updated animated listbox to work on adding to visualtree

Author: sabuto

src/CutCode.CrossPlatform/Controls/AnimatedListBoxItem.cs

@@ -1,25 +1,31 @@
 using System;
 using System.Diagnostics;
 using Avalonia;
+using Avalonia.Animation;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Input;
+using Avalonia.LogicalTree;
 using Avalonia.Styling;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace CutCode.CrossPlatform.Controls;
 
 [PseudoClasses(":Added", ":Removed")]
 public class AnimatedListBoxItem : ListBoxItem, IStyleable
 {
+    public AnimatedListBoxItem()
+    {
+    }
     Type IStyleable.StyleKey => typeof(AnimatedListBoxItem);
 
     private bool isAttached = false;
     protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
     {
-        base.OnAttachedToVisualTree(e);
         if (isAttached) return;
         PseudoClasses.Set(":Added", true);
         isAttached = true;
+        base.OnAttachedToVisualTree(e);
     }
 
     protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)

src/CutCode.CrossPlatform/Styles/AnimatedListBoxItem.axaml

@@ -32,7 +32,7 @@
 
     <Style Selector="controls|AnimatedListBoxItem:Added /template/ ContentPresenter#PART_ContentPresenter">
         <Style.Animations>
-            <Animation Duration="0:0:0.3"> 
+            <Animation Duration="0:0:3"> 
                 <KeyFrame Cue="0%">
                     <Setter Property="Opacity" Value="0.0"/>
                 </KeyFrame>
@@ -44,7 +44,7 @@
     </Style>
     <Style Selector="controls|AnimatedListBoxItem:Removed /template/ ContentPresenter#PART_ContentPresenter">
         <Style.Animations>
-            <Animation Duration="0:0:0.3"> 
+            <Animation Duration="0:1:0"> 
                 <KeyFrame Cue="0%">
                     <Setter Property="Opacity" Value="1.0"/>
                 </KeyFrame>