Fix exceptions with live update of multiple FormGroups

Buform/Buform.csproj

@@ -32,7 +32,7 @@
     </ItemGroup>
 
     <ItemGroup Condition="'$(TargetFramework)' == 'net8.0-ios'">
-        <PackageReference Include="Fedandburk.iOS.Extensions" Version="1.0.8" />
+        <PackageReference Include="Fedandburk.iOS.Extensions" Version="1.0.9" />
     </ItemGroup>
 
     <ItemGroup Condition="'$(TargetFramework)' == 'net8.0-android'">

Buform/FormGroup.cs

@@ -100,6 +100,11 @@ protected virtual void ShiftHiddenItems(int index, int shift)
         }
     }
 
+    protected void AddItem(TFormItem item)
+    {
+        InsertItem(Count, item);
+    }
+
     protected override void InsertItem(int index, TFormItem item)
     {
         ShiftHiddenItems(index, 1);

Buform/Groups/List/ListFormGroup.cs

@@ -83,9 +83,43 @@ public ListFormGroup(
 
     protected virtual void OnCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
     {
-        Reset();
+        switch (e.Action)
+        {
+            case NotifyCollectionChangedAction.Remove:
+            {
+                for (var i = 0; i < e.OldItems!.Count; i++)
+                {
+                    RemoveItem(e.OldStartingIndex);
+                }
+
+                break;
+            }
+            case NotifyCollectionChangedAction.Add:
+            {
+                var items = e.NewItems!.Cast<TValue>()
+                    .Select((item, index) => (_itemFactory!(item), e.NewStartingIndex + index))
+                    .ToList();
+
+                foreach (var (item, index) in items)
+                {
+                    InsertItem(index, item);
+                }
+
+                break;
+            }
+            case NotifyCollectionChangedAction.Reset:
+            {
+                Reset();
 
-        NotifyPropertyChanged(nameof(Source));
+                break;
+            }
+            case NotifyCollectionChangedAction.Move:
+            {
+                MoveItem(e.OldStartingIndex, e.NewStartingIndex);
+
+                break;
+            }
+        }
     }
 
     protected virtual void Reset()
@@ -106,7 +140,7 @@ protected virtual void Reset()
         {
             var item = _itemFactory(value);
 
-            Add(item);
+            AddItem(item);
         }
     }