Merge branch 'master' into fixes/5136

Documentation/build.md

@@ -6,6 +6,7 @@ Avalonia requires at least Visual Studio 2019 and .NET Core SDK 3.1 to build on
 
 ```
 git clone https://github.com/AvaloniaUI/Avalonia.git
+cd Avalonia
 git submodule update --init
 ```
 

src/Avalonia.Controls/ItemsSourceView.cs

@@ -32,8 +32,8 @@ namespace Avalonia.Controls
         /// </summary>
         public static ItemsSourceView Empty { get; } = new ItemsSourceView(Array.Empty<object>());
 
-        private protected readonly IList _inner;
-        private INotifyCollectionChanged? _notifyCollectionChanged;
+        private IList? _inner;
+        private NotifyCollectionChangedEventHandler? _collectionChanged;
 
         /// <summary>
         /// Initializes a new instance of the ItemsSourceView class for the specified data source.
@@ -42,27 +42,22 @@ namespace Avalonia.Controls
         public ItemsSourceView(IEnumerable source)
         {
             source = source ?? throw new ArgumentNullException(nameof(source));
-
-            if (source is IList list)
-            {
-                _inner = list;
-            }
-            else if (source is IEnumerable<object> objectEnumerable)
+            _inner = source switch
             {
-                _inner = new List<object>(objectEnumerable);
-            }
-            else
-            {
-                _inner = new List<object>(source.Cast<object>());
-            }
-
-            ListenToCollectionChanges();
+                ItemsSourceView _ => throw new ArgumentException("Cannot wrap an existing ItemsSourceView.", nameof(source)),
+                IList list => list,
+                INotifyCollectionChanged _ => throw new ArgumentException(
+                    "Collection implements INotifyCollectionChanged by not IList.",
+                    nameof(source)),
+                IEnumerable<object> iObj => new List<object>(iObj),
+                _ => new List<object>(source.Cast<object>())
+            };
         }
 
         /// <summary>
         /// Gets the number of items in the collection.
         /// </summary>
-        public int Count => _inner.Count;
+        public int Count => Inner.Count;
 
         /// <summary>
         /// Gets a value that indicates whether the items source can provide a unique key for each item.
@@ -72,6 +67,19 @@ namespace Avalonia.Controls
         /// </remarks>
         public bool HasKeyIndexMapping => false;
 
+        /// <summary>
+        /// Gets the inner collection.
+        /// </summary>
+        public IList Inner
+        {
+            get
+            {
+                if (_inner is null)
+                    ThrowDisposed();
+                return _inner!;
+            }
+        }
+
         /// <summary>
         /// Retrieves the item at the specified index.
         /// </summary>
@@ -82,15 +90,38 @@ namespace Avalonia.Controls
         /// <summary>
         /// Occurs when the collection has changed to indicate the reason for the change and which items changed.
         /// </summary>
-        public event NotifyCollectionChangedEventHandler? CollectionChanged;
+        public event NotifyCollectionChangedEventHandler? CollectionChanged
+        {
+            add
+            {
+                if (_collectionChanged is null && Inner is INotifyCollectionChanged incc)
+                {
+                    incc.CollectionChanged += OnCollectionChanged;
+                }
+
+                _collectionChanged += value;
+            }
+
+            remove
+            {
+                _collectionChanged -= value;
+
+                if (_collectionChanged is null && Inner is INotifyCollectionChanged incc)
+                {
+                    incc.CollectionChanged -= OnCollectionChanged;
+                }
+            }
+        }
 
         /// <inheritdoc/>
         public void Dispose()
         {
-            if (_notifyCollectionChanged != null)
+            if (_inner is INotifyCollectionChanged incc)
             {
-                _notifyCollectionChanged.CollectionChanged -= OnCollectionChanged;
+                incc.CollectionChanged -= OnCollectionChanged;
             }
+
+            _inner = null;
         }
 
         /// <summary>
@@ -98,9 +129,9 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="index">The index.</param>
         /// <returns>The item.</returns>
-        public object? GetAt(int index) => _inner[index];
+        public object? GetAt(int index) => Inner[index];
 
-        public int IndexOf(object? item) => _inner.IndexOf(item);
+        public int IndexOf(object? item) => Inner.IndexOf(item);
 
         public static ItemsSourceView GetOrCreate(IEnumerable? items)
         {
@@ -146,7 +177,7 @@ namespace Avalonia.Controls
 
         internal void AddListener(ICollectionChangedListener listener)
         {
-            if (_inner is INotifyCollectionChanged incc)
+            if (Inner is INotifyCollectionChanged incc)
             {
                 CollectionChangedEventManager.Instance.AddListener(incc, listener);
             }
@@ -154,7 +185,7 @@ namespace Avalonia.Controls
 
         internal void RemoveListener(ICollectionChangedListener listener)
         {
-            if (_inner is INotifyCollectionChanged incc)
+            if (Inner is INotifyCollectionChanged incc)
             {
                 CollectionChangedEventManager.Instance.RemoveListener(incc, listener);
             }
@@ -162,22 +193,15 @@ namespace Avalonia.Controls
 
         protected void OnItemsSourceChanged(NotifyCollectionChangedEventArgs args)
         {
-            CollectionChanged?.Invoke(this, args);
-        }
-
-        private void ListenToCollectionChanges()
-        {
-            if (_inner is INotifyCollectionChanged incc)
-            {
-                incc.CollectionChanged += OnCollectionChanged;
-                _notifyCollectionChanged = incc;
-            }
+            _collectionChanged?.Invoke(this, args);
         }
 
         private void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
         {
             OnItemsSourceChanged(e);
         }
+
+        private void ThrowDisposed() => throw new ObjectDisposedException(nameof(ItemsSourceView));
     }
 
     public class ItemsSourceView<T> : ItemsSourceView, IReadOnlyList<T>
@@ -216,10 +240,10 @@ namespace Avalonia.Controls
         /// <param name="index">The index.</param>
         /// <returns>The item.</returns>
         [return: MaybeNull]
-        public new T GetAt(int index) => (T)_inner[index];
+        public new T GetAt(int index) => (T)Inner[index];
 
-        public IEnumerator<T> GetEnumerator() => _inner.Cast<T>().GetEnumerator();
-        IEnumerator IEnumerable.GetEnumerator() => _inner.GetEnumerator();
+        public IEnumerator<T> GetEnumerator() => Inner.Cast<T>().GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator() => Inner.GetEnumerator();
 
         public static new ItemsSourceView<T> GetOrCreate(IEnumerable? items)
         {

src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs

@@ -275,7 +275,7 @@ namespace Avalonia.Controls.Platform
                 return;
             }
 
-            if (item.HasSubMenu)
+            if (item.HasSubMenu && item.IsEffectivelyEnabled)
             {
                 Open(item, true);
             }

src/Avalonia.Diagnostics/Diagnostics/Views/MainWindow.xaml.cs

@@ -160,13 +160,19 @@ namespace Avalonia.Diagnostics.Views
                 return;
             }
 
+            var root = Root;
+            if (root is null)
+            {
+                return;
+            }
+
             switch (e.Modifiers)
             {
                 case RawInputModifiers.Control | RawInputModifiers.Shift:
                 {
                     IControl? control = null;
 
-                    foreach (var popupRoot in GetPopupRoots(Root))
+                    foreach (var popupRoot in GetPopupRoots(root))
                     {
                         control = GetHoveredControl(popupRoot);
 
@@ -176,7 +182,7 @@ namespace Avalonia.Diagnostics.Views
                         }
                     }
 
-                    control ??= GetHoveredControl(Root);
+                    control ??= GetHoveredControl(root);
 
                     if (control != null)
                     {
@@ -190,7 +196,7 @@ namespace Avalonia.Diagnostics.Views
                 {
                     vm.FreezePopups = !vm.FreezePopups;
 
-                    foreach (var popupRoot in GetPopupRoots(Root))
+                    foreach (var popupRoot in GetPopupRoots(root))
                     {
                         if (popupRoot.Parent is Popup popup)
                         {

src/Avalonia.Dialogs/AboutAvaloniaDialog.xaml.cs

@@ -30,13 +30,13 @@ namespace Avalonia.Dialogs
             }
             else
             {
-                using (Process process = Process.Start(new ProcessStartInfo
+                using Process process = Process.Start(new ProcessStartInfo
                 {
                     FileName = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? url : "open",
                     Arguments = RuntimeInformation.IsOSPlatform(OSPlatform.OSX) ? $"{url}" : "",
                     CreateNoWindow = true,
                     UseShellExecute = RuntimeInformation.IsOSPlatform(OSPlatform.Windows)
-                }));
+                });
             }
         }
 

src/Avalonia.Dialogs/ManagedFileChooser.cs

@@ -1,13 +1,11 @@
 using System;
 using System.Linq;
 using System.Threading.Tasks;
-using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.LogicalTree;
-using Avalonia.Markup.Xaml;
 
 namespace Avalonia.Dialogs
 {
@@ -35,7 +33,9 @@ namespace Avalonia.Dialogs
             if (_quickLinksRoot != null)
             {
                 var isQuickLink = _quickLinksRoot.IsLogicalAncestorOf(e.Source as Control);
+#pragma warning disable CS0618 // Type or member is obsolete
                 if (e.ClickCount == 2 || isQuickLink)
+#pragma warning restore CS0618 // Type or member is obsolete
                 {
                     if (model.ItemType == ManagedFileChooserItemType.File)
                     {

src/Avalonia.Dialogs/ManagedFileChooserSources.cs

@@ -67,7 +67,7 @@ namespace Avalonia.Dialogs
                        {
                            Directory.GetFiles(x.VolumePath);
                        }
-                       catch (Exception _)
+                       catch (Exception)
                        {
                            return null;
                        }

src/Avalonia.Input/Gestures.cs

@@ -81,17 +81,21 @@ namespace Avalonia.Input
                 var e = (PointerPressedEventArgs)ev;
                 var visual = (IVisual)ev.Source;
 
-                if (e.ClickCount <= 1)
+#pragma warning disable CS0618 // Type or member is obsolete
+                var clickCount = e.ClickCount;
+#pragma warning restore CS0618 // Type or member is obsolete
+                if (clickCount <= 1)
                 {
                     s_lastPress = new WeakReference<IInteractive>(ev.Source);
                 }
-                else if (s_lastPress != null && e.ClickCount == 2 && e.GetCurrentPoint(visual).Properties.IsLeftButtonPressed)
+                else if (s_lastPress != null && clickCount == 2 && e.GetCurrentPoint(visual).Properties.IsLeftButtonPressed)
                 {
                     if (s_lastPress.TryGetTarget(out var target) && target == e.Source)
                     {
                         e.Source.RaiseEvent(new TappedEventArgs(DoubleTappedEvent, e));
                     }
                 }
+
             }
         }
 

src/Avalonia.Input/MouseDevice.cs

@@ -75,7 +75,9 @@ namespace Avalonia.Input
                 throw new InvalidOperationException("Control is not attached to visual tree.");
             }
 
+#pragma warning disable CS0618 // Type or member is obsolete
             var rootPoint = relativeTo.VisualRoot.PointToClient(Position);
+#pragma warning restore CS0618 // Type or member is obsolete
             var transform = relativeTo.VisualRoot.TransformToVisual(relativeTo);
             return rootPoint * transform!.Value;
         }

src/Avalonia.Visuals/Media/FormattedText.cs

@@ -200,7 +200,7 @@ namespace Avalonia.Media
 
         private void Set<T>(ref T field, T value)
         {
-            if (field != null && field.Equals(value))
+            if (EqualityComparer<T>.Default.Equals(field, value))
             {
                 return;
             }

src/Avalonia.Visuals/Rendering/ImmediateRenderer.cs

@@ -289,11 +289,14 @@ namespace Avalonia.Rendering
 
                 using (context.PushPostTransform(m))
                 using (context.PushOpacity(opacity))
-                using (clipToBounds 
-                    ? visual is IVisualWithRoundRectClip roundClipVisual 
+                using (clipToBounds
+#pragma warning disable CS0618 // Type or member is obsolete
+                    ? visual is IVisualWithRoundRectClip roundClipVisual
                         ? context.PushClip(new RoundedRect(bounds, roundClipVisual.ClipToBoundsRadius))
                         : context.PushClip(bounds) 
                     : default(DrawingContext.PushedState))
+#pragma warning restore CS0618 // Type or member is obsolete
+
                 using (visual.Clip != null ? context.PushGeometryClip(visual.Clip) : default(DrawingContext.PushedState))
                 using (visual.OpacityMask != null ? context.PushOpacityMask(visual.OpacityMask, bounds) : default(DrawingContext.PushedState))
                 using (context.PushTransformContainer())

src/Avalonia.Visuals/Rendering/SceneGraph/CustomDrawOperation.cs

@@ -17,7 +17,12 @@ namespace Avalonia.Rendering.SceneGraph
 
         public override bool HitTest(Point p)
         {
-            return Custom.HitTest(p * Transform);
+            if (Transform.HasInverse)
+            {
+                return Custom.HitTest(p * Transform.Invert());
+            }
+
+            return false;
         }
 
         public override void Render(IDrawingContextImpl context)

src/Avalonia.Visuals/Rendering/SceneGraph/SceneBuilder.cs

@@ -164,10 +164,12 @@ namespace Avalonia.Rendering.SceneGraph
             var visual = node.Visual;
             var opacity = visual.Opacity;
             var clipToBounds = visual.ClipToBounds;
+#pragma warning disable CS0618 // Type or member is obsolete
             var clipToBoundsRadius = visual is IVisualWithRoundRectClip roundRectClip ?
                 roundRectClip.ClipToBoundsRadius :
                 default;
-            
+#pragma warning restore CS0618 // Type or member is obsolete
+
             var bounds = new Rect(visual.Bounds.Size);
             var contextImpl = (DeferredDrawingContextImpl)context.PlatformImpl;
 

src/Avalonia.Visuals/Vector.cs

@@ -175,7 +175,7 @@ namespace Avalonia
                    MathUtilities.AreClose(_y, other._y);
         }
 
-        public override bool Equals(object obj) => obj is Vector other && Equals(other);
+        public override bool Equals(object? obj) => obj is Vector other && Equals(other);
 
         public override int GetHashCode()
         {

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs

@@ -14,7 +14,6 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
 {
     class AvaloniaXamlIlCompiler : XamlILCompiler
     {
-        private readonly TransformerConfiguration _configuration;
         private readonly IXamlType _contextType;
         private readonly AvaloniaXamlIlDesignPropertiesTransformer _designTransformer;
         private readonly AvaloniaBindingExtensionTransformer _bindingTransformer;
@@ -22,8 +21,6 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
         private AvaloniaXamlIlCompiler(TransformerConfiguration configuration, XamlLanguageEmitMappings<IXamlILEmitter, XamlILNodeEmitResult> emitMappings)
             : base(configuration, emitMappings, true)
         {
-            _configuration = configuration;
-
             void InsertAfter<T>(params IXamlAstTransformer[] t) 
                 => Transformers.InsertRange(Transformers.FindIndex(x => x is T) + 1, t);
 

src/Markup/Avalonia.Markup/Markup/Parsers/PropertyPathGrammar.cs

@@ -184,6 +184,9 @@ namespace Avalonia.Markup.Parsers
             
         }
 
+        // Don't need to override GetHashCode as the ISyntax objects will not be stored in a hash; the 
+        // only reason they have overridden Equals methods is for unit testing.
+#pragma warning disable CS0659 // Type overrides Object.Equals(object o) but does not override Object.GetHashCode()
         public class PropertySyntax : ISyntax
         {
             public string Name { get; set; } = string.Empty;
@@ -205,7 +208,7 @@ namespace Avalonia.Markup.Parsers
                    && other.TypeName == TypeName
                    && other.TypeNamespace == TypeNamespace;
         }
-        
+
         public class ChildTraversalSyntax : ISyntax
         {
             public static ChildTraversalSyntax Instance { get;  } = new ChildTraversalSyntax();
@@ -231,5 +234,6 @@ namespace Avalonia.Markup.Parsers
                    && other.TypeName == TypeName
                    && other.TypeNamespace == TypeNamespace;
         }
+#pragma warning restore CS0659 // Type overrides Object.Equals(object o) but does not override Object.GetHashCode()
     }
 }

tests/Avalonia.Controls.UnitTests/ItemsSourceViewTests.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.Text;
+using Avalonia.Collections;
+using Avalonia.Diagnostics;
+using Xunit;
+
+namespace Avalonia.Controls.UnitTests
+{
+    public class ItemsSourceViewTests
+    {
+        [Fact]
+        public void Only_Subscribes_To_Source_CollectionChanged_When_CollectionChanged_Subscribed()
+        {
+            var source = new AvaloniaList<string>();
+            var target = new ItemsSourceView<string>(source);
+            var debug = (INotifyCollectionChangedDebug)source;
+
+            Assert.Null(debug.GetCollectionChangedSubscribers());
+
+            void Handler(object sender, NotifyCollectionChangedEventArgs e) { }
+            target.CollectionChanged += Handler;
+
+            Assert.NotNull(debug.GetCollectionChangedSubscribers());
+            Assert.Equal(1, debug.GetCollectionChangedSubscribers().Length);
+
+            target.CollectionChanged -= Handler;
+
+            Assert.Null(debug.GetCollectionChangedSubscribers());
+        }
+
+        [Fact]
+        public void Cannot_Wrap_An_ItemsSourceView_In_Another()
+        {
+            var source = new ItemsSourceView<string>(new string[0]);
+            Assert.Throws<ArgumentException>(() => new ItemsSourceView<string>(source));
+        }
+
+        [Fact]
+        public void Cannot_Create_ItemsSourceView_With_Collection_That_Implements_INCC_But_Not_List()
+        {
+            var source = new InvalidCollection();
+            Assert.Throws<ArgumentException>(() => new ItemsSourceView<string>(source));
+        }
+
+        private class InvalidCollection : INotifyCollectionChanged, IEnumerable<string>
+        {
+            public event NotifyCollectionChangedEventHandler CollectionChanged;
+
+            public IEnumerator<string> GetEnumerator()
+            {
+                yield break;
+            }
+
+            IEnumerator IEnumerable.GetEnumerator()
+            {
+                yield break;
+            }
+        }
+    }
+}