From 69126a7967ecc208a0b3572686f5a89a6cfa2ad5 Mon Sep 17 00:00:00 2001
From: Giuseppe Lippolis <workgroupengineering@outlook.com>
Date: Tue, 16 Nov 2021 10:58:20 +0100
Subject: [PATCH] fixes(DevTools):  Null Annotations

---
 .../ViewModels/ControlDetailsViewModel.cs     | 25 ++++++++++---------
 .../ViewModels/TreePageViewModel.cs           |  2 +-
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
index 7b32e21fbd..9905aa4afc 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
@@ -17,16 +17,16 @@ namespace Avalonia.Diagnostics.ViewModels
     internal class ControlDetailsViewModel : ViewModelBase, IDisposable
     {
         private readonly IVisual _control;
-        private IDictionary<object, List<PropertyViewModel>> _propertyIndex;
+        private IDictionary<object, List<PropertyViewModel>>? _propertyIndex;
         private PropertyViewModel? _selectedProperty;
-        private DataGridCollectionView _propertiesView;
+        private DataGridCollectionView? _propertiesView;
         private bool _snapshotStyles;
         private bool _showInactiveStyles;
         private string? _styleStatus;
-        private object _selectedEntity;
+        private object? _selectedEntity;
         private readonly Stack<(string Name,object Entry)> _selectedEntitiesStack = new();
-        private string _selectedEntityName;
-        private string _selectedEntityType;
+        private string? _selectedEntityName;
+        private string? _selectedEntityType;
 
         public ControlDetailsViewModel(TreePageViewModel treePage, IVisual control)
         {
@@ -117,7 +117,7 @@ namespace Avalonia.Diagnostics.ViewModels
 
         public TreePageViewModel TreePage { get; }
 
-        public DataGridCollectionView PropertiesView
+        public DataGridCollectionView? PropertiesView
         {
             get => _propertiesView;
             private set => RaiseAndSetIfChanged(ref _propertiesView, value);
@@ -127,7 +127,7 @@ namespace Avalonia.Diagnostics.ViewModels
 
         public ObservableCollection<PseudoClassViewModel> PseudoClasses { get; }
 
-        public object SelectedEntity
+        public object? SelectedEntity
         {
             get => _selectedEntity;
             set
@@ -137,7 +137,7 @@ namespace Avalonia.Diagnostics.ViewModels
             }
         }
 
-        public string SelectedEntityName
+        public string? SelectedEntityName
         {
             get => _selectedEntityName;
             set
@@ -147,7 +147,7 @@ namespace Avalonia.Diagnostics.ViewModels
             }
         }
         
-        public string SelectedEntityType
+        public string? SelectedEntityType
         {
             get => _selectedEntityType;
             set
@@ -270,7 +270,7 @@ namespace Avalonia.Diagnostics.ViewModels
 
         private void ControlPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
         {
-            if (_propertyIndex.TryGetValue(e.Property, out var properties))
+            if (_propertyIndex is { } && _propertyIndex.TryGetValue(e.Property, out var properties))
             {
                 foreach (var property in properties)
                 {
@@ -284,6 +284,7 @@ namespace Avalonia.Diagnostics.ViewModels
         private void ControlPropertyChanged(object? sender, PropertyChangedEventArgs e)
         {
             if (e.PropertyName != null
+                && _propertyIndex is { }
                 && _propertyIndex.TryGetValue(e.PropertyName, out var properties))
             {
                 foreach (var property in properties)
@@ -402,7 +403,7 @@ namespace Avalonia.Diagnostics.ViewModels
             var selectedProperty = SelectedProperty;
             var selectedEntity = SelectedEntity;
             var selectedEntityName = SelectedEntityName;
-            if (selectedProperty == null)
+            if (selectedEntity == null ||  selectedProperty == null)
                 return;
 
             object? property;
@@ -419,7 +420,7 @@ namespace Avalonia.Diagnostics.ViewModels
                      ?.GetValue(selectedEntity);
             }
             if (property == null) return;
-            _selectedEntitiesStack.Push((Name:selectedEntityName,Entry:selectedEntity));
+            _selectedEntitiesStack.Push((Name:selectedEntityName!,Entry:selectedEntity));
             NavigateToProperty(property, selectedProperty.Name);
         }
 
diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/TreePageViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/TreePageViewModel.cs
index 4b18cf414a..27b28f35fc 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/TreePageViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/TreePageViewModel.cs
@@ -15,7 +15,7 @@ namespace Avalonia.Diagnostics.ViewModels
             Nodes = nodes;
 
             PropertiesFilter = new FilterViewModel();
-            PropertiesFilter.RefreshFilter += (s, e) => Details?.PropertiesView.Refresh();
+            PropertiesFilter.RefreshFilter += (s, e) => Details?.PropertiesView?.Refresh();
 
             SettersFilter = new FilterViewModel();
             SettersFilter.RefreshFilter += (s, e) => Details?.UpdateStyleFilters();