use pressed mixing to simplify loopingselector item.

src/Avalonia.Controls/DateTimePickers/LoopingSelectorItem.cs

@@ -1,8 +1,7 @@
-using Avalonia;
-using Avalonia.Controls;
+using System;
+using Avalonia.Controls.Mixins;
 using Avalonia.Input;
 using Avalonia.Interactivity;
-using System;
 
 namespace Avalonia.Controls.Primitives
 {
@@ -13,30 +12,19 @@ namespace Avalonia.Controls.Primitives
     {
         static LoopingSelectorItem()
         {
-            IsPressedProperty.Changed.AddClassHandler<LoopingSelectorItem>((x, e) => x.OnIsPressedChanged(e));
+            PressedMixin.Attach<LoopingSelectorItem>();
             IsSelectedProperty.Changed.AddClassHandler<LoopingSelectorItem>((x, e) => x.OnIsSelectedChanged(e));
         }
 
-        /// <summary>
-        /// Defines the <see cref="IsPressed"/> Property
-        /// </summary>
-        public static readonly StyledProperty<bool> IsPressedProperty =
-            AvaloniaProperty.Register<LoopingSelectorItem, bool>("IsPressed");
-
         /// <summary>
         /// Defines the <see cref="IsSelected"/> Property
         /// </summary>
         internal static readonly StyledProperty<bool> IsSelectedProperty =
-            AvaloniaProperty.Register<LoopingSelectorItem, bool>("IsSelected");
+            AvaloniaProperty.Register<LoopingSelectorItem, bool>(nameof(IsSelected));
 
-        /// <summary>
-        /// Gets whether the item is currently pressed
-        /// </summary>
-        public bool IsPressed
-        {
-            get => GetValue(IsPressedProperty);
-            private set => SetValue(IsPressedProperty, value);
-        }
+
+        public static readonly RoutedEvent<RoutedEventArgs> SelectedEvent =
+            RoutedEvent.Register<LoopingSelectorItem, RoutedEventArgs>(nameof(Selected), RoutingStrategies.Bubble);
 
         internal bool IsSelected
         {
@@ -44,37 +32,12 @@ namespace Avalonia.Controls.Primitives
             set => SetValue(IsSelectedProperty, value);
         }
 
-        private void OnIsPressedChanged(AvaloniaPropertyChangedEventArgs e)
-        {
-            PseudoClasses.Set(":pressed", (bool)e.NewValue);
-        }
-
-        protected override void OnPointerPressed(PointerPressedEventArgs e)
-        {
-            base.OnPointerPressed(e);
-            if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed)
-            {
-                IsPressed = true;
-            }
-        }
-
-        protected override void OnPointerMoved(PointerEventArgs e)
-        {
-            base.OnPointerMoved(e);
-            if (IsPressed)
-            {
-                var pt = e.GetPosition(this);
-                if (pt.X < 0 || pt.Y < 0 || pt.X > Bounds.Width || pt.Y > Bounds.Height)
-                    IsPressed = false;
-            }
-        }
-
         protected override void OnPointerReleased(PointerReleasedEventArgs e)
         {
             base.OnPointerReleased(e);
-            if (IsPressed && e.GetCurrentPoint(this).Properties.PointerUpdateKind == PointerUpdateKind.LeftButtonReleased)
+            
+            if (e.GetCurrentPoint(this).Properties.PointerUpdateKind == PointerUpdateKind.LeftButtonReleased)
             {
-                IsPressed = false;
                 //The selection event only raises when invoked by pointer events
                 RaiseEvent(new RoutedEventArgs(SelectedEvent, this));
             }
@@ -86,9 +49,6 @@ namespace Avalonia.Controls.Primitives
             PseudoClasses.Set(":selected", newValue);
         }
 
-        public static readonly RoutedEvent<RoutedEventArgs> SelectedEvent =
-            RoutedEvent.Register<LoopingSelectorItem, RoutedEventArgs>("Selected", RoutingStrategies.Bubble);
-
         public event EventHandler<RoutedEventArgs> Selected
         {
             add => AddHandler(SelectedEvent, value);