Merge branch 'master' into master

native/Avalonia.Native/src/OSX/AvnWindow.mm

@@ -33,6 +33,7 @@
     bool _isEnabled;
     bool _canBecomeKeyWindow;
     bool _isExtended;
+    bool _isTransitioningToFullScreen;
     AvnMenu* _menu;
 }
 
@@ -175,6 +176,7 @@
     [self setBackgroundColor: [NSColor clearColor]];
 
     _isExtended = false;
+    _isTransitioningToFullScreen = false;
 
     if(self.isDialog)
     {
@@ -282,6 +284,14 @@
 - (void)windowDidBecomeKey:(NSNotification *_Nonnull)notification
 {
     _parent->BringToFront();
+    
+    dispatch_async(dispatch_get_main_queue(), ^{
+        @try {
+        [self invalidateShadow];
+        }
+        @finally{
+        }
+    });
 }
 
 - (void)windowDidMiniaturize:(NSNotification *_Nonnull)notification
@@ -349,6 +359,7 @@
 
 - (void)windowWillEnterFullScreen:(NSNotification *_Nonnull)notification
 {
+    _isTransitioningToFullScreen = true;
     auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
 
     if(parent != nullptr)
@@ -359,6 +370,7 @@
 
 - (void)windowDidEnterFullScreen:(NSNotification *_Nonnull)notification
 {
+    _isTransitioningToFullScreen = false;
     auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
 
     if(parent != nullptr)
@@ -441,7 +453,10 @@
                     _parent->BaseEvents->RawMouseEvent(NonClientLeftButtonDown, static_cast<uint32>([event timestamp] * 1000), AvnInputModifiersNone, point, delta);
                 }
                 
-                _parent->BringToFront();
+                if(!_isTransitioningToFullScreen)
+                {
+                    _parent->BringToFront();
+                }
             }
             break;
 

native/Avalonia.Native/src/OSX/PopupImpl.mm

@@ -26,17 +26,13 @@ private:
     PopupImpl(IAvnWindowEvents* events, IAvnGlContext* gl) : WindowBaseImpl(events, gl)
     {
         WindowEvents = events;
+        [Window setLevel:NSPopUpMenuWindowLevel];
     }
 protected:
     virtual NSWindowStyleMask GetStyle() override
     {
         return NSWindowStyleMaskBorderless;
     }
-    
-    virtual void OnInitialiseNSWindow () override
-    {
-        [Window setLevel:NSPopUpMenuWindowLevel];
-    }
 
 public:
     virtual bool ShouldTakeFocusOnShow() override

native/Avalonia.Native/src/OSX/WindowBaseImpl.h

@@ -106,13 +106,10 @@ protected:
     virtual NSWindowStyleMask GetStyle();
 
     void UpdateStyle();
-                           
-    virtual void OnInitialiseNSWindow ();
 
 private:
     void CreateNSWindow (bool isDialog);
     void CleanNSWindow ();
-    void InitialiseNSWindow ();
 
     NSCursor *cursor;
     ComPtr<IAvnGlContext> _glContext;

native/Avalonia.Native/src/OSX/WindowBaseImpl.mm

@@ -39,7 +39,16 @@ WindowBaseImpl::WindowBaseImpl(IAvnWindowBaseEvents *events, IAvnGlContext *gl,
     lastMenu = nullptr;
     
     CreateNSWindow(usePanel);
-    InitialiseNSWindow();
+    
+    [Window setContentView:StandardContainer];
+    [Window setStyleMask:NSWindowStyleMaskBorderless];
+    [Window setBackingType:NSBackingStoreBuffered];
+
+    [Window setContentMinSize:lastMinSize];
+    [Window setContentMaxSize:lastMaxSize];
+
+    [Window setOpaque:false];
+    [Window setHasShadow:true];
 }
 
 HRESULT WindowBaseImpl::ObtainNSViewHandle(void **ret) {
@@ -90,8 +99,8 @@ HRESULT WindowBaseImpl::Show(bool activate, bool isDialog) {
     START_COM_CALL;
 
     @autoreleasepool {
-        InitialiseNSWindow();
-
+        [Window setContentSize:lastSize];
+        
         if(hasPosition)
         {
             SetPosition(lastPositionSet);
@@ -101,6 +110,8 @@ HRESULT WindowBaseImpl::Show(bool activate, bool isDialog) {
         }
 
         UpdateStyle();
+        
+        [Window invalidateShadow];
 
         if (ShouldTakeFocusOnShow() && activate) {
             [Window orderFront:Window];
@@ -292,8 +303,7 @@ HRESULT WindowBaseImpl::Resize(double x, double y, AvnPlatformResizeReason reaso
             if (!_shown) {
                 BaseEvents->Resized(AvnSize{x, y}, reason);
             }
-
-            if(Window != nullptr) {
+            else if(Window != nullptr) {
                 [Window setContentSize:lastSize];
                 [Window invalidateShadow];
             }
@@ -569,38 +579,6 @@ void WindowBaseImpl::CreateNSWindow(bool isDialog) {
     }
 }
 
-void WindowBaseImpl::OnInitialiseNSWindow()
-{
-    
-}
-
-void WindowBaseImpl::InitialiseNSWindow() {
-    if(Window != nullptr) {
-        [Window setContentView:StandardContainer];
-        [Window setStyleMask:NSWindowStyleMaskBorderless];
-        [Window setBackingType:NSBackingStoreBuffered];
-
-        [Window setContentSize:lastSize];
-        [Window setContentMinSize:lastMinSize];
-        [Window setContentMaxSize:lastMaxSize];
-
-        [Window setOpaque:false];
-        
-        [Window setHasShadow:true];
-        [Window invalidateShadow];
-
-        if (lastMenu != nullptr) {
-            [GetWindowProtocol() applyMenu:lastMenu];
-
-            if ([Window isKeyWindow]) {
-                [GetWindowProtocol() showWindowMenuWithAppMenu];
-            }
-        }
-        
-        OnInitialiseNSWindow();
-    }
-}
-
 id <AvnWindowProtocol> WindowBaseImpl::GetWindowProtocol() {
     if(Window == nullptr)
     {

native/Avalonia.Native/src/OSX/WindowImpl.h

@@ -93,8 +93,6 @@ BEGIN_INTERFACE_MAP()
 
     virtual bool IsDialog() override;
     
-    virtual void OnInitialiseNSWindow() override;
-    
     virtual void BringToFront () override;
     
     bool CanBecomeKeyWindow ();
@@ -103,6 +101,7 @@ protected:
     virtual NSWindowStyleMask GetStyle() override;
 
 private:
+    void OnInitialiseNSWindow();
     NSString *_lastTitle;
 };
 

native/Avalonia.Native/src/OSX/WindowImpl.mm

@@ -24,6 +24,8 @@ WindowImpl::WindowImpl(IAvnWindowEvents *events, IAvnGlContext *gl) : WindowBase
     _lastTitle = @"";
     _parent = nullptr;
     WindowEvents = events;
+    
+    OnInitialiseNSWindow();
 }
 
 void WindowImpl::HideOrShowTrafficLights() {
@@ -32,15 +34,16 @@ void WindowImpl::HideOrShowTrafficLights() {
     }
 
     bool wantsChrome = (_extendClientHints & AvnSystemChrome) || (_extendClientHints & AvnPreferSystemChrome);
-    bool hasTrafficLights = _isClientAreaExtended ? wantsChrome : _decorations != SystemDecorationsFull;
+    bool hasTrafficLights = _isClientAreaExtended ? wantsChrome : _decorations == SystemDecorationsFull;
     
-    [[Window standardWindowButton:NSWindowCloseButton] setHidden:hasTrafficLights];
-    [[Window standardWindowButton:NSWindowMiniaturizeButton] setHidden:hasTrafficLights];
-    [[Window standardWindowButton:NSWindowZoomButton] setHidden:hasTrafficLights];
+    [[Window standardWindowButton:NSWindowCloseButton] setHidden:!hasTrafficLights];
+    [[Window standardWindowButton:NSWindowMiniaturizeButton] setHidden:!hasTrafficLights];
+    [[Window standardWindowButton:NSWindowZoomButton] setHidden:!hasTrafficLights];
 }
 
 void WindowImpl::OnInitialiseNSWindow(){
     [GetWindowProtocol() setCanBecomeKeyWindow:true];
+    
     [Window disableCursorRects];
     [Window setTabbingMode:NSWindowTabbingModeDisallowed];
     [Window setCollectionBehavior:NSWindowCollectionBehaviorFullScreenPrimary];
@@ -52,11 +55,6 @@ void WindowImpl::OnInitialiseNSWindow(){
         [GetWindowProtocol() setIsExtended:true];
         SetExtendClientArea(true);
     }
-    
-    if(_parent != nullptr)
-    {
-        SetParent(_parent);
-    }
 }
 
 HRESULT WindowImpl::Show(bool activate, bool isDialog) {

native/Avalonia.Native/src/OSX/app.mm

@@ -82,6 +82,17 @@ ComPtr<IAvnApplicationEvents> _events;
         _isHandlingSendEvent = oldHandling;
     }
 }
+
+// This is needed for certain embedded controls DO NOT REMOVE..
+- (BOOL) isHandlingSendEvent
+{
+    return _isHandlingSendEvent;
+}
+
+- (void)setHandlingSendEvent:(BOOL)handlingSendEvent
+{
+    _isHandlingSendEvent = handlingSendEvent;
+}
 @end
 
 extern void InitializeAvnApp(IAvnApplicationEvents* events)

samples/ControlCatalog/MainWindow.xaml.cs

@@ -29,8 +29,6 @@ namespace ControlCatalog
 
             DataContext = new MainWindowViewModel(_notificationArea);
             _recentMenu = ((NativeMenu.GetMenu(this).Items[0] as NativeMenuItem).Menu.Items[2] as NativeMenuItem).Menu;
-
-            ExtendClientAreaChromeHints = Avalonia.Platform.ExtendClientAreaChromeHints.OSXThickTitleBar;
         }
 
         public static string MenuQuitHeader => RuntimeInformation.IsOSPlatform(OSPlatform.OSX) ? "Quit Avalonia" : "E_xit";

samples/ControlCatalog/ViewModels/TransitioningContentControlPageViewModel.cs

@@ -45,12 +45,12 @@ namespace ControlCatalog.ViewModels
         public List<Bitmap> Images { get; } = new List<Bitmap>();
 
 
-        private Bitmap? _SelectedImage;
+        private Bitmap _SelectedImage;
 
         /// <summary>
         /// Gets or Sets the selected image
         /// </summary>
-        public Bitmap? SelectedImage
+        public Bitmap SelectedImage
         {
             get { return _SelectedImage; }
             set { this.RaiseAndSetIfChanged(ref _SelectedImage, value); }
@@ -293,7 +293,7 @@ namespace ControlCatalog.ViewModels
         /// <remarks>
         /// Any one of the parameters may be null, but not both.
         /// </remarks>
-        private static IVisual GetVisualParent(IVisual? from, IVisual? to)
+        private static IVisual GetVisualParent(IVisual from, IVisual to)
         {
             var p1 = (from ?? to)!.VisualParent;
             var p2 = (to ?? from)!.VisualParent;

src/Android/Avalonia.Android/AvaloniaView.cs

@@ -15,7 +15,7 @@ namespace Avalonia.Android
         private EmbeddableControlRoot _root;
         private readonly ViewImpl _view;
 
-        private IDisposable? _timerSubscription;
+        private IDisposable _timerSubscription;
 
         public AvaloniaView(Context context) : base(context)
         {

src/Android/Avalonia.Android/Platform/Specific/Helpers/AndroidKeyboardEventsHelper.cs

@@ -30,7 +30,7 @@ namespace Avalonia.Android.Platform.Specific.Helpers
             return DispatchKeyEventInternal(e, out callBase);
         }
 
-        string? UnicodeTextInput(KeyEvent keyEvent)
+        string UnicodeTextInput(KeyEvent keyEvent)
         {
             return keyEvent.Action == KeyEventActions.Multiple
                 && keyEvent.RepeatCount == 0

src/Avalonia.Base/Media/GeometryDrawing.cs

@@ -68,7 +68,8 @@ namespace Avalonia.Media
 
         public override Rect GetBounds()
         {
-            return Geometry?.GetRenderBounds(s_boundsPen) ?? Rect.Empty;
+            IPen pen = Pen ?? s_boundsPen;
+			return Geometry?.GetRenderBounds(pen) ?? Rect.Empty;
         }
     }
 }

src/Avalonia.Base/Reactive/TypedBindingAdapter.cs

@@ -30,13 +30,15 @@ namespace Avalonia.Reactive
             }
             catch (InvalidCastException e)
             {
+                var unwrappedValue = value.HasValue ? value.Value : null;
+                
                 Logger.TryGet(LogEventLevel.Error, LogArea.Binding)?.Log(
                     _target,
                     "Binding produced invalid value for {$Property} ({$PropertyType}): {$Value} ({$ValueType})",
                     _property.Name,
                     _property.PropertyType,
-                    value.Value,
-                    value.Value?.GetType());
+                    unwrappedValue,
+                    unwrappedValue?.GetType());
                 PublishNext(BindingValue<T>.BindingError(e));
             }
         }

src/Avalonia.Controls/Avalonia.Controls.csproj

@@ -2,9 +2,6 @@
   <PropertyGroup>
     <TargetFrameworks>net6.0;netstandard2.0</TargetFrameworks>
   </PropertyGroup>
-  <ItemGroup>
-    <Compile Include="..\Avalonia.Base\Metadata\NullableAttributes.cs" Link="NullableAttributes.cs" />
-  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Avalonia.Base\Avalonia.Base.csproj" />
     <ProjectReference Include="..\Avalonia.Remote.Protocol\Avalonia.Remote.Protocol.csproj" />

src/Avalonia.Controls/Button.cs

@@ -232,6 +232,13 @@ namespace Avalonia.Controls
                     StopListeningForDefault(inputElement);
                 }
             }
+            if (IsCancel)
+            {
+                if (e.Root is IInputElement inputElement)
+                {
+                    StopListeningForCancel(inputElement);
+                }
+            }
         }
 
         /// <inheritdoc/>

src/Avalonia.Controls/Carousel.cs

@@ -20,8 +20,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="PageTransition"/> property.
         /// </summary>
-        public static readonly StyledProperty<IPageTransition> PageTransitionProperty =
-            AvaloniaProperty.Register<Carousel, IPageTransition>(nameof(PageTransition));
+        public static readonly StyledProperty<IPageTransition?> PageTransitionProperty =
+            AvaloniaProperty.Register<Carousel, IPageTransition?>(nameof(PageTransition));
 
         /// <summary>
         /// The default value of <see cref="ItemsControl.ItemsPanelProperty"/> for 
@@ -54,7 +54,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the transition to use when moving between pages.
         /// </summary>
-        public IPageTransition PageTransition
+        public IPageTransition? PageTransition
         {
             get { return GetValue(PageTransitionProperty); }
             set { SetValue(PageTransitionProperty, value); }

src/Avalonia.Controls/Presenters/CarouselPresenter.cs

@@ -31,7 +31,7 @@ namespace Avalonia.Controls.Presenters
         /// <summary>
         /// Defines the <see cref="PageTransition"/> property.
         /// </summary>
-        public static readonly StyledProperty<IPageTransition> PageTransitionProperty =
+        public static readonly StyledProperty<IPageTransition?> PageTransitionProperty =
             Carousel.PageTransitionProperty.AddOwner<CarouselPresenter>();
 
         private int _selectedIndex = -1;
@@ -85,7 +85,7 @@ namespace Avalonia.Controls.Presenters
         /// <summary>
         /// Gets or sets a transition to use when switching pages.
         /// </summary>
-        public IPageTransition PageTransition
+        public IPageTransition? PageTransition
         {
             get { return GetValue(PageTransitionProperty); }
             set { SetValue(PageTransitionProperty, value); }

src/Avalonia.Themes.Default/SimpleTheme.cs

@@ -44,7 +44,7 @@ namespace Avalonia.Themes.Default
             InitStyles(_baseUri);
         }
 
-        public event EventHandler OwnerChanged
+        public event EventHandler? OwnerChanged
         {
             add
             {

src/Avalonia.Themes.Fluent/FluentTheme.cs

@@ -50,7 +50,9 @@ namespace Avalonia.Themes.Fluent
         /// <param name="serviceProvider">The XAML service provider.</param>
         public FluentTheme(IServiceProvider serviceProvider)
         {
-            _baseUri = ((IUriContext)serviceProvider.GetService(typeof(IUriContext))).BaseUri;
+            var ctx  = serviceProvider.GetService(typeof(IUriContext)) as IUriContext
+                 ?? throw new NullReferenceException("Unable retrive UriContext");
+            _baseUri = ctx.BaseUri;
             InitStyles(_baseUri);
         }
 
@@ -146,7 +148,7 @@ namespace Avalonia.Themes.Fluent
 
         IReadOnlyList<IStyle> IStyle.Children => _loaded?.Children ?? Array.Empty<IStyle>();
 
-        public event EventHandler OwnerChanged
+        public event EventHandler? OwnerChanged
         {
             add
             {

src/Avalonia.X11/X11Atoms.cs

@@ -155,6 +155,7 @@ namespace Avalonia.X11
         public readonly IntPtr _NET_FRAME_EXTENTS;
         public readonly IntPtr _NET_WM_PING;
         public readonly IntPtr _NET_WM_SYNC_REQUEST;
+        public readonly IntPtr _NET_WM_SYNC_REQUEST_COUNTER;
         public readonly IntPtr _NET_SYSTEM_TRAY_S;
         public readonly IntPtr _NET_SYSTEM_TRAY_ORIENTATION;
         public readonly IntPtr _NET_SYSTEM_TRAY_OPCODE;

src/Avalonia.X11/X11Info.cs

@@ -33,6 +33,7 @@ namespace Avalonia.X11
         public IntPtr LastActivityTimestamp { get; set; }
         public XVisualInfo? TransparentVisualInfo { get; set; }
         public bool HasXim { get; set; }
+        public bool HasXSync { get; set; }
         public IntPtr DefaultFontSet { get; set; }
         
         public unsafe X11Info(IntPtr display, IntPtr deferredDisplay, bool useXim)
@@ -101,6 +102,15 @@ namespace Avalonia.X11
             {
                 //Ignore, XI is not supported
             }
+
+            try
+            {
+                HasXSync = XSyncInitialize(display, out _, out _) != Status.Success;
+            }
+            catch
+            {
+                //Ignore, XSync is not supported
+            }
         }
     }
 }

src/Avalonia.X11/X11Window.cs

@@ -45,6 +45,8 @@ namespace Avalonia.X11
         private IntPtr _handle;
         private IntPtr _xic;
         private IntPtr _renderHandle;
+        private IntPtr _xSyncCounter;
+        private XSyncValue _xSyncValue;
         private bool _mapped;
         private bool _wasMappedAtLeastOnce = false;
         private double? _scalingOverride;
@@ -190,6 +192,16 @@ namespace Avalonia.X11
                 NativeMenuExporter = DBusMenuExporter.TryCreateTopLevelNativeMenu(_handle);
             NativeControlHost = new X11NativeControlHost(_platform, this);
             InitializeIme();
+            
+            XChangeProperty(_x11.Display, _handle, _x11.Atoms.WM_PROTOCOLS, _x11.Atoms.XA_ATOM, 32,
+                PropertyMode.Replace, new[] { _x11.Atoms.WM_DELETE_WINDOW, _x11.Atoms._NET_WM_SYNC_REQUEST }, 2);
+
+            if (_x11.HasXSync)
+            {
+                _xSyncCounter = XSyncCreateCounter(_x11.Display, _xSyncValue);
+                XChangeProperty(_x11.Display, _handle, _x11.Atoms._NET_WM_SYNC_REQUEST_COUNTER,
+                    _x11.Atoms.XA_CARDINAL, 32, PropertyMode.Replace, ref _xSyncCounter, 1);
+            }
         }
 
         class SurfaceInfo  : EglGlPlatformSurface.IEglWindowGlPlatformSurfaceInfo
@@ -383,15 +395,7 @@ namespace Avalonia.X11
                      (ev.type == XEventName.VisibilityNotify &&
                       ev.VisibilityEvent.state < 2))
             {
-                if (!_triggeredExpose)
-                {
-                    _triggeredExpose = true;
-                    Dispatcher.UIThread.Post(() =>
-                    {
-                        _triggeredExpose = false;
-                        DoPaint();
-                    }, DispatcherPriority.Render);
-                }
+                EnqueuePaint();
             }
             else if (ev.type == XEventName.FocusIn)
             {
@@ -503,6 +507,7 @@ namespace Avalonia.X11
                 if (_useRenderWindow)
                     XConfigureResizeWindow(_x11.Display, _renderHandle, ev.ConfigureEvent.width,
                         ev.ConfigureEvent.height);
+                EnqueuePaint();
             }
             else if (ev.type == XEventName.DestroyNotify 
                      && ev.DestroyWindowEvent.window == _handle)
@@ -518,7 +523,11 @@ namespace Avalonia.X11
                         if (Closing?.Invoke() != true)
                             Dispose();
                     }
-
+                    else if (ev.ClientMessageEvent.ptr1 == _x11.Atoms._NET_WM_SYNC_REQUEST)
+                    {
+                        _xSyncValue.Lo = new UIntPtr(ev.ClientMessageEvent.ptr3.ToPointer()).ToUInt32();
+                        _xSyncValue.Hi = ev.ClientMessageEvent.ptr4.ToInt32();
+                    }
                 }
             }
             else if (ev.type == XEventName.KeyPress || ev.type == XEventName.KeyRelease)
@@ -730,9 +739,24 @@ namespace Avalonia.X11
             ScheduleInput(mev, ref ev);
         }
 
+        void EnqueuePaint()
+        {
+            if (!_triggeredExpose)
+            {
+                _triggeredExpose = true;
+                Dispatcher.UIThread.Post(() =>
+                {
+                    _triggeredExpose = false;
+                    DoPaint();
+                }, DispatcherPriority.Render);
+            }
+        }
+        
         void DoPaint()
         {
             Paint?.Invoke(new Rect());
+            if (_xSyncCounter != IntPtr.Zero)
+                XSyncSetCounter(_x11.Display, _xSyncCounter, _xSyncValue);
         }
         
         public void Invalidate(Rect rect)
@@ -1160,7 +1184,7 @@ namespace Avalonia.X11
             }
 
             public IntPtr Handle => _owner._renderHandle;
-            public string? HandleDescriptor => "XID";
+            public string HandleDescriptor => "XID";
         }
     }
 }

src/Avalonia.X11/XLib.cs

@@ -542,6 +542,18 @@ namespace Avalonia.X11
         public static extern int XRRQueryExtension (IntPtr dpy,
             out int event_base_return,
             out int error_base_return);
+        
+        [DllImport(libX11Ext)]
+        public static extern Status XSyncInitialize(IntPtr dpy, out int event_base_return, out int error_base_return);
+
+        [DllImport(libX11Ext)]
+        public static extern IntPtr XSyncCreateCounter(IntPtr dpy, XSyncValue initialValue);
+        
+        [DllImport(libX11Ext)]
+        public static extern int XSyncDestroyCounter(IntPtr dpy, IntPtr counter);
+        
+        [DllImport(libX11Ext)]
+        public static extern int XSyncSetCounter(IntPtr dpy, IntPtr counter, XSyncValue value);
 
         [DllImport(libX11Randr)]
         public static extern int XRRQueryVersion(IntPtr dpy,
@@ -627,6 +639,11 @@ namespace Avalonia.X11
             public int bw;
             public int d;
         }
+        
+        public struct XSyncValue {
+            public int Hi;
+            public uint Lo;
+        }
 
         public static bool XGetGeometry(IntPtr display, IntPtr window, out XGeometry geo)
         {

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/PropertyInfoAccessorFactory.cs

@@ -1,8 +1,6 @@
 using System;
-using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.ComponentModel;
-using System.Text;
 using Avalonia.Data;
 using Avalonia.Data.Core;
 using Avalonia.Data.Core.Plugins;
@@ -174,7 +172,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
                 WeakEvents.CollectionChanged.Unsubscribe(incc, this);
         }
         
-        public void OnEvent(object? sender, WeakEvent ev, NotifyCollectionChangedEventArgs args)
+        public void OnEvent(object sender, WeakEvent ev, NotifyCollectionChangedEventArgs args)
         {
             if (ShouldNotifyListeners(args))
             {

src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/ResourceInclude.cs

@@ -42,7 +42,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
 
         bool IResourceNode.HasResources => Loaded.HasResources;
 
-        public event EventHandler OwnerChanged
+        public event EventHandler? OwnerChanged
         {
             add => Loaded.OwnerChanged += value;
             remove => Loaded.OwnerChanged -= value;
@@ -52,7 +52,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions
         {
             if (!_isLoading)
             {
-                return Loaded.TryGetResource(key, out value);                
+                return Loaded.TryGetResource(key, out value);
             }
 
             value = null;

src/Markup/Avalonia.Markup.Xaml/Styling/StyleInclude.cs

@@ -64,7 +64,7 @@ namespace Avalonia.Markup.Xaml.Styling
 
         IReadOnlyList<IStyle> IStyle.Children => _loaded ?? Array.Empty<IStyle>();
 
-        public event EventHandler OwnerChanged
+        public event EventHandler? OwnerChanged
         {
             add
             {

src/Windows/Avalonia.Win32/Automation/RootAutomationNode.cs

@@ -42,7 +42,7 @@ namespace Avalonia.Win32.Automation
             return GetOrCreate(focus);
         }
 
-        public void FocusChanged(object sender, EventArgs e)
+        public void FocusChanged(object? sender, EventArgs e)
         {
             RaiseFocusChanged(GetOrCreate(Peer.GetFocus()));
         }

src/Windows/Avalonia.Win32/Avalonia.Win32.csproj

@@ -18,4 +18,8 @@
   </ItemGroup>
   <Import Project="$(MSBuildThisFileDirectory)\..\..\..\build\System.Drawing.Common.props" />
   <Import Project="..\..\..\build\DevAnalyzers.props" />
+  <PropertyGroup Label="Warnings">
+    <NoWarn Condition="'$(NoWarn)' == ''">CA1416</NoWarn>
+    <NoWarn Condition="'$(NoWarn)' != ''">$(NoWarn),CA1416</NoWarn>
+  </PropertyGroup>
 </Project>

src/Windows/Avalonia.Win32/Interop/Automation/ISelectionItemProvider.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.Runtime.InteropServices;
 

src/Windows/Avalonia.Win32/TrayIconImpl.cs

@@ -195,7 +195,7 @@ namespace Avalonia.Win32
                 ShowActivated = true;
             }
 
-            private void TrayPopupRoot_Deactivated(object sender, EventArgs e)
+            private void TrayPopupRoot_Deactivated(object? sender, EventArgs e)
             {
                 Close();
             }

src/Windows/Avalonia.Win32/WindowImpl.CustomCaptionProc.cs

@@ -109,7 +109,7 @@ namespace Avalonia.Win32
 
                             if (_owner is Window window)
                             {
-                                var visual = window.Renderer.HitTestFirst(position, _owner as Window, x =>
+                                var visual = window.Renderer.HitTestFirst(position, _owner, x =>
                                 {
                                     if (x is IInputElement ie && (!ie.IsHitTestVisible || !ie.IsVisible))
                                     {

tests/Avalonia.Benchmarks/TestBindingObservable.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using Avalonia.Data;
 
 namespace Avalonia.Benchmarks

tests/Avalonia.Controls.UnitTests/ButtonTests.cs

@@ -309,6 +309,80 @@ namespace Avalonia.Controls.UnitTests
 
             Assert.Equal(0, raised);
         }
+        
+        [Fact]
+        public void Button_IsDefault_Works()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var raised = 0;
+                var target = new Button();
+                var window = new Window { Content = target };
+                window.Show();
+                
+                target.Click += (s, e) => ++raised;
+
+                target.IsDefault = false;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Enter));
+                Assert.Equal(0, raised);
+                
+                target.IsDefault = true;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Enter));
+                Assert.Equal(1, raised);
+
+                target.IsDefault = false;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Enter));
+                Assert.Equal(1, raised);
+                
+                target.IsDefault = true;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Enter));
+                Assert.Equal(2, raised);
+                
+                window.Content = null;
+                // To check if handler was raised on the button, when it's detached, we need to pass it as a source manually.
+                window.RaiseEvent(CreateKeyDownEvent(Key.Enter, target));
+                Assert.Equal(2, raised);
+            }
+        }
+        
+        [Fact]
+        public void Button_IsCancel_Works()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var raised = 0;
+                var target = new Button();
+                var window = new Window { Content = target };
+                window.Show();
+                
+                target.Click += (s, e) => ++raised;
+
+                target.IsCancel = false;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Escape));
+                Assert.Equal(0, raised);
+                
+                target.IsCancel = true;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Escape));
+                Assert.Equal(1, raised);
+
+                target.IsCancel = false;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Escape));
+                Assert.Equal(1, raised);
+                
+                target.IsCancel = true;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Escape));
+                Assert.Equal(2, raised);
+                
+                window.Content = null;
+                window.RaiseEvent(CreateKeyDownEvent(Key.Escape, target));
+                Assert.Equal(2, raised);
+            }
+        }
+
+        private KeyEventArgs CreateKeyDownEvent(Key key, IInteractive source = null)
+        {
+            return new KeyEventArgs { RoutedEvent = InputElement.KeyDownEvent, Key = key, Source = source };
+        }
 
         private class TestButton : Button, IRenderRoot
         {

tests/Avalonia.RenderTests/Media/GeometryDrawingTests.cs

@@ -0,0 +1,52 @@
+using Avalonia.Media;
+using Xunit;
+
+#if AVALONIA_SKIA
+namespace Avalonia.Skia.RenderTests
+#else
+
+using Avalonia.Direct2D1.RenderTests;
+
+namespace Avalonia.Direct2D1.RenderTests.Media
+#endif
+{
+    public class GeometryDrawingTests : TestBase
+    {
+        public GeometryDrawingTests()
+            : base(@"Media\GeometryDrawing")
+        {
+        }
+
+        private GeometryDrawing CreateGeometryDrawing()
+        {
+            GeometryDrawing geometryDrawing = new GeometryDrawing();
+            EllipseGeometry ellipse = new EllipseGeometry();
+            ellipse.RadiusX = 100;
+            ellipse.RadiusY = 100;
+            geometryDrawing.Geometry = ellipse;
+            return geometryDrawing;
+        }
+
+        [Fact]
+        public void DrawingGeometry_WithPen()
+        {
+            GeometryDrawing geometryDrawing = CreateGeometryDrawing();
+            geometryDrawing.Pen = new Pen(new SolidColorBrush(Color.FromArgb(255, 0, 0, 0)), 10);
+
+            Assert.Equal(210, geometryDrawing.GetBounds().Height);
+            Assert.Equal(210, geometryDrawing.GetBounds().Width);
+
+        }
+
+        [Fact]
+        public void DrawingGeometry_WithoutPen()
+        {
+            GeometryDrawing geometryDrawing = CreateGeometryDrawing();
+
+            Assert.Equal(200, geometryDrawing.GetBounds().Height);
+            Assert.Equal(200, geometryDrawing.GetBounds().Width);
+        }
+
+
+    }
+}

tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextFormatterTests.cs

@@ -602,7 +602,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
 
         private class EndOfLineTextSource : ITextSource
         {
-            public TextRun? GetTextRun(int textSourceIndex)
+            public TextRun GetTextRun(int textSourceIndex)
             {
                 return new TextEndOfLine();
             }
@@ -617,7 +617,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                 _text = text;
             }
             
-            public TextRun? GetTextRun(int textSourceIndex)
+            public TextRun GetTextRun(int textSourceIndex)
             {
                 if (textSourceIndex >= _text.Length + TextRun.DefaultTextSourceLength + _text.Length)
                 {

tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextLineTests.cs

@@ -639,7 +639,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
         {
             const string Text = "_A_A";
 
-            public TextRun? GetTextRun(int textSourceIndex)
+            public TextRun GetTextRun(int textSourceIndex)
             {
                 switch (textSourceIndex)
                 {
@@ -907,7 +907,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                 _textRuns = textRuns;
             }
 
-            public TextRun? GetTextRun(int textSourceIndex)
+            public TextRun GetTextRun(int textSourceIndex)
             {
                 var currentPosition = 0;