Merge pull request #10137 from robloo/treeviewitem-styledproperty

Switch TreeViewItem.IsExpanded to a StyledProperty

src/Avalonia.Controls/TreeViewItem.cs

@@ -1,11 +1,11 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Avalonia.Controls.Generators;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
+using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.LogicalTree;
 using Avalonia.Threading;
@@ -22,11 +22,10 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="IsExpanded"/> property.
         /// </summary>
-        public static readonly DirectProperty<TreeViewItem, bool> IsExpandedProperty =
-            AvaloniaProperty.RegisterDirect<TreeViewItem, bool>(
+        public static readonly StyledProperty<bool> IsExpandedProperty =
+            AvaloniaProperty.Register<TreeViewItem, bool>(
                 nameof(IsExpanded),
-                o => o.IsExpanded,
-                (o, v) => o.IsExpanded = v);
+                defaultBindingMode: BindingMode.TwoWay);
 
         /// <summary>
         /// Defines the <see cref="IsSelected"/> property.
@@ -46,7 +45,6 @@ namespace Avalonia.Controls
 
         private TreeView? _treeView;
         private Control? _header;
-        private bool _isExpanded;
         private int _level;
         private bool _templateApplied;
         private bool _deferredBringIntoViewFlag;
@@ -68,8 +66,8 @@ namespace Avalonia.Controls
         /// </summary>
         public bool IsExpanded
         {
-            get { return _isExpanded; }
-            set { SetAndRaise(IsExpandedProperty, ref _isExpanded, value); }
+            get => GetValue(IsExpandedProperty);
+            set => SetValue(IsExpandedProperty, value);
         }
 
         /// <summary>
@@ -77,8 +75,8 @@ namespace Avalonia.Controls
         /// </summary>
         public bool IsSelected
         {
-            get { return GetValue(IsSelectedProperty); }
-            set { SetValue(IsSelectedProperty, value); }
+            get => GetValue(IsSelectedProperty);
+            set => SetValue(IsSelectedProperty, value);
         }
 
         /// <summary>
@@ -86,8 +84,8 @@ namespace Avalonia.Controls
         /// </summary>
         public int Level
         {
-            get { return _level; }
-            private set { SetAndRaise(LevelProperty, ref _level, value); }
+            get => _level;
+            private set => SetAndRaise(LevelProperty, ref _level, value);
         }
 
         internal TreeView? TreeViewOwner => _treeView;
@@ -115,11 +113,6 @@ namespace Avalonia.Controls
             }
         }
 
-        protected override void OnDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e)
-        {
-            base.OnDetachedFromLogicalTree(e);
-        }
-
         protected virtual void OnRequestBringIntoView(RequestBringIntoViewEventArgs e)
         {
             if (e.TargetObject == this)
@@ -266,7 +259,7 @@ namespace Avalonia.Controls
         }
         
         /// <summary>
-        /// Invoked when the <see cref="DoubleTapped"/> event occurs in the header.
+        /// Invoked when the <see cref="InputElement.DoubleTapped"/> event occurs in the header.
         /// </summary>
         protected virtual void OnHeaderDoubleTapped(TappedEventArgs e)
         {