tmp: devtools improvements

src/Avalonia.Diagnostics/ViewModels/ControlDetailsViewModel.cs

@@ -7,52 +7,189 @@ using System.Linq;
 using System.Reactive.Linq;
 using Avalonia.Controls;
 using Avalonia.Layout;
-using Avalonia.Threading;
-using Avalonia.VisualTree;
+using Avalonia.Markup.Xaml.Styling;
+using Avalonia.Styling;
 
 namespace Avalonia.Diagnostics.ViewModels
 {
+    using WellKNownProperties = List<WellKnownProperty>;
+    using WellKNownPropertiesReg = Dictionary<Func<object, bool>, List<WellKnownProperty>>;
+
+    internal class WellKnownProperty
+    {
+        private static IObservable<object> LayoutUpdatedEvent(object ctrl) => Observable.FromEventPattern(ctrl, nameof(Layoutable.LayoutUpdated));
+
+        private static WellKNownPropertiesReg _registry = new WellKNownPropertiesReg
+        {
+            {
+                o => true,
+                new WellKNownProperties
+                {
+                    new WellKnownProperty()
+                    {
+                        Name = "ToString()",
+                        Type = typeof(string),
+                        Getter = o => o.ToString(),
+                        Changed = o => Observable.Never<object>()
+                    }
+                }
+            },
+            {
+                o => o is Style,
+                new WellKNownProperties
+                {
+                    new WellKnownProperty()
+                    {
+                        Name = "Selector",
+                        Type = typeof(Selector),
+                        Getter = o => (o as Style).Selector.ToString(),
+                        Changed = o => Observable.Never<object>()
+                    }
+                }
+            },
+            {
+                o => o is Control,
+                new WellKNownProperties
+                {
+                    new WellKnownProperty()
+                    {
+                        Name = nameof(StyledElement.Classes),
+                        Type = typeof(string),
+                        Getter = o => string.Join(" ", (o as StyledElement).Classes),
+                        Setter = (o, v) => (o as StyledElement).Classes = Classes.Parse((v??"").ToString()),
+                        Changed = o => Observable.FromEventPattern((o as StyledElement).Classes, nameof(StyledElement.Classes.CollectionChanged))
+                    },
+                    new WellKnownProperty()
+                    {
+                        Name = "Layout State",
+                        Type = typeof(string),
+                        Getter = o =>
+                        {
+                            var l = o as ILayoutable;
+                            return $"measured: {l.IsMeasureValid} -> {l.PreviousMeasure} arranged: {l.IsArrangeValid} -> {l.PreviousArrange}";
+                        },
+                        Changed = o => LayoutUpdatedEvent(o)
+                    },
+                }
+            },
+            {
+                o => o is Grid,
+                new WellKNownProperties
+                {
+                    new WellKnownProperty()
+                    {
+                        Name = nameof(Grid.ColumnDefinitions),
+                        Type = typeof(string),
+                        Getter = o => string.Join(",", (o as Grid).ColumnDefinitions.Select(c=>c.Width.ToString())),
+                        Setter = (o,v) => (o as Grid).ColumnDefinitions = ColumnDefinitions.Parse(v?.ToString()??""),
+                        Changed = o => Observable.Never<object>()
+                    },
+                    new WellKnownProperty()
+                    {
+                        Name = nameof(Grid.ColumnDefinitions) + " (Actual)",
+                        Type = typeof(string),
+                        Getter = o => string.Join(",", (o as Grid).ColumnDefinitions.Select(c=>c.ActualWidth.ToString())),
+                        Changed = o => LayoutUpdatedEvent(o)
+                    },
+                    new WellKnownProperty()
+                    {
+                        Name = nameof(Grid.RowDefinitions),
+                        Type = typeof(string),
+                        Getter = o => string.Join(",", (o as Grid).RowDefinitions.Select(c=>c.Height.ToString())),
+                        Setter = (o,v) => (o as Grid).RowDefinitions = RowDefinitions.Parse(v?.ToString()??""),
+                        Changed = o => Observable.Never<object>()
+                    },
+                    new WellKnownProperty()
+                    {
+                        Name = nameof(Grid.RowDefinitions) + " (Actual)",
+                        Type = typeof(string),
+                        Getter = o => string.Join(",", (o as Grid).RowDefinitions.Select(c=>c.ActualHeight.ToString())),
+                        Changed = o => LayoutUpdatedEvent(o)
+                    },
+                }
+            },
+        };
+
+        public static IEnumerable<WellKnownProperty> Get(AvaloniaObject obj)
+        {
+            return _registry.Where(v => v.Key(obj)).SelectMany(v => v.Value);
+        }
+
+        public string Name;
+        public Type Type;
+        public Func<object, object> Getter;
+        public Action<object, object> Setter;
+        public Func<object, IObservable<object>> Changed;
+    }
+
     internal class ControlDetailsViewModel : ViewModelBase, IDisposable
     {
-        private IVisual _control;
+        private object _control;
 
-        public ControlDetailsViewModel(IVisual control)
+        public ControlDetailsViewModel(object avObject)
         {
-            if (control is AvaloniaObject avaloniaObject)
+            if (avObject is AvaloniaObject avaloniaObject)
             {
-                var props = AvaloniaPropertyRegistry.Instance.GetRegistered(avaloniaObject)
+                var props = WellKnownProperty.Get(avaloniaObject)
+                    .Select(x => new PropertyDetails(avaloniaObject, x))
+                    .ToList();
+
+                var avProps = AvaloniaPropertyRegistry.Instance.GetRegistered(avaloniaObject)
                     .Select(x => new PropertyDetails(avaloniaObject, x))
                     .OrderBy(x => x.IsAttached)
                     .ThenBy(x => x.Name)
                     .ToList();
 
-                if (control is Control c)
+                props.AddRange(avProps);
+
+                if (avObject is Control c)
                 {
-                    var classesProp = new PropertyDetails(c, nameof(c.Classes),
-                        () => string.Join(" ", c.Classes),
-                        v => c.Classes.Replace(Classes.Parse(v as string)),
-                        Observable.FromEventPattern(c.Classes, nameof(c.Classes.CollectionChanged))
-                    );
+                    if (c.Parent != null)
+                    {
+                        var attached = AvaloniaPropertyRegistry.Instance.GetRegistered((AvaloniaObject)c.Parent)
+                                .Where(p => p.IsAttached)
+                                .Select(x => new PropertyDetails(avaloniaObject, x))
+                                .OrderBy(x => x.Name)
+                                .ToList();
 
-                    props.Insert(0, classesProp);
+                        props.AddRange(attached);
+                    }
+                }
 
-                    var l = c as ILayoutable;
-                    DateTime? last = null;
-                    var layoutProps = new[]
+                if (avObject is Style style)
+                {
+                    WellKnownProperty forSetter(ISetter setter)
                     {
-                        new PropertyDetails(c, "Layout Props",
-                        () => $"measured: {l.IsMeasureValid} -> {l.PreviousMeasure} arranged: {l.IsArrangeValid} -> {l.PreviousArrange} ({last?.TimeOfDay})",
-                        null,
-                        Observable.FromEventPattern(c, nameof(c.LayoutUpdated)).Select(_=>(object)(last=DateTime.Now))
-                        ),
-                    };
-                    props.InsertRange(0, layoutProps);
+                        if (setter is Setter sett)
+                        {
+                            return new WellKnownProperty()
+                            {
+                                Name = sett.Property.Name,
+                                Type = sett.Property.PropertyType,
+                                Getter = o => sett.Value,
+                                Setter = (o,v) => sett.Value = v,
+                                Changed = o => Observable.Never<object>()
+                            };
+                        }
+
+                        return new WellKnownProperty()
+                        {
+                            Name = setter.GetType().Name,
+                            Type = setter.GetType(),
+                            Getter = o => setter.ToString(),
+                            Changed = o => Observable.Never<object>()
+                        };
+                    }
+
+                    var setters = style.Setters.Select(s => new PropertyDetails(style, forSetter(s))).ToList();
+
+                    props.AddRange(setters);
                 }
 
                 Properties = props;
             }
 
-            _control = control;
+            _control = avObject;
         }
 
         public IEnumerable<PropertyDetails> Properties

src/Avalonia.Diagnostics/ViewModels/LogicalTreeNode.cs

@@ -12,7 +12,8 @@ namespace Avalonia.Diagnostics.ViewModels
         public LogicalTreeNode(ILogical logical, TreeNode parent)
             : base((Control)logical, parent)
         {
-            Children = logical.LogicalChildren.CreateDerivedList(x => new LogicalTreeNode(x, this));
+            var children = logical.LogicalChildren.CreateDerivedList(x => new LogicalTreeNode(x, this));
+            Children = StyleTreeNode.WithStyles(this, children);
         }
 
         public static LogicalTreeNode[] Create(object control)

src/Avalonia.Diagnostics/ViewModels/PropertyDetails.cs

@@ -11,7 +11,10 @@ using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Data;
+using Avalonia.Diagnostics.Views;
+using Avalonia.Input;
 using Avalonia.Media;
+using Avalonia.Platform;
 
 namespace Avalonia.Diagnostics.ViewModels
 {
@@ -19,8 +22,46 @@ namespace Avalonia.Diagnostics.ViewModels
     {
         public class ParseTypeConverter : TypeConverter
         {
+            private static Dictionary<IPlatformHandle, string> _standardCursors;
+
+            private static string TryGetCursorName(Cursor cursor)
+            {
+                if (cursor?.PlatformCursor == null)
+                    return "";
+
+                if (_standardCursors == null)
+                {
+                    _standardCursors = new Dictionary<IPlatformHandle, string>();
+                    try
+                    {
+                        var platform = AvaloniaLocator.Current.GetService<IStandardCursorFactory>();
+
+                        foreach (StandardCursorType c in Enum.GetValues(typeof(StandardCursorType)))
+                        {
+                            _standardCursors[platform.GetCursor(c)] = c.ToString();
+                        }
+                    }
+                    catch
+                    {
+                    }
+                }
+
+                return cursor?.PlatformCursor != null && _standardCursors.TryGetValue(cursor.PlatformCursor, out string r) ? r : cursor?.PlatformCursor?.ToString();
+            }
+
             private readonly Func<string, CultureInfo, object> _parse;
 
+            private static Dictionary<Type, Func<object, string>> _customToString = new Dictionary<Type, Func<object, string>>()
+            {
+                //TODO: may be override ToString and remove this hardcoded functionality
+                { typeof(RelativePoint), o =>
+                                {
+                                    var rp = (RelativePoint)o;
+                                    return rp.Unit== RelativeUnit.Absolute?rp.Point.ToString():$"{rp.Point.X*100}%,{rp.Point.Y*100}%";
+                                } },
+                { typeof(Cursor), o => TryGetCursorName(o as Cursor) },
+            };
+
             public static Func<string, CultureInfo, object> TryGetParse(Type type)
             {
                 var bf = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
@@ -39,6 +80,17 @@ namespace Avalonia.Diagnostics.ViewModels
                     return (s, c) => parse.Invoke(null, new object[] { s });
                 }
 
+                parse = type.GetMethod("Parse", bf);
+                if (parse?.ReturnParameter?.ParameterType == type)
+                {
+                    var pars = parse.GetParameters();
+                    //parse with string parameter and default second argument
+                    if (pars.Length == 2 && pars[0].ParameterType == typeof(string) && pars[1].IsOptional)
+                    {
+                        return (s, c) => parse.Invoke(null, new object[] { s, Type.Missing });
+                    }
+                }
+
                 return null;
             }
 
@@ -48,23 +100,21 @@ namespace Avalonia.Diagnostics.ViewModels
             }
 
             public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
-            {
-                return sourceType == typeof(string);
-            }
+                => sourceType == typeof(string);
 
             public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
-            {
-                return _parse((string)value, culture);
-            }
+                => _parse((string)value, culture);
+
+            public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
+                => _customToString.TryGetValue(value?.GetType() ?? typeof(object), out var ts) ? ts(value) : value?.ToString();
+
+            public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
+                => destinationType == typeof(string);
         }
 
         private static Dictionary<Type, TypeConverter> _converters = new Dictionary<Type, TypeConverter>()
         {
-            {typeof(TimeSpan), new Markup.Xaml.Converters.TimeSpanTypeConverter() },
-            {typeof(FontFamily), new Markup.Xaml.Converters.FontFamilyTypeConverter() },
-            {typeof(int), null},
-            {typeof(double), null},
-            {typeof(string), null}
+            //here hard coded type converters if needed
         };
 
         static public TypeConverter TryGetTypeConverter(Type type)
@@ -97,33 +147,36 @@ namespace Avalonia.Diagnostics.ViewModels
         private object _originalValue;
         private object _value;
         private bool _isChanged = false;
-        private string _priority;
+        private string _priority = "";
         private string _diagnostic;
-
         private AvaloniaObject _object;
         private AvaloniaProperty _property;
+        private WellKnownProperty _wellKnownProperty;
         private TypeConverter _typeConverter;
-        private IEnumerable<string> _possibleValues;
-        private Func<object> _getter;
-        private Action<object> _setter;
+        private IEnumerable<string> _hintValues;
         private bool _setActive = false;
 
-        private static TypeConverter TryGetTypeConverter(AvaloniaProperty property)
+        private static TypeConverter TryGetTypeConverter(Type propertyType)
         {
+            if (propertyType == null)
+            {
+                return null;
+            }
+
             TypeConverter result;
 
-            if (_typeConverters.TryGetValue(property.PropertyType, out result))
+            if (_typeConverters.TryGetValue(propertyType, out result))
                 return result;
 
-            result = AvaloniaTypeConverters.TryGetTypeConverter(property.PropertyType) ??
-                        TypeDescriptor.GetConverter(property.PropertyType);
+            result = AvaloniaTypeConverters.TryGetTypeConverter(propertyType) ??
+                        TypeDescriptor.GetConverter(propertyType);
 
             if (result?.CanConvertFrom(typeof(string)) == false)
             {
                 result = null;
             }
 
-            return _typeConverters[property.PropertyType] = result;
+            return _typeConverters[propertyType] = result;
         }
 
         public PropertyDetails(AvaloniaObject o, AvaloniaProperty property)
@@ -132,11 +185,10 @@ namespace Avalonia.Diagnostics.ViewModels
                 $"[{property.OwnerType.Name}.{property.Name}]" :
                 property.Name;
 
-            _typeConverter = property.IsReadOnly ? null : TryGetTypeConverter(property);
+            _typeConverter = TryGetTypeConverter(property.PropertyType);
             IsAttached = property.IsAttached;
-            IsReadOnly = property.IsReadOnly || _typeConverter == null;
+            IsReadOnly = property.IsReadOnly || !(_typeConverter?.CanConvertFrom(typeof(string)) ?? false);
             bool first = true;
-            // TODO: Unsubscribe when view model is deactivated.
             _disposable = o.GetObservable(property).Where(_ => !_setActive).Subscribe(x =>
             {
                 var diagnostic = o.GetDiagnostic(property);
@@ -160,20 +212,26 @@ namespace Avalonia.Diagnostics.ViewModels
             _property = property;
         }
 
-        public PropertyDetails(AvaloniaObject o, string propertyName, Func<object> getter, Action<object> setter, IObservable<object> changed)
+        public PropertyDetails(AvaloniaObject o, WellKnownProperty property)
         {
+            _wellKnownProperty = property;
             _object = o;
-            Name = propertyName;
-            _getter = getter;
-            _setter = setter;
-            IsReadOnly = setter == null;
-            _originalValue = _getter();
-            SetValue(_getter(), false);
+            Name = _wellKnownProperty.Name;
+            _typeConverter = TryGetTypeConverter(_wellKnownProperty.Type);
+            IsReadOnly = !(_wellKnownProperty.Setter != null && (_typeConverter?.CanConvertFrom(typeof(string)) ?? true));
+
+            var getter = _wellKnownProperty.Getter;
+
+            if (_typeConverter != null)
+            {
+                getter = x => _typeConverter.ConvertTo(_wellKnownProperty.Getter(x), typeof(string)) ?? "(null)";
+            }
+
+            _originalValue = getter(o);
+            SetValue(_originalValue, false);
             var inpc = o as INotifyPropertyChanged;
-            changed = changed ?? Observable.FromEventPattern<PropertyChangedEventHandler, PropertyChangedEventArgs>
-                                (v => inpc.PropertyChanged += v, v => inpc.PropertyChanged -= v)
-                                .Where(v => v.EventArgs.PropertyName == propertyName);
-            _disposable = changed.Where(_ => !_setActive).Subscribe(_ => SetValue(_getter() ?? "(null)", false));
+            var changed = _wellKnownProperty.Changed(_object) ?? inpc.GetObservable<object>(Name);
+            _disposable = changed.Where(_ => !_setActive).Subscribe(_ => SetValue(getter(o) ?? "(null)", false));
         }
 
         private static Dictionary<Type, string[]> _typespossibleValues = new Dictionary<Type, string[]>();
@@ -182,26 +240,32 @@ namespace Avalonia.Diagnostics.ViewModels
         {
             string[] result;
 
-            if (_typespossibleValues.TryGetValue(_property.PropertyType, out result))
+            var propertyType = _property?.PropertyType ?? _wellKnownProperty?.Type ?? typeof(object);
+
+            if (_typespossibleValues.TryGetValue(propertyType, out result))
                 return result;
 
             if (_property != null)
             {
-                if (_property.PropertyType.IsEnum)
+                if (propertyType.IsEnum)
                 {
-                    result = Enum.GetNames(_property.PropertyType);
+                    result = Enum.GetNames(propertyType);
                 }
-                else if (_property.PropertyType == typeof(IBrush))
+                else if (propertyType == typeof(IBrush))
                 {
                     result = typeof(Brushes).GetProperties().Select(p => p.Name).ToArray();
                 }
-                else if (_property.PropertyType == typeof(bool))
+                else if (propertyType == typeof(bool) || propertyType == typeof(bool?))
                 {
                     result = new[] { "True", "False" };
                 }
+                else if (propertyType == typeof(Cursor))
+                {
+                    result = Enum.GetNames(typeof(StandardCursorType));
+                }
             }
 
-            return _typespossibleValues[_property.PropertyType] = result;
+            return _typespossibleValues[propertyType] = result ?? Array.Empty<string>();
         }
 
         public string Name { get; }
@@ -236,7 +300,7 @@ namespace Avalonia.Diagnostics.ViewModels
             {
                 string stringValue = (value as string)?.TrimStart(' ');
 
-                if (setback && !IsReadOnly)
+                if (setback && !IsReadOnly && _disposable != null)
                 {
                     try
                     {
@@ -244,9 +308,9 @@ namespace Avalonia.Diagnostics.ViewModels
                                             null : (_typeConverter?.ConvertFrom(stringValue) ?? stringValue);
 
                         _setActive = true;
-                        if (_setter != null)
+                        if (_wellKnownProperty != null)
                         {
-                            _setter(propValue);
+                            _wellKnownProperty?.Setter?.Invoke(_object, propValue);
                         }
                         else
                         {
@@ -304,24 +368,30 @@ namespace Avalonia.Diagnostics.ViewModels
             set { this.RaiseAndSetIfChanged(ref _hasValueError, value); }
         }
 
-        public async Task<IEnumerable<object>> PossibleValuesPopulator(string text, CancellationToken token)
+        public async Task<IEnumerable<object>> HintValuesPopulator(string text, CancellationToken token)
         {
             if (text.Equals(Value))
-                return Enumerable.Empty<string>();
+                return Array.Empty<string>();
 
             await Task.Delay(100, token);
 
-            return PossibleValues;
+            if (token.IsCancellationRequested)
+            {
+                return Array.Empty<string>();
+            }
+
+            return HintValues;
         }
 
         public void Dispose()
         {
             _disposable?.Dispose();
+            _disposable = null;
         }
 
-        public IEnumerable<string> PossibleValues
+        public IEnumerable<string> HintValues
         {
-            get => _possibleValues ?? (_possibleValues = GetPossibleValues());
+            get => _hintValues ?? (_hintValues = GetPossibleValues());
         }
     }
 }

src/Avalonia.Diagnostics/ViewModels/StylesNode.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using Avalonia.Collections;
+using Avalonia.Controls;
+using Avalonia.Styling;
+
+namespace Avalonia.Diagnostics.ViewModels
+{
+    internal class StyleTreeNode : TreeNode
+    {
+        public static IAvaloniaReadOnlyList<TreeNode> WithStyles<T>(TreeNode node, IAvaloniaReadOnlyList<T> children) where T : TreeNode
+        {
+            if (node.Visual is Control ctrl && (ctrl.Styles.Count > 0 || ctrl is TopLevel))
+            {
+                var result = new AvaloniaList<TreeNode>();
+                if (ctrl is TopLevel)
+                {
+                    result.Add(new StyleTreeNode(Application.Current.Styles, node));
+                }
+                if (ctrl.Styles.Count > 0)
+                {
+                    result.Add(new StyleTreeNode(ctrl.Styles, node));
+                }
+                var cnt = result.Count;
+                children.ForEachItem((i, v) => result.Insert(i + cnt, v),
+                                    (i, v) => result.RemoveAt(i + cnt),
+                                    () => result.RemoveRange(cnt, result.Count - cnt), 
+                                    true);
+                return result;
+            }
+            return children;
+        }
+        public StyleTreeNode(IStyle style, TreeNode parent) : base((IAvaloniaObject)style, parent)
+        {
+            Children = new AvaloniaList<TreeNode>(((style as Styles)?.OfType<Style>().Select(s => new StyleTreeNode(s, this))) ?? Array.Empty<StyleTreeNode>());
+        }
+    }
+}

src/Avalonia.Diagnostics/ViewModels/TreeNode.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Diagnostics.ViewModels
         private string _classes;
         private bool _isExpanded;
 
-        public TreeNode(IVisual visual, TreeNode parent)
+        public TreeNode(object visual, TreeNode parent)
         {
             Parent = parent;
             Type = visual.GetType().Name;
@@ -45,6 +45,10 @@ namespace Avalonia.Diagnostics.ViewModels
                         }
                     });
             }
+            else if (visual is Style s)
+            {
+                Classes = $"({s.Selector?.ToString()})";
+            }
         }
 
         public IAvaloniaReadOnlyList<TreeNode> Children
@@ -59,7 +63,7 @@ namespace Avalonia.Diagnostics.ViewModels
             private set => RaiseAndSetIfChanged(ref _classes, value);
         }
 
-        public IVisual Visual
+        public object Visual
         {
             get;
         }

src/Avalonia.Diagnostics/ViewModels/VisualTreeNode.cs

@@ -10,7 +10,7 @@ namespace Avalonia.Diagnostics.ViewModels
     internal class VisualTreeNode : TreeNode
     {
         public VisualTreeNode(IVisual visual, TreeNode parent)
-            : base(visual, parent)
+            : base((IAvaloniaObject)visual, parent)
         {
             var host = visual as IVisualTreeHost;
 

src/Avalonia.Diagnostics/Views/ControlDetailsView.cs

@@ -8,6 +8,7 @@ using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Data;
 using Avalonia.Diagnostics.ViewModels;
+using Avalonia.Input;
 using Avalonia.Markup.Xaml;
 
 namespace Avalonia.Diagnostics.Views
@@ -57,7 +58,14 @@ namespace Avalonia.Diagnostics.Views
 
             if (value != null)
             {
-                var evt = Observable.Merge(value.EventNames.Select(v => Observable.FromEventPattern(c, v)));
+                var evt = Observable.Merge(value.EventNames.Select(eventName =>
+                {
+                    if (eventName == "EnterKeyUp")
+                    {
+                        return Observable.FromEventPattern<KeyEventArgs>(c, "KeyUp").Where(v => v.EventArgs.Key == Key.Enter).OfType<object>();
+                    }
+                    return Observable.FromEventPattern(c, eventName);
+                }));
                 var avp = AvaloniaPropertyRegistry.Instance.FindRegistered(c, value.PropertyName);
                 c.Bind(Control.TagProperty, value.Binding);
                 c.GetObservable(Control.TagProperty).Subscribe(v => c.SetValue(avp, v));

src/Avalonia.Diagnostics/Views/ControlDetailsView.xaml

@@ -19,7 +19,7 @@
     </Style>
   </UserControl.Styles>
   <Grid RowDefinitions="Auto,*">
-    <Grid x:Name="headerGrid" ColumnDefinitions="200,4,1*,4,100,20" Grid.Row="0" Background="{DynamicResource ThemeBorderMidBrush}">
+    <Grid x:Name="headerGrid" ColumnDefinitions="200,auto,1*,auto,100,20" Grid.Row="0" Background="{DynamicResource ThemeBorderMidBrush}">
       <Grid.Styles>
         <Style Selector="TextBlock.header">
           <Setter Property="Foreground" Value="{DynamicResource ThemeControlMidBrush}" />
@@ -34,17 +34,19 @@
       <GridSplitter Grid.Column="1"/>
       <GridSplitter Grid.Column="3"/>
     </Grid>
-    <ScrollViewer Grid.Row="1" HorizontalScrollBarVisibility="Disabled">
-      <ItemsRepeater Items="{Binding Properties}" Tag="{Binding #headerGrid.ColumnDefinitions}">
-        <ItemsRepeater.ItemTemplate>
+    <!--<ScrollViewer Grid.Row="1" HorizontalScrollBarVisibility="Disabled">
+      <ItemsRepeater Name="itemsParent" Items="{Binding Properties}">
+        <ItemsRepeater.ItemTemplate>-->
+    <ListBox Grid.Row="1" Name="itemsParent"  ScrollViewer.HorizontalScrollBarVisibility="Disabled" Items="{Binding Properties}">
+      <ListBox.ItemTemplate>
           <DataTemplate>
             <Grid HorizontalAlignment="Stretch">
               <Grid.ColumnDefinitions>
-                <ColumnDefinition Width="{Binding $parent[ItemsRepeater].Tag[0].Width}" />
+                <ColumnDefinition Width="{Binding #headerGrid.ColumnDefinitions[0].Width}" />
                 <ColumnDefinition Width="4" />
                 <ColumnDefinition Width="1*" />
                 <ColumnDefinition Width="4" />
-                <ColumnDefinition Width="{Binding $parent[ItemsRepeater].Tag[4].Width}" />
+                <ColumnDefinition Width="{Binding #headerGrid.ColumnDefinitions[4].Width}" />
               </Grid.ColumnDefinitions>
               <Panel Background="Transparent" Grid.Column="0"  ToolTip.Tip="{Binding Diagnostic}" >
                 <TextBlock Text="{Binding Name}"  Margin="5 0 0 0" VerticalAlignment="Center" />
@@ -55,10 +57,10 @@
                 <AutoCompleteBox IsEnabled="{Binding !IsReadOnly}" Classes="editor" Margin="1"
                                     DataValidationErrors.Errors="{Binding ValueErrors}"
                                     IsTextCompletionEnabled="{Binding !IsReadOnly}"
-                                    AsyncPopulator="{Binding PossibleValuesPopulator}"
+                                    AsyncPopulator="{Binding HintValuesPopulator}"
                                   >
                   <v:BindingHelper.BindBackOnEvent>
-                    <v:BindingHelper Binding="{Binding Value, Mode=TwoWay}"  EventNames="LostFocus,DropDownClosed" PropertyName="Text" />
+                    <v:BindingHelper Binding="{Binding Value, Mode=TwoWay}"  EventNames="LostFocus,DropDownClosed,SelectionChanged,EnterKeyUp" PropertyName="Text" />
                   </v:BindingHelper.BindBackOnEvent>
                 </AutoCompleteBox>
               </Panel>
@@ -70,8 +72,10 @@
               <TextBlock Text="{Binding Priority}" Margin="5 0 0 0" Grid.Column="4" VerticalAlignment="Center" />
             </Grid>
           </DataTemplate>
-        </ItemsRepeater.ItemTemplate>
+      </ListBox.ItemTemplate>
+    </ListBox>
+        <!--</ItemsRepeater.ItemTemplate>
       </ItemsRepeater>
-    </ScrollViewer>
+    </ScrollViewer>-->
   </Grid>
 </UserControl>

src/Avalonia.Diagnostics/Views/TreePageView.xaml

@@ -3,7 +3,7 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:v="clr-namespace:Avalonia.Diagnostics.Views;assembly=Avalonia.Diagnostics"
              x:Class="Avalonia.Diagnostics.Views.TreePageView">
-    <Grid ColumnDefinitions="*,4,3*">
+    <Grid ColumnDefinitions="*,auto,3*">
         <TreeView Name="tree" Items="{Binding Nodes}" SelectedItem="{Binding SelectedNode, Mode=TwoWay}">
             <TreeView.DataTemplates>
                 <TreeDataTemplate DataType="vm:TreeNode"
@@ -21,7 +21,7 @@
             </TreeView.Styles>
         </TreeView>
 
-        <GridSplitter Width="4" Grid.Column="1"/>
+        <GridSplitter Grid.Column="1"/>
 
         <v:ControlDetailsView Grid.Column="2" DataContext="{Binding Details}" />
         <!--<ContentControl Content="{Binding Details}" Grid.Column="2"/>-->

src/Avalonia.Diagnostics/Views/TreePageView.xaml.cs

@@ -9,6 +9,7 @@ using Avalonia.Diagnostics.ViewModels;
 using Avalonia.Input;
 using Avalonia.Markup.Xaml;
 using Avalonia.Media;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Diagnostics.Views
 {
@@ -26,7 +27,12 @@ namespace Avalonia.Diagnostics.Views
         protected void AddAdorner(object sender, PointerEventArgs e)
         {
             var node = (TreeNode)((Control)sender).DataContext;
-            var layer = AdornerLayer.GetAdornerLayer(node.Visual);
+            var visual = node.Visual as IVisual;
+            if(visual == null)
+            {
+                return;
+            }
+            var layer = AdornerLayer.GetAdornerLayer(visual);
 
             if (layer != null)
             {