[Core] Fix grouped type properties not swapping properly

Fixes #525

When we moved to the new panel group system, the grouped editors weren't
accounted for and so when we try to remove their child property from the
container group it's not found since they're inside the group editor VM.

This also meant that even if removal had worked, we wouldn't properly
add new shared view model types to the group.

2 files changed, 66 insertions, 9 deletions

diff --git a/Xamarin.PropertyEditing/ViewModels/PanelViewModel.cs b/Xamarin.PropertyEditing/ViewModels/PanelViewModel.cs
index ac1102b..51921ee 100644
--- a/Xamarin.PropertyEditing/ViewModels/PanelViewModel.cs
+++ b/Xamarin.PropertyEditing/ViewModels/PanelViewModel.cs
@@ -10,11 +10,14 @@ namespace Xamarin.PropertyEditing.ViewModels
 	internal class PanelGroupViewModel
 		: NotifyingObject
 	{
-		public PanelGroupViewModel (string category, IEnumerable<EditorViewModel> editors, bool separateUncommon = true)
+		public PanelGroupViewModel (TargetPlatform targetPlatform, string category, IEnumerable<EditorViewModel> editors, bool separateUncommon = true)
 		{
+			if (targetPlatform == null)
+				throw new ArgumentNullException (nameof(targetPlatform));
 			if (editors == null)
 				throw new ArgumentNullException (nameof(editors));
 
+			this.targetPlatform = targetPlatform;
 			Category = category;
 			AddCore (editors, separateUncommon);
 		}
@@ -53,7 +56,19 @@ namespace Xamarin.PropertyEditing.ViewModels
 			if (editor == null)
 				throw new ArgumentNullException (nameof(editor));
 
-			return GetList (editor, separate: true).Remove (editor);
+			var list = GetList (editor, separate: true);
+			if (editor is PropertyViewModel pvm && this.targetPlatform.GroupedTypes != null && this.targetPlatform.GroupedTypes.TryGetValue (pvm.Property.Type, out string groupName)) {
+				var group = list.OfType<PropertyGroupViewModel> ().First (gvm => gvm.Category == groupName);
+				if (group != null) {
+					bool found = group.Remove (pvm);
+					if (!group.HasChildElements)
+						list.Remove (group);
+
+					return found;
+				}
+			}
+
+			return list.Remove (editor);
 		}
 
 		public bool GetIsExpanded (PropertyArrangeMode mode)
@@ -80,6 +95,7 @@ namespace Xamarin.PropertyEditing.ViewModels
 		private Dictionary<PropertyArrangeMode, bool> isExpanded;
 		private readonly ObservableCollectionEx<EditorViewModel> editors = new ObservableCollectionEx<EditorViewModel> ();
 		private readonly ObservableCollectionEx<EditorViewModel> uncommonEditors = new ObservableCollectionEx<EditorViewModel> ();
+		private readonly TargetPlatform targetPlatform;
 
 		private void AddCore (IEnumerable<EditorViewModel> editors, bool separate)
 		{
@@ -95,7 +111,16 @@ namespace Xamarin.PropertyEditing.ViewModels
 			if (editor == null)
 				throw new ArgumentNullException (nameof (editor));
 
-			GetList (editor, separate).Add (editor);
+			var list = GetList (editor, separate);
+			if (editor is PropertyViewModel pvm && this.targetPlatform.GroupedTypes != null && this.targetPlatform.GroupedTypes.TryGetValue (pvm.Property.Type, out string groupName)) {
+				var group = list.OfType<PropertyGroupViewModel> ().First (gvm => gvm.Category == groupName);
+				if (group != null)
+					group.Add (pvm);
+				else
+					list.Add (editor);
+			} else
+				list.Add (editor);
+
 			OnPropertyChanged (nameof(HasChildElements));
 			OnPropertyChanged (nameof(HasUncommonElements));
 		}
@@ -249,9 +274,9 @@ namespace Xamarin.PropertyEditing.ViewModels
 				string key = grouping.Key;
 				if (remainingItems != null) {// TODO: pretty sure this was out of order before, add test
 					if (remainingItems.Count > 0)
-						this.arranged.Add (key, new PanelGroupViewModel (key, grouping.Where (evm => remainingItems.Contains (evm))));
+						this.arranged.Add (key, new PanelGroupViewModel (TargetPlatform, key, grouping.Where (evm => remainingItems.Contains (evm))));
 				} else
-					this.arranged.Add (key, new PanelGroupViewModel (key, grouping, separateUncommon: !isFlat));
+					this.arranged.Add (key, new PanelGroupViewModel (TargetPlatform, key, grouping, separateUncommon: !isFlat));
 
 				AutoExpandGroup (key);
 			}
@@ -259,7 +284,7 @@ namespace Xamarin.PropertyEditing.ViewModels
 			if (groupedTypeProperties != null) { // Insert type-grouped properties back in sorted.
 				int i = 0;
 				foreach (var kvp in groupedTypeProperties.OrderBy (kvp => kvp.Key, CategoryComparer.Instance)) {
-					var group = new PanelGroupViewModel (kvp.Key, new[] { new PropertyGroupViewModel (TargetPlatform, kvp.Key, kvp.Value, ObjectEditors) });
+					var group = new PanelGroupViewModel (TargetPlatform, kvp.Key, new[] { new PropertyGroupViewModel (TargetPlatform, kvp.Key, kvp.Value, ObjectEditors) });
 
 					bool added = false;
 					for (; i < this.arranged.Count; i++) {
@@ -385,7 +410,14 @@ namespace Xamarin.PropertyEditing.ViewModels
 
 		private string GetGroup (EditorViewModel vm)
 		{
-			return (ArrangeMode == PropertyArrangeMode.Name) ? "0" : (vm.Category ?? String.Empty);
+			if (ArrangeMode == PropertyArrangeMode.Name)
+				return "0";
+			if (vm is PropertyViewModel pvm) {
+				if (TargetPlatform.GroupedTypes != null && TargetPlatform.GroupedTypes.TryGetValue (pvm.Property.Type, out string groupName))
+					return groupName;
+			}
+
+			return vm.Category ?? String.Empty;
 		}
 
 		private bool MatchesFilter (EditorViewModel vm)
diff --git a/Xamarin.PropertyEditing/ViewModels/PropertyGroupViewModel.cs b/Xamarin.PropertyEditing/ViewModels/PropertyGroupViewModel.cs
index 9890ee5..f20a9b3 100644
--- a/Xamarin.PropertyEditing/ViewModels/PropertyGroupViewModel.cs
+++ b/Xamarin.PropertyEditing/ViewModels/PropertyGroupViewModel.cs
@@ -20,7 +20,7 @@ namespace Xamarin.PropertyEditing.ViewModels
 
 			Category = category;
 
-			this.properties = properties.ToArray ();
+			this.properties = properties.ToList ();
 			foreach (var vm in this.properties) {
 				if (vm.IsAvailable)
 					this.propertiesView.Add (vm);
@@ -55,10 +55,35 @@ namespace Xamarin.PropertyEditing.ViewModels
 			}
 		}
 
-		private readonly PropertyViewModel[] properties;
+		public void Add (PropertyViewModel property)
+		{
+			if (property == null)
+				throw new ArgumentNullException (nameof(property));
+
+			this.properties.Add (property);
+			Reload ();
+		}
+
+		public bool Remove (PropertyViewModel property)
+		{
+			if (property == null)
+				throw new ArgumentNullException (nameof(property));
+
+			if (this.properties.Remove (property))
+				return this.propertiesView.Remove (property);
+
+			return false;
+		}
+
+		private readonly List<PropertyViewModel> properties;
 		private readonly ObservableCollectionEx<PropertyViewModel> propertiesView = new ObservableCollectionEx<PropertyViewModel> ();
 		private string filterText;
 
+		private void Reload ()
+		{
+			Filter (null);
+		}
+
 		private void Filter (string oldFilter)
 		{
 			bool hadChildren = HasChildElements;