Create EventToCommand.SelectableItemsView.SelectionChanged.cs

NuGet/RapidXaml.MAUI/EventToCommand/EventToCommand.SelectableItemsView.SelectionChanged.cs

@@ -0,0 +1,64 @@
+namespace RapidXaml;
+
+public partial class EventToCommand : BindableObject
+{
+	public static Command<SelectionChangedEventArgs> GetSelectionChanged(BindableObject obj)
+		=> (Command<SelectionChangedEventArgs>)obj.GetValue(SelectionChangedProperty);
+
+	public static void SetSelectionChanged(BindableObject obj, Command<SelectionChangedEventArgs> value)
+		=> obj.SetValue(SelectionChangedProperty, value);
+
+	public static readonly BindableProperty SelectionChangedProperty =
+		BindableProperty.CreateAttached("SelectionChanged", typeof(Command<SelectionChangedEventArgs>), typeof(EventToCommand), defaultValue: null, propertyChanged: OnSelectionChangedChanged);
+
+	private static void OnSelectionChangedChanged(BindableObject bindable, object oldValue, object newValue)
+	{
+		if (bindable is SelectableItemsView siv)
+		{
+			if (oldValue is Command<SelectionChangedEventArgs> oldCmd)
+			{
+				for (int i = siv.Behaviors.Count - 1; i >= 0; i--)
+				{
+					if (siv.Behaviors[i] is EventToCommandSelectionChangedBehavior oldBehavior && oldBehavior.CommandToInvoke == oldCmd)
+					{
+						siv.Behaviors.Remove(oldBehavior);
+						break;
+					}
+				}
+			}
+
+			if (newValue is Command<SelectionChangedEventArgs> newCmd)
+			{
+				siv.Behaviors.Add(new EventToCommandSelectionChangedBehavior { CommandToInvoke = newCmd });
+			}
+		}
+	}
+
+	internal partial class EventToCommandSelectionChangedBehavior : Behavior<SelectableItemsView>
+	{
+		public Command<SelectionChangedEventArgs>? CommandToInvoke { get; set; }
+
+		protected override void OnAttachedTo(SelectableItemsView selItemsView)
+		{
+			selItemsView.SelectionChanged += OnSelectableItemsViewSelectionChanged;
+			base.OnAttachedTo(selItemsView);
+		}
+
+		protected override void OnDetachingFrom(SelectableItemsView selItemsView)
+		{
+			selItemsView.Focused -= OnSelectableItemsViewSelectionChanged;
+			base.OnDetachingFrom(selItemsView);
+		}
+
+		private void OnSelectableItemsViewSelectionChanged(object? sender, EventArgs e)
+		{
+			if (this.CommandToInvoke != null)
+			{
+				if (this.CommandToInvoke.CanExecute(null))
+				{
+					this.CommandToInvoke.Execute(e);
+				}
+			}
+		}
+	}
+}