Removed todo comment beacuse fixed

Photos/Animations/CardHoverEffectBehavior.cs

@@ -0,0 +1,159 @@
+using System;
+using System.Numerics;
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Rendering.Composition;
+
+namespace Photos.Animations;
+
+public static class CardHoverEffectBehavior
+{
+    private static readonly TimeSpan _animationDuration = TimeSpan.FromMilliseconds(150);
+
+    public static readonly AttachedProperty<bool> IsEnabledProperty =
+        AvaloniaProperty.RegisterAttached<Control, bool>(
+            "IsEnabled",
+            typeof(CardHoverEffectBehavior),
+            false);
+
+    public static readonly AttachedProperty<double> MaxRotationAngleProperty =
+        AvaloniaProperty.RegisterAttached<Control, double>(
+            "MaxRotationAngle",
+            typeof(CardHoverEffectBehavior),
+            5.5);
+
+    public static readonly AttachedProperty<double> ScaleFactorProperty =
+        AvaloniaProperty.RegisterAttached<Control, double>(
+            "ScaleFactor",
+            typeof(CardHoverEffectBehavior),
+            0.99);
+
+    static CardHoverEffectBehavior()
+    {
+        IsEnabledProperty.Changed.AddClassHandler<Control>(OnIsEnabledChanged);
+    }
+
+    public static bool GetIsEnabled(AvaloniaObject obj) => obj.GetValue(IsEnabledProperty);
+    public static void SetIsEnabled(AvaloniaObject obj, bool value) => obj.SetValue(IsEnabledProperty, value);
+
+    public static double GetMaxRotationAngle(AvaloniaObject obj) => obj.GetValue(MaxRotationAngleProperty);
+    public static void SetMaxRotationAngle(AvaloniaObject obj, double value) => obj.SetValue(MaxRotationAngleProperty, value);
+
+    public static double GetScaleFactor(AvaloniaObject obj) => obj.GetValue(ScaleFactorProperty);
+    public static void SetScaleFactor(AvaloniaObject obj, double value) => obj.SetValue(ScaleFactorProperty, value);
+
+    private static void OnIsEnabledChanged(Control c, AvaloniaPropertyChangedEventArgs e)
+    {
+        if (e.NewValue is not bool enabled)
+            return;
+
+        if (enabled)
+        {
+            c.PointerEntered += Element_PointerEntered;
+            c.PointerMoved += Element_PointerMoved;
+            c.PointerExited += Element_PointerExited;
+        }
+        else
+        {
+            c.PointerEntered -= Element_PointerEntered;
+            c.PointerMoved -= Element_PointerMoved;
+            c.PointerExited -= Element_PointerExited;
+        }
+    }
+
+    private static void Element_PointerEntered(object? sender, PointerEventArgs e)
+    {
+        if (sender is not Control element)
+            return;
+
+        element.ZIndex = 1;
+        var visual = ElementComposition.GetElementVisual(element);
+        var compositor = visual?.Compositor;
+
+        if (visual is null || compositor is null)
+            return;
+
+        var scaleFactor = (float)GetScaleFactor(element);
+
+        var width = (float)element.Bounds.Width;
+        var height = (float)element.Bounds.Height;
+
+        if (width <= 0 || height <= 0)
+            return;
+
+        visual.CenterPoint = new Vector3(width / 2f, height / 2f, 0f);
+
+        var scaleAnimation = compositor.CreateVector3KeyFrameAnimation();
+        scaleAnimation.InsertKeyFrame(1.0f, new Vector3(scaleFactor, scaleFactor, 1f));
+        scaleAnimation.Duration = _animationDuration;
+
+        var orientationAnimation = compositor.CreateQuaternionKeyFrameAnimation();
+        orientationAnimation.InsertKeyFrame(1.0f, Quaternion.Identity);
+        orientationAnimation.Duration = _animationDuration;
+
+        visual.StartAnimation("Scale", scaleAnimation);
+        visual.StartAnimation(nameof(visual.Orientation), orientationAnimation);
+    }
+
+    private static void Element_PointerMoved(object? sender, PointerEventArgs e)
+    {
+        if (sender is not Control element)
+            return;
+
+        var visual = ElementComposition.GetElementVisual(element);
+
+        if (visual is null)
+            return;
+
+        var maxRotationAngle = (float)GetMaxRotationAngle(element);
+
+        var width = element.Bounds.Width;
+        var height = element.Bounds.Height;
+
+        if (width <= 0 || height <= 0)
+            return;
+
+        var position = e.GetPosition(element);
+        var centerX = width / 2.0;
+        var centerY = height / 2.0;
+
+        var normalizedX = (position.X - centerX) / centerX;
+        var normalizedY = (position.Y - centerY) / centerY;
+
+        var rotationY_deg = (float)(normalizedX * maxRotationAngle);
+        var rotationX_deg = (float)(-normalizedY * maxRotationAngle);
+
+        var rotationX_rad = (float)(Math.PI / 180.0 * rotationX_deg);
+        var rotationY_rad = (float)(Math.PI / 180.0 * rotationY_deg);
+
+        var qx = Quaternion.CreateFromAxisAngle(Vector3.UnitX, rotationX_rad);
+        var qy = Quaternion.CreateFromAxisAngle(Vector3.UnitY, rotationY_rad);
+
+        visual.Orientation = qy * qx;
+    }
+
+    private static void Element_PointerExited(object? sender, PointerEventArgs e)
+    {
+        if (sender is not Control element)
+            return;
+
+        element.ZIndex = 0;
+        var visual = ElementComposition.GetElementVisual(element);
+        var compositor = visual?.Compositor;
+
+        if (visual is null || compositor is null)
+            return;
+
+        var scaleAnimation = compositor.CreateVector3KeyFrameAnimation();
+        scaleAnimation.InsertKeyFrame(1.0f, new Vector3(1f, 1f, 1f));
+        scaleAnimation.Duration = _animationDuration;
+
+        var orientationAnimation = compositor.CreateQuaternionKeyFrameAnimation();
+        orientationAnimation.InsertKeyFrame(1.0f, Quaternion.Identity);
+        orientationAnimation.Duration = _animationDuration;
+
+        visual.StartAnimation("Scale", scaleAnimation);
+        visual.StartAnimation(nameof(visual.Orientation), orientationAnimation);
+    }
+}

Photos/Models/Photo.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
@@ -96,7 +97,7 @@ public static partial class PhotoExtension
                     .ToList();
     }
 
-    public static void CreateAndAddPhotosToList(List<string> photos, string rootPath, IList<Photo> toAddTo)
+    public static void CreateAndAddPhotosToList(List<string> photos, string rootPath, ObservableCollection<Photo> toAddTo)
     {
         var bag = new ConcurrentBag<Photo>();
 
@@ -105,12 +106,12 @@ public static partial class PhotoExtension
             bag.Add(new Photo(p, rootPath));
         });
 
-        Dispatcher.UIThread.InvokeAsync(() =>
+        Dispatcher.UIThread.Invoke(() =>
         {
             foreach (var photo in bag)
             {
                 toAddTo.Add(photo);
             }
-        }).GetAwaiter().GetResult(); // TODO: When reopening folder this throws exception
+        });
     }
 }

Photos/ViewModels/MainWindowViewModel.cs

@@ -35,7 +35,8 @@ public partial class MainWindowViewModel : ViewModelBase
         var folder = await _folderPickerService.PickFolderAsync();
         if (folder is null) return;
 
-        foreach(var p in Photos) p.Dispose();
+        // foreach(var p in Photos) p.Dispose();
+        Photos.Clear();
 
         LibraryPath = folder;
         await AddPhotosAsync(folder);

Photos/Views/MainWindow.axaml

@@ -6,6 +6,7 @@
         xmlns:i="using:Avalonia.Xaml.Interactivity"
         xmlns:ic="using:Avalonia.Xaml.Interactions.Core"
         xmlns:models="using:Photos.Models"
+        xmlns:anim="using:Photos.Animations"
         mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
         x:Class="Photos.Views.MainWindow"
         x:DataType="vm:MainWindowViewModel"
@@ -31,16 +32,30 @@
             <Button Content="Open Directory" Command="{Binding OpenDirectory}"/>
         </Menu>
         <ScrollViewer Grid.Column="1">
-            <ItemsRepeater ItemsSource="{Binding Photos}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
+            <ItemsRepeater ItemsSource="{Binding Photos}"
+                           HorizontalAlignment="Stretch"
+                           VerticalAlignment="Stretch"
+                           Margin="5"
+                           >
                 <ItemsRepeater.Layout>
                     <UniformGridLayout MinItemWidth="190"
                                        MinItemHeight="240"
                                        MinRowSpacing="12"
-                                       MinColumnSpacing="12" />
+                                       MinColumnSpacing="12"
+                                       >
+                    </UniformGridLayout>
                 </ItemsRepeater.Layout>
 
                 <ItemsRepeater.ItemTemplate>
                     <DataTemplate DataType="models:Photo">
+                        <Border BorderBrush="Black"
+                                Background="#aa000000"
+                                BorderThickness="1"
+                                CornerRadius="7.5"
+                                anim:CardHoverEffectBehavior.IsEnabled="True"
+                                anim:CardHoverEffectBehavior.MaxRotationAngle="3.5"
+                                anim:CardHoverEffectBehavior.ScaleFactor="1.5"
+                                >
                             <StackPanel Orientation="Vertical" Margin="12">
                                 <i:Interaction.Behaviors>
                                     <ic:EventTriggerBehavior EventName="PointerReleased">
@@ -49,24 +64,40 @@
                                 </i:Interaction.Behaviors>
                                     <Image Source="{Binding PreviewImage}"
                                            Width="150"
-                                   Height="150" />
+                                           Height="150"/>
                                     <TextBlock Text="{Binding DisplayName}"
                                                HorizontalAlignment="Center"
                                                Width="150" />
                                     <TextBlock Text="{Binding DisplayPath}" HorizontalAlignment="Center" Width="150"/>
                             </StackPanel>
+                        </Border>
                     </DataTemplate>
                 </ItemsRepeater.ItemTemplate>
             </ItemsRepeater>
         </ScrollViewer>
-        <Grid Grid.Column="0" Grid.ColumnSpan="2" IsEnabled="{Binding SelectedPhoto}">
-            <Image Source="{Binding SelectedPhoto.FullImage}" Margin="50">
+        <TransitioningContentControl Grid.Column="0"
+                                     Grid.ColumnSpan="2"
+                                     Content="{Binding SelectedPhoto}">
+            <TransitioningContentControl.PageTransition>
+                <CrossFade Duration="0:0:0.18" />
+            </TransitioningContentControl.PageTransition>
+
+            <TransitioningContentControl.ContentTemplate>
+                <DataTemplate DataType="models:Photo">
+                    <Border Background="#AA000000">
+                        <Image Source="{Binding FullImage}"
+                               Margin="50"
+                               Stretch="Uniform"
+                               >
                             <i:Interaction.Behaviors>
                                 <ic:EventTriggerBehavior EventName="PointerReleased">
-                        <ic:InvokeCommandAction Command="{Binding Path=SelectedPhotoClicked}"/>
+                                    <ic:InvokeCommandAction Command="{Binding Path=DataContext.SelectedPhotoClicked, ElementName=Root}"/>
                                 </ic:EventTriggerBehavior>
                             </i:Interaction.Behaviors>
                         </Image>
-        </Grid>
+                    </Border>
+                </DataTemplate>
+            </TransitioningContentControl.ContentTemplate>
+        </TransitioningContentControl>
     </Grid>
 </Window>