From 9317aeda6a73c734c9091559a73b28865696b020 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Fri, 4 Oct 2019 00:07:21 +0200
Subject: [PATCH] Added "Randomize Heights" to ItemsRepeaterPage.

---
 .../Pages/ItemsRepeaterPage.xaml              |  9 ++++-
 .../Pages/ItemsRepeaterPage.xaml.cs           |  2 +-
 .../ViewModels/ItemsRepeaterPageViewModel.cs  | 39 ++++++++++++++++---
 3 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml b/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml
index d0631d2cbd..103c016298 100644
--- a/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml
+++ b/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml
@@ -14,12 +14,19 @@
         <ComboBoxItem>UniformGrid - Horizontal</ComboBoxItem>
       </ComboBox>
       <Button Command="{Binding AddItem}">Add Item</Button>
+      <Button Command="{Binding RandomizeHeights}">Randomize Heights</Button>
     </StackPanel>
     <Border BorderThickness="1" BorderBrush="{DynamicResource ThemeBorderMidBrush}" Margin="0 0 0 16">
       <ScrollViewer Name="scroller"
                     HorizontalScrollBarVisibility="Auto"
                     VerticalScrollBarVisibility="Auto">
-        <ItemsRepeater Name="repeater" Background="Transparent" Items="{Binding Items}"/>
+        <ItemsRepeater Name="repeater" Background="Transparent" Items="{Binding Items}">
+          <ItemsRepeater.ItemTemplate>
+            <DataTemplate>
+              <TextBlock Height="{Binding Height}" Text="{Binding Text}"/>
+            </DataTemplate>
+          </ItemsRepeater.ItemTemplate>
+        </ItemsRepeater>
       </ScrollViewer>
     </Border>
   </DockPanel>
diff --git a/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs b/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs
index 1a607342f3..decd849adc 100644
--- a/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs
@@ -74,7 +74,7 @@ namespace ControlCatalog.Pages
 
         private void RepeaterClick(object sender, PointerPressedEventArgs e)
         {
-            var item = (e.Source as TextBlock)?.DataContext as string;
+            var item = (e.Source as TextBlock)?.DataContext as ItemsRepeaterPageViewModel.Item;
             ((ItemsRepeaterPageViewModel)DataContext).SelectedItem = item;
         }
     }
diff --git a/samples/ControlCatalog/ViewModels/ItemsRepeaterPageViewModel.cs b/samples/ControlCatalog/ViewModels/ItemsRepeaterPageViewModel.cs
index 25fd550520..bc2ce80714 100644
--- a/samples/ControlCatalog/ViewModels/ItemsRepeaterPageViewModel.cs
+++ b/samples/ControlCatalog/ViewModels/ItemsRepeaterPageViewModel.cs
@@ -1,4 +1,5 @@
-using System.Collections.ObjectModel;
+using System;
+using System.Collections.ObjectModel;
 using System.Linq;
 using ReactiveUI;
 
@@ -10,18 +11,44 @@ namespace ControlCatalog.ViewModels
 
         public ItemsRepeaterPageViewModel()
         {
-            Items = new ObservableCollection<string>(
-                Enumerable.Range(1, 100000).Select(i => $"Item {i.ToString()}"));
+            Items = new ObservableCollection<Item>(
+                Enumerable.Range(1, 100000).Select(i => new Item
+                {
+                    Text = $"Item {i.ToString()}",
+                }));
         }
 
-        public ObservableCollection<string> Items { get; }
+        public ObservableCollection<Item> Items { get; }
 
-        public string SelectedItem { get; set; }
+        public Item SelectedItem { get; set; }
 
         public void AddItem()
         {
             var index = SelectedItem != null ? Items.IndexOf(SelectedItem) : -1;
-            Items.Insert(index + 1, $"New Item {newItemIndex++}");
+            Items.Insert(index + 1, new Item { Text = $"New Item {newItemIndex++}" });
+        }
+
+        public void RandomizeHeights()
+        {
+            var random = new Random();
+
+            foreach (var i in Items)
+            {
+                i.Height = random.Next(240) + 10;
+            }
+        }
+
+        public class Item : ReactiveObject
+        {
+            private double _height = double.NaN;
+
+            public string Text { get; set; }
+            
+            public double Height 
+            {
+                get => _height;
+                set => this.RaiseAndSetIfChanged(ref _height, value);
+            }
         }
     }
 }