support Range for ToNotifyCollectionChanged #67

README.md

@@ -355,6 +355,10 @@ public class WpfDispatcherCollection(Dispatcher dispatcher) : ICollectionEventDi
 }
 ```
 
+`ToNotifyCollectionChanged()` can also be called without going through a View. In this case, it's guaranteed that no filters will be applied, making it faster. If you want to apply filters, please generate a View before calling it. Additionally, `ObservableList` has a variation called `ToNotifyCollectionChangedSlim()`. This option doesn't generate a list for the View and shares the actual data, making it the fastest and most memory-efficient option. However, range operations such as `AddRange`, `InsertRange` and `RemoveRange` are not supported by WPF (or Avalonia), so they will throw runtime exceptions.
+
+Views and ToNotifyCollectionChanged are internally connected by events, so they need to be `Dispose` to release those connections.
+
 Unity
 ---
 In Unity projects, you can installing `ObservableCollections` with [NugetForUnity](https://github.com/GlitchEnzo/NuGetForUnity). If R3 integration is required, similarly install `ObservableCollections.R3` via NuGetForUnity.

sandbox/AvaloniaApp/MainWindow.axaml

@@ -8,6 +8,13 @@
 	<StackPanel>
 		<ListBox ItemsSource="{Binding ItemsView}" x:CompileBindings="False" />
 		<Button Content="Add" Command="{Binding AddCommand}"  x:CompileBindings="False"/>
+		<Button Content="AddRange" Command="{Binding AddRangeCommand}"  x:CompileBindings="False"/>
+		<Button Content="Insert" Command="{Binding InsertAtRandomCommand}" x:CompileBindings="False" />
+		<Button Content="Remove" Command="{Binding RemoveAtRandomCommand}" x:CompileBindings="False" />
 		<Button Content="Clear" Command="{Binding ClearCommand}"  x:CompileBindings="False"/>
+		<Button Content="Reverse" Command="{Binding ReverseCommand}" x:CompileBindings="False" />
+		<Button Content="Sort" Command="{Binding SortCommand}"  x:CompileBindings="False"/>
+		<Button Content="AttachFilter" Command="{Binding AttachFilterCommand}" x:CompileBindings="False" />
+		<Button Content="ResetFilter" Command="{Binding ResetFilterCommand}" x:CompileBindings="False" />
 	</StackPanel>
 </Window>

sandbox/AvaloniaApp/MainWindow.axaml.cs

@@ -26,22 +26,27 @@ namespace AvaloniaApp
         private ObservableList<int> observableList { get; } = new ObservableList<int>();
         public INotifyCollectionChangedSynchronizedViewList<int> ItemsView { get; }
         public ReactiveCommand<Unit> AddCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> AddRangeCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> InsertAtRandomCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> RemoveAtRandomCommand { get; } = new ReactiveCommand<Unit>();
         public ReactiveCommand<Unit> ClearCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> ReverseCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> SortCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> AttachFilterCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> ResetFilterCommand { get; } = new ReactiveCommand<Unit>();
 
         public ViewModel()
         {
             observableList.Add(1);
             observableList.Add(2);
 
-            //ItemsView = observableList.CreateView(x => x).ToNotifyCollectionChanged(SynchronizationContextCollectionEventDispatcher.Current);
+            var view = observableList.CreateView(x => x);
+            ItemsView = view.ToNotifyCollectionChanged(SynchronizationContextCollectionEventDispatcher.Current);
 
-            ItemsView = observableList.CreateView(x => x).ToNotifyCollectionChanged();
 
-            //var test = ItemsView.ToArray();
+            // check for optimize list
-            //INotifyCollectionChangedSynchronizedView<int>
+            // ItemsView = observableList.ToNotifyCollectionChanged(SynchronizationContextCollectionEventDispatcher.Current);
-            // ItemsView = observableList.CreateView(x => x).ToNotifyCollectionChanged();
 
-            // BindingOperations.EnableCollectionSynchronization(ItemsView, new object());
 
             AddCommand.Subscribe(_ =>
             {
@@ -51,12 +56,49 @@ namespace AvaloniaApp
                 });
             });
 
-            // var iii = 10;
+            AddRangeCommand.Subscribe(_ =>
+            {
+                var xs = Enumerable.Range(1, 5).Select(_ => Random.Shared.Next()).ToArray();
+                observableList.AddRange(xs);
+            });
+
+            InsertAtRandomCommand.Subscribe(_ =>
+            {
+                var from = Random.Shared.Next(0, view.Count);
+                observableList.Insert(from, Random.Shared.Next());
+            });
+
+            RemoveAtRandomCommand.Subscribe(_ =>
+            {
+                var from = Random.Shared.Next(0, view.Count);
+                observableList.RemoveAt(from);
+            });
+
             ClearCommand.Subscribe(_ =>
             {
-                // observableList.Add(iii++);
                 observableList.Clear();
             });
+
+
+            ReverseCommand.Subscribe(_ =>
+            {
+                observableList.Reverse();
+            });
+
+            SortCommand.Subscribe(_ =>
+            {
+                observableList.Sort();
+            });
+
+            AttachFilterCommand.Subscribe(_ =>
+            {
+                view.AttachFilter(x => x % 2 == 0);
+            });
+
+            ResetFilterCommand.Subscribe(_ =>
+            {
+                view.ResetFilter();
+            });
         }
     }
 }

sandbox/WpfApp/MainWindow.xaml

@@ -20,8 +20,10 @@
     <StackPanel>
         <ListBox ItemsSource="{Binding ItemsView}" />
         <Button Content="Add" Command="{Binding AddCommand}" />
+        <Button Content="AddRange" Command="{Binding AddRangeCommand}" />
         <Button Content="Insert" Command="{Binding InsertAtRandomCommand}" />
         <Button Content="Remove" Command="{Binding RemoveAtRandomCommand}" />
+        <Button Content="RemoveRange" Command="{Binding RemoveRangeCommand}" />
         <Button Content="Clear" Command="{Binding ClearCommand}" />
         <Button Content="Reverse" Command="{Binding ReverseCommand}" />
         <Button Content="Sort" Command="{Binding SortCommand}" />

sandbox/WpfApp/MainWindow.xaml.cs

@@ -2,6 +2,7 @@
 using R3;
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using System.Diagnostics;
 using System.Linq;
@@ -76,8 +77,10 @@ namespace WpfApp
         private ObservableList<int> observableList { get; } = new ObservableList<int>();
         public INotifyCollectionChangedSynchronizedViewList<int> ItemsView { get; }
         public ReactiveCommand<Unit> AddCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> AddRangeCommand { get; } = new ReactiveCommand<Unit>();
         public ReactiveCommand<Unit> InsertAtRandomCommand { get; } = new ReactiveCommand<Unit>();
         public ReactiveCommand<Unit> RemoveAtRandomCommand { get; } = new ReactiveCommand<Unit>();
+        public ReactiveCommand<Unit> RemoveRangeCommand { get; } = new ReactiveCommand<Unit>();
         public ReactiveCommand<Unit> ClearCommand { get; } = new ReactiveCommand<Unit>();
         public ReactiveCommand<Unit> ReverseCommand { get; } = new ReactiveCommand<Unit>();
         public ReactiveCommand<Unit> SortCommand { get; } = new ReactiveCommand<Unit>();
@@ -90,8 +93,8 @@ namespace WpfApp
             observableList.Add(2);
 
             var view = observableList.CreateView(x => x);
-            ItemsView = view.ToNotifyCollectionChanged(SynchronizationContextCollectionEventDispatcher.Current);
+            //ItemsView = view.ToNotifyCollectionChanged();
-
+            ItemsView = observableList.ToNotifyCollectionChanged();
 
             // check for optimize list
             // ItemsView = observableList.ToNotifyCollectionChanged(SynchronizationContextCollectionEventDispatcher.Current);
@@ -99,10 +102,16 @@ namespace WpfApp
 
             AddCommand.Subscribe(_ =>
             {
-                ThreadPool.QueueUserWorkItem(_ =>
+                // ThreadPool.QueueUserWorkItem(_ =>
                 {
                     observableList.Add(Random.Shared.Next());
+                }
             });
+
+            AddRangeCommand.Subscribe(_ =>
+            {
+                var xs = Enumerable.Range(1, 5).Select(_ => Random.Shared.Next()).ToArray();
+                observableList.AddRange(xs);
             });
 
             InsertAtRandomCommand.Subscribe(_ =>
@@ -117,6 +126,11 @@ namespace WpfApp
                 observableList.RemoveAt(from);
             });
 
+            RemoveRangeCommand.Subscribe(_ =>
+            {
+                observableList.RemoveRange(2, 5);
+            });
+
             ClearCommand.Subscribe(_ =>
             {
                 observableList.Clear();

src/ObservableCollections/AlternateIndexList.cs

@@ -178,7 +178,7 @@ public class AlternateIndexList<T> : IEnumerable<T>
 
         object IEnumerator.Current => Current;
 
-        public void Dispose() => iter.Reset();
+        public void Dispose() => iter.Dispose();
 
         public bool MoveNext()
         {
@@ -191,7 +191,7 @@ public class AlternateIndexList<T> : IEnumerable<T>
             return false;
         }
 
-        public void Reset() => iter.Reset();
+        public void Reset() { }
 
         public IEnumerator<IndexedValue> GetEnumerator() => this;
 

src/ObservableCollections/ObservableList.OptimizeView.cs

@@ -21,12 +21,18 @@ public sealed partial class ObservableList<T> : IList<T>, IReadOnlyObservableLis
     //    return new NonFilteredSynchronizedViewList<T, TView>(collection.CreateView(transform));
     //}
 
-    public INotifyCollectionChangedSynchronizedViewList<T> ToNotifyCollectionChanged()
+    /// <summary>
+    /// Create faster, compact INotifyCollectionChanged view, however it does not support ***Range.
+    /// </summary>
+    public INotifyCollectionChangedSynchronizedViewList<T> ToNotifyCollectionChangedSlim()
     {
         return new ObservableListSynchronizedViewList<T>(this, null);
     }
 
-    public INotifyCollectionChangedSynchronizedViewList<T> ToNotifyCollectionChanged(ICollectionEventDispatcher? collectionEventDispatcher)
+    /// <summary>
+    /// Create faster, compact INotifyCollectionChanged view, however it does not support ***Range.
+    /// </summary>
+    public INotifyCollectionChangedSynchronizedViewList<T> ToNotifyCollectionChangedSlim(ICollectionEventDispatcher? collectionEventDispatcher)
     {
         return new ObservableListSynchronizedViewList<T>(this, collectionEventDispatcher);
     }

src/ObservableCollections/SynchronizedViewList.cs

@@ -5,6 +5,7 @@ using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Linq;
+using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
@@ -16,6 +17,8 @@ internal class FiltableSynchronizedViewList<T, TView> : ISynchronizedViewList<TV
     protected readonly AlternateIndexList<TView> listView;
     protected readonly object gate = new object();
 
+    protected virtual bool IsSupportRangeFeature => true;
+
     public FiltableSynchronizedViewList(ISynchronizedView<T, TView> parent)
     {
         this.parent = parent;
@@ -66,10 +69,23 @@ internal class FiltableSynchronizedViewList<T, TView> : ISynchronizedViewList<TV
                         return;
                     }
                     else
+                    {
+                        if (IsSupportRangeFeature)
                         {
                             using var array = new CloneCollection<TView>(e.NewViews);
                             var index = listView.InsertRange(e.NewStartingIndex, array.AsEnumerable());
                             OnCollectionChanged(e.WithNewStartingIndex(index));
+                        }
+                        else
+                        {
+                            var span = e.NewViews;
+                            for (int i = 0; i < span.Length; i++)
+                            {
+                                var index = listView.Insert(e.NewStartingIndex + i, span[i]);
+                                var ev = new SynchronizedViewChangedEventArgs<T, TView>(e.Action, true, newItem: (e.NewValues[i], span[i]), newStartingIndex: index);
+                                OnCollectionChanged(ev);
+                            }
+                        }
                         return;
                     }
                 case NotifyCollectionChangedAction.Remove: // Remove
@@ -98,9 +114,23 @@ internal class FiltableSynchronizedViewList<T, TView> : ISynchronizedViewList<TV
                                 return;
                             }
                             else
+                            {
+                                if (IsSupportRangeFeature)
                                 {
                                     index = listView.RemoveRange(e.OldStartingIndex, e.OldViews.Length);
                                 }
+                                else
+                                {
+                                    var span = e.OldViews;
+                                    for (int i = 0; i < span.Length; i++)
+                                    {
+                                        index = listView.RemoveAt(e.OldStartingIndex); // when removed, next remove index is same.
+                                        var ev = new SynchronizedViewChangedEventArgs<T, TView>(e.Action, true, oldItem: (e.OldValues[i], span[i]), oldStartingIndex: index);
+                                        OnCollectionChanged(ev);
+                                    }
+                                    return;
+                                }
+                            }
                         }
                         OnCollectionChanged(e.WithOldStartingIndex(index));
                         return;
@@ -192,7 +222,7 @@ internal class FiltableSynchronizedViewList<T, TView> : ISynchronizedViewList<TV
 
     IEnumerator IEnumerable.GetEnumerator()
     {
-        return listView.GetEnumerator();
+        return GetEnumerator();
     }
 
     public void Dispose()
@@ -207,6 +237,8 @@ internal class NonFilteredSynchronizedViewList<T, TView> : ISynchronizedViewList
     protected readonly List<TView> listView; // no filter can be faster
     protected readonly object gate = new object();
     
+    protected virtual bool IsSupportRangeFeature => true;
+
     public NonFilteredSynchronizedViewList(ISynchronizedView<T, TView> parent)
     {
         this.parent = parent;
@@ -231,6 +263,8 @@ internal class NonFilteredSynchronizedViewList<T, TView> : ISynchronizedViewList
                     }
                     else
                     {
+                        if (IsSupportRangeFeature)
+                        {
 #if NET8_0_OR_GREATER
                             listView.InsertRange(e.NewStartingIndex, e.NewViews);
 #else
@@ -238,6 +272,19 @@ internal class NonFilteredSynchronizedViewList<T, TView> : ISynchronizedViewList
                             listView.InsertRange(e.NewStartingIndex, array.AsEnumerable());
 #endif
                         }
+                        else
+                        {
+                            var span = e.NewViews;
+                            for (int i = 0; i < span.Length; i++)
+                            {
+                                var index = e.NewStartingIndex + i;
+                                listView.Insert(index, span[i]);
+                                var ev = new SynchronizedViewChangedEventArgs<T, TView>(e.Action, true, newItem: (e.NewValues[i], span[i]), newStartingIndex: index);
+                                OnCollectionChanged(ev);
+                            }
+                            return;
+                        }
+                    }
                     break;
                 case NotifyCollectionChangedAction.Remove: // Remove
                     {
@@ -268,9 +315,23 @@ internal class NonFilteredSynchronizedViewList<T, TView> : ISynchronizedViewList
                                 return;
                             }
                             else
+                            {
+                                if (IsSupportRangeFeature)
                                 {
                                     listView.RemoveRange(e.OldStartingIndex, e.OldViews.Length);
                                 }
+                                else
+                                {
+                                    var span = e.OldViews;
+                                    for (int i = 0; i < span.Length; i++)
+                                    {
+                                        listView.RemoveAt(e.OldStartingIndex); // when removed, next remove index is same.
+                                        var ev = new SynchronizedViewChangedEventArgs<T, TView>(e.Action, true, oldItem: (e.OldValues[i], span[i]), oldStartingIndex: e.OldStartingIndex);
+                                        OnCollectionChanged(ev);
+                                    }
+                                    return;
+                                }
+                            }
                         }
                         break;
                     }
@@ -320,9 +381,6 @@ internal class NonFilteredSynchronizedViewList<T, TView> : ISynchronizedViewList
                     }
                     else
                     {
-
-
-
 #if NET6_0_OR_GREATER
 #pragma warning disable CS0436
                         if (parent is ObservableList<T>.View<TView> observableListView && typeof(T) == typeof(TView))
@@ -408,7 +466,7 @@ internal class NonFilteredSynchronizedViewList<T, TView> : ISynchronizedViewList
 
     IEnumerator IEnumerable.GetEnumerator()
     {
-        return listView.GetEnumerator();
+        return GetEnumerator();
     }
 
     public void Dispose()
@@ -428,6 +486,8 @@ internal class NotifyCollectionChangedSynchronizedViewList<T, TView> :
 
     readonly ICollectionEventDispatcher eventDispatcher;
 
+    protected override bool IsSupportRangeFeature => false; // WPF, Avalonia etc does not support range notification
+
     public event NotifyCollectionChangedEventHandler? CollectionChanged;
     public event PropertyChangedEventHandler? PropertyChanged;
 
@@ -676,6 +736,8 @@ internal class NonFilteredNotifyCollectionChangedSynchronizedViewList<T, TView>
     public event NotifyCollectionChangedEventHandler? CollectionChanged;
     public event PropertyChangedEventHandler? PropertyChanged;
 
+    protected override bool IsSupportRangeFeature => false; // WPF, Avalonia etc does not support range notification
+
     public NonFilteredNotifyCollectionChangedSynchronizedViewList(ISynchronizedView<T, TView> parent, ICollectionEventDispatcher? eventDispatcher)
         : base(parent)
     {