WIP: Trying to repro #2957

And failing...

samples/ControlCatalog/Pages/CarouselPage.xaml

@@ -1,43 +1,11 @@
 <UserControl xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              x:Class="ControlCatalog.Pages.CarouselPage">
-  <StackPanel Orientation="Vertical" Spacing="4">
-    <TextBlock Classes="h1">Carousel</TextBlock>
-    <TextBlock Classes="h2">An items control that displays its items as pages that fill the control.</TextBlock>
-
-    <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0 16 0 0" Spacing="8">
-      <Button Name="left" VerticalAlignment="Center" Padding="20">
-        <Path Data="M20,11V13H8L13.5,18.5L12.08,19.92L4.16,12L12.08,4.08L13.5,5.5L8,11H20Z" Fill="Black"/>
-      </Button>
-      <Carousel Name="carousel">
-        <Carousel.PageTransition>
-          <PageSlide Duration="0.25" Orientation="Vertical" />
-        </Carousel.PageTransition>
-        <Image Source="/Assets/delicate-arch-896885_640.jpg"/>
-        <Image Source="/Assets/hirsch-899118_640.jpg"/>
-        <Image Source="/Assets/maple-leaf-888807_640.jpg"/>
-      </Carousel>
-      <Button Name="right" VerticalAlignment="Center" Padding="20">
-        <Path Data="M4,11V13H16L10.5,18.5L11.92,19.92L19.84,12L11.92,4.08L10.5,5.5L16,11H4Z" Fill="Black"/>
-      </Button>
-    </StackPanel>
-
-    <StackPanel Orientation="Horizontal" Spacing="4">
-      <TextBlock VerticalAlignment="Center">Transition</TextBlock>
-      <ComboBox Name="transition" SelectedIndex="1" VerticalAlignment="Center">
-        <ComboBoxItem>None</ComboBoxItem>
-        <ComboBoxItem>Slide</ComboBoxItem>
-        <ComboBoxItem>Crossfade</ComboBoxItem>
-      </ComboBox>
-    </StackPanel>
-
-    <StackPanel Orientation="Horizontal" Spacing="4">
-      <TextBlock VerticalAlignment="Center">Orientation</TextBlock>
-      <ComboBox Name="orientation" SelectedIndex="1" VerticalAlignment="Center">
-        <ComboBoxItem>Horizontal</ComboBoxItem>
-        <ComboBoxItem>Vertical</ComboBoxItem>
-      </ComboBox>
-    </StackPanel>
-    
-  </StackPanel>
+  <DockPanel>
+    <Button Name="left" DockPanel.Dock="Left" VerticalAlignment="Center">Left</Button>
+    <Button Name="right" DockPanel.Dock="Right" VerticalAlignment="Center">Right</Button>
+    <Button Name="add" DockPanel.Dock="Top">Add</Button>
+    <Carousel Name="carousel" Items="{Binding Items}" SelectedItem="{Binding SelectedItem}">
+    </Carousel>
+  </DockPanel>
 </UserControl>

samples/ControlCatalog/Pages/CarouselPage.xaml.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.ObjectModel;
 using Avalonia.Animation;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
@@ -10,16 +11,17 @@ namespace ControlCatalog.Pages
         private Carousel _carousel;
         private Button _left;
         private Button _right;
-        private ComboBox _transition;
-        private ComboBox _orientation;
+        private Button _add;
 
         public CarouselPage()
         {
             this.InitializeComponent();
+
+            var vm = new ViewModel();
+            DataContext = vm;
             _left.Click += (s, e) => _carousel.Previous();
             _right.Click += (s, e) => _carousel.Next();
-            _transition.SelectionChanged += TransitionChanged;
-            _orientation.SelectionChanged += TransitionChanged;
+            _add.Click += (s, e) => vm.Items.Add("boo");
         }
 
         private void InitializeComponent()
@@ -28,24 +30,19 @@ namespace ControlCatalog.Pages
             _carousel = this.FindControl<Carousel>("carousel");
             _left = this.FindControl<Button>("left");
             _right = this.FindControl<Button>("right");
-            _transition = this.FindControl<ComboBox>("transition");
-            _orientation = this.FindControl<ComboBox>("orientation");
+            _add = this.FindControl<Button>("add");
         }
 
-        private void TransitionChanged(object sender, SelectionChangedEventArgs e)
+        private class ViewModel
         {
-            switch (_transition.SelectedIndex)
+            public ViewModel()
             {
-                case 0:
-                    _carousel.PageTransition = null;
-                    break;
-                case 1:
-                    _carousel.PageTransition = new PageSlide(TimeSpan.FromSeconds(0.25), _orientation.SelectedIndex == 0 ? PageSlide.SlideAxis.Horizontal : PageSlide.SlideAxis.Vertical);
-                    break;
-                case 2:
-                    _carousel.PageTransition = new CrossFade(TimeSpan.FromSeconds(0.25));
-                    break;
+                Items = new ObservableCollection<string> { "foo", "bar", "baz" };
             }
+
+            public ObservableCollection<string> Items { get; }
+
+            public object SelectedItem { get; set; } = "foo";
         }
     }
 }