException();
+        }
+    }
+
     public class NegateConverter : IValueConverter
     {
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)

ucalc/Controls/HighlightButton.cs

@@ -64,6 +64,9 @@ namespace UCalc.Controls
                     case Label label:
                         label.Foreground = foreground;
                         break;
+                    case TextBlock block:
+                        block.Foreground = foreground;
+                        break;
                     case Path path:
                         path.Fill = foreground;
                         break;

ucalc/Models/CostProperty.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using UCalc.Data;
 
@@ -13,13 +14,16 @@ namespace UCalc.Models
 
         protected override string ValidateValue()
         {
+            var affectedFlats = ((CostProperty) Parent).AffectedFlats;
+
             using var validator = Model.BeginValidation();
-            validator.Validate(((CostProperty) Parent).AffectedFlats);
+            validator.Validate(affectedFlats);
+
             return "";
         }
     }
 
-    public class AffectedFlatsProperty : Property
+    public class AffectedFlatsProperty : Property, IReadOnlyCollection<FlatProperty>
     {
         private const string NoFlatsError = "Betroffene Wohnungen: Es wurde keine Wohnung zugewiesen.";
         private readonly HashSet<FlatProperty> _flats;
@@ -81,7 +85,21 @@ namespace UCalc.Models
 
             using var validator = Model.BeginValidation();
             validator.Notify(this, "Errors");
+
+            Model.Root.Costs.NotifyChanged((CostProperty) Parent);
         }
+
+        public IEnumerator<FlatProperty> GetEnumerator()
+        {
+            return _flats.GetEnumerator();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+
+        public int Count => _flats.Count;
     }
 
     public class CostProperty : NestedProperty

ucalc/Models/Properties.cs

@@ -285,6 +285,18 @@ namespace UCalc.Models
             validator.ValidateRange(_properties);
         }
 
+        public void NotifyChanged(T property)
+        {
+            var index = _properties.IndexOf(property);
+            if (index == -1)
+            {
+                return;
+            }
+
+            CollectionChanged?.Invoke(this,
+                new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+        }
+
         public sealed override void OnPropertyChanged(string propertyName = null)
         {
             switch (propertyName)

ucalc/Pages/CostsPage.xaml

@@ -11,6 +11,7 @@
     <Page.Resources>
         <controls:EmptyMultiPropertyToVisibilityConverter x:Key="EmptyMultiPropertyToVisibilityConverter" />
         <controls:NameToTextConverter x:Key="NameToTextConverter" />
+        <controls:CostToAffectedConverter x:Key="CostToAffectedConverter" />
     </Page.Resources>
 
     <DockPanel>
@@ -88,8 +89,13 @@
                                                     DockPanel.Dock="Left"
                                                     Margin="12, 12, 8, 12" />
 
-                                <Label Content="{Binding Path=Name.Value, Converter={StaticResource NameToTextConverter}}"
-                                       VerticalAlignment="Center" />
+                                <TextBlock VerticalAlignment="Center">
+                                    <Run
+                                        Text="{Binding Path=Name.Value, Converter={StaticResource NameToTextConverter}}" />
+                                    <LineBreak />
+                                    <Run
+                                        Text="{Binding Path=., Converter={StaticResource CostToAffectedConverter}}" />
+                                </TextBlock>
                             </controls:HighlightButton>
                         </DockPanel>
                     </DataTemplate>