[Core] Allow TargetPlatform to specify arrange modes

Author: Eric Maupin

Xamarin.PropertyEditing/TargetPlatform.cs

@@ -111,6 +111,15 @@ public IReadOnlyCollection<string> AutoExpandGroups
 			set;
 		}
 
+		/// <summary>
+		/// Gets or sets a list of the allowed arrange modes.
+		/// </summary>
+		public IReadOnlyList<PropertyArrangeMode> ArrangeModes
+		{
+			get;
+			set;
+		} = new[] { PropertyArrangeMode.Name, PropertyArrangeMode.Category };
+
 		/// <summary>
 		/// Gets or sets a callback for errors that should be edge cases and/or don't have a defined way of displaying in the UI.
 		/// </summary>
@@ -145,6 +154,7 @@ internal TargetPlatform WithProvider (IEditorProvider provider)
 				SupportsBrushOpacity = SupportsBrushOpacity,
 				GroupedTypes = GroupedTypes,
 				AutoExpandGroups = AutoExpandGroups,
+				ArrangeModes = ArrangeModes,
 				ErrorHandler = ErrorHandler
 			};
 		}

Xamarin.PropertyEditing/ViewModels/PanelViewModel.cs

@@ -115,10 +115,18 @@ internal class PanelViewModel
 		public PanelViewModel (TargetPlatform targetPlatform)
 			: base (targetPlatform)
 		{
-			ArrangeModes = new List<ArrangeModeViewModel> {
-				new ArrangeModeViewModel (PropertyArrangeMode.Name, this),
-				new ArrangeModeViewModel (PropertyArrangeMode.Category, this)
-			};
+			if (targetPlatform == null)
+				throw new ArgumentNullException (nameof(targetPlatform));
+
+			var modes = new List<ArrangeModeViewModel> ();
+			if (targetPlatform.ArrangeModes == null || targetPlatform.ArrangeModes.Count == 0)
+				modes.Add (new ArrangeModeViewModel (PropertyArrangeMode.Name, this));
+			else {
+				for (int i = 0; i < targetPlatform.ArrangeModes.Count; i++)
+					modes.Add (new ArrangeModeViewModel (targetPlatform.ArrangeModes[i], this));
+			}
+
+			ArrangeModes = modes;
 		}
 
 		public event EventHandler ArrangedPropertiesChanged;