Improve DevTools previewer of setter values by including all value priorities

api/Avalonia.nupkg.xml

@@ -1015,6 +1015,18 @@
     <Left>baseline/netstandard2.0/Avalonia.Base.dll</Left>
     <Right>target/netstandard2.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Diagnostics.AppliedStyle</Target>
+    <Left>baseline/netstandard2.0/Avalonia.Base.dll</Left>
+    <Right>target/netstandard2.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Diagnostics.StyleDiagnostics</Target>
+    <Left>baseline/netstandard2.0/Avalonia.Base.dll</Left>
+    <Right>target/netstandard2.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:Avalonia.Input.FocusManager.&lt;GetFocusScopeAncestors&gt;d__18</Target>
@@ -1069,6 +1081,12 @@
     <Left>baseline/netstandard2.0/Avalonia.Controls.dll</Left>
     <Right>target/netstandard2.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Diagnostics.StyledElementExtensions.GetStyleDiagnostics(Avalonia.StyledElement)</Target>
+    <Left>baseline/netstandard2.0/Avalonia.Base.dll</Left>
+    <Right>target/netstandard2.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>P:Avalonia.Rendering.Composition.ICompositionGpuImportedObject.ImportCompleted</Target>

src/Avalonia.Base/Diagnostics/IValueFrameDiagnostic.cs

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using Avalonia.Data;
+using Avalonia.Metadata;
+
+namespace Avalonia.Diagnostics;
+
+public record ValueEntryDiagnostic(AvaloniaProperty Property, object? Value);
+
+[Unstable]
+[NotClientImplementable]
+public interface IValueFrameDiagnostic
+{
+    public enum FrameType
+    {
+        Unknown = 0,
+        Local,
+        Theme,
+        Style,
+        Template
+    }
+
+    string? Description { get; }
+    FrameType Type { get; }
+    bool IsActive { get; }
+    BindingPriority Priority { get; }
+    IEnumerable<ValueEntryDiagnostic> Values { get; } 
+}

src/Avalonia.Base/Diagnostics/LocalValueFrameDiagnostic.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using Avalonia.Data;
+
+namespace Avalonia.Diagnostics;
+
+internal class LocalValueFrameDiagnostic : IValueFrameDiagnostic
+{
+    public LocalValueFrameDiagnostic(IEnumerable<ValueEntryDiagnostic> values)
+    {
+        Values = values;
+    }
+
+    public string? Description => null;
+    public IValueFrameDiagnostic.FrameType Type => IValueFrameDiagnostic.FrameType.Local;
+    public bool IsActive => true;
+    public BindingPriority Priority => BindingPriority.LocalValue;
+    public IEnumerable<ValueEntryDiagnostic> Values { get; }
+}

src/Avalonia.Base/Diagnostics/StyleValueFrameDiagnostic.cs

@@ -0,0 +1,63 @@
+using System.Collections.Generic;
+using Avalonia.Data;
+using Avalonia.PropertyStore;
+using Avalonia.Styling;
+
+namespace Avalonia.Diagnostics;
+
+internal class StyleValueFrameDiagnostic : IValueFrameDiagnostic
+{
+    private readonly StyleInstance _styleInstance;
+
+    internal StyleValueFrameDiagnostic(StyleInstance styleInstance)
+    {
+        _styleInstance = styleInstance;
+    }
+
+    public string? Description => _styleInstance.Source switch
+    {
+        Style s => GetFullSelector(s),
+        ControlTheme t => t.TargetType?.Name,
+        _ => null
+    };
+
+    public IValueFrameDiagnostic.FrameType Type => _styleInstance.Source switch
+    {
+        Style => IValueFrameDiagnostic.FrameType.Style,
+        ControlTheme => IValueFrameDiagnostic.FrameType.Theme,
+        _ => IValueFrameDiagnostic.FrameType.Unknown
+    };
+
+    public bool IsActive => _styleInstance.IsActive();
+    public BindingPriority Priority => _styleInstance.FramePriority.ToBindingPriority();
+    public IEnumerable<ValueEntryDiagnostic> Values
+    {
+        get
+        {
+            foreach (var setter in ((StyleBase)_styleInstance.Source!).Setters)
+            {
+                if (setter is Setter { Property: not null } regularSetter)
+                {
+                    yield return new ValueEntryDiagnostic(regularSetter.Property, regularSetter.Value);
+                }
+            }
+        }
+    }
+
+    private string GetFullSelector(Style? style)
+    {
+        var selectors = new Stack<string>();
+
+        while (style is not null)
+        {
+            if (style.Selector is not null)
+            {
+                selectors.Push(style.Selector.ToString());
+            }
+
+            style = style.Parent as Style;
+        }
+
+        return string.Concat(selectors);
+    }
+}

src/Avalonia.Base/Diagnostics/StyledElementExtensions.cs

@@ -1,17 +1,16 @@
-namespace Avalonia.Diagnostics
+namespace Avalonia.Diagnostics;
+
+/// <summary>
+/// Defines diagnostic extensions on <see cref="StyledElement"/>s.
+/// </summary>
+public static class StyledElementExtensions
 {
     /// <summary>
-    /// Defines diagnostic extensions on <see cref="StyledElement"/>s.
+    /// Gets a style diagnostics for a <see cref="StyledElement"/>.
     /// </summary>
-    public static class StyledElementExtensions
+    /// <param name="styledElement">The element.</param>
+    public static ValueStoreDiagnostic GetValueStoreDiagnostic(this StyledElement styledElement)
     {
-        /// <summary>
-        /// Gets a style diagnostics for a <see cref="StyledElement"/>.
-        /// </summary>
-        /// <param name="styledElement">The element.</param>
-        public static StyleDiagnostics GetStyleDiagnostics(this StyledElement styledElement)
-        {
-            return styledElement.GetStyleDiagnosticsInternal();
-        }
+        return styledElement.GetValueStore().GetStoreDiagnostic();
     }
 }

src/Avalonia.Base/Diagnostics/ValueFrameDiagnostic.cs

@@ -0,0 +1,37 @@
+using System.Collections.Generic;
+using Avalonia.Data;
+using Avalonia.PropertyStore;
+using Avalonia.Styling;
+
+namespace Avalonia.Diagnostics;
+
+internal sealed class ValueFrameDiagnostic : IValueFrameDiagnostic
+{
+    private readonly ValueFrame _valueFrame;
+
+    internal ValueFrameDiagnostic(ValueFrame valueFrame)
+    {
+        _valueFrame = valueFrame;
+    }
+
+    public string? Description => (_valueFrame.Owner?.Owner as StyledElement)?.StyleKey.Name;
+
+    public IValueFrameDiagnostic.FrameType Type => IValueFrameDiagnostic.FrameType.Template;
+
+    public bool IsActive => _valueFrame.IsActive();
+    public BindingPriority Priority => _valueFrame.FramePriority.ToBindingPriority();
+    public IEnumerable<ValueEntryDiagnostic> Values
+    {
+        get
+        {
+            for (var i = 0; i < _valueFrame.EntryCount; i++)
+            {
+                var entry = _valueFrame.GetEntry(i);
+                if (entry.HasValue())
+                {
+                    yield return new ValueEntryDiagnostic(entry.Property, entry.GetValue());
+                }
+            }
+        }
+    }
+}

src/Avalonia.Base/Diagnostics/ValueStoreDiagnostic.cs

@@ -0,0 +1,17 @@
+using System.Collections.Generic;
+using Avalonia.Styling;
+
+namespace Avalonia.Diagnostics;
+
+public class ValueStoreDiagnostic
+{
+    /// <summary>
+    /// Currently applied frames.
+    /// </summary>
+    public IReadOnlyList<IValueFrameDiagnostic> AppliedFrames { get; }
+
+    internal ValueStoreDiagnostic(IReadOnlyList<IValueFrameDiagnostic> appliedFrames)
+    {
+        AppliedFrames = appliedFrames;
+    }
+}

src/Avalonia.Base/PropertyStore/FramePriority.cs

@@ -28,6 +28,12 @@ public static FramePriority ToFramePriority(this BindingPriority priority, Frame
             return (FramePriority)(p * 3 + (int)type);
         }
 
+        public static BindingPriority ToBindingPriority(this FramePriority priority)
+        {
+            var p = (int)priority / 3;
+            return p == 0 ? BindingPriority.Animation : (BindingPriority)p;
+        }
+
         public static bool IsType(this FramePriority priority, FrameType type)
         {
             return (FrameType)((int)priority % 3) == type;

src/Avalonia.Base/PropertyStore/ValueStore.cs

@@ -689,6 +689,40 @@ public AvaloniaPropertyValue GetDiagnostic(AvaloniaProperty property)
                 overridden);
         }
 
+        public ValueStoreDiagnostic GetStoreDiagnostic()
+        {
+            var frames = new List<IValueFrameDiagnostic>();
+
+            var effectiveLocalValues = new List<ValueEntryDiagnostic>(_effectiveValues.Count);
+            for (var i = 0; i < _effectiveValues.Count; i++)
+            {
+                _effectiveValues.GetKeyValue(i, out var key, out var effectiveValue);
+                if (effectiveValue.Priority == BindingPriority.LocalValue)
+                {
+                    effectiveLocalValues.Add(new ValueEntryDiagnostic(key, effectiveValue.Value));
+                }
+            }
+
+            if (effectiveLocalValues.Count > 0)
+            {
+                frames.Add(new LocalValueFrameDiagnostic(effectiveLocalValues));
+            }
+
+            foreach (var frame in Frames)
+            {
+                if (frame is StyleInstance { Source: StyleBase } styleInstance)
+                {
+                    frames.Add(new StyleValueFrameDiagnostic(styleInstance));
+                }
+                else
+                {
+                    frames.Add(new ValueFrameDiagnostic(frame));   
+                }
+            }
+
+            return new ValueStoreDiagnostic(frames);
+        }
+
         private int InsertFrame(ValueFrame frame)
         {
             Debug.Assert(!_frames.Contains(frame));

src/Avalonia.Base/StyledElement.cs

@@ -418,19 +418,6 @@ protected void InitializeIfNeeded()
             }
         }
 
-        internal StyleDiagnostics GetStyleDiagnosticsInternal()
-        {
-            var styles = new List<AppliedStyle>();
-
-            foreach (var frame in GetValueStore().Frames)
-            {
-                if (frame is IStyleInstance style)
-                    styles.Add(new(style));
-            }
-
-            return new StyleDiagnostics(styles);
-        }
-
         /// <inheritdoc/>
         void ILogical.NotifyAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e)
         {

src/Avalonia.Diagnostics/Diagnostics/Controls/BrushEditor.axaml.cs

@@ -23,7 +23,14 @@ partial class BrushEditor : TemplatedControl
         public BrushEditor()
         {
             FlyoutBase.SetAttachedFlyout(this, new Flyout { Content = _colorView });
-            _colorView.ColorChanged += (_, e) => Brush = new ImmutableSolidColorBrush(e.NewColor);
+            _colorView.ColorChanged += (_, e) =>
+            {
+                // Avoid unnecessary value setters by checking if color was actually changed.
+                if (Brush is null || Brush is not ISolidColorBrush oldSolidBrush || oldSolidBrush.Color != e.NewColor)
+                {
+                    Brush = new ImmutableSolidColorBrush(e.NewColor);
+                }
+            };
             clearHandler = (s, e) => Brush = default;
         }