Store direct property bindings in ValueStore.

We already have a place to store them in the `_localValueBindings` list, so use that rather than having a separate `_directBindings` list in `AvaloniaObject`.

src/Avalonia.Base/AvaloniaObject.cs

@@ -18,7 +18,6 @@ namespace Avalonia
     public class AvaloniaObject : IAvaloniaObject, IAvaloniaObjectDebug, INotifyPropertyChanged
     {
         private AvaloniaObject? _inheritanceParent;
-        private List<IDisposable>? _directBindings;
         private PropertyChangedEventHandler? _inpcChanged;
         private EventHandler<AvaloniaPropertyChangedEventArgs>? _propertyChanged;
         private List<AvaloniaObject>? _inheritanceChildren;
@@ -336,6 +335,7 @@ namespace Avalonia
             property = property ?? throw new ArgumentNullException(nameof(property));
             VerifyAccess();
 
+            property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
             LogPropertySet(property, value, BindingPriority.LocalValue);
             SetDirectValueUnchecked(property, value);
         }
@@ -343,7 +343,6 @@ namespace Avalonia
         /// <summary>
         /// Binds a <see cref="AvaloniaProperty"/> to an observable.
         /// </summary>
-        /// <typeparam name="T">The type of the property.</typeparam>
         /// <param name="property">The property.</param>
         /// <param name="source">The observable.</param>
         /// <param name="priority">The priority of the binding.</param>
@@ -355,7 +354,6 @@ namespace Avalonia
             IObservable<object?> source,
             BindingPriority priority = BindingPriority.LocalValue) => property.RouteBind(this, source, priority);
 
-
         /// <summary>
         /// Binds a <see cref="AvaloniaProperty"/> to an observable.
         /// </summary>
@@ -433,10 +431,9 @@ namespace Avalonia
         /// </returns>
         public IDisposable Bind<T>(
             DirectPropertyBase<T> property,
-            IObservable<BindingValue<T>> source)
+            IObservable<object?> source)
         {
             property = property ?? throw new ArgumentNullException(nameof(property));
-            source = source ?? throw new ArgumentNullException(nameof(source));
             VerifyAccess();
 
             property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
@@ -446,15 +443,59 @@ namespace Avalonia
                 throw new ArgumentException($"The property {property.Name} is readonly.");
             }
 
-            Logger.TryGet(LogEventLevel.Verbose, LogArea.Property)?.Log(
+            return _values.AddBinding(property, source);
-                this,
+        }
-                "Bound {Property} to {Binding} with priority LocalValue",
+
-                property,
+        /// <summary>
-                GetDescription(source));
+        /// Binds a <see cref="AvaloniaProperty"/> to an observable.
+        /// </summary>
+        /// <typeparam name="T">The type of the property.</typeparam>
+        /// <param name="property">The property.</param>
+        /// <param name="source">The observable.</param>
+        /// <returns>
+        /// A disposable which can be used to terminate the binding.
+        /// </returns>
+        public IDisposable Bind<T>(
+            DirectPropertyBase<T> property,
+            IObservable<T> source)
+        {
+            property = property ?? throw new ArgumentNullException(nameof(property));
+            VerifyAccess();
+
+            property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
 
-            _directBindings ??= new List<IDisposable>();
+            if (property.IsReadOnly)
+            {
+                throw new ArgumentException($"The property {property.Name} is readonly.");
+            }
 
-            return new DirectBindingSubscription<T>(this, property, source);
+            return _values.AddBinding(property, source);
+        }
+
+        /// <summary>
+        /// Binds a <see cref="AvaloniaProperty"/> to an observable.
+        /// </summary>
+        /// <typeparam name="T">The type of the property.</typeparam>
+        /// <param name="property">The property.</param>
+        /// <param name="source">The observable.</param>
+        /// <returns>
+        /// A disposable which can be used to terminate the binding.
+        /// </returns>
+        public IDisposable Bind<T>(
+            DirectPropertyBase<T> property,
+            IObservable<BindingValue<T>> source)
+        {
+            property = property ?? throw new ArgumentNullException(nameof(property));
+            VerifyAccess();
+
+            property = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
+
+            if (property.IsReadOnly)
+            {
+                throw new ArgumentException($"The property {property.Name} is readonly.");
+            }
+
+            return _values.AddBinding(property, source);
         }
 
         /// <summary>
@@ -562,7 +603,7 @@ namespace Avalonia
         {
         }
 
-        // <summary>
+        /// <summary>
         /// Raises the <see cref="PropertyChanged"/> event for a direct property.
         /// </summary>
         /// <param name="property">The property that has changed.</param>
@@ -644,17 +685,15 @@ namespace Avalonia
         /// </summary>
         /// <param name="property">The property.</param>
         /// <param name="value">The value.</param>
-        private void SetDirectValueUnchecked<T>(DirectPropertyBase<T> property, T value)
+        internal void SetDirectValueUnchecked<T>(DirectPropertyBase<T> property, T value)
         {
-            var p = AvaloniaPropertyRegistry.Instance.GetRegisteredDirect(this, property);
-
             if (value is UnsetValueType)
             {
-                p.InvokeSetter(this, p.GetUnsetValue(GetType()));
+                property.InvokeSetter(this, property.GetUnsetValue(GetType()));
             }
             else if (!(value is DoNothingType))
             {
-                p.InvokeSetter(this, value);
+                property.InvokeSetter(this, value);
             }
         }
 
@@ -663,15 +702,8 @@ namespace Avalonia
         /// </summary>
         /// <param name="property">The property.</param>
         /// <param name="value">The value.</param>
-        private void SetDirectValueUnchecked<T>(DirectPropertyBase<T> property, BindingValue<T> value)
+        internal void SetDirectValueUnchecked<T>(DirectPropertyBase<T> property, BindingValue<T> value)
         {
-            var p = AvaloniaPropertyRegistry.Instance.FindRegisteredDirect(this, property);
-
-            if (p == null)
-            {
-                throw new ArgumentException($"Property '{property.Name} not registered on '{this.GetType()}");
-            }
-
             LoggingUtils.LogIfNecessary(this, property, value);
 
             switch (value.Type)
@@ -691,7 +723,7 @@ namespace Avalonia
                     break;
             }
 
-            var metadata = p.GetMetadata(GetType());
+            var metadata = property.GetMetadata(GetType());
 
             if (metadata.EnableDataValidation == true)
             {
@@ -725,50 +757,5 @@ namespace Avalonia
                 value,
                 priority);
         }
-
-        private class DirectBindingSubscription<T> : IObserver<BindingValue<T>>, IDisposable
-        {
-            private readonly AvaloniaObject _owner;
-            private readonly DirectPropertyBase<T> _property;
-            private readonly IDisposable _subscription;
-
-            public DirectBindingSubscription(
-                AvaloniaObject owner,
-                DirectPropertyBase<T> property,
-                IObservable<BindingValue<T>> source)
-            {
-                _owner = owner;
-                _property = property;
-                _owner._directBindings!.Add(this);
-                _subscription = source.Subscribe(this);
-            }
-
-            public void Dispose()
-            {
-                // _subscription can be null, if Subscribe failed with an exception.
-                _subscription?.Dispose();
-                _owner._directBindings!.Remove(this);
-            }
-
-            public void OnCompleted() => Dispose();
-            public void OnError(Exception error) => Dispose();
-            public void OnNext(BindingValue<T> value)
-            {
-                if (Dispatcher.UIThread.CheckAccess())
-                {
-                    _owner.SetDirectValueUnchecked(_property, value);
-                }
-                else
-                {
-                    // To avoid allocating closure in the outer scope we need to capture variables
-                    // locally. This allows us to skip most of the allocations when on UI thread.
-                    var instance = _owner;
-                    var property = _property;
-                    var newValue = value;
-
-                    Dispatcher.UIThread.Post(() => instance.SetDirectValueUnchecked(property, newValue));
-                }
-            }
-        }
     }
 }

src/Avalonia.Base/AvaloniaObjectExtensions.cs

@@ -261,7 +261,6 @@ namespace Avalonia
             }
 
             throw new NotSupportedException("Custom implementations of IAvaloniaObject not supported.");
-
         }
 
         /// <summary>
@@ -280,14 +279,17 @@ namespace Avalonia
             IObservable<T> source,
             BindingPriority priority = BindingPriority.LocalValue)
         {
-            target = target ?? throw new ArgumentNullException(nameof(target));
+            if (target is AvaloniaObject ao)
-            property = property ?? throw new ArgumentNullException(nameof(property));
+            {
-            source = source ?? throw new ArgumentNullException(nameof(source));
+                return property switch
+                {
+                    StyledPropertyBase<T> styled => ao.Bind(styled, source, priority),
+                    DirectPropertyBase<T> direct => ao.Bind(direct, source),
+                    _ => throw new NotSupportedException("Unsupported AvaloniaProperty type."),
+                };
+            }
 
-            return target.Bind(
+            throw new NotSupportedException("Custom implementations of IAvaloniaObject not supported.");
-                property,
-                source.ToBindingValue(),
-                priority);
         }
 
         /// <summary>

src/Avalonia.Base/AvaloniaProperty.cs

@@ -505,17 +505,6 @@ namespace Avalonia
             IObservable<object?> source,
             BindingPriority priority);
 
-        /// <summary>
-        /// Routes an untyped Bind call to a typed call.
-        /// </summary>
-        /// <param name="o">The object instance.</param>
-        /// <param name="source">The binding source.</param>
-        /// <param name="priority">The priority.</param>
-        internal abstract IDisposable RouteBind(
-            AvaloniaObject o,
-            IObservable<BindingValue<object?>> source,
-            BindingPriority priority);
-
         /// <summary>
         /// Overrides the metadata for the property on the specified type.
         /// </summary>

src/Avalonia.Base/Data/BindingNotification.cs

@@ -241,26 +241,6 @@ namespace Avalonia.Data
             _value = value;
         }
 
-        public BindingValue<object?> ToBindingValue()
-        {
-            if (ErrorType == BindingErrorType.None)
-            {
-                return HasValue ? new BindingValue<object?>(Value) : BindingValue<object?>.Unset;
-            }
-            else if (ErrorType == BindingErrorType.Error)
-            {
-                return BindingValue<object?>.BindingError(
-                    Error!,
-                    HasValue ? new Optional<object?>(Value) : Optional<object?>.Empty);
-            }
-            else
-            {
-                return BindingValue<object?>.DataValidationError(
-                    Error!,
-                    HasValue ? new Optional<object?>(Value) : Optional<object?>.Empty);
-            }
-        }
-
         /// <inheritdoc/>
         public override string ToString()
         {

src/Avalonia.Base/Data/BindingValue.cs

@@ -231,19 +231,64 @@ namespace Avalonia.Data
 
         /// <summary>
         /// Creates a <see cref="BindingValue{T}"/> from an object, handling the special values
-        /// <see cref="AvaloniaProperty.UnsetValue"/> and <see cref="BindingOperations.DoNothing"/>.
+        /// <see cref="AvaloniaProperty.UnsetValue"/>, <see cref="BindingOperations.DoNothing"/> and
+        /// <see cref="BindingNotification"/>.
         /// </summary>
         /// <param name="value">The untyped value.</param>
         /// <returns>The typed binding value.</returns>
         public static BindingValue<T> FromUntyped(object? value)
         {
-            return value switch
+            if (value == AvaloniaProperty.UnsetValue)
+                return Unset;
+            else if (value == BindingOperations.DoNothing)
+                return DoNothing;
+
+            var type = BindingValueType.Value;
+            T? v = default;
+            Exception? error = null;
+            List<Exception>? errors = null;
+
+            if (value is BindingNotification n)
             {
-                UnsetValueType _ => Unset,
+                error = n.Error;
-                DoNothingType _ => DoNothing,
+                type = n.ErrorType switch
-                BindingNotification n => n.ToBindingValue().Cast<T>(),
+                {
-                _ => new BindingValue<T>((T)value!)
+                    BindingErrorType.Error => BindingValueType.BindingError,
-            };
+                    BindingErrorType.DataValidationError => BindingValueType.DataValidationError,
+                    _ => BindingValueType.Value,
+                };
+
+                if (n.HasValue)
+                    type |= BindingValueType.HasValue;
+                value = n.Value;
+            }
+
+            if ((type & BindingValueType.HasValue) != 0)
+            {
+                if (TypeUtilities.TryConvertImplicit(typeof(T), value, out var typed))
+                    v = (T)typed!;
+                else
+                {
+                    var e = new InvalidCastException(
+                        $"Unable to convert object '{value ?? "(null)"}' " +
+                        $"of type '{value?.GetType()}' to type '{typeof(T)}'.");
+
+                    if (error is null)
+                        error = e;
+                    else
+                    {
+                        errors ??= new List<Exception>() { error };
+                        errors.Add(e);
+                    }
+
+                    type = BindingValueType.BindingError;
+                }
+            }
+
+            if (errors is not null)
+                error = new AggregateException(errors);
+
+            return new BindingValue<T>(type, v, error);
         }
 
         public static bool operator !=(BindingValue<T> x, Optional<T> y)
@@ -401,61 +446,4 @@ namespace Avalonia.Data
             }
         }
     }
-
-    public static class BindingValueExtensions
-    {
-        /// <summary>
-        /// Casts the type of a <see cref="BindingValue{T}"/> using only the C# cast operator.
-        /// </summary>
-        /// <typeparam name="T">The target type.</typeparam>
-        /// <param name="value">The binding value.</param>
-        /// <returns>The cast value.</returns>
-        public static BindingValue<T> Cast<T>(this BindingValue<object?> value)
-        {
-            return value.Type switch
-            {
-                BindingValueType.DoNothing => BindingValue<T>.DoNothing,
-                BindingValueType.UnsetValue => BindingValue<T>.Unset,
-                BindingValueType.Value => new BindingValue<T>((T)value.Value!),
-                BindingValueType.BindingError => BindingValue<T>.BindingError(value.Error!),
-                BindingValueType.BindingErrorWithFallback => BindingValue<T>.BindingError(
-                        value.Error!,
-                        (T)value.Value!),
-                BindingValueType.DataValidationError => BindingValue<T>.DataValidationError(value.Error!),
-                BindingValueType.DataValidationErrorWithFallback => BindingValue<T>.DataValidationError(
-                        value.Error!,
-                        (T)value.Value!),
-                _ => throw new NotSupportedException("Invalid BindingValue type."),
-            };
-        }
-
-        /// <summary>
-        /// Casts the type of a <see cref="BindingValue{T}"/> using the implicit conversions
-        /// allowed by the C# language.
-        /// </summary>
-        /// <typeparam name="T">The target type.</typeparam>
-        /// <param name="value">The binding value.</param>
-        /// <returns>The cast value.</returns>
-        /// <remarks>
-        /// Note that this method uses reflection and as such may be slow.
-        /// </remarks>
-        public static BindingValue<T> Convert<T>(this BindingValue<object?> value)
-        {
-            return value.Type switch
-            {
-                BindingValueType.DoNothing => BindingValue<T>.DoNothing,
-                BindingValueType.UnsetValue => BindingValue<T>.Unset,
-                BindingValueType.Value => new BindingValue<T>(TypeUtilities.ConvertImplicit<T>(value.Value!)),
-                BindingValueType.BindingError => BindingValue<T>.BindingError(value.Error!),
-                BindingValueType.BindingErrorWithFallback => BindingValue<T>.BindingError(
-                        value.Error!,
-                        TypeUtilities.ConvertImplicit<T>(value.Value!)),
-                BindingValueType.DataValidationError => BindingValue<T>.DataValidationError(value.Error!),
-                BindingValueType.DataValidationErrorWithFallback => BindingValue<T>.DataValidationError(
-                        value.Error!,
-                        TypeUtilities.ConvertImplicit<T>(value.Value!)),
-                _ => throw new NotSupportedException("Invalid BindingValue type."),
-            };
-        }
-    }
 }

src/Avalonia.Base/DirectPropertyBase.cs

@@ -178,19 +178,7 @@ namespace Avalonia
             IObservable<object?> source,
             BindingPriority priority)
         {
-            // TODO: this requires a double adapter, we should make AvaloniaObject
+            return o.Bind(this, source);
-            // accept an `IObservable<object?>` for direct properties directly.
-            return RouteBind(o, source.ToBindingValue(), priority);
-        }
-
-        /// <inheritdoc/>
-        internal override IDisposable RouteBind(
-            AvaloniaObject o,
-            IObservable<BindingValue<object?>> source,
-            BindingPriority priority)
-        {
-            var adapter = TypedBindingAdapter<TValue>.Create(o, this, source);
-            return o.Bind<TValue>(this, adapter);
         }
     }
 }

src/Avalonia.Base/PropertyStore/DirectBindingObserver.cs

@@ -0,0 +1,76 @@
+using System;
+using Avalonia.Data;
+using Avalonia.Threading;
+
+namespace Avalonia.PropertyStore
+{
+    internal class DirectBindingObserver<T> : IObserver<T>,
+        IObserver<BindingValue<T>>,
+        IDisposable
+    {
+        private readonly ValueStore _owner;
+        private IDisposable? _subscription;
+
+        public DirectBindingObserver(ValueStore owner, DirectPropertyBase<T> property)
+        {
+            _owner = owner;
+            Property = property;
+        }
+
+        public DirectPropertyBase<T> Property { get;}
+
+        public void Start(IObservable<T> source)
+        {
+            _subscription = source.Subscribe(this);
+        }
+
+        public void Start(IObservable<BindingValue<T>> source)
+        {
+            _subscription = source.Subscribe(this);
+        }
+
+        public void Dispose()
+        {
+            _subscription?.Dispose();
+            _subscription = null;
+            _owner.OnLocalValueBindingCompleted(Property, this);
+        }
+
+        public void OnCompleted() => _owner.OnLocalValueBindingCompleted(Property, this);
+        public void OnError(Exception error) => OnCompleted();
+
+        public void OnNext(T value)
+        {
+            if (Dispatcher.UIThread.CheckAccess())
+            {
+                _owner.Owner.SetDirectValueUnchecked<T>(Property, value);
+            }
+            else
+            {
+                // To avoid allocating closure in the outer scope we need to capture variables
+                // locally. This allows us to skip most of the allocations when on UI thread.
+                var instance = _owner.Owner;
+                var property = Property;
+                var newValue = value;
+                Dispatcher.UIThread.Post(() => instance.SetDirectValueUnchecked(property, newValue));
+            }
+        }
+
+        public void OnNext(BindingValue<T> value)
+        {
+            if (Dispatcher.UIThread.CheckAccess())
+            {
+                _owner.Owner.SetDirectValueUnchecked<T>(Property, value);
+            }
+            else
+            {
+                // To avoid allocating closure in the outer scope we need to capture variables
+                // locally. This allows us to skip most of the allocations when on UI thread.
+                var instance = _owner.Owner;
+                var property = Property;
+                var newValue = value;
+                Dispatcher.UIThread.Post(() => instance.SetDirectValueUnchecked(property, newValue));
+            }
+        }
+    }
+}

src/Avalonia.Base/PropertyStore/DirectUntypedBindingObserver.cs

@@ -0,0 +1,55 @@
+using System;
+using Avalonia.Data;
+using Avalonia.Threading;
+
+namespace Avalonia.PropertyStore
+{
+    internal class DirectUntypedBindingObserver<T> : IObserver<object?>,
+        IDisposable
+    {
+        private readonly ValueStore _owner;
+        private IDisposable? _subscription;
+
+        public DirectUntypedBindingObserver(ValueStore owner, DirectPropertyBase<T> property)
+        {
+            _owner = owner;
+            Property = property;
+        }
+
+        public DirectPropertyBase<T> Property { get;}
+
+        public void Start(IObservable<object?> source)
+        {
+            _subscription = source.Subscribe(this);
+        }
+
+        public void Dispose()
+        {
+            _subscription?.Dispose();
+            _subscription = null;
+            _owner.OnLocalValueBindingCompleted(Property, this);
+        }
+
+        public void OnCompleted() => _owner.OnLocalValueBindingCompleted(Property, this);
+        public void OnError(Exception error) => OnCompleted();
+
+        public void OnNext(object? value)
+        {
+            var typed = BindingValue<T>.FromUntyped(value);
+
+            if (Dispatcher.UIThread.CheckAccess())
+            {
+                _owner.Owner.SetDirectValueUnchecked<T>(Property, typed);
+            }
+            else
+            {
+                // To avoid allocating closure in the outer scope we need to capture variables
+                // locally. This allows us to skip most of the allocations when on UI thread.
+                var instance = _owner.Owner;
+                var property = Property;
+                var newValue = value;
+                Dispatcher.UIThread.Post(() => instance.SetDirectValueUnchecked(property, typed));
+            }
+        }
+    }
+}

src/Avalonia.Base/PropertyStore/ValueStore.cs

@@ -120,6 +120,36 @@ namespace Avalonia.PropertyStore
             }
         }
 
+        public IDisposable AddBinding<T>(DirectPropertyBase<T> property, IObservable<BindingValue<T>> source)
+        {
+            var observer = new DirectBindingObserver<T>(this, property);
+            DisposeExistingLocalValueBinding(property);
+            _localValueBindings ??= new();
+            _localValueBindings[property.Id] = observer;
+            observer.Start(source);
+            return observer;
+        }
+
+        public IDisposable AddBinding<T>(DirectPropertyBase<T> property, IObservable<T> source)
+        {
+            var observer = new DirectBindingObserver<T>(this, property);
+            DisposeExistingLocalValueBinding(property);
+            _localValueBindings ??= new();
+            _localValueBindings[property.Id] = observer;
+            observer.Start(source);
+            return observer;
+        }
+
+        public IDisposable AddBinding<T>(DirectPropertyBase<T> property, IObservable<object?> source)
+        {
+            var observer = new DirectUntypedBindingObserver<T>(this, property);
+            DisposeExistingLocalValueBinding(property);
+            _localValueBindings ??= new();
+            _localValueBindings[property.Id] = observer;
+            observer.Start(source);
+            return observer;
+        }
+
         public void ClearLocalValue(AvaloniaProperty property)
         {
             if (TryGetEffectiveValue(property, out var effective) &&
@@ -470,7 +500,8 @@ namespace Avalonia.PropertyStore
         }
 
         /// <summary>
-        /// Called when a <see cref="LocalValueBindingObserver{T}"/> completes.
+        /// Called when a <see cref="LocalValueBindingObserver{T}"/> or
+        /// <see cref="DirectBindingObserver{T}"/> completes.
         /// </summary>
         /// <param name="property">The previously bound property.</param>
         /// <param name="observer">The observer.</param>
@@ -641,7 +672,6 @@ namespace Avalonia.PropertyStore
         /// Adds a new effective value, raises the initial <see cref="AvaloniaObject.PropertyChanged"/>
         /// event and notifies inheritance children if necessary .
         /// </summary>
-        /// <typeparam name="T">The property type.</typeparam>
         /// <param name="property">The property.</param>
         /// <param name="value">The property value.</param>
         /// <param name="priority">The value priority.</param>

src/Avalonia.Base/Reactive/BindingValueAdapter.cs

@@ -1,59 +0,0 @@
-using System;
-using System.Reactive.Subjects;
-using Avalonia.Data;
-
-namespace Avalonia.Reactive
-{
-    internal class BindingValueAdapter<T> : SingleSubscriberObservableBase<BindingValue<T>>,
-        IObserver<T>
-    {
-        private readonly IObservable<T> _source;
-        private IDisposable? _subscription;
-
-        public BindingValueAdapter(IObservable<T> source) => _source = source;
-        public void OnCompleted() => PublishCompleted();
-        public void OnError(Exception error) => PublishError(error);
-        public void OnNext(T value) => PublishNext(BindingValue<T>.FromUntyped(value));
-        protected override void Subscribed() => _subscription = _source.Subscribe(this);
-        protected override void Unsubscribed() => _subscription?.Dispose();
-    }
-
-    internal class BindingValueSubjectAdapter<T> : SingleSubscriberObservableBase<BindingValue<T>>,
-        ISubject<BindingValue<T>>
-    {
-        private readonly ISubject<T> _source;
-        private readonly Inner _inner;
-        private IDisposable? _subscription;
-
-        public BindingValueSubjectAdapter(ISubject<T> source)
-        {
-            _source = source;
-            _inner = new Inner(this);
-        }
-
-        public void OnCompleted() => _source.OnCompleted();
-        public void OnError(Exception error) => _source.OnError(error);
-        
-        public void OnNext(BindingValue<T> value)
-        {
-            if (value.HasValue)
-            {
-                _source.OnNext(value.Value);
-            }
-        }
-
-        protected override void Subscribed() => _subscription = _source.Subscribe(_inner);
-        protected override void Unsubscribed() => _subscription?.Dispose();
-
-        private class Inner : IObserver<T>
-        {
-            private readonly BindingValueSubjectAdapter<T> _owner;
-
-            public Inner(BindingValueSubjectAdapter<T> owner) => _owner = owner;
-
-            public void OnCompleted() => _owner.PublishCompleted();
-            public void OnError(Exception error) => _owner.PublishError(error);
-            public void OnNext(T value) => _owner.PublishNext(BindingValue<T>.FromUntyped(value));
-        }
-    }
-}

src/Avalonia.Base/Reactive/BindingValueExtensions.cs

@@ -1,33 +0,0 @@
-using System;
-using System.Reactive.Subjects;
-using Avalonia.Data;
-
-namespace Avalonia.Reactive
-{
-    public static class BindingValueExtensions
-    {
-        public static IObservable<BindingValue<T>> ToBindingValue<T>(this IObservable<T> source)
-        {
-            source = source ?? throw new ArgumentNullException(nameof(source));
-            return new BindingValueAdapter<T>(source);
-        }
-
-        public static ISubject<BindingValue<T>> ToBindingValue<T>(this ISubject<T> source)
-        {
-            source = source ?? throw new ArgumentNullException(nameof(source));
-            return new BindingValueSubjectAdapter<T>(source);
-        }
-
-        public static IObservable<object?> ToUntyped<T>(this IObservable<BindingValue<T>> source)
-        {
-            source = source ?? throw new ArgumentNullException(nameof(source));
-            return new UntypedBindingAdapter<T>(source);
-        }
-
-        public static ISubject<object?> ToUntyped<T>(this ISubject<BindingValue<T>> source)
-        {
-            source = source ?? throw new ArgumentNullException(nameof(source));
-            return new UntypedBindingSubjectAdapter<T>(source);
-        }
-    }
-}

src/Avalonia.Base/Reactive/TypedBindingAdapter.cs

@@ -1,62 +0,0 @@
-using System;
-using Avalonia.Data;
-using Avalonia.Logging;
-
-namespace Avalonia.Reactive
-{
-    internal class TypedBindingAdapter<T> : SingleSubscriberObservableBase<BindingValue<T>>,
-        IObserver<BindingValue<object?>>
-    {
-        private readonly IAvaloniaObject _target;
-        private readonly AvaloniaProperty<T> _property;
-        private readonly IObservable<BindingValue<object?>> _source;
-        private IDisposable? _subscription;
-
-        public TypedBindingAdapter(
-            IAvaloniaObject target,
-            AvaloniaProperty<T> property,
-            IObservable<BindingValue<object?>> source)
-        {
-            _target = target;
-            _property = property;
-            _source = source;
-        }
-
-        public void OnNext(BindingValue<object?> value)
-        {
-            try
-            {
-                PublishNext(value.Convert<T>());
-            }
-            catch (InvalidCastException e)
-            {
-                var unwrappedValue = value.HasValue ? value.Value : null;
-                
-                Logger.TryGet(LogEventLevel.Error, LogArea.Binding)?.Log(
-                    _target,
-                    "Binding produced invalid value for {$Property} ({$PropertyType}): {$Value} ({$ValueType})",
-                    _property.Name,
-                    _property.PropertyType,
-                    unwrappedValue,
-                    unwrappedValue?.GetType());
-                PublishNext(BindingValue<T>.BindingError(e));
-            }
-        }
-
-        public void OnCompleted() => PublishCompleted();
-        public void OnError(Exception error) => PublishError(error);
-
-        public static IObservable<BindingValue<T>> Create(
-            IAvaloniaObject target,
-            AvaloniaProperty<T> property,
-            IObservable<BindingValue<object?>> source)
-        {
-            return source is IObservable<BindingValue<T>> result ?
-                result :
-                new TypedBindingAdapter<T>(target, property, source);
-        }
-
-        protected override void Subscribed() => _subscription = _source.Subscribe(this);
-        protected override void Unsubscribed() => _subscription?.Dispose();
-    }
-}

src/Avalonia.Base/Reactive/UntypedBindingAdapter.cs

@@ -1,55 +0,0 @@
-using System;
-using System.Reactive.Subjects;
-using Avalonia.Data;
-
-namespace Avalonia.Reactive
-{
-    internal class UntypedBindingAdapter<T> : SingleSubscriberObservableBase<object?>,
-        IObserver<BindingValue<T>>
-    {
-        private readonly IObservable<BindingValue<T>> _source;
-        private IDisposable? _subscription;
-
-        public UntypedBindingAdapter(IObservable<BindingValue<T>> source) => _source = source;
-        public void OnCompleted() => PublishCompleted();
-        public void OnError(Exception error) => PublishError(error);
-        public void OnNext(BindingValue<T> value) => value.ToUntyped();
-        protected override void Subscribed() => _subscription = _source.Subscribe(this);
-        protected override void Unsubscribed() => _subscription?.Dispose();
-    }
-
-    internal class UntypedBindingSubjectAdapter<T> : SingleSubscriberObservableBase<object?>,
-        ISubject<object?>
-    {
-        private readonly ISubject<BindingValue<T>> _source;
-        private readonly Inner _inner;
-        private IDisposable? _subscription;
-
-        public UntypedBindingSubjectAdapter(ISubject<BindingValue<T>> source)
-        {
-            _source = source;
-            _inner = new Inner(this);
-        }
-
-        public void OnCompleted() => _source.OnCompleted();
-        public void OnError(Exception error) => _source.OnError(error);
-        public void OnNext(object? value)
-        {
-            _source.OnNext(BindingValue<T>.FromUntyped(value));
-        }
-
-        protected override void Subscribed() => _subscription = _source.Subscribe(_inner);
-        protected override void Unsubscribed() => _subscription?.Dispose();
-
-        private class Inner : IObserver<BindingValue<T>>
-        {
-            private readonly UntypedBindingSubjectAdapter<T> _owner;
-
-            public Inner(UntypedBindingSubjectAdapter<T> owner) => _owner = owner;
-
-            public void OnCompleted() => _owner.PublishCompleted();
-            public void OnError(Exception error) => _owner.PublishError(error);
-            public void OnNext(BindingValue<T> value) => _owner.PublishNext(value.ToUntyped());
-        }
-    }
-}

src/Avalonia.Base/StyledPropertyBase.cs

@@ -239,16 +239,6 @@ namespace Avalonia
             return target.Bind<TValue>(this, source, priority);
         }
 
-        /// <inheritdoc/>
-        internal override IDisposable RouteBind(
-            AvaloniaObject o,
-            IObservable<BindingValue<object?>> source,
-            BindingPriority priority)
-        {
-            var adapter = TypedBindingAdapter<TValue>.Create(o, this, source);
-            return o.Bind<TValue>(this, adapter, priority);
-        }
-
         private object? GetDefaultBoxedValue(Type type)
         {
             _ = type ?? throw new ArgumentNullException(nameof(type));

tests/Avalonia.Base.UnitTests/AvaloniaPropertyTests.cs

@@ -156,14 +156,6 @@ namespace Avalonia.Base.UnitTests
                 throw new NotImplementedException();
             }
 
-            internal override IDisposable RouteBind(
-                AvaloniaObject o,
-                IObservable<BindingValue<object>> source,
-                BindingPriority priority)
-            {
-                throw new NotImplementedException();
-            }
-
             internal override void RouteClearValue(AvaloniaObject o)
             {
                 throw new NotImplementedException();