Add back PlacementMode properties as obsolete aliases of Placement

src/Avalonia.Controls/ContextMenu.cs

@@ -54,12 +54,22 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<PopupGravity> PlacementGravityProperty =
             Popup.PlacementGravityProperty.AddOwner<ContextMenu>();
 
+        /// <summary>
+        /// Defines the <see cref="PlacementMode"/> property.
+        /// </summary>
+        [Obsolete("Use the Placement property instead.")]
+        public static readonly StyledProperty<PlacementMode> PlacementModeProperty = PlacementProperty;
+
+#pragma warning disable AVP1013 // AvaloniaProperty owners should not be added superfluously
+
         /// <summary>
         /// Defines the <see cref="Placement"/> property.
         /// </summary>
         public static readonly StyledProperty<PlacementMode> PlacementProperty =
             Popup.PlacementProperty.AddOwner<ContextMenu>();
 
+#pragma warning restore AVP1013 // AvaloniaProperty owners should not be added superfluously
+
         /// <summary>
         /// Defines the <see cref="PlacementRect"/> property.
         /// </summary>
@@ -149,6 +159,14 @@ namespace Avalonia.Controls
             set => SetValue(PlacementGravityProperty, value);
         }
 
+        /// <inheritdoc cref="Placement"/>
+        [Obsolete("Use the Placement property instead.")]
+        public PlacementMode PlacementMode
+        {
+            get => GetValue(PlacementProperty);
+            set => SetValue(PlacementProperty, value);
+        }
+
         /// <inheritdoc cref="Popup.Placement"/>
         public PlacementMode Placement
         {

src/Avalonia.Controls/Primitives/Popup.cs

@@ -65,6 +65,12 @@ namespace Avalonia.Controls.Primitives
         public static readonly StyledProperty<PopupGravity> PlacementGravityProperty =
             AvaloniaProperty.Register<Popup, PopupGravity>(nameof(PlacementGravity));
 
+        /// <summary>
+        /// Defines the <see cref="PlacementMode"/> property.
+        /// </summary>
+        [Obsolete("Use the Placement property instead.")]
+        public static readonly StyledProperty<PlacementMode> PlacementModeProperty = PlacementProperty;
+
         /// <summary>
         /// Defines the <see cref="Placement"/> property.
         /// </summary>
@@ -234,6 +240,14 @@ namespace Avalonia.Controls.Primitives
             set => SetValue(PlacementGravityProperty, value);
         }
 
+        /// <inheritdoc cref="Placement"/>
+        [Obsolete("Use the Placement property instead.")]
+        public PlacementMode PlacementMode
+        {
+            get => GetValue(PlacementProperty);
+            set => SetValue(PlacementProperty, value);
+        }
+
         /// <summary>
         /// Gets or sets the desired placement of the popup in relation to the <see cref="PlacementTarget"/>.
         /// </summary>