Merge branch 'master' into fixes/textProcessingFixes

Avalonia.sln

@@ -38,6 +38,7 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Shared", "Shared", "{A689DEF5-D50F-4975-8B72-124C9EB54066}"
 	ProjectSection(SolutionItems) = preProject
 		.editorconfig = .editorconfig
+		src\Shared\IsExternalInit.cs = src\Shared\IsExternalInit.cs
 		src\Shared\ModuleInitializer.cs = src\Shared\ModuleInitializer.cs
 		src\Shared\SourceGeneratorAttributes.cs = src\Shared\SourceGeneratorAttributes.cs
 	EndProjectSection

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

@@ -127,7 +127,11 @@
         [self updateRenderTarget];
 
         auto reason = [self inLiveResize] ? ResizeUser : _resizeReason;
-        _parent->BaseEvents->Resized(AvnSize{newSize.width, newSize.height}, reason);
+        
+        if(_parent->IsShown())
+        {
+            _parent->BaseEvents->Resized(AvnSize{newSize.width, newSize.height}, reason);
+        }
     }
 }
 

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

@@ -13,6 +13,7 @@
 {
     @public IOSurfaceRef surface;
     @public AvnPixelSize size;
+    @public bool hasContent;
     @public float scale;
     ComPtr<IAvnGlContext> _context;
     GLuint _framebuffer, _texture, _renderbuffer;
@@ -41,6 +42,7 @@
     self->scale = scale;
     self->size = size;
     self->_context = context;
+    self->hasContent = false;
     return self;
 }
 
@@ -92,6 +94,7 @@
     _context->MakeCurrent(release.getPPV());
     glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
     glFlush();
+    self->hasContent = true;
 }
 
 -(void) dealloc
@@ -170,6 +173,8 @@ static IAvnGlSurfaceRenderTarget* CreateGlRenderTarget(IOSurfaceRenderTarget* ta
         @synchronized (lock) {
             if(_layer == nil)
                 return;
+            if(!surface->hasContent)
+                return;
             [CATransaction begin];
             [_layer setContents: nil];
             if(surface != nil)
@@ -213,6 +218,7 @@ static IAvnGlSurfaceRenderTarget* CreateGlRenderTarget(IOSurfaceRenderTarget* ta
             memcpy(pSurface + y*sstride, pFb + y*fstride, wbytes);
         }
         IOSurfaceUnlock(surf, 0, nil);
+        surface->hasContent = true;
         [self updateLayer];
         return S_OK;
     }

samples/ControlCatalog/Pages/ProgressBarPage.xaml

@@ -1,22 +1,37 @@
 <UserControl xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="ControlCatalog.Pages.ProgressBarPage">
   <StackPanel Orientation="Vertical" Spacing="4">
     <TextBlock Classes="h2">A progress bar control</TextBlock>
-    <StackPanel>
+    <StackPanel Spacing="5">
+      <StackPanel Orientation="Horizontal" Spacing="5">
+        <TextBlock VerticalAlignment="Center">Maximum</TextBlock>
+        <NumericUpDown x:Name="maximum" Value="100" VerticalAlignment="Center"/>
+      </StackPanel>
+      <StackPanel Orientation="Horizontal" Spacing="5">
+        <TextBlock VerticalAlignment="Center">Minimum</TextBlock>
+        <NumericUpDown x:Name="minimum" Value="0" VerticalAlignment="Center"/>
+      </StackPanel>
+      <StackPanel Orientation="Horizontal" Spacing="5">
+        <TextBlock VerticalAlignment="Center">Progress Text Format</TextBlock>
+        <TextBox x:Name="stringFormat" Text="{}{0:0}%" VerticalAlignment="Center"/>
+      </StackPanel>
       <CheckBox x:Name="showProgress" Margin="10,16,0,0" Content="Show Progress Text" />
       <CheckBox x:Name="isIndeterminate" Margin="10,16,0,0" Content="Toggle Indeterminate" />
       <StackPanel Orientation="Horizontal" Margin="0,16,0,0" HorizontalAlignment="Center" Spacing="16">
         <StackPanel Spacing="16">
-          <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #hprogress.Value}" />
+          <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #hprogress.Value}" 
+                       Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" ProgressTextFormat="{Binding #stringFormat.Text}"/>
         </StackPanel>
-        <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #vprogress.Value}" Orientation="Vertical" />
+        <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #vprogress.Value}" Orientation="Vertical" 
+                     Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" ProgressTextFormat="{Binding #stringFormat.Text}"/>
       </StackPanel>
       <StackPanel Margin="16">
-        <Slider Name="hprogress" Maximum="100" Value="40" />
+        <Slider Name="hprogress" Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" Value="40" />
-        <Slider Name="vprogress" Maximum="100" Value="60" />
+        <Slider Name="vprogress" Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" Value="60" />
       </StackPanel>
 
       <StackPanel Spacing="10">
-        <ProgressBar VerticalAlignment="Center" IsIndeterminate="True" />
+        <ProgressBar VerticalAlignment="Center" IsIndeterminate="True" 
+                     Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.value}"/>
         <ProgressBar VerticalAlignment="Center" Value="5" Maximum="10" />
         <ProgressBar VerticalAlignment="Center" Value="50" />
         <ProgressBar VerticalAlignment="Center" Value="50" Minimum="25" Maximum="75" />

src/Avalonia.Base/Controls/IPseudoClasses.cs

@@ -19,5 +19,12 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="name">The pseudoclass name.</param>
         bool Remove(string name);
+
+        /// <summary>
+        /// Returns whether a pseudoclass is present in the collection.
+        /// </summary>
+        /// <param name="name">The pseudoclass name.</param>
+        /// <returns>Whether the pseudoclass is present.</returns>
+        bool Contains(string name);
     }
 }

src/Avalonia.Base/Layout/LayoutManager.cs

@@ -350,7 +350,7 @@ namespace Avalonia.Layout
                 {
                     for (var i = 0; i < count; ++i)
                     {
-                        var l = _effectiveViewportChangedListeners[i];
+                        var l = listeners[i];
 
                         if (!l.Listener.IsAttachedToVisualTree)
                         {
@@ -362,7 +362,7 @@ namespace Avalonia.Layout
                         if (viewport != l.Viewport)
                         {
                             l.Listener.EffectiveViewportChanged(new EffectiveViewportChangedEventArgs(viewport));
-                            _effectiveViewportChangedListeners[i] = new EffectiveViewportChangedListener(l.Listener, viewport);
+                            l.Viewport = viewport;
                         }
                     }
                 }
@@ -414,7 +414,7 @@ namespace Avalonia.Layout
             }
         }
 
-        private readonly struct EffectiveViewportChangedListener
+        private class EffectiveViewportChangedListener
         {
             public EffectiveViewportChangedListener(ILayoutable listener, Rect viewport)
             {
@@ -423,7 +423,7 @@ namespace Avalonia.Layout
             }
 
             public ILayoutable Listener { get; }
-            public Rect Viewport { get; }
+            public Rect Viewport { get; set; }
         }
     }
 }

src/Avalonia.Controls.DataGrid/Themes/Fluent.xaml

@@ -7,7 +7,7 @@
     <StreamGeometry x:Key="DataGridSortIconDescendingPath">M1875 1011l-787 787v-1798h-128v1798l-787 -787l-90 90l941 941l941 -941z</StreamGeometry>
     <StreamGeometry x:Key="DataGridSortIconAscendingPath">M1965 947l-941 -941l-941 941l90 90l787 -787v1798h128v-1798l787 787z</StreamGeometry>
     <StreamGeometry x:Key="DataGridRowGroupHeaderIconClosedPath">M515 93l930 931l-930 931l90 90l1022 -1021l-1022 -1021z</StreamGeometry>
-    <StreamGeometry x:Key="DataGridRowGroupHeaderIconOpenedPath">M1939 1581l90 -90l-1005 -1005l-1005 1005l90 90l915 -915z</StreamGeometry>
+    <StreamGeometry x:Key="DataGridRowGroupHeaderIconOpenedPath">M109 486 19 576 1024 1581 2029 576 1939 486 1024 1401z</StreamGeometry>
 
     <SolidColorBrush x:Key="DataGridColumnHeaderForegroundBrush" Color="{DynamicResource SystemBaseMediumColor}" />
     <SolidColorBrush x:Key="DataGridColumnHeaderBackgroundBrush" Color="{DynamicResource SystemAltHighColor}" />
@@ -499,12 +499,12 @@
   </Style>
 
   <Style Selector="DataGridRowGroupHeader /template/ ToggleButton#ExpanderButton /template/ Path">
-    <Setter Property="Data" Value="{StaticResource DataGridRowGroupHeaderIconOpenedPath}" />
+    <Setter Property="Data" Value="{StaticResource DataGridRowGroupHeaderIconClosedPath}" />
     <Setter Property="Stretch" Value="Uniform" />
   </Style>
 
   <Style Selector="DataGridRowGroupHeader /template/ ToggleButton#ExpanderButton:checked /template/ Path">
-    <Setter Property="Data" Value="{StaticResource DataGridRowGroupHeaderIconClosedPath}" />
+    <Setter Property="Data" Value="{StaticResource DataGridRowGroupHeaderIconOpenedPath}" />
     <Setter Property="Stretch" Value="UniformToFill" />
   </Style>
 

src/Avalonia.Controls/Converters/StringFormatConverter.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+
+namespace Avalonia.Controls.Converters;
+
+/// <summary>
+/// Calls <see cref="string.Format(string, object[])"/> on the passed in values, where the first element in the list
+/// is the string, and everything after it is passed into the object array in order.
+/// </summary>
+public class StringFormatConverter : IMultiValueConverter
+{
+    public object? Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
+    {
+        try
+        {
+            return string.Format((string)values[0]!, values.Skip(1).ToArray());
+        }
+        catch (Exception e)
+        {
+            return new BindingNotification(e, BindingErrorType.Error);
+        }
+    }
+}

src/Avalonia.Controls/Primitives/TemplatedControl.cs

@@ -387,6 +387,7 @@ namespace Avalonia.Controls.Primitives
         /// Sets the TemplatedParent property for the created template children.
         /// </summary>
         /// <param name="control">The control.</param>
+        /// <param name="templatedParent">The templated parent to apply.</param>
         internal static void ApplyTemplatedParent(IStyledElement control, ITemplatedControl? templatedParent)
         {
             control.SetValue(TemplatedParentProperty, templatedParent);
@@ -396,7 +397,7 @@ namespace Avalonia.Controls.Primitives
 
             for (var i = 0; i < count; i++)
             {
-                if (children[i] is IStyledElement child)
+                if (children[i] is IStyledElement child && child.TemplatedParent is null)
                 {
                     ApplyTemplatedParent(child, templatedParent);
                 }

src/Avalonia.Controls/ProgressBar.cs

@@ -96,6 +96,7 @@ namespace Avalonia.Controls
             }
         }
 
+        private double _percentage;
         private double _indeterminateStartingOffset;
         private double _indeterminateEndingOffset;
         private Border? _indicator;
@@ -106,9 +107,17 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<bool> ShowProgressTextProperty =
             AvaloniaProperty.Register<ProgressBar, bool>(nameof(ShowProgressText));
 
+        public static readonly StyledProperty<string> ProgressTextFormatProperty =
+            AvaloniaProperty.Register<ProgressBar, string>(nameof(ProgressTextFormat), "{1:0}%");
+        
         public static readonly StyledProperty<Orientation> OrientationProperty =
             AvaloniaProperty.Register<ProgressBar, Orientation>(nameof(Orientation), Orientation.Horizontal);
 
+        public static readonly DirectProperty<ProgressBar, double> PercentageProperty =
+            AvaloniaProperty.RegisterDirect<ProgressBar, double>(
+                nameof(Percentage),
+                o => o.Percentage);
+
         [Obsolete("To be removed when Avalonia.Themes.Default is discontinued.")]
         public static readonly DirectProperty<ProgressBar, double> IndeterminateStartingOffsetProperty =
             AvaloniaProperty.RegisterDirect<ProgressBar, double>(
@@ -123,6 +132,12 @@ namespace Avalonia.Controls
                 p => p.IndeterminateEndingOffset,
                 (p, o) => p.IndeterminateEndingOffset = o);
 
+        public double Percentage
+        {
+            get { return _percentage; }
+            private set { SetAndRaise(PercentageProperty, ref _percentage, value); }
+        }
+        
         [Obsolete("To be removed when Avalonia.Themes.Default is discontinued.")]
         public double IndeterminateStartingOffset
         {
@@ -165,6 +180,12 @@ namespace Avalonia.Controls
             set => SetValue(ShowProgressTextProperty, value);
         }
 
+        public string ProgressTextFormat
+        {
+            get => GetValue(ProgressTextFormatProperty);
+            set => SetValue(ProgressTextFormatProperty, value);
+        }
+
         public Orientation Orientation
         {
             get => GetValue(OrientationProperty);
@@ -174,7 +195,7 @@ namespace Avalonia.Controls
         /// <inheritdoc/>
         protected override Size ArrangeOverride(Size finalSize)
         {
-            UpdateIndicator(finalSize);
+            UpdateIndicator();
             return base.ArrangeOverride(finalSize);
         }
 
@@ -197,18 +218,21 @@ namespace Avalonia.Controls
         {
             _indicator = e.NameScope.Get<Border>("PART_Indicator");
 
-            UpdateIndicator(Bounds.Size);
+            UpdateIndicator();
         }
 
-        private void UpdateIndicator(Size bounds)
+        private void UpdateIndicator()
         {
+            // Gets the size of the parent indicator container
+            var barSize = _indicator?.Parent?.Bounds.Size ?? Bounds.Size;
+            
             if (_indicator != null)
             {
                 if (IsIndeterminate)
                 {
                     // Pulled from ModernWPF.
 
-                    var dim = Orientation == Orientation.Horizontal ? bounds.Width : bounds.Height;
+                    var dim = Orientation == Orientation.Horizontal ? barSize.Width : barSize.Height;
                     var barIndicatorWidth = dim * 0.4; // Indicator width at 40% of ProgressBar
                     var barIndicatorWidth2 = dim * 0.6; // Indicator width at 60% of ProgressBar
 
@@ -233,8 +257,8 @@ namespace Avalonia.Controls
                         new Rect(
                             padding.Left,
                             padding.Top,
-                            bounds.Width - (padding.Right + padding.Left),
+                            barSize.Width - (padding.Right + padding.Left),
-                            bounds.Height - (padding.Bottom + padding.Top)
+                            barSize.Height - (padding.Bottom + padding.Top)
                             ));
                 }
                 else
@@ -242,16 +266,18 @@ namespace Avalonia.Controls
                     double percent = Maximum == Minimum ? 1.0 : (Value - Minimum) / (Maximum - Minimum);
 
                     if (Orientation == Orientation.Horizontal)
-                        _indicator.Width = bounds.Width * percent;
+                        _indicator.Width = barSize.Width * percent;
                     else
-                        _indicator.Height = bounds.Height * percent;
+                        _indicator.Height = barSize.Height * percent;
+
+                    Percentage = percent * 100;
                 }
             }
         }
 
         private void UpdateIndicatorWhenPropChanged(AvaloniaPropertyChangedEventArgs e)
         {
-            UpdateIndicator(Bounds.Size);
+            UpdateIndicator();
         }
 
         private void UpdatePseudoClasses(

src/Avalonia.Controls/TrayIcon.cs

@@ -189,7 +189,10 @@ namespace Avalonia.Controls
             var app = Application.Current ?? throw new InvalidOperationException("Application not yet initialized.");
             var trayIcons = GetIcons(app);
 
-            RemoveIcons(trayIcons);
+            if (trayIcons != null)
+            {
+                RemoveIcons(trayIcons);
+            }
         }
 
         private static void Icons_CollectionChanged(object? sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)

src/Avalonia.Controls/Window.cs

@@ -681,8 +681,8 @@ namespace Avalonia.Controls
             IsVisible = true;
 
             var initialSize = new Size(
-                double.IsNaN(Width) ? ClientSize.Width : Width,
+                double.IsNaN(Width) ? Math.Max(MinWidth, ClientSize.Width) : Width,
-                double.IsNaN(Height) ? ClientSize.Height : Height);
+                double.IsNaN(Height) ? Math.Max(MinHeight, ClientSize.Height) : Height);
 
             if (initialSize != ClientSize)
             {

src/Avalonia.FreeDesktop/Avalonia.FreeDesktop.csproj

@@ -5,6 +5,10 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="..\Shared\IsExternalInit.cs" Link="IsExternalInit.cs" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\Avalonia.Controls\Avalonia.Controls.csproj" />
     <ProjectReference Include="..\Avalonia.Dialogs\Avalonia.Dialogs.csproj" />

src/Avalonia.FreeDesktop/DBusCallQueue.cs

@@ -8,10 +8,9 @@ namespace Avalonia.FreeDesktop
     {
         private readonly Func<Exception, Task> _errorHandler;
 
-        class Item
+        record Item(Func<Task> Callback)
         {
-            public Func<Task> Callback;
+            public Action<Exception?>? OnFinish;
-            public Action<Exception> OnFinish;
         }
         private Queue<Item> _q = new Queue<Item>();
         private bool _processing;
@@ -23,19 +22,15 @@ namespace Avalonia.FreeDesktop
         
         public void Enqueue(Func<Task> cb)
         {
-            _q.Enqueue(new Item
+            _q.Enqueue(new Item(cb));
-            {
-                Callback = cb
-            });
             Process();
         }
 
         public Task EnqueueAsync(Func<Task> cb)
         {
             var tcs = new TaskCompletionSource<int>(TaskCreationOptions.RunContinuationsAsynchronously);
-            _q.Enqueue(new Item
+            _q.Enqueue(new Item(cb)
             {
-                Callback = cb,
                 OnFinish = e =>
                 {
                     if (e == null)
@@ -51,13 +46,12 @@ namespace Avalonia.FreeDesktop
         public Task<T> EnqueueAsync<T>(Func<Task<T>> cb)
         {
             var tcs = new TaskCompletionSource<T>(TaskCreationOptions.RunContinuationsAsynchronously);
-            _q.Enqueue(new Item
+            _q.Enqueue(new Item(async () =>
-            {
-                Callback = async () =>
                 {
                     var res = await cb();
                     tcs.TrySetResult(res);
-                },
+                })
+            {
                 OnFinish = e =>
                 {
                     if (e != null)

src/Avalonia.FreeDesktop/DBusHelper.cs

@@ -17,7 +17,7 @@ namespace Avalonia.FreeDesktop
             private readonly object _lock = new();
             private SynchronizationContext? _ctx;
 
-            public override void Post(SendOrPostCallback d, object state)
+            public override void Post(SendOrPostCallback d, object? state)
             {
                 lock (_lock)
                 {
@@ -29,7 +29,7 @@ namespace Avalonia.FreeDesktop
                 }
             }
 
-            public override void Send(SendOrPostCallback d, object state)
+            public override void Send(SendOrPostCallback d, object? state)
             {
                 lock (_lock)
                 {

src/Avalonia.FreeDesktop/DBusIme/DBusTextInputMethodBase.cs

@@ -1,9 +1,7 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Reflection;
 using System.Threading.Tasks;
-using Avalonia.FreeDesktop.DBusIme.Fcitx;
 using Avalonia.Input.Raw;
 using Avalonia.Input.TextInput;
 using Avalonia.Logging;
@@ -26,7 +24,7 @@ namespace Avalonia.FreeDesktop.DBusIme
             return (im, im);
         }
     }
-    
+
     internal abstract class DBusTextInputMethodBase : IX11InputMethodControl, ITextInputMethodImpl
     {
         private List<IDisposable> _disposables = new List<IDisposable>();
@@ -34,7 +32,7 @@ namespace Avalonia.FreeDesktop.DBusIme
         protected Connection Connection { get; }
         private readonly string[] _knownNames;
         private bool _connecting;
-        private string _currentName;
+        private string? _currentName;
         private DBusCallQueue _queue;
         private bool _controlActive, _windowActive;
         private bool? _imeActive;
@@ -42,9 +40,9 @@ namespace Avalonia.FreeDesktop.DBusIme
         private PixelRect? _lastReportedRect;
         private double _scaling = 1;
         private PixelPoint _windowPosition;
-        
+
         protected bool IsConnected => _currentName != null;
-        
+
         public DBusTextInputMethodBase(Connection connection, params string[] knownNames)
         {
             _queue = new DBusCallQueue(QueueOnError);
@@ -58,18 +56,18 @@ namespace Avalonia.FreeDesktop.DBusIme
             foreach (var name in _knownNames)
                 _disposables.Add(await Connection.ResolveServiceOwnerAsync(name, OnNameChange));
         }
-        
+
         protected abstract Task<bool> Connect(string name);
 
         protected string GetAppName() =>
-            Application.Current.Name ?? Assembly.GetEntryAssembly()?.GetName()?.Name ?? "Avalonia";
+            Application.Current?.Name ?? Assembly.GetEntryAssembly()?.GetName()?.Name ?? "Avalonia";
-        
+
         private async void OnNameChange(ServiceOwnerChangedEventArgs args)
         {
             if (args.NewOwner != null && _currentName == null)
             {
                 _onlineNamesQueue.Enqueue(args.ServiceName);
-                if(!_connecting)
+                if (!_connecting)
                 {
                     _connecting = true;
                     try
@@ -98,25 +96,25 @@ namespace Avalonia.FreeDesktop.DBusIme
                         _connecting = false;
                     }
                 }
-                
+
             }
-            
+
             // IME has crashed
             if (args.NewOwner == null && args.ServiceName == _currentName)
             {
                 _currentName = null;
-                foreach(var s in _disposables)
+                foreach (var s in _disposables)
                     s.Dispose();
                 _disposables.Clear();
-                
+
                 OnDisconnected();
                 Reset();
-                
+
                 // Watch again
                 Watch();
             }
         }
-        
+
         protected virtual Task Disconnect()
         {
             return Task.CompletedTask;
@@ -124,7 +122,7 @@ namespace Avalonia.FreeDesktop.DBusIme
 
         protected virtual void OnDisconnected()
         {
-            
+
         }
 
         protected virtual void Reset()
@@ -149,10 +147,14 @@ namespace Avalonia.FreeDesktop.DBusIme
             OnDisconnected();
             _currentName = null;
         }
-        
+
         protected void Enqueue(Func<Task> cb) => _queue.Enqueue(cb);
 
-        protected void AddDisposable(IDisposable d) => _disposables.Add(d);
+        protected void AddDisposable(IDisposable? d)
+        {
+            if(d is { })
+                _disposables.Add(d);
+        }
         
         public void Dispose()
         {
@@ -198,7 +200,7 @@ namespace Avalonia.FreeDesktop.DBusIme
             UpdateActive();
         }
         
-        void ITextInputMethodImpl.SetClient(ITextInputMethodClient client)
+        void ITextInputMethodImpl.SetClient(ITextInputMethodClient? client)
         {
             _controlActive = client is { };
             UpdateActive();
@@ -225,7 +227,7 @@ namespace Avalonia.FreeDesktop.DBusIme
             }
         }
 
-        private Action<string> _onCommit;
+        private Action<string>? _onCommit;
         event Action<string> IX11InputMethodControl.Commit
         {
             add => _onCommit += value;
@@ -234,7 +236,7 @@ namespace Avalonia.FreeDesktop.DBusIme
 
         protected void FireCommit(string s) => _onCommit?.Invoke(s);
         
-        private Action<X11InputMethodForwardedKey> _onForward;
+        private Action<X11InputMethodForwardedKey>? _onForward;
         event Action<X11InputMethodForwardedKey> IX11InputMethodControl.ForwardKey
         {
             add => _onForward += value;

src/Avalonia.FreeDesktop/DBusIme/Fcitx/FcitxDBus.cs

@@ -31,15 +31,15 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
         Task SetSurroundingTextPositionAsync(uint Cursor, uint Anchor);
         Task DestroyICAsync();
         Task<int> ProcessKeyEventAsync(uint Keyval, uint Keycode, uint State, int Type, uint Time);
-        Task<IDisposable> WatchEnableIMAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchEnableIMAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchCloseIMAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchCloseIMAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchCommitStringAsync(Action<string> handler, Action<Exception> onError = null);
+        Task<IDisposable?> WatchCommitStringAsync(Action<string> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchCurrentIMAsync(Action<(string name, string uniqueName, string langCode)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchCurrentIMAsync(Action<(string name, string uniqueName, string langCode)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdatePreeditAsync(Action<(string str, int cursorpos)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdatePreeditAsync(Action<(string str, int cursorpos)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdateFormattedPreeditAsync(Action<((string, int)[] str, int cursorpos)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdateFormattedPreeditAsync(Action<((string, int)[] str, int cursorpos)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdateClientSideUIAsync(Action<(string auxup, string auxdown, string preedit, string candidateword, string imname, int cursorpos)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdateClientSideUIAsync(Action<(string auxup, string auxdown, string preedit, string candidateword, string imname, int cursorpos)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchForwardKeyAsync(Action<(uint keyval, uint state, int type)> handler, Action<Exception> onError = null);
+        Task<IDisposable?> WatchForwardKeyAsync(Action<(uint keyval, uint state, int type)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchDeleteSurroundingTextAsync(Action<(int offset, uint nchar)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchDeleteSurroundingTextAsync(Action<(int offset, uint nchar)> handler, Action<Exception>? onError = null);
     }
     
     [DBusInterface("org.fcitx.Fcitx.InputContext1")]
@@ -54,11 +54,11 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
         Task SetSurroundingTextPositionAsync(uint Cursor, uint Anchor);
         Task DestroyICAsync();
         Task<bool> ProcessKeyEventAsync(uint Keyval, uint Keycode, uint State, bool Type, uint Time);
-        Task<IDisposable> WatchCommitStringAsync(Action<string> handler, Action<Exception> onError = null);
+        Task<IDisposable?> WatchCommitStringAsync(Action<string> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchCurrentIMAsync(Action<(string name, string uniqueName, string langCode)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchCurrentIMAsync(Action<(string name, string uniqueName, string langCode)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdateFormattedPreeditAsync(Action<((string, int)[] str, int cursorpos)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdateFormattedPreeditAsync(Action<((string, int)[] str, int cursorpos)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchForwardKeyAsync(Action<(uint keyval, uint state, bool type)> handler, Action<Exception> onError = null);
+        Task<IDisposable?> WatchForwardKeyAsync(Action<(uint keyval, uint state, bool type)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchDeleteSurroundingTextAsync(Action<(int offset, uint nchar)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchDeleteSurroundingTextAsync(Action<(int offset, uint nchar)> handler, Action<Exception>? onError = null);
     }
 
     [DBusInterface("org.fcitx.Fcitx.InputMethod1")]

src/Avalonia.FreeDesktop/DBusIme/Fcitx/FcitxICWrapper.cs

@@ -5,8 +5,8 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
 {
     internal class FcitxICWrapper
     {
-        private readonly IFcitxInputContext1 _modern;
+        private readonly IFcitxInputContext1? _modern;
-        private readonly IFcitxInputContext _old;
+        private readonly IFcitxInputContext? _old;
 
         public FcitxICWrapper(IFcitxInputContext old)
         {
@@ -18,34 +18,37 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
             _modern = modern;
         }
 
-        public Task FocusInAsync() => _old?.FocusInAsync() ?? _modern.FocusInAsync();
+        public Task FocusInAsync() => _old?.FocusInAsync() ?? _modern?.FocusInAsync() ?? Task.CompletedTask;
 
-        public Task FocusOutAsync() => _old?.FocusOutAsync() ?? _modern.FocusOutAsync();
+        public Task FocusOutAsync() => _old?.FocusOutAsync() ?? _modern?.FocusOutAsync() ?? Task.CompletedTask;
         
-        public Task ResetAsync() => _old?.ResetAsync() ?? _modern.ResetAsync();
+        public Task ResetAsync() => _old?.ResetAsync() ?? _modern?.ResetAsync() ?? Task.CompletedTask;
 
         public Task SetCursorRectAsync(int x, int y, int w, int h) =>
-            _old?.SetCursorRectAsync(x, y, w, h) ?? _modern.SetCursorRectAsync(x, y, w, h);
+            _old?.SetCursorRectAsync(x, y, w, h) ?? _modern?.SetCursorRectAsync(x, y, w, h) ?? Task.CompletedTask;
-        public Task DestroyICAsync() => _old?.DestroyICAsync() ?? _modern.DestroyICAsync();
+        public Task DestroyICAsync() => _old?.DestroyICAsync() ?? _modern?.DestroyICAsync() ?? Task.CompletedTask;
 
         public async Task<bool> ProcessKeyEventAsync(uint keyVal, uint keyCode, uint state, int type, uint time)
         {
             if(_old!=null)
                 return await _old.ProcessKeyEventAsync(keyVal, keyCode, state, type, time) != 0;
-            return await _modern.ProcessKeyEventAsync(keyVal, keyCode, state, type > 0, time);
+            return await (_modern?.ProcessKeyEventAsync(keyVal, keyCode, state, type > 0, time) ?? Task.FromResult(false));
         }
 
-        public Task<IDisposable> WatchCommitStringAsync(Action<string> handler) =>
+        public Task<IDisposable?> WatchCommitStringAsync(Action<string> handler) =>
-            _old?.WatchCommitStringAsync(handler) ?? _modern.WatchCommitStringAsync(handler);
+            _old?.WatchCommitStringAsync(handler) 
+                ?? _modern?.WatchCommitStringAsync(handler) 
+                    ?? Task.FromResult(default(IDisposable?));
 
-        public Task<IDisposable> WatchForwardKeyAsync(Action<(uint keyval, uint state, int type)> handler)
+        public Task<IDisposable?> WatchForwardKeyAsync(Action<(uint keyval, uint state, int type)> handler)
         {
             return _old?.WatchForwardKeyAsync(handler)
-                   ?? _modern.WatchForwardKeyAsync(ev =>
+                   ?? _modern?.WatchForwardKeyAsync(ev =>
-                       handler((ev.keyval, ev.state, ev.type ? 1 : 0)));
+                       handler((ev.keyval, ev.state, ev.type ? 1 : 0)))
+                    ?? Task.FromResult(default(IDisposable?));
         }
 
         public Task SetCapacityAsync(uint flags) =>
-            _old?.SetCapacityAsync(flags) ?? _modern.SetCapabilityAsync(flags);
+            _old?.SetCapacityAsync(flags) ?? _modern?.SetCapabilityAsync(flags) ?? Task.CompletedTask;
     }
 }

src/Avalonia.FreeDesktop/DBusIme/Fcitx/FcitxX11TextInputMethod.cs

@@ -12,7 +12,7 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
 {
     internal class FcitxX11TextInputMethod : DBusTextInputMethodBase
     {
-        private FcitxICWrapper _context;
+        private FcitxICWrapper? _context;
         private FcitxCapabilityFlags? _lastReportedFlags;
 
         public FcitxX11TextInputMethod(Connection connection) : base(connection,
@@ -49,7 +49,7 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
             return true;
         }
 
-        protected override Task Disconnect() => _context.DestroyICAsync();
+        protected override Task Disconnect() => _context?.DestroyICAsync() ?? Task.CompletedTask;
 
         protected override void OnDisconnected() => _context = null;
 
@@ -60,18 +60,18 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
         }
 
         protected override Task SetCursorRectCore(PixelRect cursorRect) =>
-            _context.SetCursorRectAsync(cursorRect.X, cursorRect.Y, Math.Max(1, cursorRect.Width),
+            _context?.SetCursorRectAsync(cursorRect.X, cursorRect.Y, Math.Max(1, cursorRect.Width),
-                Math.Max(1, cursorRect.Height));
+                Math.Max(1, cursorRect.Height))
-
+            ?? Task.CompletedTask;
-        protected override Task SetActiveCore(bool active)
+
-        {
+        protected override Task SetActiveCore(bool active)=> (active 
-            if (active)
+                ? _context?.FocusInAsync()
-                return _context.FocusInAsync();
+                : _context?.FocusOutAsync())
-            else
+             ?? Task.CompletedTask;
-                return _context.FocusOutAsync();
+        
-        }
 
-        protected override Task ResetContextCore() => _context.ResetAsync();
+        protected override Task ResetContextCore() => _context?.ResetAsync() 
+            ?? Task.CompletedTask;
 
         protected override async Task<bool> HandleKeyCore(RawKeyEventArgs args, int keyVal, int keyCode)
         {
@@ -88,9 +88,15 @@ namespace Avalonia.FreeDesktop.DBusIme.Fcitx
             var type = args.Type == RawKeyEventType.KeyDown ?
                 FcitxKeyEventType.FCITX_PRESS_KEY :
                 FcitxKeyEventType.FCITX_RELEASE_KEY;
-            
+            if (_context is { })
-            return await _context.ProcessKeyEventAsync((uint)keyVal, (uint)keyCode, (uint)state, (int)type,
+            {
-                (uint)args.Timestamp).ConfigureAwait(false);
+                return await _context.ProcessKeyEventAsync((uint)keyVal, (uint)keyCode, (uint)state, (int)type,
+                    (uint)args.Timestamp).ConfigureAwait(false);
+            }
+            else
+            {
+                return false;
+            }
         }
         
         public override void SetOptions(TextInputOptions options) =>

src/Avalonia.FreeDesktop/DBusIme/IBus/IBusDBus.cs

@@ -22,25 +22,25 @@ namespace Avalonia.FreeDesktop.DBusIme.IBus
         Task<object> GetEngineAsync();
         Task DestroyAsync();
         Task SetSurroundingTextAsync(object Text, uint CursorPos, uint AnchorPos);
-        Task<IDisposable> WatchCommitTextAsync(Action<object> cb, Action<Exception> onError = null);
+        Task<IDisposable> WatchCommitTextAsync(Action<object> cb, Action<Exception>? onError = null);
-        Task<IDisposable> WatchForwardKeyEventAsync(Action<(uint keyval, uint keycode, uint state)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchForwardKeyEventAsync(Action<(uint keyval, uint keycode, uint state)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchRequireSurroundingTextAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchRequireSurroundingTextAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchDeleteSurroundingTextAsync(Action<(int offset, uint nchars)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchDeleteSurroundingTextAsync(Action<(int offset, uint nchars)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdatePreeditTextAsync(Action<(object text, uint cursorPos, bool visible)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdatePreeditTextAsync(Action<(object text, uint cursorPos, bool visible)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchShowPreeditTextAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchShowPreeditTextAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchHidePreeditTextAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchHidePreeditTextAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdateAuxiliaryTextAsync(Action<(object text, bool visible)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdateAuxiliaryTextAsync(Action<(object text, bool visible)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchShowAuxiliaryTextAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchShowAuxiliaryTextAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchHideAuxiliaryTextAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchHideAuxiliaryTextAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdateLookupTableAsync(Action<(object table, bool visible)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdateLookupTableAsync(Action<(object table, bool visible)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchShowLookupTableAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchShowLookupTableAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchHideLookupTableAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchHideLookupTableAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchPageUpLookupTableAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchPageUpLookupTableAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchPageDownLookupTableAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchPageDownLookupTableAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchCursorUpLookupTableAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchCursorUpLookupTableAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchCursorDownLookupTableAsync(Action handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchCursorDownLookupTableAsync(Action handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchRegisterPropertiesAsync(Action<object> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchRegisterPropertiesAsync(Action<object> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchUpdatePropertyAsync(Action<object> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchUpdatePropertyAsync(Action<object> handler, Action<Exception>? onError = null);
     }
     
     

src/Avalonia.FreeDesktop/DBusIme/IBus/IBusX11TextInputMethod.cs

@@ -9,7 +9,7 @@ namespace Avalonia.FreeDesktop.DBusIme.IBus
 {
     internal class IBusX11TextInputMethod : DBusTextInputMethodBase
     {
-        private IIBusInputContext _context;
+        private IIBusInputContext? _context;
 
         public IBusX11TextInputMethod(Connection connection) : base(connection, 
             "org.freedesktop.portal.IBus")
@@ -53,16 +53,16 @@ namespace Avalonia.FreeDesktop.DBusIme.IBus
         private void OnCommitText(object wtf)
         {
             // Hello darkness, my old friend
-            var prop = wtf.GetType().GetField("Item3");
+            if (wtf.GetType().GetField("Item3") is { } prop)
-            if (prop != null)
             {
-                var text = (string)prop.GetValue(wtf);
+                var text = prop.GetValue(wtf) as string;
                 if (!string.IsNullOrEmpty(text))
-                    FireCommit(text);
+                    FireCommit(text!);
             }
         }
 
-        protected override Task Disconnect() => _context.DestroyAsync();
+        protected override Task Disconnect() => _context?.DestroyAsync()
+            ?? Task.CompletedTask;
 
         protected override void OnDisconnected()
         {
@@ -71,13 +71,15 @@ namespace Avalonia.FreeDesktop.DBusIme.IBus
         }
 
         protected override Task SetCursorRectCore(PixelRect rect) 
-            => _context.SetCursorLocationAsync(rect.X, rect.Y, rect.Width, rect.Height);
+            => _context?.SetCursorLocationAsync(rect.X, rect.Y, rect.Width, rect.Height)
+            ?? Task.CompletedTask;
 
         protected override Task SetActiveCore(bool active)
-            => active ? _context.FocusInAsync() : _context.FocusOutAsync();
+            => (active ? _context?.FocusInAsync() : _context?.FocusOutAsync())
+                ?? Task.CompletedTask;
 
         protected override Task ResetContextCore()
-            => _context.ResetAsync();
+            => _context?.ResetAsync() ?? Task.CompletedTask;
 
         protected override Task<bool> HandleKeyCore(RawKeyEventArgs args, int keyVal, int keyCode)
         {
@@ -94,7 +96,15 @@ namespace Avalonia.FreeDesktop.DBusIme.IBus
             if (args.Type == RawKeyEventType.KeyUp)
                 state |= IBusModifierMask.ReleaseMask;
 
-            return _context.ProcessKeyEventAsync((uint)keyVal, (uint)keyCode, (uint)state);
+            if(_context is { })
+            {
+                return _context.ProcessKeyEventAsync((uint)keyVal, (uint)keyCode, (uint)state);
+            }
+            else
+            {
+                return Task.FromResult(false);
+            }
+            
         }
 
         public override void SetOptions(TextInputOptions options)

src/Avalonia.FreeDesktop/DBusIme/X11DBusImeHelper.cs

@@ -17,7 +17,7 @@ namespace Avalonia.FreeDesktop.DBusIme
                     new DBusInputMethodFactory<IBusX11TextInputMethod>(_ => new IBusX11TextInputMethod(conn))
             };
         
-        static Func<Connection, IX11InputMethodFactory> DetectInputMethod()
+        static Func<Connection, IX11InputMethodFactory>? DetectInputMethod()
         {
             foreach (var name in new[] { "AVALONIA_IM_MODULE", "GTK_IM_MODULE", "QT_IM_MODULE" })
             {

src/Avalonia.FreeDesktop/DBusMenu.cs

@@ -28,18 +28,18 @@ namespace Avalonia.FreeDesktop.DBusMenu
         Task<int[]> EventGroupAsync((int id, string eventId, object data, uint timestamp)[] events);
         Task<bool> AboutToShowAsync(int Id);
         Task<(int[] updatesNeeded, int[] idErrors)> AboutToShowGroupAsync(int[] Ids);
-        Task<IDisposable> WatchItemsPropertiesUpdatedAsync(Action<((int, IDictionary<string, object>)[] updatedProps, (int, string[])[] removedProps)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchItemsPropertiesUpdatedAsync(Action<((int, IDictionary<string, object>)[] updatedProps, (int, string[])[] removedProps)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchLayoutUpdatedAsync(Action<(uint revision, int parent)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchLayoutUpdatedAsync(Action<(uint revision, int parent)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchItemActivationRequestedAsync(Action<(int id, uint timestamp)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchItemActivationRequestedAsync(Action<(int id, uint timestamp)> handler, Action<Exception>? onError = null);
     }
 
     [Dictionary]
     class DBusMenuProperties
     {
         public uint Version { get; set; } = default (uint);
-        public string TextDirection { get; set; } = default (string);
+        public string? TextDirection { get; set; } = default (string);
-        public string Status { get; set; } = default (string);
+        public string? Status { get; set; } = default (string);
-        public string[] IconThemePath { get; set; } = default (string[]);
+        public string[]? IconThemePath { get; set; } = default (string[]);
     }
 
 
@@ -50,7 +50,7 @@ namespace Avalonia.FreeDesktop.DBusMenu
         Task UnregisterWindowAsync(uint WindowId);
         Task<(string service, ObjectPath menuObjectPath)> GetMenuForWindowAsync(uint WindowId);
         Task<(uint, string, ObjectPath)[]> GetMenusAsync();
-        Task<IDisposable> WatchWindowRegisteredAsync(Action<(uint windowId, string service, ObjectPath menuObjectPath)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchWindowRegisteredAsync(Action<(uint windowId, string service, ObjectPath menuObjectPath)> handler, Action<Exception>? onError = null);
-        Task<IDisposable> WatchWindowUnregisteredAsync(Action<uint> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchWindowUnregisteredAsync(Action<uint> handler, Action<Exception>? onError = null);
     }
 }

src/Avalonia.FreeDesktop/DBusMenuExporter.cs

@@ -17,7 +17,7 @@ namespace Avalonia.FreeDesktop
 {
     public class DBusMenuExporter
     {
-        public static ITopLevelNativeMenuExporter TryCreateTopLevelNativeMenu(IntPtr xid)
+        public static ITopLevelNativeMenuExporter? TryCreateTopLevelNativeMenu(IntPtr xid)
         {
             if (DBusHelper.Connection == null)
                 return null;
@@ -37,10 +37,10 @@ namespace Avalonia.FreeDesktop
         {
             private readonly Connection _dbus;
             private readonly uint _xid;
-            private IRegistrar _registrar;
+            private IRegistrar? _registrar;
             private bool _disposed;
             private uint _revision = 1;
-            private NativeMenu _menu;
+            private NativeMenu? _menu;
             private readonly Dictionary<int, NativeMenuItemBase> _idsToItems = new Dictionary<int, NativeMenuItemBase>();
             private readonly Dictionary<NativeMenuItemBase, int> _itemsToIds = new Dictionary<NativeMenuItemBase, int>();
             private readonly HashSet<NativeMenu> _menus = new HashSet<NativeMenu>();
@@ -73,10 +73,10 @@ namespace Avalonia.FreeDesktop
                     if (_appMenu)
                     {
                         await _dbus.RegisterObjectAsync(this);
-                        _registrar = DBusHelper.Connection.CreateProxy<IRegistrar>(
+                        _registrar = DBusHelper.Connection?.CreateProxy<IRegistrar>(
                             "com.canonical.AppMenu.Registrar",
                             "/com/canonical/AppMenu/Registrar");
-                        if (!_disposed)
+                        if (!_disposed && _registrar is { })
                             await _registrar.RegisterWindowAsync(_xid, ObjectPath);
                     }
                     else
@@ -109,9 +109,9 @@ namespace Avalonia.FreeDesktop
 
 
             public bool IsNativeMenuExported { get; private set; }
-            public event EventHandler OnIsNativeMenuExportedChanged;
+            public event EventHandler? OnIsNativeMenuExportedChanged;
 
-            public void SetNativeMenu(NativeMenu menu)
+            public void SetNativeMenu(NativeMenu? menu)
             {
                 if (menu == null)
                     menu = new NativeMenu();
@@ -153,7 +153,7 @@ namespace Avalonia.FreeDesktop
                 Dispatcher.UIThread.Post(DoLayoutReset, DispatcherPriority.Background);
             }
 
-            private (NativeMenuItemBase item, NativeMenu menu) GetMenu(int id)
+            private (NativeMenuItemBase? item, NativeMenu? menu) GetMenu(int id)
             {
                 if (id == 0)
                     return (null, _menu);
@@ -161,7 +161,7 @@ namespace Avalonia.FreeDesktop
                 return (item, (item as NativeMenuItem)?.Menu);
             }
 
-            private void EnsureSubscribed(NativeMenu menu)
+            private void EnsureSubscribed(NativeMenu? menu)
             {
                 if(menu!=null && _menus.Add(menu))
                     ((INotifyCollectionChanged)menu.Items).CollectionChanged += OnMenuItemsChanged;
@@ -180,12 +180,12 @@ namespace Avalonia.FreeDesktop
                 return id;
             }
 
-            private void OnMenuItemsChanged(object sender, NotifyCollectionChangedEventArgs e)
+            private void OnMenuItemsChanged(object? sender, NotifyCollectionChangedEventArgs e)
             {
                 QueueReset();
             }
 
-            private void OnItemPropertyChanged(object sender, AvaloniaPropertyChangedEventArgs e)
+            private void OnItemPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
             {
                 QueueReset();
             }
@@ -216,7 +216,7 @@ namespace Avalonia.FreeDesktop
                 "type", "label", "enabled", "visible", "shortcut", "toggle-type", "children-display", "toggle-state", "icon-data"
             };
             
-            object GetProperty((NativeMenuItemBase item, NativeMenu menu) i, string name)
+            object? GetProperty((NativeMenuItemBase? item, NativeMenu? menu) i, string name)
             {
                 var (it, menu) = i;
 
@@ -302,7 +302,7 @@ namespace Avalonia.FreeDesktop
             }
 
             private List<KeyValuePair<string, object>> _reusablePropertyList = new List<KeyValuePair<string, object>>();
-            KeyValuePair<string, object>[] GetProperties((NativeMenuItemBase item, NativeMenu menu) i, string[] names)
+            KeyValuePair<string, object>[] GetProperties((NativeMenuItemBase? item, NativeMenu? menu) i, string[] names)
             {
                 if (names?.Length > 0 != true)
                     names = AllProperties;
@@ -336,7 +336,7 @@ namespace Avalonia.FreeDesktop
                 return Task.FromResult(rv);
             }
 
-            (int, KeyValuePair<string, object>[], object[]) GetLayout(NativeMenuItemBase item, NativeMenu menu, int depth, string[] propertyNames)
+            (int, KeyValuePair<string, object>[], object[]) GetLayout(NativeMenuItemBase? item, NativeMenu? menu, int depth, string[] propertyNames)
             {
                 var id = item == null ? 0 : GetId(item);
                 var props = GetProperties((item, menu), propertyNames);
@@ -414,22 +414,22 @@ namespace Avalonia.FreeDesktop
 
             private event Action<((int, IDictionary<string, object>)[] updatedProps, (int, string[])[] removedProps)>
                 ItemsPropertiesUpdated { add { } remove { } }
-            private event Action<(uint revision, int parent)> LayoutUpdated;
+            private event Action<(uint revision, int parent)>? LayoutUpdated;
             private event Action<(int id, uint timestamp)> ItemActivationRequested { add { } remove { } }
             private event Action<PropertyChanges> PropertiesChanged { add { } remove { } }
 
-            async Task<IDisposable> IDBusMenu.WatchItemsPropertiesUpdatedAsync(Action<((int, IDictionary<string, object>)[] updatedProps, (int, string[])[] removedProps)> handler, Action<Exception> onError)
+            async Task<IDisposable> IDBusMenu.WatchItemsPropertiesUpdatedAsync(Action<((int, IDictionary<string, object>)[] updatedProps, (int, string[])[] removedProps)> handler, Action<Exception>? onError)
             {
                 ItemsPropertiesUpdated += handler;
                 return Disposable.Create(() => ItemsPropertiesUpdated -= handler);
             }
-            async Task<IDisposable> IDBusMenu.WatchLayoutUpdatedAsync(Action<(uint revision, int parent)> handler, Action<Exception> onError)
+            async Task<IDisposable> IDBusMenu.WatchLayoutUpdatedAsync(Action<(uint revision, int parent)> handler, Action<Exception>? onError)
             {
                 LayoutUpdated += handler;
                 return Disposable.Create(() => LayoutUpdated -= handler);
             }
 
-            async Task<IDisposable> IDBusMenu.WatchItemActivationRequestedAsync(Action<(int id, uint timestamp)> handler, Action<Exception> onError)
+            async Task<IDisposable> IDBusMenu.WatchItemActivationRequestedAsync(Action<(int id, uint timestamp)> handler, Action<Exception>? onError)
             {
                 ItemActivationRequested+= handler;
                 return Disposable.Create(() => ItemActivationRequested -= handler);

src/Avalonia.FreeDesktop/DBusRequest.cs

@@ -11,6 +11,6 @@ namespace Avalonia.FreeDesktop
     internal interface IRequest : IDBusObject
     {
         Task CloseAsync();
-        Task<IDisposable> WatchResponseAsync(Action<(uint response, IDictionary<string, object> results)> handler, Action<Exception> onError = null);
+        Task<IDisposable> WatchResponseAsync(Action<(uint response, IDictionary<string, object> results)> handler, Action<Exception>? onError = null);
     }
 }

src/Avalonia.FreeDesktop/LinuxMountedVolumeInfoProvider.cs

@@ -10,7 +10,7 @@ namespace Avalonia.FreeDesktop
         public IDisposable Listen(ObservableCollection<MountedVolumeInfo> mountedDrives)
         {
             Contract.Requires<ArgumentNullException>(mountedDrives != null);
-            return new LinuxMountedVolumeInfoListener(ref mountedDrives);
+            return new LinuxMountedVolumeInfoListener(ref mountedDrives!);
         }
     }
 }

src/Avalonia.SourceGenerator/Avalonia.SourceGenerator.csproj

@@ -11,6 +11,7 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.1.0" />
+    <Compile Include="..\Shared\IsExternalInit.cs" Link="IsExternalInit.cs" />
     <Compile Include="..\Shared\SourceGeneratorAttributes.cs" />
   </ItemGroup>
 

src/Avalonia.Themes.Default/Controls/ProgressBar.xaml

@@ -1,4 +1,6 @@
-<Styles xmlns="https://github.com/avaloniaui">
+<Styles xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:converters="clr-namespace:Avalonia.Controls.Converters;assembly=Avalonia.Controls">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="10">
@@ -11,10 +13,13 @@
     </Border>
   </Design.PreviewWith>
   <Style Selector="ProgressBar">
+    <Style.Resources>
+      <converters:StringFormatConverter x:Key="StringFormatConverter"/>
+    </Style.Resources>
     <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush4}"/>
     <Setter Property="Foreground" Value="{DynamicResource ThemeAccentBrush}"/>
     <Setter Property="Template">
-      <ControlTemplate>
+      <ControlTemplate TargetType="ProgressBar">
         <Grid>
           <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding CornerRadius}">
             <Panel>
@@ -23,7 +28,17 @@
             </Panel>
           </Border>
           <LayoutTransformControl HorizontalAlignment="Center" VerticalAlignment="Center" IsVisible="{Binding ShowProgressText, RelativeSource={RelativeSource TemplatedParent}}" Name="PART_LayoutTransformControl">
-            <TextBlock Foreground="{DynamicResource ThemeForegroundBrush}" Text="{Binding Value, RelativeSource={RelativeSource TemplatedParent}, StringFormat={}{0:0}%}" />
+            <TextBlock Foreground="{DynamicResource ThemeForegroundBrush}">
+              <TextBlock.Text>
+                <MultiBinding Converter="{StaticResource StringFormatConverter}">
+                  <TemplateBinding Property="ProgressTextFormat"/>
+                  <Binding Path="Value" RelativeSource="{RelativeSource TemplatedParent}"/>
+                  <TemplateBinding Property="Percentage"/>
+                  <TemplateBinding Property="Minimum"/>
+                  <TemplateBinding Property="Maximum"/>
+                </MultiBinding>
+              </TextBlock.Text>
+            </TextBlock>
           </LayoutTransformControl>
         </Grid>
       </ControlTemplate>

src/Avalonia.Themes.Fluent/Controls/ProgressBar.xaml

@@ -1,5 +1,6 @@
 <Styles xmlns="https://github.com/avaloniaui" 
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:converters="clr-namespace:Avalonia.Controls.Converters;assembly=Avalonia.Controls"
         x:CompileBindings="True">
   <Design.PreviewWith>
     <Border Padding="20">
@@ -13,6 +14,9 @@
     </Border>
   </Design.PreviewWith>
   <Style Selector="ProgressBar">
+    <Style.Resources>
+      <converters:StringFormatConverter x:Key="StringFormatConverter"/>
+    </Style.Resources>
     <Setter Property="Foreground" Value="{DynamicResource SystemControlHighlightAccentBrush}" />
     <Setter Property="Background" Value="{DynamicResource SystemControlBackgroundBaseLowBrush}" />
     <Setter Property="BorderThickness" Value="{DynamicResource ProgressBarBorderThemeThickness}" />
@@ -32,7 +36,17 @@
                 <Border x:Name="IndeterminateProgressBarIndicator2" CornerRadius="{TemplateBinding CornerRadius}" Margin="{TemplateBinding Padding}" Background="{TemplateBinding Foreground}" />
               </Panel>
               <LayoutTransformControl x:Name="PART_LayoutTransformControl" HorizontalAlignment="Center" VerticalAlignment="Center" IsVisible="{TemplateBinding ShowProgressText}">
-                <TextBlock Foreground="{DynamicResource SystemControlForegroundBaseHighBrush}" Text="{Binding Value, RelativeSource={RelativeSource TemplatedParent}, StringFormat={}{0:0}%}" />
+                <TextBlock Foreground="{DynamicResource SystemControlForegroundBaseHighBrush}">
+                  <TextBlock.Text>
+                    <MultiBinding Converter="{StaticResource StringFormatConverter}">
+                      <TemplateBinding Property="ProgressTextFormat"/>
+                      <Binding Path="Value" RelativeSource="{RelativeSource TemplatedParent}"/>
+                      <TemplateBinding Property="Percentage"/>
+                      <TemplateBinding Property="Minimum"/>
+                      <TemplateBinding Property="Maximum"/>
+                    </MultiBinding>
+                  </TextBlock.Text>
+                </TextBlock>
               </LayoutTransformControl>
             </Panel>
         </Border>

src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs

@@ -133,7 +133,7 @@ namespace Avalonia.LinuxFramebuffer.Output
             var device = gbm_create_device(card.Fd);
             _gbmTargetSurface = gbm_surface_create(device, modeInfo.Resolution.Width, modeInfo.Resolution.Height,
                 GbmColorFormats.GBM_FORMAT_XRGB8888, GbmBoFlags.GBM_BO_USE_SCANOUT | GbmBoFlags.GBM_BO_USE_RENDERING);
-            if(_gbmTargetSurface == null)
+            if(_gbmTargetSurface == IntPtr.Zero)
                 throw new InvalidOperationException("Unable to create GBM surface");
 
             _eglDisplay = new EglDisplay(new EglInterface(eglGetProcAddress), false, 0x31D7, device, null);

tests/Avalonia.Base.UnitTests/Layout/LayoutableTests_EffectiveViewportChanged.cs

@@ -312,6 +312,30 @@ namespace Avalonia.Base.UnitTests.Layout
             });
         }
 
+        [Fact]
+        public async Task Event_Unsubscribed_While_Inside_Callback()
+        {
+            await RunOnUIThread.Execute(async () =>
+            {
+                var root = CreateRoot();
+                var target = new Canvas();
+                var raised = 0;
+
+                void OnTargetOnEffectiveViewportChanged(object s, EffectiveViewportChangedEventArgs e)
+                {
+                    target.EffectiveViewportChanged -= OnTargetOnEffectiveViewportChanged;
+                    ++raised;
+                }
+                target.EffectiveViewportChanged += OnTargetOnEffectiveViewportChanged;
+
+                root.Child = target;
+
+                await ExecuteInitialLayoutPass(root);
+
+                Assert.Equal(1, raised);
+            });
+        }
+
         private TestRoot CreateRoot() => new TestRoot { Width = 1200, Height = 900 };
 
         private Task ExecuteInitialLayoutPass(TestRoot root)

tests/Avalonia.Controls.UnitTests/MenuItemTests.cs

@@ -8,6 +8,7 @@ using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Platform;
 using Avalonia.UnitTests;
+using Avalonia.VisualTree;
 using Moq;
 using Xunit;
 
@@ -301,6 +302,49 @@ namespace Avalonia.Controls.UnitTests
                 Assert.Equal(3, canExecuteCallCount);
             }
         }
+
+
+        [Fact]
+        public void TemplatedParent_Should_Not_Be_Applied_To_Submenus()
+        {
+            using (Application())
+            {
+                MenuItem topLevelMenu;
+                MenuItem childMenu1;
+                MenuItem childMenu2;
+                var menu = new Menu
+                {
+                    Items = new[]
+                    {
+                        (topLevelMenu = new MenuItem
+                        {
+                            Header = "Foo",
+                            Items = new[]
+                            {
+                                (childMenu1 = new MenuItem { Header = "Bar" }),
+                                (childMenu2 = new MenuItem { Header = "Baz" }),
+                            }
+                        }),
+                    }
+                };
+
+                var window = new Window { Content = menu };
+                window.LayoutManager.ExecuteInitialLayoutPass();
+
+                topLevelMenu.IsSubMenuOpen = true;
+
+                Assert.True(((IVisual)childMenu1).IsAttachedToVisualTree);
+                Assert.Null(childMenu1.TemplatedParent);
+                Assert.Null(childMenu2.TemplatedParent);
+
+                topLevelMenu.IsSubMenuOpen = false;
+                topLevelMenu.IsSubMenuOpen = true;
+
+                Assert.Null(childMenu1.TemplatedParent);
+                Assert.Null(childMenu2.TemplatedParent);
+            }
+        }
+
         private IDisposable Application()
         {
             var screen = new PixelRect(new PixelPoint(), new PixelSize(100, 100));

tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs

@@ -295,7 +295,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         }
 
         [Fact]
-        public void Templated_Control_With_Popup_In_Template_Should_Set_TemplatedParent()
+        public void ContentControl_With_Popup_In_Template_Should_Set_TemplatedParent()
         {
             // Test uses OverlayPopupHost default template
             using (CreateServices())
@@ -384,6 +384,134 @@ namespace Avalonia.Controls.UnitTests.Primitives
             }
         }
 
+        [Fact]
+        public void ItemsControl_With_Popup_In_Template_Should_Set_TemplatedParent()
+        {
+            // Test uses OverlayPopupHost default template
+            using (CreateServices())
+            {
+                PopupItemsControl target;
+                var item = new Border();
+                var root = PreparedWindow(target = new PopupItemsControl
+                {
+                    Items = new[] { item },
+                    Template = new FuncControlTemplate<PopupItemsControl>(PopupItemsControlTemplate),
+                }); ;
+                root.Show();
+
+                target.ApplyTemplate();
+
+                var popup = (Popup)target.GetTemplateChildren().First(x => x.Name == "popup");
+                popup.Open();
+
+                var popupRoot = (Control)popup.Host;
+                popupRoot.Measure(Size.Infinity);
+                popupRoot.Arrange(new Rect(popupRoot.DesiredSize));
+
+                var children = popupRoot.GetVisualDescendants().ToList();
+                var types = children.Select(x => x.GetType().Name).ToList();
+
+                if (UsePopupHost)
+                {
+                    Assert.Equal(
+                        new[]
+                        {
+                            "LayoutTransformControl",
+                            "VisualLayerManager",
+                            "ContentPresenter",
+                            "ItemsPresenter",
+                            "StackPanel",
+                            "Border",
+                        },
+                        types);
+                }
+                else
+                {
+                    Assert.Equal(
+                        new[]
+                        {
+                            "LayoutTransformControl",
+                            "Panel",
+                            "Border",
+                            "VisualLayerManager",
+                            "ContentPresenter",
+                            "ItemsPresenter",
+                            "StackPanel",
+                            "Border",
+                        },
+                        types);
+                }
+
+                var templatedParents = children
+                    .OfType<IControl>()
+                    .Select(x => x.TemplatedParent).ToList();
+
+                if (UsePopupHost)
+                {
+                    Assert.Equal(
+                        new object[]
+                        {
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            target,
+                            target,
+                            null,
+                        },
+                        templatedParents);
+                }
+                else
+                {
+                    Assert.Equal(
+                        new object[]
+                        {
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            popupRoot,
+                            target,
+                            target,
+                            null,
+                        },
+                        templatedParents);
+                }
+            }
+        }
+
+        [Fact]
+        public void Should_Not_Overwrite_TemplatedParent_Of_Item_In_ItemsControl_With_Popup_On_Second_Open()
+        {
+            // Test uses OverlayPopupHost default template
+            using (CreateServices())
+            {
+                PopupItemsControl target;
+                var item = new Border();
+                var root = PreparedWindow(target = new PopupItemsControl
+                {
+                    Items = new[] { item },
+                    Template = new FuncControlTemplate<PopupItemsControl>(PopupItemsControlTemplate),
+                });
+                root.Show();
+
+                target.ApplyTemplate();
+
+                var popup = (Popup)target.GetTemplateChildren().First(x => x.Name == "popup");
+                popup.Open();
+
+                var popupRoot = (Control)popup.Host;
+                popupRoot.Measure(Size.Infinity);
+                popupRoot.Arrange(new Rect(popupRoot.DesiredSize));
+
+                Assert.Null(item.TemplatedParent);
+
+                popup.Close();
+                popup.Open();
+
+                Assert.Null(item.TemplatedParent);
+            }
+        }
+
         [Fact]
         public void DataContextBeginUpdate_Should_Not_Be_Called_For_Controls_That_Dont_Inherit()
         {
@@ -979,10 +1107,27 @@ namespace Avalonia.Controls.UnitTests.Primitives
             }.RegisterInNameScope(scope);
         }
 
+        private static IControl PopupItemsControlTemplate(PopupItemsControl control, INameScope scope)
+        {
+            return new Popup
+            {
+                Name = "popup",
+                PlacementTarget = control,
+                Child = new ItemsPresenter
+                {
+                    [~ItemsPresenter.ItemsProperty] = control[~ItemsControl.ItemsProperty],
+                }
+            }.RegisterInNameScope(scope);
+        }
+
         private class PopupContentControl : ContentControl
         {
         }
 
+        private class PopupItemsControl : ItemsControl
+        {
+        }
+
         private class TestControl : Decorator
         {
             public event EventHandler DataContextBeginUpdate;

tests/Avalonia.Controls.UnitTests/WindowTests.cs

@@ -540,6 +540,33 @@ namespace Avalonia.Controls.UnitTests
                 Assert.Equal(window.Position, expectedPosition);
             }
         }
+        
+        [Fact]
+        public void Window_Should_Be_Sized_To_MinSize_If_InitialSize_Less_Than_MinSize()
+        {
+            var screen1 = new Mock<Screen>(1.75, new PixelRect(new PixelSize(1920, 1080)), new PixelRect(new PixelSize(1920, 966)), true);
+            var screens = new Mock<IScreenImpl>();
+            screens.Setup(x => x.AllScreens).Returns(new Screen[] { screen1.Object });
+            screens.Setup(x => x.ScreenFromPoint(It.IsAny<PixelPoint>())).Returns(screen1.Object);
+            
+            var windowImpl = MockWindowingPlatform.CreateWindowMock(400, 300);
+            windowImpl.Setup(x => x.DesktopScaling).Returns(1.75);
+            windowImpl.Setup(x => x.RenderScaling).Returns(1.75);
+            windowImpl.Setup(x => x.Screen).Returns(screens.Object);
+            
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var window = new Window(windowImpl.Object);
+                window.WindowStartupLocation = WindowStartupLocation.CenterScreen;
+                window.MinWidth = 720;
+                window.MinHeight = 480;
+
+                window.Show();
+                
+                Assert.Equal(new PixelPoint(330, 63), window.Position);
+                Assert.Equal(new Size(720, 480), window.Bounds.Size);
+            }
+        }
 
         [Fact]
         public void Window_Should_Be_Centered_Relative_To_Owner_When_WindowStartupLocation_Is_CenterOwner()

tests/Avalonia.UnitTests/MockWindowingPlatform.cs

@@ -21,11 +21,11 @@ namespace Avalonia.UnitTests
             _popupImpl = popupImpl;
         }
 
-        public static Mock<IWindowImpl> CreateWindowMock()
+        public static Mock<IWindowImpl> CreateWindowMock(double initialWidth = 800, double initialHeight = 600)
         {
             var windowImpl = new Mock<IWindowImpl>();
             var position = new PixelPoint();
-            var clientSize = new Size(800, 600);
+            var clientSize = new Size(initialWidth,  initialHeight);
 
             windowImpl.SetupAllProperties();
             windowImpl.Setup(x => x.ClientSize).Returns(() => clientSize);
@@ -55,12 +55,18 @@ namespace Avalonia.UnitTests
             windowImpl.Setup(x => x.Resize(It.IsAny<Size>(), It.IsAny<PlatformResizeReason>()))
                 .Callback<Size, PlatformResizeReason>((x, y) =>
             {
-                clientSize = x.Constrain(s_screenSize);
+                var constrainedSize = x.Constrain(s_screenSize);
-                windowImpl.Object.Resized?.Invoke(clientSize, y);
+                
+                if (constrainedSize != clientSize)
+                {
+                    clientSize = constrainedSize;
+                    windowImpl.Object.Resized?.Invoke(clientSize, y);
+                }
             });
 
             windowImpl.Setup(x => x.Show(true, It.IsAny<bool>())).Callback(() =>
             {
+                windowImpl.Object.Resized?.Invoke(windowImpl.Object.ClientSize, PlatformResizeReason.Unspecified);
                 windowImpl.Object.Activated?.Invoke();
             });