Add Close and ClearAll api for INotificationManager and IManagedNotificationManager (#15628)

* Add Close and ClearAll api for INotificationManager

* Remove notification card item on close

* Make _notificationCards readonly

* Clear _notificationCards when detached from visual tree

* Update Avalonia.nupkg.xml

* Use cancellationToken = default instead of null

* Rename ClearAll to CloseAll for consistency with Close method naming

* Remove cancellationToken param from Show method for better compatibility

* Update Avalonia.nupkg.xml

---------

Co-authored-by: Jumar Macato <16554748+jmacato@users.noreply.github.com>

api/Avalonia.nupkg.xml

@@ -1105,4 +1105,22 @@
     <Left>baseline/netstandard2.0/Avalonia.Base.dll</Left>
     <Right>target/netstandard2.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Avalonia.Controls.Notifications.IManagedNotificationManager.Close(System.Object)</Target>
+    <Left>baseline/netstandard2.0/Avalonia.Controls.dll</Left>
+    <Right>target/netstandard2.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Avalonia.Controls.Notifications.INotificationManager.Close(Avalonia.Controls.Notifications.INotification)</Target>
+    <Left>baseline/netstandard2.0/Avalonia.Controls.dll</Left>
+    <Right>target/netstandard2.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0006</DiagnosticId>
+    <Target>M:Avalonia.Controls.Notifications.INotificationManager.CloseAll</Target>
+    <Left>baseline/netstandard2.0/Avalonia.Controls.dll</Left>
+    <Right>target/netstandard2.0/Avalonia.Controls.dll</Right>
+  </Suppression>
 </Suppressions>

src/Avalonia.Controls/Notifications/IManagedNotificationManager.cs

@@ -1,4 +1,4 @@
-using System;
+using System.Threading;
 using Avalonia.Metadata;
 
 namespace Avalonia.Controls.Notifications
@@ -20,5 +20,11 @@ namespace Avalonia.Controls.Notifications
         /// </summary>
         /// <param name="content">The content to be displayed.</param>
         void Show(object content);
+
+        /// <summary>
+        /// Closes a notification.
+        /// </summary>
+        /// <param name="content">The content to be closed.</param>
+        void Close(object content);
     }
 }

src/Avalonia.Controls/Notifications/INotificationManager.cs

@@ -14,5 +14,16 @@ namespace Avalonia.Controls.Notifications
         /// </summary>
         /// <param name="notification">The notification to be displayed.</param>
         void Show(INotification notification);
+
+        /// <summary>
+        /// Closes a notification.
+        /// </summary>
+        /// <param name="notification">The notification to be closed.</param>
+        void Close(INotification notification);
+
+        /// <summary>
+        /// Closes all notifications.
+        /// </summary>
+        void CloseAll();
     }
 }

src/Avalonia.Controls/Notifications/WindowNotificationManager.cs

@@ -3,7 +3,6 @@ using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
-using Avalonia.Collections;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Threading;
@@ -19,6 +18,8 @@ namespace Avalonia.Controls.Notifications
     public class WindowNotificationManager : TemplatedControl, IManagedNotificationManager
     {
         private IList? _items;
+        private readonly Dictionary<object, NotificationCard> _notificationCards = new ();
+
         /// <summary>
         /// Defines the <see cref="Position"/> property.
         /// </summary>
@@ -103,7 +104,7 @@ namespace Avalonia.Controls.Notifications
                 Show(content, NotificationType.Information);
             }
         }
-        
+
         /// <summary>
         /// Shows a Notification
         /// </summary>
@@ -121,7 +122,7 @@ namespace Avalonia.Controls.Notifications
             string[]? classes = null)
         {
             Dispatcher.UIThread.VerifyAccess();
-            
+
             var notificationControl = new NotificationCard
             {
                 Content = content,
@@ -136,12 +137,13 @@ namespace Avalonia.Controls.Notifications
                     notificationControl.Classes.Add(@class);
                 }
             }
-            
+
             notificationControl.NotificationClosed += (sender, args) =>
             {
                 onClose?.Invoke();
 
                 _items?.Remove(sender);
+                _notificationCards.Remove(content);
             };
 
             notificationControl.PointerPressed += (sender, args) =>
@@ -154,6 +156,7 @@ namespace Avalonia.Controls.Notifications
             Dispatcher.UIThread.Post(() =>
             {
                 _items?.Add(notificationControl);
+                _notificationCards.Add(content, notificationControl);
 
                 if (_items?.OfType<NotificationCard>().Count(i => !i.IsClosing) > MaxItems)
                 {
@@ -169,6 +172,43 @@ namespace Avalonia.Controls.Notifications
             await Task.Delay(expiration ?? TimeSpan.FromSeconds(5));
 
             notificationControl.Close();
+ 
+            _notificationCards.Remove(content);
+        }
+
+        /// <inheritdoc/>
+        public void Close(INotification notification)
+        {
+            Dispatcher.UIThread.VerifyAccess();
+
+            if (_notificationCards.Remove(notification, out var notificationCard))
+            {
+                notificationCard.Close();
+            }
+        }
+
+        /// <inheritdoc/>
+        public void Close(object content)
+        {
+            Dispatcher.UIThread.VerifyAccess();
+
+            if (_notificationCards.Remove(content, out var notificationCard))
+            {
+                notificationCard.Close();
+            }
+        }
+
+        /// <inheritdoc/>
+        public void CloseAll()
+        {
+            Dispatcher.UIThread.VerifyAccess();
+
+            foreach (var kvp in _notificationCards)
+            {
+                kvp.Value.Close();
+            }
+            
+            _notificationCards.Clear();
         }
 
         protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
@@ -181,6 +221,13 @@ namespace Avalonia.Controls.Notifications
             }
         }
 
+        protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)
+        {
+            base.OnDetachedFromVisualTree(e);
+
+            _notificationCards.Clear();
+        }
+
         /// <summary>
         /// Installs the <see cref="WindowNotificationManager"/> within the <see cref="AdornerLayer"/>
         /// </summary>