[mac] ViewModel is allowed to be null

6 files changed, 34 insertions, 24 deletions

diff --git a/Xamarin.PropertyEditing.Mac/Controls/CombinablePropertyEditor.cs b/Xamarin.PropertyEditing.Mac/Controls/CombinablePropertyEditor.cs
index cf58bdc..f7974e6 100644
--- a/Xamarin.PropertyEditing.Mac/Controls/CombinablePropertyEditor.cs
+++ b/Xamarin.PropertyEditing.Mac/Controls/CombinablePropertyEditor.cs
@@ -58,6 +58,11 @@ namespace Xamarin.PropertyEditing.Mac
 
 		protected override void OnViewModelChanged (PropertyViewModel oldModel)
 		{
+			base.OnViewModelChanged (oldModel);
+
+			if (ViewModel == null)
+				return;
+
 			nint rowHeight = GetHeight (ViewModel);
 
 			float top = checkHeight;
@@ -99,9 +104,6 @@ namespace Xamarin.PropertyEditing.Mac
 			// Set our tabable order
 			this.firstKeyView = this.combinableList.KeyAt (0);
 			this.lastKeyView = this.combinableList.KeyAt (this.combinableList.Count - 1);
-
-			base.OnViewModelChanged (oldModel);
-
 		}
 
 		protected override void UpdateValue ()
diff --git a/Xamarin.PropertyEditing.Mac/Controls/Custom/BrushTabViewController.cs b/Xamarin.PropertyEditing.Mac/Controls/Custom/BrushTabViewController.cs
index dd63955..dc956e3 100644
--- a/Xamarin.PropertyEditing.Mac/Controls/Custom/BrushTabViewController.cs
+++ b/Xamarin.PropertyEditing.Mac/Controls/Custom/BrushTabViewController.cs
@@ -58,7 +58,7 @@ namespace Xamarin.PropertyEditing.Mac
 			this.inhibitSelection = true;
 			base.OnViewModelChanged (oldModel);

 

-			var existing = new HashSet<CommonBrushType> (ViewModel?.BrushTypes?.Values ?? Array.Empty<CommonBrushType> ());

+			var existing = new HashSet<CommonBrushType> (oldModel?.BrushTypes?.Values ?? Array.Empty<CommonBrushType> ());

 			existing.IntersectWith (this.brushTypeTable.Keys);

 

 			var removed = new HashSet<CommonBrushType> (this.brushTypeTable.Keys);

diff --git a/Xamarin.PropertyEditing.Mac/Controls/Custom/PropertyButton.cs b/Xamarin.PropertyEditing.Mac/Controls/Custom/PropertyButton.cs
index fab17c6..9846e2c 100644
--- a/Xamarin.PropertyEditing.Mac/Controls/Custom/PropertyButton.cs
+++ b/Xamarin.PropertyEditing.Mac/Controls/Custom/PropertyButton.cs
@@ -18,14 +18,15 @@ namespace Xamarin.PropertyEditing.Mac
 		{
 			get { return viewModel; }
 			set {
-				if (viewModel != null) {
-					viewModel.PropertyChanged -= OnPropertyChanged;
+				if (this.viewModel != null) {
+					this.viewModel.PropertyChanged -= OnPropertyChanged;
 				}
 
-				viewModel = value;
-				viewModel.PropertyChanged += OnPropertyChanged;
-
-				ValueSourceChanged (viewModel.ValueSource);
+				this.viewModel = value;
+				if (this.viewModel != null) {
+					this.viewModel.PropertyChanged += OnPropertyChanged;
+					ValueSourceChanged (this.viewModel.ValueSource);
+				}
 			}
 		}
 
diff --git a/Xamarin.PropertyEditing.Mac/Controls/NumericEditorControl.cs b/Xamarin.PropertyEditing.Mac/Controls/NumericEditorControl.cs
index e6b1277..e15e206 100644
--- a/Xamarin.PropertyEditing.Mac/Controls/NumericEditorControl.cs
+++ b/Xamarin.PropertyEditing.Mac/Controls/NumericEditorControl.cs
@@ -133,6 +133,11 @@ namespace Xamarin.PropertyEditing.Mac
 
 		protected override void OnViewModelChanged (PropertyViewModel oldModel)
 		{
+			base.OnViewModelChanged (oldModel);
+
+			if (ViewModel == null)
+				return;
+
 			if (ViewModel.HasInputModes) {
 				if (this.inputModePopup == null) {
 					this.inputModePopup = new NSPopUpButton {
@@ -169,8 +174,6 @@ namespace Xamarin.PropertyEditing.Mac
 			// If we are reusing the control we'll have to hid the inputMode if this doesn't have InputMode.
 			if (this.inputModePopup != null)
 				this.inputModePopup.Hidden = !ViewModel.HasInputModes;
-
-			base.OnViewModelChanged (oldModel);
 		}
 	}
 }
diff --git a/Xamarin.PropertyEditing.Mac/Controls/PropertyEditorControl.cs b/Xamarin.PropertyEditing.Mac/Controls/PropertyEditorControl.cs
index efa2171..5b33084 100644
--- a/Xamarin.PropertyEditing.Mac/Controls/PropertyEditorControl.cs
+++ b/Xamarin.PropertyEditing.Mac/Controls/PropertyEditorControl.cs
@@ -32,9 +32,9 @@ namespace Xamarin.PropertyEditing.Mac
 
 		PropertyViewModel viewModel;
 		public PropertyViewModel ViewModel {
-			get { return viewModel; }
+			get { return this.viewModel; }
 			set {
-				if (viewModel == value)
+				if (this.ViewModel == value)
 					return;
 
 				PropertyViewModel oldModel = this.viewModel;
@@ -45,10 +45,10 @@ namespace Xamarin.PropertyEditing.Mac
 
 				this.viewModel = value;
 				OnViewModelChanged (oldModel);
-				viewModel.PropertyChanged += OnPropertyChanged;
-
-				// FIXME: figure out what we want errors to display as (tooltip, etc.)
-				viewModel.ErrorsChanged += HandleErrorsChanged;
+				if (this.viewModel != null) {
+					this.viewModel.PropertyChanged += OnPropertyChanged;
+					this.viewModel.ErrorsChanged += HandleErrorsChanged;
+				}
 			}
 		}
 
@@ -103,11 +103,12 @@ namespace Xamarin.PropertyEditing.Mac
 
 		protected virtual void OnViewModelChanged (PropertyViewModel oldModel)
 		{
-			SetEnabled ();
-			UpdateValue ();
-			UpdateAccessibilityValues ();
+			if (ViewModel != null) {
+				SetEnabled ();
+				UpdateValue ();
+				UpdateAccessibilityValues ();
+			}
 
-			// Hook this up so we know when to reset values 
 			PropertyButton.ViewModel = viewModel;
 		}
 
diff --git a/Xamarin.PropertyEditing.Mac/Controls/StringEditorControl.cs b/Xamarin.PropertyEditing.Mac/Controls/StringEditorControl.cs
index 75f46d4..ee32d25 100644
--- a/Xamarin.PropertyEditing.Mac/Controls/StringEditorControl.cs
+++ b/Xamarin.PropertyEditing.Mac/Controls/StringEditorControl.cs
@@ -65,6 +65,11 @@ namespace Xamarin.PropertyEditing.Mac
 
 		protected override void OnViewModelChanged (PropertyViewModel oldModel)
 		{
+			base.OnViewModelChanged (oldModel);
+
+			if (ViewModel == null)
+				return;
+
 			if (ViewModel.HasInputModes) {
 				if (this.inputModePopup == null) {
 					this.inputModePopup = new NSPopUpButton {
@@ -101,8 +106,6 @@ namespace Xamarin.PropertyEditing.Mac
 			// If we are reusing the control we'll have to hid the inputMode if this doesn't have InputMode.
 			if (this.inputModePopup != null)
 				this.inputModePopup.Hidden = !ViewModel.HasInputModes;
-
-			base.OnViewModelChanged (oldModel);
 		}
 
 		protected override void UpdateErrorsDisplayed (IEnumerable errors)