Extra binding stuff

src/Avalonia.Markup.Declarative/ControlPropertyExtensions.cs

@@ -48,16 +48,48 @@ public static class ControlPropertyExtensions
 
         return control;
     }
+
     public static TControl _setCommonEx<TControl>(this TControl control, string sourcePropertyPathString, Action setAction,
                         BindingMode? bindingMode, IValueConverter converter, object bindingSource)
         where TControl : AvaloniaObject
     {
         setAction();
-        if (control is IDeclarativeViewBase viewBase) 
+        if (control is IDeclarativeViewBase viewBase)
             viewBase.UpdateState();
         return control;
     }
 
+    /// <summary>
+    /// Userd by autogenerated extensions from source generator for binding Common properties to ViewBase components
+    /// </summary>
+    /// <typeparam name="TControl"></typeparam>
+    /// <typeparam name="TValue"></typeparam>
+    /// <param name="control"></param>
+    /// <param name="setAction"></param>
+    /// <param name="binding"></param>
+    /// <returns></returns>
+    public static TControl _setCommonBindingEx<TControl, TValue>(this TControl control, Action<TValue> setAction, IBinding ibinding)
+        where TControl : AvaloniaObject
+    {
+        if (ibinding is ViewBase.BindingEx bindingEx)
+        {
+            TValue val = (TValue)bindingEx.Value;
+            setAction(val);
+
+            if (control is ViewBase targetView)
+            {
+                targetView.UpdateState();
+
+                if (bindingEx.Source is ViewBase sourceView)
+                {
+                    targetView.AddExternalState(sourceView, bindingEx.Path);
+                }
+            }
+        }
+
+        return control;
+    }
+
     public static TElement DataContext<TElement>(
         this TElement control,
         object value,

src/Avalonia.Markup.Declarative/ViewBase.cs

@@ -201,15 +201,23 @@ public abstract class ViewBase : Decorator, IReloadable, INotifyPropertyChanged,
     }
 
 
+
+    #region Property States
+
+
     ViewPropertyState[]? _propertyStates = null;
+    List<ViewPropertyState> _externalPropertyStates = null;
     private void InitStateMembers()
     {
         var viewType = GetType();
-        _propertyStates = viewType
+        var viewPropertyStates = viewType
             .GetProperties()
             .Where(p => p.DeclaringType == viewType)
-            .Select(p => new ViewPropertyState(p, this))
-            .ToArray();
+            .Select(p => new ViewPropertyState(p, this));
+        
+        _propertyStates = _externalPropertyStates == null 
+            ? viewPropertyStates.ToArray() 
+            : viewPropertyStates.Concat(_externalPropertyStates).ToArray();
     }
     public void UpdateState()
     {
@@ -226,6 +234,16 @@ public abstract class ViewBase : Decorator, IReloadable, INotifyPropertyChanged,
                 OnPropertyChanged(prop.Name);
     }
 
+    public void AddExternalState<TContorl>(TContorl source, string propertyName) 
+        where TContorl : ViewBase
+    {
+        _externalPropertyStates ??= new List<ViewPropertyState>();
+
+        var propInfo = source.GetType().GetProperty(propertyName);
+
+        _externalPropertyStates.Add(new ViewPropertyState(propInfo, source));
+    }
+
     protected IBinding Bind(object value, BindingMode bindingMode = BindingMode.Default, [CallerArgumentExpression("value")] string bindingString = null)
     {
         object bindingSource = this;
@@ -251,14 +269,20 @@ public abstract class ViewBase : Decorator, IReloadable, INotifyPropertyChanged,
         if(useStateValueAsSource)
             bindingSource = stateInfo.Value;
 
-        return new Binding()
+        return new BindingEx()
         {
             Source = bindingSource,
             Path = propName,
             Mode = bindingMode,
+            Value = value
         };
     }
 
+    public class BindingEx : Binding 
+    {
+        public object Value { get; set; }
+    }
+
     private ViewPropertyState FindStateForBindingString(string stateName) =>
         _propertyStates?.FirstOrDefault(x => x.Name == stateName);
 
@@ -267,6 +291,7 @@ public abstract class ViewBase : Decorator, IReloadable, INotifyPropertyChanged,
     {
         PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
     }
+    #endregion
 
     #region Hot reload stuff
 

src/AvaloniaMurkup.Declarative.SourceGenerator/AvaloniaPropertyExtensionsGenerator.cs

@@ -78,12 +78,13 @@ public class AvaloniaPropertyExtensionsGenerator : ISourceGenerator
                     && HasPublicSetter(property) 
                     && IsCommonProperty(property, members))
                 {
-                    var extensionString = GetCommonPropertySetterExtension(typeName, property);
-                    if (!string.IsNullOrWhiteSpace(extensionString))
-                    {
-                        //extensions.Add(extensionString);
-                        sb.AppendLine(extensionString);
-                    }
+                    var valueSetterExtensionString = GetCommonPropertySetterExtension(typeName, property);
+                    if (!string.IsNullOrWhiteSpace(valueSetterExtensionString))
+                        sb.AppendLine(valueSetterExtensionString);
+
+                    var bindingSetterExtensionString = GetCommonPropertyBindingSetterExtension(typeName, property);
+                    if (!string.IsNullOrWhiteSpace(bindingSetterExtensionString))
+                        sb.AppendLine(bindingSetterExtensionString);
                 }
 
                 //PROCESS AVALONIA PROPERTIES
@@ -213,16 +214,12 @@ public class AvaloniaPropertyExtensionsGenerator : ISourceGenerator
     private string GetCommonPropertyBindingSetterExtension(string controlTypeName, PropertyDeclarationSyntax property)
     {
         var extensionName = property.Identifier.ToString();
-
         var valueTypeSource = property.Type.ToString();
 
-        var argsString = $"{valueTypeSource} value, BindingMode? bindingMode = null, IValueConverter converter = null, object bindingSource = null,"
-                         + $" [CallerArgumentExpression(\"value\")] string ps = null";
-
         var extensionText =
             $"public static {controlTypeName} {extensionName}"
-            + $"(this {controlTypeName} control, {argsString})"
-            + $"=> control._setCommonEx(ps, () => control.{extensionName} = value, bindingMode, converter, bindingSource);";
+            + $"(this {controlTypeName} control, IBinding binding)"
+            + $"=> control._setCommonBindingEx(({valueTypeSource} value) => control.{extensionName} = value, binding);";
 
         return extensionText;
     }

src/Samples/AvaloniaMarkupSample/MvuSample/MvuSampleView.cs

@@ -1,4 +1,6 @@
-namespace AvaloniaMarkupSample.MvuSample;
+using Avalonia.Markup.Declarative;
+
+namespace AvaloniaMarkupSample.MvuSample;
 
 public class MvuSampleView : ViewBase
 {
@@ -23,9 +25,10 @@ public class MvuSampleView : ViewBase
                     .Background(Colors.Aquamarine.ToBrush())
                     .Child(
                         new MvuComponent()
+                            .Ref(out _nestedComponent)
                             .ComponentParameter(Bind(MvuComponentParam))
                     ),
-                
+
                 new Button()
                     .Content("Change nested component parameter")
                     .OnClick(OnButton3Click)
@@ -33,6 +36,8 @@ public class MvuSampleView : ViewBase
             );
 
     private string _myNotifiedProperty1 = "Click me";
+    private MvuComponent _nestedComponent;
+
     public string MyNotifiedProperty
     {
         get => _myNotifiedProperty1;
@@ -66,8 +71,7 @@ public class MvuSampleView : ViewBase
 
     private void OnButton3Click(RoutedEventArgs obj)
     {
-        throw new NotImplementedException();
+        MvuComponentParam = "I changed from external view!";
+        _nestedComponent.UpdateState();
     }
-
-
 }