Shared UI - Resolved all remaining warnings

UI - Resolved all remaining warnings
Layer properties - Fixed DisableKeyframes layer property attribute not being applied

src/Artemis.UI.Shared/Controls/DeviceVisualizer.cs

@@ -184,7 +184,7 @@ namespace Artemis.UI.Shared
             return rotationRect.Size;
         }
 
-        private void OnUnloaded(object sender, RoutedEventArgs e)
+        private void OnUnloaded(object? sender, RoutedEventArgs e)
         {
             _timer.Stop();
 
@@ -196,12 +196,12 @@ namespace Artemis.UI.Shared
             }
         }
 
-        private void OnLoaded(object sender, RoutedEventArgs e)
+        private void OnLoaded(object? sender, RoutedEventArgs e)
         {
             _timer.Start();
         }
 
-        private void TimerOnTick(object sender, EventArgs e)
+        private void TimerOnTick(object? sender, EventArgs e)
         {
             if (ShowColors && Visibility == Visibility.Visible)
                 Render();

src/Artemis.UI.Shared/Converters/ColorToStringConverter.cs

@@ -13,20 +13,20 @@ namespace Artemis.UI.Shared
     public class ColorToStringConverter : IValueConverter
     {
         /// <inheritdoc />
-        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        public object? Convert(object? value, Type targetType, object parameter, CultureInfo culture)
         {
             return value?.ToString()?.ToUpper();
         }
 
         /// <inheritdoc />
-        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        public object? ConvertBack(object? value, Type targetType, object parameter, CultureInfo culture)
         {
             try
             {
-                if (string.IsNullOrWhiteSpace((string) value))
+                if (string.IsNullOrWhiteSpace(value as string))
                     return default(Color);
 
-                object color = ColorConverter.ConvertFromString((string) value);
+                object? color = ColorConverter.ConvertFromString((string) value!);
                 if (color is Color c)
                     return c;
 

src/Artemis.UI.Shared/Converters/SKColorToStringConverter.cs

@@ -14,18 +14,18 @@ namespace Artemis.UI.Shared
     public class SKColorToStringConverter : IValueConverter
     {
         /// <inheritdoc />
-        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        public object? Convert(object? value, Type targetType, object parameter, CultureInfo culture)
         {
             return value?.ToString();
         }
 
         /// <inheritdoc />
-        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        public object ConvertBack(object? value, Type targetType, object parameter, CultureInfo culture)
         {
-            if (string.IsNullOrWhiteSpace((string) value))
+            if (string.IsNullOrWhiteSpace(value as string))
                 return SKColor.Empty;
 
-            return SKColor.TryParse((string) value, out SKColor color) ? color : SKColor.Empty;
+            return SKColor.TryParse((string) value!, out SKColor color) ? color : SKColor.Empty;
         }
     }
 }

src/Artemis.UI.Shared/Converters/TypeToStringConverter.cs

@@ -11,7 +11,7 @@ namespace Artemis.UI.Shared
     public class TypeToStringConverter : IValueConverter
     {
         /// <inheritdoc />
-        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        public object? Convert(object value, Type targetType, object? parameter, CultureInfo culture)
         {
             bool humanizeProvided = bool.TryParse(parameter?.ToString(), out bool humanize);
             if (value is Type type)

src/Artemis.UI.Shared/DataModelVisualization/DataModelDisplayViewModel.cs

@@ -1,4 +1,5 @@
-using Artemis.Core.DataModelExpansions;
+using System.Diagnostics.CodeAnalysis;
+using Artemis.Core.DataModelExpansions;
 using Stylet;
 
 namespace Artemis.UI.Shared
@@ -9,11 +10,13 @@ namespace Artemis.UI.Shared
     /// <typeparam name="T">The type of the data model</typeparam>
     public abstract class DataModelDisplayViewModel<T> : DataModelDisplayViewModel
     {
-        private T _displayValue;
+        [AllowNull]
+        private T _displayValue = default!;
 
         /// <summary>
         ///     Gets or sets value that the view model must display
         /// </summary>
+        [AllowNull]
         public T DisplayValue
         {
             get => _displayValue;
@@ -24,10 +27,10 @@ namespace Artemis.UI.Shared
             }
         }
 
-        internal override object InternalGuard => null;
+        internal override object InternalGuard => new object();
 
         /// <inheritdoc />
-        public override void UpdateValue(object model)
+        public override void UpdateValue(object? model)
         {
             DisplayValue = model is T value ? value : default;
         }
@@ -45,12 +48,12 @@ namespace Artemis.UI.Shared
     /// </summary>
     public abstract class DataModelDisplayViewModel : PropertyChangedBase
     {
-        private DataModelPropertyAttribute _propertyDescription;
+        private DataModelPropertyAttribute? _propertyDescription;
 
         /// <summary>
         ///     Gets the property description of this value
         /// </summary>
-        public DataModelPropertyAttribute PropertyDescription
+        public DataModelPropertyAttribute? PropertyDescription
         {
             get => _propertyDescription;
             internal set => SetAndNotify(ref _propertyDescription, value);
@@ -65,6 +68,6 @@ namespace Artemis.UI.Shared
         ///     Updates the display value
         /// </summary>
         /// <param name="model">The value to set</param>
-        public abstract void UpdateValue(object model);
+        public abstract void UpdateValue(object? model);
     }
 }

src/Artemis.UI.Shared/DataModelVisualization/DataModelInputViewModel.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Data;
@@ -16,7 +17,7 @@ namespace Artemis.UI.Shared
     public abstract class DataModelInputViewModel<T> : DataModelInputViewModel
     {
         private bool _closed;
-        private T _inputValue;
+        [AllowNull] private T _inputValue = default!;
 
         /// <summary>
         ///     Creates a new instance of the <see cref="DataModelInputViewModel{T}" /> class
@@ -32,6 +33,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets or sets the value shown in the input
         /// </summary>
+        [AllowNull]
         public T InputValue
         {
             get => _inputValue;
@@ -82,13 +84,13 @@ namespace Artemis.UI.Shared
         // ReSharper disable once UnusedMember.Global
         internal abstract object InternalGuard { get; }
 
-        internal Action<object, bool> UpdateCallback { get; set; }
+        internal Action<object?, bool> UpdateCallback { get; set; } = null!; // Set right after construction
 
         /// <summary>
         ///     Gets the types this input view model can support through type conversion. This list is defined when registering the
         ///     view model.
         /// </summary>
-        internal IReadOnlyCollection<Type> CompatibleConversionTypes { get; set; }
+        internal IReadOnlyCollection<Type>? CompatibleConversionTypes { get; set; }
 
         /// <summary>
         ///     Submits the input value and removes this view model.
@@ -133,6 +135,6 @@ namespace Artemis.UI.Shared
         }
 
         /// <inheritdoc />
-        public UIElement View { get; set; }
+        public UIElement? View { get; set; }
     }
 }

src/Artemis.UI.Shared/DataModelVisualization/Input/DataModelDynamicViewModel.cs

@@ -12,21 +12,25 @@ using Stylet;
 
 namespace Artemis.UI.Shared.Input
 {
+    /// <summary>
+    ///     Represents a view model that allows selecting a data model property used by boolean operations on a certain data
+    ///     model property
+    /// </summary>
     public class DataModelDynamicViewModel : PropertyChangedBase, IDisposable
     {
         private readonly IDataModelUIService _dataModelUIService;
         private readonly Module _module;
         private readonly Timer _updateTimer;
         private SolidColorBrush _buttonBrush = new SolidColorBrush(Color.FromRgb(171, 71, 188));
-        private DataModelPath _dataModelPath;
-        private DataModelPropertiesViewModel _dataModelViewModel;
+        private DataModelPath? _dataModelPath;
+        private DataModelPropertiesViewModel? _dataModelViewModel;
         private bool _displaySwitchButton;
-        private Type[] _filterTypes;
+        private Type[] _filterTypes = new Type[0];
         private bool _isDataModelViewModelOpen;
         private bool _isEnabled = true;
         private string _placeholder = "Select a property";
 
-        public DataModelDynamicViewModel(Module module, ISettingsService settingsService, IDataModelUIService dataModelUIService)
+        internal DataModelDynamicViewModel(Module module, ISettingsService settingsService, IDataModelUIService dataModelUIService)
         {
             _module = module;
             _dataModelUIService = dataModelUIService;
@@ -39,6 +43,9 @@ namespace Artemis.UI.Shared.Input
             Initialize();
         }
 
+        /// <summary>
+        ///     Gets or sets the brush to use for the input button
+        /// </summary>
         public SolidColorBrush ButtonBrush
         {
             get => _buttonBrush;
@@ -49,26 +56,41 @@ namespace Artemis.UI.Shared.Input
             }
         }
 
+        /// <summary>
+        ///     Gets the brush to use for the switch button
+        /// </summary>
         public SolidColorBrush SwitchButtonBrush => new SolidColorBrush(ButtonBrush.Color.Darken());
 
+        /// <summary>
+        ///     Gets or sets the placeholder text when no value is entered
+        /// </summary>
         public string Placeholder
         {
             get => _placeholder;
             set => SetAndNotify(ref _placeholder, value);
         }
 
+        /// <summary>
+        ///     Gets or sets the enabled state of the input
+        /// </summary>
         public bool IsEnabled
         {
             get => _isEnabled;
             set => SetAndNotify(ref _isEnabled, value);
         }
 
+        /// <summary>
+        ///     Gets or sets whether the switch button should be displayed
+        /// </summary>
         public bool DisplaySwitchButton
         {
             get => _displaySwitchButton;
             set => SetAndNotify(ref _displaySwitchButton, value);
         }
 
+        /// <summary>
+        ///     Gets or sets the types of properties this view model will allow to be selected
+        /// </summary>
         public Type[] FilterTypes
         {
             get => _filterTypes;
@@ -79,18 +101,38 @@ namespace Artemis.UI.Shared.Input
             }
         }
 
+        /// <summary>
+        ///     Gets a bindable collection of extra data model view models to show
+        /// </summary>
         public BindableCollection<DataModelPropertiesViewModel> ExtraDataModelViewModels { get; }
+
+        /// <summary>
+        ///     Gets a boolean indicating whether there are any extra data models
+        /// </summary>
         public bool HasExtraDataModels => ExtraDataModelViewModels.Any();
 
+        /// <summary>
+        ///     Command used by view
+        /// </summary>
         public DelegateCommand SelectPropertyCommand { get; }
+
+        /// <summary>
+        ///     Setting used by view
+        /// </summary>
         public PluginSetting<bool> ShowDataModelValues { get; }
 
-        public DataModelPropertiesViewModel DataModelViewModel
+        /// <summary>
+        ///     Gets or sets root the data model view model
+        /// </summary>
+        public DataModelPropertiesViewModel? DataModelViewModel
         {
             get => _dataModelViewModel;
             private set => SetAndNotify(ref _dataModelViewModel, value);
         }
 
+        /// <summary>
+        ///     Gets or sets a boolean indicating whether the data model is open
+        /// </summary>
         public bool IsDataModelViewModelOpen
         {
             get => _isDataModelViewModelOpen;
@@ -101,7 +143,10 @@ namespace Artemis.UI.Shared.Input
             }
         }
 
-        public DataModelPath DataModelPath
+        /// <summary>
+        ///     Gets or sets the data model path of the currently selected data model property
+        /// </summary>
+        public DataModelPath? DataModelPath
         {
             get => _dataModelPath;
             private set
@@ -113,9 +158,19 @@ namespace Artemis.UI.Shared.Input
             }
         }
 
+        /// <summary>
+        ///     Gets a boolean indicating whether the current selection is valid
+        /// </summary>
         public bool IsValid => DataModelPath?.IsValid ?? true;
-        public string DisplayValue => DataModelPath?.GetPropertyDescription()?.Name ?? DataModelPath?.Segments.LastOrDefault()?.Identifier;
 
+        /// <summary>
+        ///     Gets the display name of the currently selected property
+        /// </summary>
+        public string? DisplayValue => DataModelPath?.GetPropertyDescription()?.Name ?? DataModelPath?.Segments.LastOrDefault()?.Identifier;
+
+        /// <summary>
+        ///     Gets the human readable path of the currently selected property
+        /// </summary>
         public string DisplayPath
         {
             get
@@ -128,8 +183,16 @@ namespace Artemis.UI.Shared.Input
             }
         }
 
+        /// <summary>
+        ///     Gets or sets a boolean indicating whether event child VMs should be loaded, defaults to <see langword="true" />
+        /// </summary>
         public bool LoadEventChildren { get; set; } = true;
 
+        /// <summary>
+        ///     Changes the root data model VM stored in <see cref="DataModelViewModel" /> to the provided
+        ///     <paramref name="dataModel" />
+        /// </summary>
+        /// <param name="dataModel">The data model VM to set the new root data model to</param>
         public void ChangeDataModel(DataModelPropertiesViewModel dataModel)
         {
             if (DataModelViewModel != null)
@@ -141,12 +204,19 @@ namespace Artemis.UI.Shared.Input
                 DataModelViewModel.UpdateRequested += DataModelOnUpdateRequested;
         }
 
-        public void ChangeDataModelPath(DataModelPath dataModelPath)
+        /// <summary>
+        ///     Changes the currently selected property by its path
+        /// </summary>
+        /// <param name="dataModelPath">The path of the property to set the selection to</param>
+        public void ChangeDataModelPath(DataModelPath? dataModelPath)
         {
             DataModelPath?.Dispose();
             DataModelPath = dataModelPath != null ? new DataModelPath(dataModelPath) : null;
         }
 
+        /// <summary>
+        ///     Requests switching the input type to static using a <see cref="DataModelStaticViewModel" />
+        /// </summary>
         public void SwitchToStatic()
         {
             ChangeDataModelPath(null);
@@ -158,13 +228,14 @@ namespace Artemis.UI.Shared.Input
         {
             // Get the data models
             DataModelViewModel = _dataModelUIService.GetPluginDataModelVisualization(_module, true);
-            DataModelViewModel.UpdateRequested += DataModelOnUpdateRequested;
+            if (DataModelViewModel != null)
+                DataModelViewModel.UpdateRequested += DataModelOnUpdateRequested;
             ExtraDataModelViewModels.CollectionChanged += ExtraDataModelViewModelsOnCollectionChanged;
             _updateTimer.Start();
             _updateTimer.Elapsed += OnUpdateTimerOnElapsed;
         }
 
-        private void ExecuteSelectPropertyCommand(object context)
+        private void ExecuteSelectPropertyCommand(object? context)
         {
             if (!(context is DataModelVisualizationViewModel selected))
                 return;
@@ -173,40 +244,61 @@ namespace Artemis.UI.Shared.Input
             OnPropertySelected(new DataModelInputDynamicEventArgs(DataModelPath));
         }
 
+        #region IDisposable
+
+        /// <summary>
+        ///     Releases the unmanaged resources used by the object and optionally releases the managed resources.
+        /// </summary>
+        /// <param name="disposing">
+        ///     <see langword="true" /> to release both managed and unmanaged resources;
+        ///     <see langword="false" /> to release only unmanaged resources.
+        /// </param>
+        protected virtual void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                _updateTimer.Stop();
+                _updateTimer.Dispose();
+                _updateTimer.Elapsed -= OnUpdateTimerOnElapsed;
+
+                DataModelPath?.Dispose();
+            }
+        }
+
+        /// <inheritdoc />
         public void Dispose()
         {
-            _updateTimer.Stop();
-            _updateTimer.Dispose();
-            _updateTimer.Elapsed -= OnUpdateTimerOnElapsed;
-
-            DataModelPath?.Dispose();
+            Dispose(true);
+            GC.SuppressFinalize(this);
         }
 
+        #endregion
+
         #region Event handlers
 
-        private void DataModelOnUpdateRequested(object sender, EventArgs e)
+        private void DataModelOnUpdateRequested(object? sender, EventArgs e)
         {
-            DataModelViewModel.ApplyTypeFilter(true, FilterTypes);
+            DataModelViewModel?.ApplyTypeFilter(true, FilterTypes);
             foreach (DataModelPropertiesViewModel extraDataModelViewModel in ExtraDataModelViewModels)
                 extraDataModelViewModel.ApplyTypeFilter(true, FilterTypes);
         }
 
-        private void ExtraDataModelViewModelsOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+        private void ExtraDataModelViewModelsOnCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
         {
             NotifyOfPropertyChange(nameof(HasExtraDataModels));
         }
 
-        private void OnUpdateTimerOnElapsed(object sender, ElapsedEventArgs e)
+        private void OnUpdateTimerOnElapsed(object? sender, ElapsedEventArgs e)
         {
             if (!IsDataModelViewModelOpen)
                 return;
-            
+
             UpdateDataModelVisualization();
         }
 
         private void UpdateDataModelVisualization()
         {
-            DataModelViewModel.Update(_dataModelUIService, new DataModelUpdateConfiguration(LoadEventChildren));
+            DataModelViewModel?.Update(_dataModelUIService, new DataModelUpdateConfiguration(LoadEventChildren));
             foreach (DataModelPropertiesViewModel extraDataModelViewModel in ExtraDataModelViewModels)
                 extraDataModelViewModel.Update(_dataModelUIService, new DataModelUpdateConfiguration(LoadEventChildren));
         }
@@ -215,14 +307,28 @@ namespace Artemis.UI.Shared.Input
 
         #region Events
 
-        public event EventHandler<DataModelInputDynamicEventArgs> PropertySelected;
-        public event EventHandler SwitchToStaticRequested;
+        /// <summary>
+        ///     Occurs when anew property has been selected
+        /// </summary>
+        public event EventHandler<DataModelInputDynamicEventArgs>? PropertySelected;
 
+        /// <summary>
+        ///     Occurs when a switch to static input has been requested
+        /// </summary>
+        public event EventHandler? SwitchToStaticRequested;
+
+        /// <summary>
+        ///     Invokes the <see cref="PropertySelected" /> event
+        /// </summary>
+        /// <param name="e"></param>
         protected virtual void OnPropertySelected(DataModelInputDynamicEventArgs e)
         {
             PropertySelected?.Invoke(this, e);
         }
 
+        /// <summary>
+        ///     Invokes the <see cref="SwitchToStaticRequested" /> event
+        /// </summary>
         protected virtual void OnSwitchToStaticRequested()
         {
             SwitchToStaticRequested?.Invoke(this, EventArgs.Empty);

src/Artemis.UI.Shared/DataModelVisualization/Input/DataModelStaticViewModel.cs

@@ -11,29 +11,33 @@ using Stylet;
 
 namespace Artemis.UI.Shared.Input
 {
+    /// <summary>
+    ///     Represents a view model that allows inputting a static value used by boolean operations on a certain data model
+    ///     property
+    /// </summary>
     public class DataModelStaticViewModel : PropertyChangedBase, IDisposable
     {
         private readonly IDataModelUIService _dataModelUIService;
-        private readonly Window _rootView;
+        private readonly Window? _rootView;
         private SolidColorBrush _buttonBrush = new SolidColorBrush(Color.FromRgb(171, 71, 188));
         private bool _displaySwitchButton;
-        private DataModelDisplayViewModel _displayViewModel;
-        private DataModelInputViewModel _inputViewModel;
+        private DataModelDisplayViewModel? _displayViewModel;
+        private DataModelInputViewModel? _inputViewModel;
         private bool _isEnabled;
         private string _placeholder = "Enter a value";
         private DataModelPropertyAttribute _targetDescription;
         private Type _targetType;
-        private object _value;
+        private object? _value;
 
-        public DataModelStaticViewModel(Type targetType, DataModelPropertyAttribute targetDescription, IDataModelUIService dataModelUIService)
+        internal DataModelStaticViewModel(Type targetType, DataModelPropertyAttribute targetDescription, IDataModelUIService dataModelUIService)
         {
             _dataModelUIService = dataModelUIService;
             _rootView = Application.Current.Windows.OfType<Window>().SingleOrDefault(x => x.IsActive);
 
-            TargetType = targetType;
-            TargetDescription = targetDescription;
-            IsEnabled = TargetType != null;
-            DisplayViewModel = _dataModelUIService.GetDataModelDisplayViewModel(TargetType ?? typeof(object), TargetDescription, true);
+            _targetType = targetType;
+            _targetDescription = targetDescription;
+            _isEnabled = TargetType != null;
+            _displayViewModel = _dataModelUIService.GetDataModelDisplayViewModel(TargetType ?? typeof(object), TargetDescription, true);
 
             if (_rootView != null)
             {
@@ -63,7 +67,7 @@ namespace Artemis.UI.Shared.Input
         /// <summary>
         ///     Gets the view model used to display the value
         /// </summary>
-        public DataModelDisplayViewModel DisplayViewModel
+        public DataModelDisplayViewModel? DisplayViewModel
         {
             get => _displayViewModel;
             private set => SetAndNotify(ref _displayViewModel, value);
@@ -72,7 +76,7 @@ namespace Artemis.UI.Shared.Input
         /// <summary>
         ///     Gets the view model used to edit the value
         /// </summary>
-        public DataModelInputViewModel InputViewModel
+        public DataModelInputViewModel? InputViewModel
         {
             get => _inputViewModel;
             private set => SetAndNotify(ref _inputViewModel, value);
@@ -99,7 +103,7 @@ namespace Artemis.UI.Shared.Input
         /// <summary>
         ///     Gets or sets the value of the target
         /// </summary>
-        public object Value
+        public object? Value
         {
             get => _value;
             set
@@ -173,7 +177,7 @@ namespace Artemis.UI.Shared.Input
         }
 
         /// <summary>
-        ///     Requests switching the input type to dynamic
+        ///     Requests switching the input type to dynamic using a <see cref="DataModelDynamicViewModel"/>
         /// </summary>
         public void SwitchToDynamic()
         {
@@ -183,7 +187,7 @@ namespace Artemis.UI.Shared.Input
             OnSwitchToDynamicRequested();
         }
 
-        private void ApplyFreeInput(object value, bool submitted)
+        private void ApplyFreeInput(object? value, bool submitted)
         {
             if (submitted)
                 OnValueUpdated(new DataModelInputStaticEventArgs(value));
@@ -204,11 +208,13 @@ namespace Artemis.UI.Shared.Input
         protected virtual void Dispose(bool disposing)
         {
             if (disposing)
+            {
                 if (_rootView != null)
                 {
                     _rootView.MouseUp -= RootViewOnMouseUp;
                     _rootView.KeyUp -= RootViewOnKeyUp;
                 }
+            }
         }
 
         /// <inheritdoc />

src/Artemis.UI.Shared/DataModelVisualization/Shared/DataModelEventViewModel.cs

@@ -6,21 +6,28 @@ using Artemis.UI.Shared.Services;
 
 namespace Artemis.UI.Shared
 {
+    /// <summary>
+    ///     Represents a view model that visualizes an event data model property
+    /// </summary>
     public class DataModelEventViewModel : DataModelVisualizationViewModel
     {
-        private Type _displayValueType;
+        private Type? _displayValueType;
 
         internal DataModelEventViewModel(DataModel dataModel, DataModelVisualizationViewModel parent, DataModelPath dataModelPath) : base(dataModel, parent, dataModelPath)
         {
         }
 
-        public Type DisplayValueType
+        /// <summary>
+        ///     Gets the type of event arguments this event triggers and that must be displayed as children
+        /// </summary>
+        public Type? DisplayValueType
         {
             get => _displayValueType;
             set => SetAndNotify(ref _displayValueType, value);
         }
 
-        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration configuration)
+        /// <inheritdoc />
+        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration)
         {
             DisplayValueType = DataModelPath?.GetPropertyType();
 
@@ -40,13 +47,16 @@ namespace Artemis.UI.Shared
                 dataModelVisualizationViewModel.Update(dataModelUIService, configuration);
         }
 
-        public override object GetCurrentValue()
+        /// <summary>
+        /// Always returns <see langword="null"/> for data model events
+        /// </summary>
+        public override object? GetCurrentValue()
         {
             return null;
         }
 
         /// <inheritdoc />
-        public override string ToString()
+        public override string? ToString()
         {
             return DisplayPath ?? Path;
         }

src/Artemis.UI.Shared/DataModelVisualization/Shared/DataModelListPropertiesViewModel.cs

@@ -5,43 +5,63 @@ using Artemis.UI.Shared.Services;
 
 namespace Artemis.UI.Shared
 {
+    /// <summary>
+    ///     Represents a view model that wraps a regular <see cref="DataModelPropertiesViewModel" /> but contained in
+    ///     a <see cref="DataModelListViewModel" />
+    /// </summary>
     public class DataModelListPropertiesViewModel : DataModelPropertiesViewModel
     {
-        private object _displayValue;
+        private readonly ListPredicateWrapperDataModel _listPredicateWrapper;
+        private object? _displayValue;
         private int _index;
-        private Type _listType;
+        private Type? _listType;
 
-        public DataModelListPropertiesViewModel(Type listType) : base(null, null, null)
+        internal DataModelListPropertiesViewModel(Type listType) : base(null, null, null)
         {
-            DataModel = ListPredicateWrapperDataModel.Create(listType);
+            _listPredicateWrapper = ListPredicateWrapperDataModel.Create(listType);
+            DataModel = _listPredicateWrapper;
             ListType = listType;
         }
 
+        /// <summary>
+        ///     Gets the index of the element within the list
+        /// </summary>
         public int Index
         {
             get => _index;
             set => SetAndNotify(ref _index, value);
         }
 
-        public Type ListType
+        /// <summary>
+        ///     Gets the type of elements contained in the list
+        /// </summary>
+        public Type? ListType
         {
             get => _listType;
             set => SetAndNotify(ref _listType, value);
         }
 
-        public new object DisplayValue
+        /// <summary>
+        ///     Gets the value of the property that is being visualized
+        /// </summary>
+        public new object? DisplayValue
         {
             get => _displayValue;
             set => SetAndNotify(ref _displayValue, value);
         }
 
-        public DataModelVisualizationViewModel DisplayViewModel => Children.FirstOrDefault();
+        /// <summary>
+        ///     Gets the view model that handles displaying the property
+        /// </summary>
+        public DataModelVisualizationViewModel? DisplayViewModel => Children.FirstOrDefault();
 
-        public override string DisplayPath => null;
+        /// <inheritdoc />
+        public override string? DisplayPath => null;
 
-        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration configuration)
+        /// <inheritdoc />
+        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration)
         {
-            ((ListPredicateWrapperDataModel) DataModel).UntypedValue = DisplayValue;
+            _listPredicateWrapper.UntypedValue = DisplayValue;
 
             PopulateProperties(dataModelUIService, configuration);
             if (DisplayViewModel == null)
@@ -52,7 +72,8 @@ namespace Artemis.UI.Shared
             DisplayViewModel.Update(dataModelUIService, null);
         }
 
-        public override object GetCurrentValue()
+        /// <inheritdoc />
+        public override object? GetCurrentValue()
         {
             return DisplayValue;
         }

src/Artemis.UI.Shared/DataModelVisualization/Shared/DataModelListPropertyViewModel.cs

@@ -10,19 +10,22 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class DataModelListPropertyViewModel : DataModelPropertyViewModel
     {
+        private readonly ListPredicateWrapperDataModel _listPredicateWrapper;
         private int _index;
-        private Type _listType;
+        private Type? _listType;
 
         internal DataModelListPropertyViewModel(Type listType, DataModelDisplayViewModel displayViewModel) : base(null, null, null)
         {
-            DataModel = ListPredicateWrapperDataModel.Create(listType);
+            _listPredicateWrapper = ListPredicateWrapperDataModel.Create(listType);
+            DataModel = _listPredicateWrapper;
             ListType = listType;
             DisplayViewModel = displayViewModel;
         }
 
         internal DataModelListPropertyViewModel(Type listType) : base(null, null, null)
         {
-            DataModel = ListPredicateWrapperDataModel.Create(listType);
+            _listPredicateWrapper = ListPredicateWrapperDataModel.Create(listType);
+            DataModel = _listPredicateWrapper;
             ListType = listType;
         }
 
@@ -38,26 +41,26 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the type of elements contained in the list
         /// </summary>
-        public Type ListType
+        public Type? ListType
         {
             get => _listType;
             private set => SetAndNotify(ref _listType, value);
         }
 
         /// <inheritdoc />
-        public override object GetCurrentValue()
+        public override object? GetCurrentValue()
         {
             return DisplayValue;
         }
 
         /// <inheritdoc />
-        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration configuration)
+        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration)
         {
             // Display value gets updated by parent, don't do anything if it is null
             if (DisplayValue == null)
                 return;
 
-            ((ListPredicateWrapperDataModel) DataModel).UntypedValue = DisplayValue;
+            _listPredicateWrapper.UntypedValue = DisplayValue;
 
             if (DisplayViewModel == null)
                 DisplayViewModel = dataModelUIService.GetDataModelDisplayViewModel(DisplayValue.GetType(), PropertyDescription, true);

src/Artemis.UI.Shared/DataModelVisualization/Shared/DataModelListViewModel.cs

@@ -13,21 +13,22 @@ namespace Artemis.UI.Shared
     public class DataModelListViewModel : DataModelVisualizationViewModel
     {
         private string _countDisplay;
-        private Type _displayValueType;
-        private IEnumerable _list;
+        private Type? _displayValueType;
+        private IEnumerable? _list;
         private BindableCollection<DataModelVisualizationViewModel> _listChildren;
         private int _listCount;
 
         internal DataModelListViewModel(DataModel dataModel, DataModelVisualizationViewModel parent, DataModelPath dataModelPath)
             : base(dataModel, parent, dataModelPath)
         {
-            ListChildren = new BindableCollection<DataModelVisualizationViewModel>();
+            _countDisplay = "0 items";
+            _listChildren = new BindableCollection<DataModelVisualizationViewModel>();
         }
 
         /// <summary>
         ///     Gets the instance of the list that is being visualized
         /// </summary>
-        public IEnumerable List
+        public IEnumerable? List
         {
             get => _list;
             private set => SetAndNotify(ref _list, value);
@@ -45,7 +46,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the type of elements this list contains and that must be displayed as children
         /// </summary>
-        public Type DisplayValueType
+        public Type? DisplayValueType
         {
             get => _displayValueType;
             set => SetAndNotify(ref _displayValueType, value);
@@ -70,7 +71,7 @@ namespace Artemis.UI.Shared
         }
 
         /// <inheritdoc />
-        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration configuration)
+        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration)
         {
             if (Parent != null && !Parent.IsVisualizationExpanded)
                 return;
@@ -86,10 +87,12 @@ namespace Artemis.UI.Shared
                 if (item == null)
                     continue;
 
-                DataModelVisualizationViewModel child;
+                DataModelVisualizationViewModel? child;
                 if (ListChildren.Count <= index)
                 {
                     child = CreateListChild(dataModelUIService, item.GetType());
+                    if (child == null)
+                        continue;
                     ListChildren.Add(child);
                 }
                 else
@@ -126,10 +129,10 @@ namespace Artemis.UI.Shared
             return $"[List] {DisplayPath ?? Path} - {ListCount} item(s)";
         }
 
-        private DataModelVisualizationViewModel CreateListChild(IDataModelUIService dataModelUIService, Type listType)
+        private DataModelVisualizationViewModel? CreateListChild(IDataModelUIService dataModelUIService, Type listType)
         {
             // If a display VM was found, prefer to use that in any case
-            DataModelDisplayViewModel typeViewModel = dataModelUIService.GetDataModelDisplayViewModel(listType, PropertyDescription);
+            DataModelDisplayViewModel? typeViewModel = dataModelUIService.GetDataModelDisplayViewModel(listType, PropertyDescription);
             if (typeViewModel != null)
                 return new DataModelListPropertyViewModel(listType, typeViewModel);
             // For primitives, create a property view model, it may be null that is fine

src/Artemis.UI.Shared/DataModelVisualization/Shared/DataModelPropertiesViewModel.cs

@@ -10,10 +10,10 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class DataModelPropertiesViewModel : DataModelVisualizationViewModel
     {
-        private object _displayValue;
-        private Type _displayValueType;
+        private object? _displayValue;
+        private Type? _displayValueType;
 
-        internal DataModelPropertiesViewModel(DataModel dataModel, DataModelVisualizationViewModel parent, DataModelPath dataModelPath)
+        internal DataModelPropertiesViewModel(DataModel? dataModel, DataModelVisualizationViewModel? parent, DataModelPath? dataModelPath)
             : base(dataModel, parent, dataModelPath)
         {
         }
@@ -21,7 +21,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the type of the property that is being visualized
         /// </summary>
-        public Type DisplayValueType
+        public Type? DisplayValueType
         {
             get => _displayValueType;
             private set => SetAndNotify(ref _displayValueType, value);
@@ -30,19 +30,19 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the value of the property that is being visualized
         /// </summary>
-        public object DisplayValue
+        public object? DisplayValue
         {
             get => _displayValue;
             private set => SetAndNotify(ref _displayValue, value);
         }
 
         /// <inheritdoc />
-        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration configuration)
+        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration)
         {
             DisplayValueType = DataModelPath?.GetPropertyType();
 
             // Only set a display value if ToString returns useful information and not just the type name
-            object currentValue = GetCurrentValue();
+            object? currentValue = GetCurrentValue();
             if (currentValue != null && currentValue.ToString() != currentValue.GetType().ToString())
                 DisplayValue = currentValue.ToString();
             else
@@ -60,7 +60,7 @@ namespace Artemis.UI.Shared
         }
 
         /// <inheritdoc />
-        public override object GetCurrentValue()
+        public override object? GetCurrentValue()
         {
             if (Parent == null || Parent.IsRootViewModel || IsRootViewModel)
                 return DataModel;
@@ -68,7 +68,7 @@ namespace Artemis.UI.Shared
         }
 
         /// <inheritdoc />
-        public override string ToString()
+        public override string? ToString()
         {
             return DisplayPath ?? Path;
         }

src/Artemis.UI.Shared/DataModelVisualization/Shared/DataModelPropertyViewModel.cs

@@ -11,11 +11,11 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class DataModelPropertyViewModel : DataModelVisualizationViewModel
     {
-        private object _displayValue;
-        private Type _displayValueType;
-        private DataModelDisplayViewModel _displayViewModel;
+        private object? _displayValue;
+        private Type? _displayValueType;
+        private DataModelDisplayViewModel? _displayViewModel;
 
-        internal DataModelPropertyViewModel(DataModel dataModel, DataModelVisualizationViewModel parent, DataModelPath dataModelPath)
+        internal DataModelPropertyViewModel(DataModel? dataModel, DataModelVisualizationViewModel? parent, DataModelPath? dataModelPath)
             : base(dataModel, parent, dataModelPath)
         {
         }
@@ -23,7 +23,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the value of the property that is being visualized
         /// </summary>
-        public object DisplayValue
+        public object? DisplayValue
         {
             get => _displayValue;
             internal set => SetAndNotify(ref _displayValue, value);
@@ -32,7 +32,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the type of the property that is being visualized
         /// </summary>
-        public Type DisplayValueType
+        public Type? DisplayValueType
         {
             get => _displayValueType;
             protected set => SetAndNotify(ref _displayValueType, value);
@@ -41,26 +41,31 @@ namespace Artemis.UI.Shared
         /// <summary>
         /// Gets the view model used to display the display value
         /// </summary>
-        public DataModelDisplayViewModel DisplayViewModel
+        public DataModelDisplayViewModel? DisplayViewModel
         {
             get => _displayViewModel;
             internal set => SetAndNotify(ref _displayViewModel, value);
         }
 
         /// <inheritdoc />
-        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration configuration)
+        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration)
         {
             if (Parent != null && !Parent.IsVisualizationExpanded && !Parent.IsRootViewModel)
                 return;
 
             if (DisplayViewModel == null)
             {
-                DisplayViewModel = dataModelUIService.GetDataModelDisplayViewModel(DataModelPath.GetPropertyType(), PropertyDescription, true);
-                DisplayViewModel.PropertyDescription = DataModelPath.GetPropertyDescription();
+                Type? propertyType = DataModelPath?.GetPropertyType();
+                if (propertyType != null)
+                {
+                    DisplayViewModel = dataModelUIService.GetDataModelDisplayViewModel(propertyType, PropertyDescription, true);
+                    if (DisplayViewModel != null) 
+                        DisplayViewModel.PropertyDescription = DataModelPath?.GetPropertyDescription();
+                }
             }
 
             DisplayValue = GetCurrentValue();
-            DisplayValueType = DisplayValue != null ? DisplayValue.GetType() : DataModelPath.GetPropertyType();
+            DisplayValueType = DisplayValue != null ? DisplayValue.GetType() : DataModelPath?.GetPropertyType();
 
             DisplayViewModel?.UpdateValue(DisplayValue);
         }

src/Artemis.UI.Shared/DataModelVisualization/Shared/DataModelVisualizationViewModel.cs

@@ -17,24 +17,24 @@ namespace Artemis.UI.Shared
     {
         private const int MaxDepth = 4;
         private BindableCollection<DataModelVisualizationViewModel> _children;
-        private DataModel _dataModel;
+        private DataModel? _dataModel;
         private bool _isMatchingFilteredTypes;
         private bool _isVisualizationExpanded;
-        private DataModelVisualizationViewModel _parent;
-        private DataModelPropertyAttribute _propertyDescription;
+        private DataModelVisualizationViewModel? _parent;
+        private DataModelPropertyAttribute? _propertyDescription;
 
-        internal DataModelVisualizationViewModel(DataModel dataModel, DataModelVisualizationViewModel parent, DataModelPath dataModelPath)
+        internal DataModelVisualizationViewModel(DataModel? dataModel, DataModelVisualizationViewModel? parent, DataModelPath? dataModelPath)
         {
-            DataModel = dataModel;
-            Parent = parent;
+            _dataModel = dataModel;
+            _children = new BindableCollection<DataModelVisualizationViewModel>();
+            _parent = parent;
             DataModelPath = dataModelPath;
-            Children = new BindableCollection<DataModelVisualizationViewModel>();
             IsMatchingFilteredTypes = true;
 
             if (parent == null)
                 IsRootViewModel = true;
             else
-                PropertyDescription = DataModelPath?.GetPropertyDescription() ?? DataModel.DataModelDescription;
+                PropertyDescription = DataModelPath?.GetPropertyDescription() ?? DataModel?.DataModelDescription;
         }
 
         /// <summary>
@@ -45,12 +45,12 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the data model path to the property this view model is visualizing
         /// </summary>
-        public DataModelPath DataModelPath { get; }
+        public DataModelPath? DataModelPath { get; }
 
         /// <summary>
         ///     Gets a string representation of the path backing this model
         /// </summary>
-        public string Path => DataModelPath?.Path;
+        public string? Path => DataModelPath?.Path;
 
         /// <summary>
         ///     Gets the property depth of the view model
@@ -60,7 +60,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the data model backing this view model
         /// </summary>
-        public DataModel DataModel
+        public DataModel? DataModel
         {
             get => _dataModel;
             protected set => SetAndNotify(ref _dataModel, value);
@@ -69,7 +69,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the property description of the property this view model is visualizing
         /// </summary>
-        public DataModelPropertyAttribute PropertyDescription
+        public DataModelPropertyAttribute? PropertyDescription
         {
             get => _propertyDescription;
             protected set => SetAndNotify(ref _propertyDescription, value);
@@ -78,7 +78,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the parent of this view model
         /// </summary>
-        public DataModelVisualizationViewModel Parent
+        public DataModelVisualizationViewModel? Parent
         {
             get => _parent;
             protected set => SetAndNotify(ref _parent, value);
@@ -119,7 +119,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets a user-friendly representation of the <see cref="DataModelPath" />
         /// </summary>
-        public virtual string DisplayPath => DataModelPath != null
+        public virtual string? DisplayPath => DataModelPath != null
             ? string.Join(" › ", DataModelPath.Segments.Select(s => s.GetPropertyDescription()?.Name ?? s.Identifier))
             : null;
 
@@ -128,18 +128,18 @@ namespace Artemis.UI.Shared
         /// </summary>
         /// <param name="dataModelUIService">The data model UI service used during update</param>
         /// <param name="configuration">The configuration to apply while updating</param>
-        public abstract void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration configuration);
+        public abstract void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration);
 
         /// <summary>
         ///     Gets the current value of the property being visualized
         /// </summary>
         /// <returns>The current value of the property being visualized</returns>
-        public virtual object GetCurrentValue()
+        public virtual object? GetCurrentValue()
         {
             if (IsRootViewModel)
                 return null;
 
-            return DataModelPath.GetValue();
+            return DataModelPath?.GetValue();
         }
 
         /// <summary>
@@ -148,7 +148,7 @@ namespace Artemis.UI.Shared
         /// </summary>
         /// <param name="looseMatch">Whether the type may be a loose match, meaning it can be cast or converted</param>
         /// <param name="filteredTypes">The types to filter</param>
-        public void ApplyTypeFilter(bool looseMatch, params Type[] filteredTypes)
+        public void ApplyTypeFilter(bool looseMatch, params Type[]? filteredTypes)
         {
             if (filteredTypes != null)
             {
@@ -176,7 +176,7 @@ namespace Artemis.UI.Shared
             }
 
             // If the type couldn't be retrieved either way, assume false
-            Type type = DataModelPath?.GetPropertyType();
+            Type? type = DataModelPath?.GetPropertyType();
             if (type == null)
             {
                 IsMatchingFilteredTypes = false;
@@ -197,12 +197,14 @@ namespace Artemis.UI.Shared
             return 0;
         }
 
-        internal void PopulateProperties(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration dataModelUpdateConfiguration)
+        internal void PopulateProperties(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? dataModelUpdateConfiguration)
         {
             if (IsRootViewModel && DataModel == null)
                 return;
 
-            Type modelType = IsRootViewModel ? DataModel.GetType() : DataModelPath.GetPropertyType();
+            Type? modelType = IsRootViewModel ? DataModel?.GetType() : DataModelPath?.GetPropertyType();
+            if (modelType == null)
+                throw new ArtemisSharedUIException("Failed to populate data model visualization properties, couldn't get a property type");
 
             // Add missing static children
             foreach (PropertyInfo propertyInfo in modelType.GetProperties(BindingFlags.Public | BindingFlags.Instance).OrderBy(t => t.MetadataToken))
@@ -212,27 +214,30 @@ namespace Artemis.UI.Shared
                     continue;
                 if (propertyInfo.GetCustomAttribute<DataModelIgnoreAttribute>() != null)
                     continue;
-                MethodInfo getMethod = propertyInfo.GetGetMethod();
+                MethodInfo? getMethod = propertyInfo.GetGetMethod();
                 if (getMethod == null || getMethod.GetParameters().Any())
                     continue;
 
-                DataModelVisualizationViewModel child = CreateChild(dataModelUIService, childPath, GetChildDepth());
+                DataModelVisualizationViewModel? child = CreateChild(dataModelUIService, childPath, GetChildDepth());
                 if (child != null)
                     Children.Add(child);
             }
 
             // Remove static children that should be hidden
-            ReadOnlyCollection<PropertyInfo> hiddenProperties = DataModel.GetHiddenProperties();
-            foreach (PropertyInfo hiddenProperty in hiddenProperties)
+            if (DataModel != null)
             {
-                string childPath = AppendToPath(hiddenProperty.Name);
-                DataModelVisualizationViewModel toRemove = Children.FirstOrDefault(c => c.Path != null && c.Path == childPath);
-                if (toRemove != null)
-                    Children.Remove(toRemove);
+                ReadOnlyCollection<PropertyInfo> hiddenProperties = DataModel.GetHiddenProperties();
+                foreach (PropertyInfo hiddenProperty in hiddenProperties)
+                {
+                    string childPath = AppendToPath(hiddenProperty.Name);
+                    DataModelVisualizationViewModel? toRemove = Children.FirstOrDefault(c => c.Path != null && c.Path == childPath);
+                    if (toRemove != null)
+                        Children.Remove(toRemove);
+                }
             }
 
             // Add missing dynamic children
-            object value = Parent == null || Parent.IsRootViewModel ? DataModel : DataModelPath.GetValue();
+            object? value = Parent == null || Parent.IsRootViewModel ? DataModel : DataModelPath?.GetValue();
             if (value is DataModel dataModel)
                 foreach (KeyValuePair<string, DataModel> kvp in dataModel.DynamicDataModels)
                 {
@@ -240,19 +245,21 @@ namespace Artemis.UI.Shared
                     if (Children.Any(c => c.Path != null && c.Path.Equals(childPath)))
                         continue;
 
-                    DataModelVisualizationViewModel child = CreateChild(dataModelUIService, childPath, GetChildDepth());
+                    DataModelVisualizationViewModel? child = CreateChild(dataModelUIService, childPath, GetChildDepth());
                     if (child != null)
                         Children.Add(child);
                 }
 
             // Remove dynamic children that have been removed from the data model
-            List<DataModelVisualizationViewModel> toRemoveDynamic = Children.Where(c => !c.DataModelPath.IsValid).ToList();
+            List<DataModelVisualizationViewModel> toRemoveDynamic = Children.Where(c => c.DataModelPath != null && !c.DataModelPath.IsValid).ToList();
             if (toRemoveDynamic.Any())
                 Children.RemoveRange(toRemoveDynamic);
         }
 
-        private DataModelVisualizationViewModel CreateChild(IDataModelUIService dataModelUIService, string path, int depth)
+        private DataModelVisualizationViewModel? CreateChild(IDataModelUIService dataModelUIService, string path, int depth)
         {
+            if (DataModel == null)
+                throw new ArtemisSharedUIException("Cannot create a data model visualization child VM for a parent without a data model");
             if (depth > MaxDepth)
                 return null;
 
@@ -260,8 +267,8 @@ namespace Artemis.UI.Shared
             if (!dataModelPath.IsValid)
                 return null;
 
-            PropertyInfo propertyInfo = dataModelPath.GetPropertyInfo();
-            Type propertyType = dataModelPath.GetPropertyType();
+            PropertyInfo? propertyInfo = dataModelPath.GetPropertyInfo();
+            Type? propertyType = dataModelPath.GetPropertyType();
 
             // Skip properties decorated with DataModelIgnore
             if (propertyInfo != null && Attribute.IsDefined(propertyInfo, typeof(DataModelIgnoreAttribute)))
@@ -270,8 +277,11 @@ namespace Artemis.UI.Shared
             if (DataModel.GetHiddenProperties().Any(p => p.Equals(propertyInfo)))
                 return null;
 
+            if (propertyType == null)
+                return null;
+
             // If a display VM was found, prefer to use that in any case
-            DataModelDisplayViewModel typeViewModel = dataModelUIService.GetDataModelDisplayViewModel(propertyType, PropertyDescription);
+            DataModelDisplayViewModel? typeViewModel = dataModelUIService.GetDataModelDisplayViewModel(propertyType, PropertyDescription);
             if (typeViewModel != null)
                 return new DataModelPropertyViewModel(DataModel, this, dataModelPath) {DisplayViewModel = typeViewModel, Depth = depth};
             // For primitives, create a property view model, it may be null that is fine

src/Artemis.UI.Shared/Events/DataModelInputDynamicEventArgs.cs

@@ -9,7 +9,7 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class DataModelInputDynamicEventArgs : EventArgs
     {
-        internal DataModelInputDynamicEventArgs(DataModelPath dataModelPath)
+        internal DataModelInputDynamicEventArgs(DataModelPath? dataModelPath)
         {
             DataModelPath = dataModelPath;
         }
@@ -17,6 +17,6 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the data model path that was selected
         /// </summary>
-        public DataModelPath DataModelPath { get; }
+        public DataModelPath? DataModelPath { get; }
     }
 }

src/Artemis.UI.Shared/Events/DataModelInputStaticEventArgs.cs

@@ -8,7 +8,7 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class DataModelInputStaticEventArgs : EventArgs
     {
-        internal DataModelInputStaticEventArgs(object value)
+        internal DataModelInputStaticEventArgs(object? value)
         {
             Value = value;
         }
@@ -16,6 +16,6 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     The value that was submitted
         /// </summary>
-        public object Value { get; }
+        public object? Value { get; }
     }
 }

src/Artemis.UI.Shared/Events/ProfileEventArgs.cs

@@ -8,12 +8,12 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class ProfileEventArgs : EventArgs
     {
-        internal ProfileEventArgs(Profile profile)
+        internal ProfileEventArgs(Profile? profile)
         {
             Profile = profile;
         }
 
-        internal ProfileEventArgs(Profile profile, Profile previousProfile)
+        internal ProfileEventArgs(Profile? profile, Profile? previousProfile)
         {
             Profile = profile;
             PreviousProfile = previousProfile;
@@ -22,7 +22,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the profile the event was raised for
         /// </summary>
-        public Profile Profile { get; }
+        public Profile? Profile { get; }
 
         /// <summary>
         ///     If applicable, the previous active profile before the event was raised

src/Artemis.UI.Shared/Events/RenderProfileElementEventArgs.cs

@@ -8,12 +8,12 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class RenderProfileElementEventArgs : EventArgs
     {
-        internal RenderProfileElementEventArgs(RenderProfileElement renderProfileElement)
+        internal RenderProfileElementEventArgs(RenderProfileElement? renderProfileElement)
         {
             RenderProfileElement = renderProfileElement;
         }
 
-        internal RenderProfileElementEventArgs(RenderProfileElement renderProfileElement, RenderProfileElement previousRenderProfileElement)
+        internal RenderProfileElementEventArgs(RenderProfileElement? renderProfileElement, RenderProfileElement? previousRenderProfileElement)
         {
             RenderProfileElement = renderProfileElement;
             PreviousRenderProfileElement = previousRenderProfileElement;
@@ -22,7 +22,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets the profile element the event was raised for
         /// </summary>
-        public RenderProfileElement RenderProfileElement { get; }
+        public RenderProfileElement? RenderProfileElement { get; }
 
         /// <summary>
         ///     If applicable, the previous active profile element before the event was raised

src/Artemis.UI.Shared/Plugins/LayerBrushes/LayerBrushConfigurationDialog.cs

@@ -15,11 +15,6 @@ namespace Artemis.UI.Shared.LayerBrushes
     /// </summary>
     public abstract class LayerBrushConfigurationDialog : ILayerBrushConfigurationDialog
     {
-        /// <summary>
-        ///     The layer brush this dialog belongs to
-        /// </summary>
-        internal BaseLayerBrush LayerBrush { get; set; }
-
         /// <summary>
         ///     The type of view model the tab contains
         /// </summary>

src/Artemis.UI.Shared/Plugins/LayerEffects/LayerEffectConfigurationDialog.cs

@@ -15,10 +15,11 @@ namespace Artemis.UI.Shared.LayerEffects
     /// </summary>
     public abstract class LayerEffectConfigurationDialog : ILayerEffectConfigurationDialog
     {
+        // TODO: See if this is still in use
         /// <summary>
         ///     The layer effect this dialog belongs to
         /// </summary>
-        internal BaseLayerEffect LayerEffect { get; set; }
+        public BaseLayerEffect? LayerEffect { get; set; }
 
         /// <summary>
         ///     The type of view model the tab contains

src/Artemis.UI.Shared/Plugins/PluginConfigurationDialog.cs

@@ -15,11 +15,6 @@ namespace Artemis.UI.Shared
     /// </summary>
     public abstract class PluginConfigurationDialog : IPluginConfigurationDialog
     {
-        /// <summary>
-        ///     The layer brush this dialog belongs to
-        /// </summary>
-        internal PluginFeature PluginFeature { get; set; }
-
         /// <summary>
         ///     The type of view model the tab contains
         /// </summary>

src/Artemis.UI.Shared/Properties/Annotations.cs

@@ -22,9 +22,10 @@ SOFTWARE. */
 
 using System;
 
-// ReSharper disable InheritdocConsiderUsage
-
+#pragma warning disable 8618
 #pragma warning disable 1591
+
+// ReSharper disable InheritdocConsiderUsage
 // ReSharper disable UnusedMember.Global
 // ReSharper disable MemberCanBePrivate.Global
 // ReSharper disable UnusedAutoPropertyAccessor.Global

src/Artemis.UI.Shared/PropertyInput/PropertyInputViewModel.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using Artemis.Core;
 using Artemis.UI.Shared.Services;
 using Stylet;
@@ -12,7 +13,7 @@ namespace Artemis.UI.Shared
     public abstract class PropertyInputViewModel<T> : PropertyInputViewModel
     {
         private bool _inputDragging;
-        private T _inputValue;
+        [AllowNull] private T _inputValue = default!;
 
         /// <summary>
         ///     Creates a new instance of the <see cref="PropertyInputViewModel" /> class
@@ -73,6 +74,7 @@ namespace Artemis.UI.Shared
         /// <summary>
         ///     Gets or sets the input value
         /// </summary>
+        [AllowNull]
         public T InputValue
         {
             get => _inputValue;

src/Artemis.UI.Shared/Screens/Dialogs/ConfirmDialogViewModel.cs

@@ -19,13 +19,13 @@ namespace Artemis.UI.Shared.Screens.Dialogs
 
         public void Confirm()
         {
-            if (!Session.IsEnded)
+            if (Session != null && !Session.IsEnded)
                 Session.Close(true);
         }
 
         public void Cancel()
         {
-            if (!Session.IsEnded)
+            if (Session != null && !Session.IsEnded)
                 Session.Close(false);
         }
     }

src/Artemis.UI.Shared/Screens/Exceptions/ExceptionViewModel.cs

@@ -9,12 +9,12 @@ namespace Artemis.UI.Shared.Screens.Exceptions
     {
         private List<DialogException> _exceptions;
 
-        public ExceptionViewModel(string message, Exception exception)
+        public ExceptionViewModel(string message, Exception? exception)
         {
             Header = message;
-            Exceptions = new List<DialogException>();
+            _exceptions = new List<DialogException>();
 
-            Exception currentException = exception;
+            Exception? currentException = exception;
             while (currentException != null)
             {
                 Exceptions.Add(new DialogException(currentException));

src/Artemis.UI.Shared/Screens/GradientEditor/ColorStopViewModel.cs

@@ -59,7 +59,7 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
             set => SetAndNotify(ref _willRemoveColorStop, value);
         }
 
-        private void ColorStopOnPropertyChanged(object sender, PropertyChangedEventArgs e)
+        private void ColorStopOnPropertyChanged(object? sender, PropertyChangedEventArgs e)
         {
             _gradientEditorViewModel.ColorGradient.OnColorValuesUpdated();
         }
@@ -90,7 +90,7 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
             if (!((IInputElement) sender).IsMouseCaptured)
                 return;
 
-            Canvas parent = VisualTreeUtilities.FindParent<Canvas>((DependencyObject) sender, null);
+            Canvas? parent = VisualTreeUtilities.FindParent<Canvas>((DependencyObject) sender, null);
             Point position = e.GetPosition(parent);
             if (position.Y > 50)
             {
@@ -103,8 +103,8 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
             double minValue = 0.0;
             double maxValue = _gradientEditorViewModel.PreviewWidth;
             List<ColorGradientStop> stops = _gradientEditorViewModel.ColorGradient.Stops.OrderBy(s => s.Position).ToList();
-            ColorGradientStop previous = stops.IndexOf(ColorStop) >= 1 ? stops[stops.IndexOf(ColorStop) - 1] : null;
-            ColorGradientStop next = stops.IndexOf(ColorStop) + 1 < stops.Count ? stops[stops.IndexOf(ColorStop) + 1] : null;
+            ColorGradientStop? previous = stops.IndexOf(ColorStop) >= 1 ? stops[stops.IndexOf(ColorStop) - 1] : null;
+            ColorGradientStop? next = stops.IndexOf(ColorStop) + 1 < stops.Count ? stops[stops.IndexOf(ColorStop) + 1] : null;
             if (previous != null)
                 minValue = previous.Position * _gradientEditorViewModel.PreviewWidth;
             if (next != null)

src/Artemis.UI.Shared/Screens/GradientEditor/GradientEditorViewModel.cs

@@ -14,7 +14,7 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
     {
         private readonly List<ColorGradientStop> _originalStops;
         private double _previewWidth;
-        private ColorStopViewModel _selectedColorStopViewModel;
+        private ColorStopViewModel? _selectedColorStopViewModel;
 
         public GradientEditorViewModel(ColorGradient colorGradient)
         {
@@ -28,7 +28,7 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
 
         public BindableCollection<ColorStopViewModel> ColorStopViewModels { get; set; }
 
-        public ColorStopViewModel SelectedColorStopViewModel
+        public ColorStopViewModel? SelectedColorStopViewModel
         {
             get => _selectedColorStopViewModel;
             set
@@ -50,7 +50,7 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
 
         public void AddColorStop(object sender, MouseEventArgs e)
         {
-            Canvas child = VisualTreeUtilities.FindChild<Canvas>((DependencyObject) sender, null);
+            Canvas? child = VisualTreeUtilities.FindChild<Canvas>((DependencyObject) sender, null);
             float position = (float) (e.GetPosition(child).X / PreviewWidth);
             ColorGradientStop stop = new ColorGradientStop(ColorGradient.GetColor(position), position);
             ColorGradient.Stops.Add(stop);
@@ -74,11 +74,11 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
 
         public Point GetPositionInPreview(object sender, MouseEventArgs e)
         {
-            Canvas parent = VisualTreeUtilities.FindParent<Canvas>((DependencyObject) sender, null);
+            Canvas? parent = VisualTreeUtilities.FindParent<Canvas>((DependencyObject) sender, null);
             return e.GetPosition(parent);
         }
 
-        public void SelectColorStop(ColorStopViewModel colorStopViewModel)
+        public void SelectColorStop(ColorStopViewModel? colorStopViewModel)
         {
             SelectedColorStopViewModel = colorStopViewModel;
             foreach (ColorStopViewModel stopViewModel in ColorStopViewModels)
@@ -87,7 +87,7 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
 
         public void Confirm()
         {
-            if (!Session.IsEnded)
+            if (Session != null && !Session.IsEnded)
                 Session.Close(true);
         }
 
@@ -98,11 +98,11 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
             ColorGradient.Stops.AddRange(_originalStops);
             ColorGradient.OnColorValuesUpdated();
 
-            if (!Session.IsEnded)
+            if (Session != null && !Session.IsEnded)
                 Session.Close(false);
         }
 
-        private void UpdateColorStopViewModels(object sender, PropertyChangedEventArgs e)
+        private void UpdateColorStopViewModels(object? sender, PropertyChangedEventArgs e)
         {
             if (e.PropertyName != nameof(PreviewWidth)) return;
             foreach (ColorGradientStop colorStop in ColorGradient.Stops.OrderBy(s => s.Position))

src/Artemis.UI.Shared/Services/ColorPickerService.cs

@@ -56,7 +56,7 @@ namespace Artemis.UI.Shared.Services
             _overlayColor = new SKColor(color.R, color.G, color.B, color.A);
         }
 
-        private void RenderColorPickerOverlay(object sender, FrameRenderingEventArgs e)
+        private void RenderColorPickerOverlay(object? sender, FrameRenderingEventArgs e)
         {
             if (_mustRenderOverlay)
                 _overlayOpacity += 0.2f;

src/Artemis.UI.Shared/Services/DataModelUIService.cs

@@ -46,7 +46,9 @@ namespace Artemis.UI.Shared.Services
 
         public void UpdateModules(DataModelPropertiesViewModel mainDataModelVisualization)
         {
-            List<DataModelVisualizationViewModel> disabledChildren = mainDataModelVisualization.Children.Where(d => !d.DataModel.Feature.IsEnabled).ToList();
+            List<DataModelVisualizationViewModel> disabledChildren = mainDataModelVisualization.Children
+                .Where(d => d.DataModel != null && !d.DataModel.Feature.IsEnabled)
+                .ToList();
             foreach (DataModelVisualizationViewModel child in disabledChildren)
                 mainDataModelVisualization.Children.Remove(child);
 
@@ -63,24 +65,24 @@ namespace Artemis.UI.Shared.Services
             mainDataModelVisualization.Update(this, null);
         }
 
-        public DataModelPropertiesViewModel GetPluginDataModelVisualization(PluginFeature pluginFeature, bool includeMainDataModel)
+        public DataModelPropertiesViewModel? GetPluginDataModelVisualization(PluginFeature pluginFeature, bool includeMainDataModel)
         {
             if (includeMainDataModel)
             {
                 DataModelPropertiesViewModel mainDataModel = GetMainDataModelVisualization();
 
                 // If the main data model already includes the plugin data model we're done
-                if (mainDataModel.Children.Any(c => c.DataModel.Feature == pluginFeature))
+                if (mainDataModel.Children.Any(c => c.DataModel?.Feature == pluginFeature))
                     return mainDataModel;
                 // Otherwise get just the plugin data model and add it
-                DataModelPropertiesViewModel pluginDataModel = GetPluginDataModelVisualization(pluginFeature, false);
+                DataModelPropertiesViewModel? pluginDataModel = GetPluginDataModelVisualization(pluginFeature, false);
                 if (pluginDataModel != null)
                     mainDataModel.Children.Add(pluginDataModel);
 
                 return mainDataModel;
             }
 
-            DataModel dataModel = _dataModelService.GetPluginDataModel(pluginFeature);
+            DataModel? dataModel = _dataModelService.GetPluginDataModel(pluginFeature);
             if (dataModel == null)
                 return null;
 
@@ -93,15 +95,14 @@ namespace Artemis.UI.Shared.Services
             return viewModel;
         }
 
-        public DataModelVisualizationRegistration RegisterDataModelInput<T>(Plugin plugin, IReadOnlyCollection<Type> compatibleConversionTypes = null) where T : DataModelInputViewModel
+        public DataModelVisualizationRegistration RegisterDataModelInput<T>(Plugin plugin, IReadOnlyCollection<Type>? compatibleConversionTypes = null) where T : DataModelInputViewModel
         {
-            if (compatibleConversionTypes == null)
-                compatibleConversionTypes = new List<Type>();
+            compatibleConversionTypes ??= new List<Type>();
             Type viewModelType = typeof(T);
             lock (_registeredDataModelEditors)
             {
-                Type supportedType = viewModelType.BaseType.GetGenericArguments()[0];
-                DataModelVisualizationRegistration existing = _registeredDataModelEditors.FirstOrDefault(r => r.SupportedType == supportedType);
+                Type supportedType = viewModelType.BaseType!.GetGenericArguments()[0];
+                DataModelVisualizationRegistration? existing = _registeredDataModelEditors.FirstOrDefault(r => r.SupportedType == supportedType);
                 if (existing != null)
                 {
                     if (existing.Plugin != plugin)
@@ -129,8 +130,8 @@ namespace Artemis.UI.Shared.Services
             Type viewModelType = typeof(T);
             lock (_registeredDataModelDisplays)
             {
-                Type supportedType = viewModelType.BaseType.GetGenericArguments()[0];
-                DataModelVisualizationRegistration existing = _registeredDataModelDisplays.FirstOrDefault(r => r.SupportedType == supportedType);
+                Type supportedType = viewModelType.BaseType!.GetGenericArguments()[0];
+                DataModelVisualizationRegistration? existing = _registeredDataModelDisplays.FirstOrDefault(r => r.SupportedType == supportedType);
                 if (existing != null)
                 {
                     if (existing.Plugin != plugin)
@@ -174,15 +175,21 @@ namespace Artemis.UI.Shared.Services
             }
         }
 
-        public DataModelDisplayViewModel GetDataModelDisplayViewModel(Type propertyType, DataModelPropertyAttribute description, bool fallBackToDefault)
+        public DataModelDisplayViewModel? GetDataModelDisplayViewModel(Type propertyType, DataModelPropertyAttribute? description, bool fallBackToDefault)
         {
             lock (_registeredDataModelDisplays)
             {
-                DataModelDisplayViewModel result;
+                DataModelDisplayViewModel? result;
 
-                DataModelVisualizationRegistration match = _registeredDataModelDisplays.FirstOrDefault(d => d.SupportedType == propertyType);
+                DataModelVisualizationRegistration? match = _registeredDataModelDisplays.FirstOrDefault(d => d.SupportedType == propertyType);
                 if (match != null)
+                {
+                    // If this ever happens something is likely wrong with the plugin unload detection
+                    if (match.Plugin.Kernel == null)
+                        throw new ArtemisSharedUIException("Cannot GetDataModelDisplayViewModel for a registration by an uninitialized plugin");
+
                     result = (DataModelDisplayViewModel) match.Plugin.Kernel.Get(match.ViewModelType);
+                }
                 else if (!fallBackToDefault)
                     result = null;
                 else
@@ -195,15 +202,15 @@ namespace Artemis.UI.Shared.Services
             }
         }
 
-        public DataModelInputViewModel GetDataModelInputViewModel(Type propertyType, DataModelPropertyAttribute description, object initialValue, Action<object, bool> updateCallback)
+        public DataModelInputViewModel? GetDataModelInputViewModel(Type propertyType, DataModelPropertyAttribute? description, object? initialValue, Action<object?, bool> updateCallback)
         {
             lock (_registeredDataModelEditors)
             {
                 // Prefer a VM that natively supports the type
-                DataModelVisualizationRegistration match = _registeredDataModelEditors.FirstOrDefault(d => d.SupportedType == propertyType);
+                DataModelVisualizationRegistration? match = _registeredDataModelEditors.FirstOrDefault(d => d.SupportedType == propertyType);
                 // Fall back on a VM that supports the type through conversion
                 if (match == null)
-                    match = _registeredDataModelEditors.FirstOrDefault(d => d.CompatibleConversionTypes.Contains(propertyType));
+                    match = _registeredDataModelEditors.FirstOrDefault(d => d.CompatibleConversionTypes != null && d.CompatibleConversionTypes.Contains(propertyType));
                 // Lastly try getting an enum VM if the provided type is an enum
                 if (match == null && propertyType.IsEnum)
                     match = _registeredDataModelEditors.FirstOrDefault(d => d.SupportedType == typeof(Enum));
@@ -229,7 +236,7 @@ namespace Artemis.UI.Shared.Services
             return _dataModelVmFactory.DataModelStaticViewModel(targetType, targetDescription);
         }
 
-        private DataModelInputViewModel InstantiateDataModelInputViewModel(DataModelVisualizationRegistration registration, DataModelPropertyAttribute description, object initialValue)
+        private DataModelInputViewModel InstantiateDataModelInputViewModel(DataModelVisualizationRegistration registration, DataModelPropertyAttribute? description, object? initialValue)
         {
             // This assumes the type can be converted, that has been checked when the VM was created
             if (initialValue != null && initialValue.GetType() != registration.SupportedType)
@@ -240,6 +247,11 @@ namespace Artemis.UI.Shared.Services
                 new ConstructorArgument("targetDescription", description),
                 new ConstructorArgument("initialValue", initialValue)
             };
+
+            // If this ever happens something is likely wrong with the plugin unload detection
+            if (registration.Plugin.Kernel == null)
+                throw new ArtemisSharedUIException("Cannot InstantiateDataModelInputViewModel for a registration by an uninitialized plugin");
+
             DataModelInputViewModel viewModel = (DataModelInputViewModel) registration.Plugin.Kernel.Get(registration.ViewModelType, parameters);
             viewModel.CompatibleConversionTypes = registration.CompatibleConversionTypes;
             return viewModel;

src/Artemis.UI.Shared/Services/Dialog/DialogService.cs

@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
-using System.Reflection;
 using System.Threading.Tasks;
 using System.Windows;
 using Artemis.Core;
@@ -16,13 +14,12 @@ using Stylet;
 
 namespace Artemis.UI.Shared.Services
 {
-    // TODO: Become plugin-aware and use plugin kernel if injected into a plugin
     internal class DialogService : IDialogService
     {
         private readonly IKernel _kernel;
+        private readonly IPluginManagementService _pluginManagementService;
         private readonly IViewManager _viewManager;
         private readonly IWindowManager _windowManager;
-        private readonly IPluginManagementService _pluginManagementService;
 
         public DialogService(IKernel kernel, IViewManager viewManager, IWindowManager windowManager, IPluginManagementService pluginManagementService)
         {
@@ -35,12 +32,12 @@ namespace Artemis.UI.Shared.Services
         private async Task<object> ShowDialog<T>(IParameter[] parameters) where T : DialogViewModelBase
         {
             if (parameters == null) throw new ArgumentNullException(nameof(parameters));
-            return await ShowDialog("RootDialog", _kernel.Get<T>(parameters));
+            return await ShowDialog("RootDialog", GetBestKernel().Get<T>(parameters));
         }
 
-        private async Task<object> ShowDialog(string identifier, DialogViewModelBase viewModel)
+        private async Task<object> ShowDialog(string? identifier, DialogViewModelBase viewModel)
         {
-            Task<object> result = null;
+            Task<object>? result = null;
             await Execute.OnUIThreadAsync(() =>
             {
                 UIElement view = _viewManager.CreateViewForModel(viewModel);
@@ -52,12 +49,22 @@ namespace Artemis.UI.Shared.Services
                     result = DialogHost.Show(view, identifier, viewModel.OnDialogOpened, viewModel.OnDialogClosed);
             });
 
+            if (result == null)
+                throw new ArtemisSharedUIException("Failed to show dialog host");
             return await result;
         }
 
+        private async Task<object> ShowDialogAt<T>(string identifier, IParameter[] parameters) where T : DialogViewModelBase
+        {
+            if (parameters == null)
+                throw new ArgumentNullException(nameof(parameters));
+            return await ShowDialog(identifier, GetBestKernel().Get<T>(parameters));
+        }
+
         public async Task<bool> ShowConfirmDialog(string header, string text, string confirmText = "Confirm", string cancelText = "Cancel")
         {
-            IParameter[] arguments = {
+            IParameter[] arguments =
+            {
                 new ConstructorArgument("header", header),
                 new ConstructorArgument("text", text),
                 new ConstructorArgument("confirmText", confirmText.ToUpper()),
@@ -69,7 +76,9 @@ namespace Artemis.UI.Shared.Services
 
         public async Task<bool> ShowConfirmDialogAt(string identifier, string header, string text, string confirmText = "Confirm", string cancelText = "Cancel")
         {
-            IParameter[] arguments = {
+            if (identifier == null) throw new ArgumentNullException(nameof(identifier));
+            IParameter[] arguments =
+            {
                 new ConstructorArgument("header", header),
                 new ConstructorArgument("text", text),
                 new ConstructorArgument("confirmText", confirmText.ToUpper()),
@@ -81,7 +90,7 @@ namespace Artemis.UI.Shared.Services
 
         public async Task<object> ShowDialog<T>() where T : DialogViewModelBase
         {
-            return await ShowDialog("RootDialog", _kernel.Get<T>());
+            return await ShowDialog("RootDialog", GetBestKernel().Get<T>());
         }
 
         public Task<object> ShowDialog<T>(Dictionary<string, object> parameters) where T : DialogViewModelBase
@@ -95,32 +104,28 @@ namespace Artemis.UI.Shared.Services
 
         public async Task<object> ShowDialogAt<T>(string identifier) where T : DialogViewModelBase
         {
-            return await ShowDialog(identifier, _kernel.Get<T>());
+            if (identifier == null) throw new ArgumentNullException(nameof(identifier));
+            return await ShowDialog(identifier, GetBestKernel().Get<T>());
         }
 
         public async Task<object> ShowDialogAt<T>(string identifier, Dictionary<string, object> parameters) where T : DialogViewModelBase
         {
-            if (parameters == null)
-                throw new ArgumentNullException(nameof(parameters));
+            if (identifier == null) throw new ArgumentNullException(nameof(identifier));
+            if (parameters == null) throw new ArgumentNullException(nameof(parameters));
 
             IParameter[] paramsArray = parameters.Select(kv => new ConstructorArgument(kv.Key, kv.Value)).Cast<IParameter>().ToArray();
             return await ShowDialogAt<T>(identifier, paramsArray);
         }
 
-        private async Task<object> ShowDialogAt<T>(string identifier, IParameter[] parameters) where T : DialogViewModelBase
-        {
-            Plugin callingPlugin = _pluginManagementService.GetCallingPlugin();
-            if (parameters == null)
-                throw new ArgumentNullException(nameof(parameters));
-
-            if (callingPlugin != null)
-                return await ShowDialog(identifier, callingPlugin.Kernel.Get<T>(parameters));
-            return await ShowDialog(identifier, _kernel.Get<T>(parameters));
-        }
-
         public void ShowExceptionDialog(string message, Exception exception)
         {
             _windowManager.ShowDialog(new ExceptionViewModel(message, exception));
         }
+
+        private IKernel GetBestKernel()
+        {
+            Plugin? callingPlugin = _pluginManagementService.GetCallingPlugin();
+            return callingPlugin?.Kernel ?? _kernel;
+        }
     }
 }

src/Artemis.UI.Shared/Services/Dialog/DialogViewModelHost.cs

@@ -13,7 +13,7 @@ namespace Artemis.UI.Shared.Services
             _viewManager = viewManager;
         }
 
-        public DialogViewModelBase ActiveDialogViewModel { get; set; }
+        public DialogViewModelBase? ActiveDialogViewModel { get; set; }
         public bool IsOpen { get; set; }
 
         public void OpenDialog(DialogViewModelBase viewModel, string dialogIdentifier)

src/Artemis.UI.Shared/Services/Interfaces/IDataModelUIService.cs

@@ -37,7 +37,7 @@ namespace Artemis.UI.Shared.Services
         /// <param name="pluginFeature">The plugin feature to create hte data model visualization view model for</param>
         /// <param name="includeMainDataModel">Whether or not also to include the main data model</param>
         /// <returns>A data model visualization view model containing the data model of the provided feature</returns>
-        DataModelPropertiesViewModel GetPluginDataModelVisualization(PluginFeature pluginFeature, bool includeMainDataModel);
+        DataModelPropertiesViewModel? GetPluginDataModelVisualization(PluginFeature pluginFeature, bool includeMainDataModel);
 
         /// <summary>
         ///     Updates the children of the provided main data model visualization, removing disabled children and adding newly
@@ -89,7 +89,7 @@ namespace Artemis.UI.Shared.Services
         ///     returned if nothing else is found
         /// </param>
         /// <returns>The most appropriate display view model for the provided <paramref name="propertyType"></paramref></returns>
-        DataModelDisplayViewModel GetDataModelDisplayViewModel(Type propertyType, DataModelPropertyAttribute description, bool fallBackToDefault = false);
+        DataModelDisplayViewModel? GetDataModelDisplayViewModel(Type propertyType, DataModelPropertyAttribute? description, bool fallBackToDefault = false);
 
         /// <summary>
         ///     Creates the most appropriate input view model for the provided <paramref name="propertyType" /> that allows
@@ -100,7 +100,7 @@ namespace Artemis.UI.Shared.Services
         /// <param name="initialValue">The initial value to show in the input</param>
         /// <param name="updateCallback">A function to call whenever the input was updated (submitted or not)</param>
         /// <returns>The most appropriate input view model for the provided <paramref name="propertyType" /></returns>
-        DataModelInputViewModel GetDataModelInputViewModel(Type propertyType, DataModelPropertyAttribute description, object initialValue, Action<object, bool> updateCallback);
+        DataModelInputViewModel? GetDataModelInputViewModel(Type propertyType, DataModelPropertyAttribute? description, object? initialValue, Action<object?, bool> updateCallback);
 
         /// <summary>
         ///     Creates a view model that allows selecting a value from the data model

src/Artemis.UI.Shared/Services/Interfaces/IProfileEditorService.cs

@@ -14,17 +14,17 @@ namespace Artemis.UI.Shared.Services
         /// <summary>
         ///     Gets the currently selected profile
         /// </summary>
-        Profile SelectedProfile { get; }
+        Profile? SelectedProfile { get; }
 
         /// <summary>
         ///     Gets the currently selected profile element
         /// </summary>
-        RenderProfileElement SelectedProfileElement { get; }
+        RenderProfileElement? SelectedProfileElement { get; }
 
         /// <summary>
         ///     Gets the currently selected data binding property
         /// </summary>
-        ILayerProperty SelectedDataBinding { get; }
+        ILayerProperty? SelectedDataBinding { get; }
 
         /// <summary>
         ///     Gets or sets the current time
@@ -45,7 +45,7 @@ namespace Artemis.UI.Shared.Services
         ///     Changes the selected profile
         /// </summary>
         /// <param name="profile">The profile to select</param>
-        void ChangeSelectedProfile(Profile profile);
+        void ChangeSelectedProfile(Profile? profile);
 
         /// <summary>
         ///     Updates the selected profile and saves it to persistent storage
@@ -56,7 +56,7 @@ namespace Artemis.UI.Shared.Services
         ///     Changes the selected profile element
         /// </summary>
         /// <param name="profileElement">The profile element to select</param>
-        void ChangeSelectedProfileElement(RenderProfileElement profileElement);
+        void ChangeSelectedProfileElement(RenderProfileElement? profileElement);
 
         /// <summary>
         ///     Updates the selected profile element and saves the profile it is contained in to persistent storage
@@ -67,7 +67,7 @@ namespace Artemis.UI.Shared.Services
         ///     Changes the selected data binding property
         /// </summary>
         /// <param name="layerProperty">The data binding property to select</param>
-        void ChangeSelectedDataBinding(ILayerProperty layerProperty);
+        void ChangeSelectedDataBinding(ILayerProperty? layerProperty);
 
         /// <summary>
         ///     Updates the profile preview, forcing UI-elements to re-render
@@ -90,7 +90,7 @@ namespace Artemis.UI.Shared.Services
         ///     Gets the current module the profile editor is initialized for
         /// </summary>
         /// <returns>The current module the profile editor is initialized for</returns>
-        ProfileModule GetCurrentModule();
+        ProfileModule? GetCurrentModule();
 
         /// <summary>
         ///     Occurs when a new profile is selected
@@ -173,6 +173,6 @@ namespace Artemis.UI.Shared.Services
         ///     If a matching registration is found, creates a new <see cref="PropertyInputViewModel{T}" /> supporting
         ///     <typeparamref name="T" />
         /// </summary>
-        PropertyInputViewModel<T> CreatePropertyInputViewModel<T>(LayerProperty<T> layerProperty);
+        PropertyInputViewModel<T>? CreatePropertyInputViewModel<T>(LayerProperty<T> layerProperty);
     }
 }

src/Artemis.UI.Shared/Services/ProfileEditorService.cs

@@ -22,7 +22,7 @@ namespace Artemis.UI.Shared.Services
         private readonly object _selectedProfileLock = new object();
         private TimeSpan _currentTime;
         private int _pixelsPerSecond;
-        private IKernel _kernel;
+        private readonly IKernel _kernel;
 
         public ProfileEditorService(IProfileService profileService, IKernel kernel, ILogger logger, ICoreService coreService)
         {
@@ -42,9 +42,9 @@ namespace Artemis.UI.Shared.Services
         }
 
         public ReadOnlyCollection<PropertyInputRegistration> RegisteredPropertyEditors => _registeredPropertyEditors.AsReadOnly();
-        public Profile SelectedProfile { get; private set; }
-        public RenderProfileElement SelectedProfileElement { get; private set; }
-        public ILayerProperty SelectedDataBinding { get; private set; }
+        public Profile? SelectedProfile { get; private set; }
+        public RenderProfileElement? SelectedProfileElement { get; private set; }
+        public ILayerProperty? SelectedDataBinding { get; private set; }
 
         public TimeSpan CurrentTime
         {
@@ -71,7 +71,7 @@ namespace Artemis.UI.Shared.Services
             }
         }
 
-        public void ChangeSelectedProfile(Profile profile)
+        public void ChangeSelectedProfile(Profile? profile)
         {
             lock (_selectedProfileLock)
             {
@@ -103,14 +103,16 @@ namespace Artemis.UI.Shared.Services
             lock (_selectedProfileLock)
             {
                 _logger.Verbose("UpdateSelectedProfile {profile}", SelectedProfile);
-                _profileService.UpdateProfile(SelectedProfile, true);
+                if (SelectedProfile == null)
+                    return;
 
+                _profileService.UpdateProfile(SelectedProfile, true);
                 OnSelectedProfileChanged(new ProfileEventArgs(SelectedProfile));
                 UpdateProfilePreview();
             }
         }
 
-        public void ChangeSelectedProfileElement(RenderProfileElement profileElement)
+        public void ChangeSelectedProfileElement(RenderProfileElement? profileElement)
         {
             lock (_selectedProfileElementLock)
             {
@@ -131,13 +133,16 @@ namespace Artemis.UI.Shared.Services
             lock (_selectedProfileElementLock)
             {
                 _logger.Verbose("UpdateSelectedProfileElement {profile}", SelectedProfileElement);
+                if (SelectedProfile == null)
+                    return;
+
                 _profileService.UpdateProfile(SelectedProfile, true);
-                UpdateProfilePreview();
                 OnSelectedProfileElementUpdated(new RenderProfileElementEventArgs(SelectedProfileElement));
+                UpdateProfilePreview();
             }
         }
 
-        public void ChangeSelectedDataBinding(ILayerProperty layerProperty)
+        public void ChangeSelectedDataBinding(ILayerProperty? layerProperty)
         {
             SelectedDataBinding = layerProperty;
             OnSelectedDataBindingChanged();
@@ -159,6 +164,9 @@ namespace Artemis.UI.Shared.Services
 
         public bool UndoUpdateProfile()
         {
+            if (SelectedProfile == null)
+                return false;
+
             bool undid = _profileService.UndoUpdateProfile(SelectedProfile);
             if (!undid)
                 return false;
@@ -169,6 +177,9 @@ namespace Artemis.UI.Shared.Services
 
         public bool RedoUpdateProfile()
         {
+            if (SelectedProfile == null)
+                return false;
+
             bool redid = _profileService.RedoUpdateProfile(SelectedProfile);
             if (!redid)
                 return false;
@@ -189,7 +200,8 @@ namespace Artemis.UI.Shared.Services
 
             lock (_registeredPropertyEditors)
             {
-                Type supportedType = viewModelType.BaseType.GetGenericArguments()[0];
+                // Indirectly checked if there's a BaseType above
+                Type supportedType = viewModelType.BaseType!.GetGenericArguments()[0];
                 // If the supported type is a generic, assume there is a base type
                 if (supportedType.IsGenericParameter)
                 {
@@ -198,7 +210,7 @@ namespace Artemis.UI.Shared.Services
                     supportedType = supportedType.BaseType;
                 }
 
-                PropertyInputRegistration existing = _registeredPropertyEditors.FirstOrDefault(r => r.SupportedType == supportedType);
+                PropertyInputRegistration? existing = _registeredPropertyEditors.FirstOrDefault(r => r.SupportedType == supportedType);
                 if (existing != null)
                 {
                     if (existing.Plugin != plugin)
@@ -228,9 +240,9 @@ namespace Artemis.UI.Shared.Services
             }
         }
 
-        public TimeSpan SnapToTimeline(TimeSpan time, TimeSpan tolerance, bool snapToSegments, bool snapToCurrentTime, List<TimeSpan> snapTimes = null)
+        public TimeSpan SnapToTimeline(TimeSpan time, TimeSpan tolerance, bool snapToSegments, bool snapToCurrentTime, List<TimeSpan>? snapTimes = null)
         {
-            if (snapToSegments)
+            if (snapToSegments && SelectedProfileElement != null)
             {
                 // Snap to the end of the start segment
                 if (Math.Abs(time.TotalMilliseconds - SelectedProfileElement.Timeline.StartSegmentEndPosition.TotalMilliseconds) < tolerance.TotalMilliseconds)
@@ -255,7 +267,7 @@ namespace Artemis.UI.Shared.Services
             if (snapTimes != null)
             {
                 // Find the closest keyframe
-                TimeSpan closeSnapTime = snapTimes.FirstOrDefault(s => Math.Abs(time.TotalMilliseconds - s.TotalMilliseconds) < tolerance.TotalMilliseconds);
+                TimeSpan closeSnapTime = snapTimes.FirstOrDefault(s => Math.Abs(time.TotalMilliseconds - s.TotalMilliseconds) < tolerance.TotalMilliseconds)!;
                 if (closeSnapTime != TimeSpan.Zero)
                     return closeSnapTime;
             }
@@ -263,10 +275,10 @@ namespace Artemis.UI.Shared.Services
             return time;
         }
 
-        public PropertyInputViewModel<T> CreatePropertyInputViewModel<T>(LayerProperty<T> layerProperty)
+        public PropertyInputViewModel<T>? CreatePropertyInputViewModel<T>(LayerProperty<T> layerProperty)
         {
-            Type viewModelType = null;
-            PropertyInputRegistration registration = RegisteredPropertyEditors.FirstOrDefault(r => r.SupportedType == typeof(T));
+            Type? viewModelType = null;
+            PropertyInputRegistration? registration = RegisteredPropertyEditors.FirstOrDefault(r => r.SupportedType == typeof(T));
 
             // Check for enums if no supported type was found
             if (registration == null && typeof(T).IsEnum)
@@ -281,22 +293,30 @@ namespace Artemis.UI.Shared.Services
             else
                 return null;
 
+            if (viewModelType == null)
+                return null;
+
             ConstructorArgument parameter = new ConstructorArgument("layerProperty", layerProperty);
-            IKernel kernel = registration != null ? registration.Plugin.Kernel : _kernel;
+            // ReSharper disable once InconsistentlySynchronizedField
+            // When you've just spent the last 2 hours trying to figure out a deadlock and reach this line, I'm so, so sorry. I thought this would be fine.
+            IKernel kernel = registration?.Plugin.Kernel ?? _kernel;
             return (PropertyInputViewModel<T>) kernel.Get(viewModelType, parameter);
         }
 
-        public ProfileModule GetCurrentModule()
+        public ProfileModule? GetCurrentModule()
         {
             return SelectedProfile?.Module;
         }
 
         private void ReloadProfile()
         {
+            if (SelectedProfile == null)
+                return;
+
             // Trigger a profile change
             OnSelectedProfileChanged(new ProfileEventArgs(SelectedProfile, SelectedProfile));
             // Trigger a selected element change
-            RenderProfileElement previousSelectedProfileElement = SelectedProfileElement;
+            RenderProfileElement? previousSelectedProfileElement = SelectedProfileElement;
             if (SelectedProfileElement is Folder folder)
                 SelectedProfileElement = SelectedProfile.GetAllFolders().FirstOrDefault(f => f.EntityId == folder.EntityId);
             else if (SelectedProfileElement is Layer layer)
@@ -305,22 +325,24 @@ namespace Artemis.UI.Shared.Services
             // Trigger selected data binding change
             if (SelectedDataBinding != null)
             {
-                SelectedDataBinding = SelectedProfileElement?.GetAllLayerProperties()?.FirstOrDefault(p => p.Path == SelectedDataBinding.Path);
+                SelectedDataBinding = SelectedProfileElement?.GetAllLayerProperties().FirstOrDefault(p => p.Path == SelectedDataBinding.Path);
                 OnSelectedDataBindingChanged();
             }
 
             UpdateProfilePreview();
         }
 
-        public event EventHandler<ProfileEventArgs> ProfileSelected;
-        public event EventHandler<ProfileEventArgs> SelectedProfileUpdated;
-        public event EventHandler<RenderProfileElementEventArgs> ProfileElementSelected;
-        public event EventHandler<RenderProfileElementEventArgs> SelectedProfileElementUpdated;
-        public event EventHandler SelectedDataBindingChanged;
-        public event EventHandler CurrentTimeChanged;
-        public event EventHandler PixelsPerSecondChanged;
-        public event EventHandler ProfilePreviewUpdated;
-        public event EventHandler CurrentTimelineChanged;
+        #region Events
+
+        public event EventHandler<ProfileEventArgs>? ProfileSelected;
+        public event EventHandler<ProfileEventArgs>? SelectedProfileUpdated;
+        public event EventHandler<RenderProfileElementEventArgs>? ProfileElementSelected;
+        public event EventHandler<RenderProfileElementEventArgs>? SelectedProfileElementUpdated;
+        public event EventHandler? SelectedDataBindingChanged;
+        public event EventHandler? CurrentTimeChanged;
+        public event EventHandler? PixelsPerSecondChanged;
+        public event EventHandler? ProfilePreviewUpdated;
+        public event EventHandler? CurrentTimelineChanged;
 
         protected virtual void OnSelectedProfileChanged(ProfileEventArgs e)
         {
@@ -367,10 +389,13 @@ namespace Artemis.UI.Shared.Services
             SelectedDataBindingChanged?.Invoke(this, EventArgs.Empty);
         }
 
-        private void SelectedProfileOnDeactivated(object sender, EventArgs e)
+        private void SelectedProfileOnDeactivated(object? sender, EventArgs e)
         {
             // Execute.PostToUIThread(() => ChangeSelectedProfile(null));
             ChangeSelectedProfile(null);
         }
+
+        #endregion
+
     }
 }

src/Artemis.UI.Shared/Utilities/ShortcutUtilities.cs

@@ -9,8 +9,8 @@ namespace Artemis.UI.Shared
     /// </summary>
     public class ShortcutUtilities
     {
-        private static readonly Type m_type = Type.GetTypeFromProgID("WScript.Shell");
-        private static readonly object m_shell = Activator.CreateInstance(m_type);
+        private static readonly Type MType = Type.GetTypeFromProgID("WScript.Shell")!;
+        private static readonly object MShell = Activator.CreateInstance(MType)!;
 
         /// <summary>
         ///     Creates a shortcut
@@ -24,7 +24,10 @@ namespace Artemis.UI.Shared
         /// <param name="iconPath">The icon path of the shortcut</param>
         public static void Create(string fileName, string targetPath, string arguments, string workingDirectory, string description, string hotkey, string iconPath)
         {
-            IWshShortcut shortcut = (IWshShortcut) m_type.InvokeMember("CreateShortcut", BindingFlags.InvokeMethod, null, m_shell, new object[] {fileName});
+            IWshShortcut? shortcut = (IWshShortcut?) MType.InvokeMember("CreateShortcut", BindingFlags.InvokeMethod, null, MShell, new object[] {fileName});
+            if (shortcut == null)
+                throw new ArtemisSharedUIException("InvokeMember CreateShortcut returned null");
+
             shortcut.Description = description;
             shortcut.Hotkey = hotkey;
             shortcut.TargetPath = targetPath;
@@ -34,7 +37,7 @@ namespace Artemis.UI.Shared
                 shortcut.IconLocation = iconPath;
             shortcut.Save();
         }
-
+            
         [ComImport]
         [TypeLibType(0x1040)]
         [Guid("F935DC23-1CF0-11D0-ADB9-00C04FD58A0B")]
@@ -118,14 +121,7 @@ namespace Artemis.UI.Shared
             }
 
             [DispId(0x3ee)]
-            int WindowStyle
-            {
-                [DispId(0x3ee)]
-                get;
-                [param: In]
-                [DispId(0x3ee)]
-                set;
-            }
+            int WindowStyle { [DispId(0x3ee)] get; [param: In] [DispId(0x3ee)] set; }
 
             [DispId(0x3ef)]
             string WorkingDirectory
@@ -141,6 +137,7 @@ namespace Artemis.UI.Shared
 
             [TypeLibFunc(0x40)]
             [DispId(0x7d0)]
+            // ReSharper disable once InconsistentNaming - No idea if that breaks it and cba to test
             void Load([In] [MarshalAs(UnmanagedType.BStr)] string PathLink);
 
             [DispId(0x7d1)]

src/Artemis.UI.Shared/Utilities/VisualTreeUtilities.cs

@@ -20,12 +20,12 @@ namespace Artemis.UI.Shared
         ///     If not matching item can be found,
         ///     a null parent is being returned.
         /// </returns>
-        public static T FindChild<T>(DependencyObject parent, string childName) where T : DependencyObject
+        public static T? FindChild<T>(DependencyObject? parent, string? childName) where T : DependencyObject
         {
             // Confirm parent and childName are valid. 
             if (parent == null) return null;
 
-            T foundChild = null;
+            T? foundChild = null;
 
             int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
             for (int i = 0; i < childrenCount; i++)
@@ -72,10 +72,10 @@ namespace Artemis.UI.Shared
         ///     If not matching item can be found,
         ///     a null parent is being returned.
         /// </returns>
-        public static T FindParent<T>(DependencyObject child, string parentName) where T : DependencyObject
+        public static T? FindParent<T>(DependencyObject child, string? parentName) where T : DependencyObject
         {
             // Get parent item
-            DependencyObject parentObject = VisualTreeHelper.GetParent(child);
+            DependencyObject? parentObject = VisualTreeHelper.GetParent(child);
 
             // We've reached the end of the tree
             if (parentObject == null)