Add ShouldAddChildrenToParent to INonPhysicalChild

src/BlazorBindings.Core/INonPhysicalChild.cs

@@ -25,4 +25,11 @@ public interface INonPhysicalChild
     /// This is useful so that this component can unapply its effects from parent element.
     /// </summary>
     void RemoveFromParent(object parentElement);
+
+    /// <summary>
+    /// If this property is true, then renderer will pass children of this component to parent.
+    /// This is useful if you want to apply some effects to children (e.g. attached properties),
+    /// but still add them to parent element.
+    /// </summary>
+    internal bool ShouldAddChildrenToParent { get => false; }
 }

src/BlazorBindings.Core/NativeComponentAdapter.cs

@@ -104,8 +104,8 @@ internal void ApplyEdits(int componentId, ArrayBuilderSegment<RenderTreeEdit> ed
     private void ApplyRemoveFrame(int siblingIndex)
     {
         var childToRemove = Children[siblingIndex];
-        Children.RemoveAt(siblingIndex);
         RemoveChildElementAndDescendants(childToRemove);
+        Children.RemoveAt(siblingIndex);
     }
 
     private void RemoveChildElementAndDescendants(NativeComponentAdapter childToRemove)
@@ -116,6 +116,12 @@ private void RemoveChildElementAndDescendants(NativeComponentAdapter childToRemo
             // remove all descendants.
             var index = PhysicalTarget.GetChildPhysicalIndex(childToRemove);
             Renderer.ElementManager.RemoveChildElement(PhysicalTarget._targetElement, childToRemove._targetElement, index);
+
+            if (PhysicalTarget._targetElement is INonPhysicalChild { ShouldAddChildrenToParent: true })
+            {
+                // Since element was added to parent previosly, we have to remove it from there.
+                PhysicalTarget.Parent.PhysicalTarget.RemoveChildElementAndDescendants(childToRemove);
+            }
         }
         else
         {
@@ -202,6 +208,11 @@ private void AddElementAsChildElement(NativeComponentAdapter childAdapter)
     {
         var elementIndex = PhysicalTarget.GetChildPhysicalIndex(childAdapter);
         Renderer.ElementManager.AddChildElement(PhysicalTarget._targetElement, childAdapter._targetElement, elementIndex);
+
+        if (PhysicalTarget._targetElement is INonPhysicalChild { ShouldAddChildrenToParent: true })
+        {
+            PhysicalTarget.Parent.AddElementAsChildElement(childAdapter);
+        }
     }
 
     /// <summary>
@@ -235,12 +246,12 @@ static bool FindChildPhysicalIndexRecursive(NativeComponentAdapter parent, Nativ
                 if (child == targetChild)
                     return true;
 
-                if (child._targetElement != null)
+                if (child._targetElement != null && child._targetElement is not INonPhysicalChild)
                 {
-                    if (child._targetElement is not INonPhysicalChild)
-                        index++;
+                    index++;
                 }
-                else
+
+                if (child._targetElement == null || child._targetElement is INonPhysicalChild { ShouldAddChildrenToParent: true })
                 {
                     if (FindChildPhysicalIndexRecursive(child, targetChild, ref index))
                         return true;

src/BlazorBindings.Core/Properties/AttributeInfo.cs

@@ -3,4 +3,5 @@
 
 using System.Runtime.CompilerServices;
 
-[assembly: InternalsVisibleTo("BlazorBindings.UnitTests")]
+[assembly: InternalsVisibleTo("BlazorBindings.UnitTests")]
+[assembly: InternalsVisibleTo("BlazorBindings.Maui")]

src/BlazorBindings.Maui/Elements/GridCell.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 
+using BlazorBindings.Maui.Extensions;
 using MC = Microsoft.Maui.Controls;
 
 namespace BlazorBindings.Maui.Elements;
@@ -16,9 +17,6 @@ public class GridCell : NativeControlComponentBase, IContainerElementHandler, IN
 
 
     private readonly List<MC.View> _children = new();
-    private MC.Grid _parentGrid;
-
-    object IElementHandler.TargetElement => null;
 
     public override Task SetParametersAsync(ParameterView parameters)
     {
@@ -73,55 +71,24 @@ public override Task SetParametersAsync(ParameterView parameters)
 
     public void AddChild(object child, int physicalSiblingIndex)
     {
-        if (child is not MC.View childView)
-        {
-            throw new ArgumentException($"Expected parent to be of type {typeof(MC.View).FullName} but it is of type {child?.GetType().FullName}.", nameof(child));
-        }
+        var childView = child.Cast<MC.View>();
 
         MC.Grid.SetColumn(childView, Column ?? 0);
         MC.Grid.SetColumnSpan(childView, ColumnSpan ?? 1);
         MC.Grid.SetRow(childView, Row ?? 0);
         MC.Grid.SetRowSpan(childView, RowSpan ?? 1);
 
         _children.Add(childView);
-        _parentGrid.Children.Add(childView);
     }
 
     public void RemoveChild(object child, int physicalSiblingIndex)
     {
-        if (child is not MC.View childView)
-        {
-            throw new ArgumentException($"Expected parent to be of type {typeof(MC.View).FullName} but it is of type {child?.GetType().FullName}.", nameof(child));
-        }
-
+        var childView = child.Cast<MC.View>();
         _children.Remove(childView);
-        _parentGrid.Children.Remove(childView);
     }
 
-    public int GetChildIndex(object child)
-    {
-        return child is MC.View childView
-            ? _children.IndexOf(childView)
-            : -1;
-    }
-
-    void INonPhysicalChild.SetParent(object parentElement)
-    {
-        _parentGrid = parentElement as MC.Grid
-            ?? throw new ArgumentException($"Expected parent to be of type {typeof(MC.Grid).FullName} but it is of type {parentElement?.GetType().FullName}.", nameof(parentElement));
-    }
-
-    void INonPhysicalChild.RemoveFromParent(object parentElement)
-    {
-        if (_parentGrid != null)
-        {
-            foreach (var child in _children)
-            {
-                _parentGrid.Children.Remove(child);
-            }
-
-            _children.Clear();
-            _parentGrid = null;
-        }
-    }
+    object IElementHandler.TargetElement => null;
+    void INonPhysicalChild.SetParent(object parentElement) { }
+    void INonPhysicalChild.RemoveFromParent(object parentElement) { }
+    bool INonPhysicalChild.ShouldAddChildrenToParent => true;
 }

src/BlazorBindings.Maui/Elements/Handlers/ApplicationHandler.cs

@@ -18,11 +18,6 @@ public void AddChild(object child, int physicalSiblingIndex)
         _application.MainPage = child.Cast<MC.Page>();
     }
 
-    public int GetChildIndex(object child)
-    {
-        return Equals(_application.MainPage, child) ? 0 : -1;
-    }
-
     public void RemoveChild(object child, int physicalSiblingIndex)
     {
         // It is not allowed to have no MainPage.

src/BlazorBindings.Maui/Navigation/NavigationHandler.cs

@@ -83,7 +83,5 @@ public async void AddChild(object child, int physicalSiblingIndex)
         await AddChildAsync((MC.Page)child);
     }
 
-    public int GetChildIndex(object child) => -1;
-    public object ElementControl => null;
     public object TargetElement => null;
 }

src/BlazorBindings.UnitTests/Elements/GridTests.razor

@@ -134,8 +134,7 @@
     </Grid>
     );
 
-        // Order of children doesn't really matter for Grid.
-        var labels = grid.Children.Cast<MC.Label>().OrderBy(l => l.Text).ToArray();
+        var labels = grid.Children.Cast<MC.Label>().ToArray();
         var label00a = labels[0];
         var label00b = labels[1];
         var label01a = labels[2];
@@ -172,7 +171,7 @@
         insertItems = false;
         StateHasChanged();
 
-        labels = grid.Children.Cast<MC.Label>().OrderBy(l => l.Text).ToArray();
+        labels = grid.Children.Cast<MC.Label>().ToArray();
         label00b = labels[0];
         label01a = labels[1];
         label10a = labels[2];
@@ -193,7 +192,7 @@
         insertItems = true;
         StateHasChanged();
 
-        labels = grid.Children.Cast<MC.Label>().OrderBy(l => l.Text).ToArray();
+        labels = grid.Children.Cast<MC.Label>().ToArray();
         label00a = labels[0];
         label00b = labels[1];
         label01a = labels[2];