fix warnings and remove redundant code.

src/Web/Avalonia.Web.Blazor/AvaloniaBlazorAppBuilder.cs

@@ -1,4 +1,3 @@
-using System;
 using Avalonia.Controls;
 using Avalonia.Platform;
 
@@ -16,4 +15,4 @@ namespace Avalonia.Web.Blazor
             UseWindowingSubsystem(BlazorWindowingPlatform.Register);
         }
     }
-}
+}

src/Web/Avalonia.Web.Blazor/AvaloniaView.razor.cs

@@ -20,7 +20,7 @@ namespace Avalonia.Web.Blazor
         private SKHtmlCanvasInterop _interop = null!;
         private SizeWatcherInterop _sizeWatcher = null!;
         private DpiWatcherInterop _dpiWatcher = null!;
-        private SKHtmlCanvasInterop.GLInfo _jsGlInfo = null!;
+        private SKHtmlCanvasInterop.GLInfo? _jsGlInfo = null!;
         private InputHelperInterop _inputHelper = null!;
         private ElementReference _htmlCanvas;
         private ElementReference _inputElement;
@@ -33,7 +33,7 @@ namespace Avalonia.Web.Blazor
 
         private bool _initialised;
 
-        [Inject] IJSRuntime Js { get; set; } = null!;
+        [Inject] private IJSRuntime Js { get; set; } = null!;
 
         public AvaloniaView()
         {

src/Web/Avalonia.Web.Blazor/BlazorRuntimePlatform.cs

@@ -4,9 +4,10 @@ using Avalonia.Shared.PlatformSupport;
 
 namespace Avalonia.Web.Blazor
 {
-    class BlazorRuntimePlatform : IRuntimePlatform
+    internal class BlazorRuntimePlatform : IRuntimePlatform
     {
-        public static IRuntimePlatform Instance = new BlazorRuntimePlatform();
+        public static readonly IRuntimePlatform Instance = new BlazorRuntimePlatform();
+        
         public IDisposable StartSystemTimer(TimeSpan interval, Action tick)
         {
             return new Timer(_ => tick(), null, interval, interval);
@@ -25,24 +26,24 @@ namespace Avalonia.Web.Blazor
             };
         }
 
-        class BasicBlob : IUnmanagedBlob
+        private class BasicBlob : IUnmanagedBlob
         {
-            private IntPtr _data;
             public BasicBlob(int size)
             {
-                _data = Marshal.AllocHGlobal(size);
+                Address = Marshal.AllocHGlobal(size);
                 Size = size;
             }
             public void Dispose()
             {
-                if (_data != IntPtr.Zero)
-                    Marshal.FreeHGlobal(_data);
-                _data = IntPtr.Zero;
+                if (Address != IntPtr.Zero)
+                    Marshal.FreeHGlobal(Address);
+                Address = IntPtr.Zero;
             }
 
-            public IntPtr Address => _data;
+            public IntPtr Address { get; private set; }
+
             public int Size { get; }
-            public bool IsDisposed => _data == IntPtr.Zero;
+            public bool IsDisposed => Address == IntPtr.Zero;
         }
 
         public IUnmanagedBlob AllocBlob(int size)

src/Web/Avalonia.Web.Blazor/BlazorSingleViewLifetime.cs

@@ -6,7 +6,7 @@ namespace Avalonia.Web.Blazor
 {
     public class BlazorSingleViewLifetime : ISingleViewApplicationLifetime
     {
-        public Control MainView { get; set; }
+        public Control? MainView { get; set; }
     }
 
     public static class WebAppBuilder

src/Web/Avalonia.Web.Blazor/BlazorSkiaGpu.cs

@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using Avalonia.Skia;
 
 namespace Avalonia.Web.Blazor
@@ -18,7 +17,7 @@ namespace Avalonia.Web.Blazor
             return null;
         }
 
-        public ISkiaSurface TryCreateSurface(PixelSize size, ISkiaGpuRenderSession session)
+        public ISkiaSurface? TryCreateSurface(PixelSize size, ISkiaGpuRenderSession session)
         {
             return null;
         }

src/Web/Avalonia.Web.Blazor/BlazorSkiaSurface.cs

@@ -5,6 +5,16 @@ namespace Avalonia.Web.Blazor
 {
     internal class BlazorSkiaSurface
     {
+        public BlazorSkiaSurface(GRContext context, SKHtmlCanvasInterop.GLInfo glInfo, SKColorType colorType, PixelSize size, double scaling, GRSurfaceOrigin origin)
+        {
+            Context = context;
+            GlInfo = glInfo;
+            ColorType = colorType;
+            Size = size;
+            Scaling = scaling;
+            Origin = origin;
+        }
+        
         public SKColorType ColorType { get; set; }
 
         public PixelSize Size { get; set; }

src/Web/Avalonia.Web.Blazor/CustomFontManagerImpl.cs

@@ -1,6 +1,4 @@
-using System.Collections.Generic;
-using System.Globalization;
-using System.Linq;
+using System.Globalization;
 using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Skia;
@@ -34,8 +32,6 @@ namespace Avalonia.Web.Blazor
             return _customTypefaces.Select(x => x.FontFamily.Name);
         }
 
-        private readonly string[] _bcp47 = { CultureInfo.CurrentCulture.ThreeLetterISOLanguageName, CultureInfo.CurrentCulture.TwoLetterISOLanguageName };
-
         public bool TryMatchCharacter(int codepoint, FontStyle fontStyle, FontWeight fontWeight, FontFamily fontFamily,
             CultureInfo culture, out Typeface typeface)
         {

src/Web/Avalonia.Web.Blazor/ExampleJsInterop.cs

@@ -1,37 +0,0 @@
-using Microsoft.JSInterop;
-
-namespace Avalonia.Web.Blazor
-{
-    // This class provides an example of how JavaScript functionality can be wrapped
-    // in a .NET class for easy consumption. The associated JavaScript module is
-    // loaded on demand when first needed.
-    //
-    // This class can be registered as scoped DI service and then injected into Blazor
-    // components for use.
-
-    public class ExampleJsInterop : IAsyncDisposable
-    {
-        private readonly Lazy<Task<IJSObjectReference>> moduleTask;
-
-        public ExampleJsInterop(IJSRuntime jsRuntime)
-        {
-            moduleTask = new(() => jsRuntime.InvokeAsync<IJSObjectReference>(
-               "import", "./_content//exampleJsInterop.js").AsTask());
-        }
-
-        public async ValueTask<string> Prompt(string message)
-        {
-            var module = await moduleTask.Value;
-            return await module.InvokeAsync<string>("showPrompt", message);
-        }
-
-        public async ValueTask DisposeAsync()
-        {
-            if (moduleTask.IsValueCreated)
-            {
-                var module = await moduleTask.Value;
-                await module.DisposeAsync();
-            }
-        }
-    }
-}

src/Web/Avalonia.Web.Blazor/Keycodes.cs

@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using Avalonia.Input;
 
 namespace Avalonia.Web.Blazor

src/Web/Avalonia.Web.Blazor/ManualTriggerRenderTimer.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Diagnostics;
 using Avalonia.Rendering;
 
@@ -6,12 +5,12 @@ namespace Avalonia.Web.Blazor
 {
     public class ManualTriggerRenderTimer : IRenderTimer
     {
-        private static readonly Stopwatch _sw = Stopwatch.StartNew();
+        private static readonly Stopwatch s_sw = Stopwatch.StartNew();
 
-        public static ManualTriggerRenderTimer Instance { get; } = new ManualTriggerRenderTimer();
+        public static ManualTriggerRenderTimer Instance { get; } = new();
 
-        public void RaiseTick() => Tick?.Invoke(_sw.Elapsed);
+        public void RaiseTick() => Tick?.Invoke(s_sw.Elapsed);
 
-        public event Action<TimeSpan> Tick;
+        public event Action<TimeSpan>? Tick;
     }
-}
+}

src/Web/Avalonia.Web.Blazor/RazorViewTopLevelImpl.cs

@@ -9,6 +9,8 @@ using Avalonia.Rendering;
 using Avalonia.Web.Blazor.Interop;
 using SkiaSharp;
 
+#nullable enable
+
 namespace Avalonia.Web.Blazor
 {
     internal class RazorViewTopLevelImpl : ITopLevelImplWithTextInputMethod
@@ -16,13 +18,15 @@ namespace Avalonia.Web.Blazor
         private Size _clientSize;
         private BlazorSkiaSurface? _currentSurface;
         private IInputRoot? _inputRoot;
-        private Stopwatch _sw = Stopwatch.StartNew();
+        private readonly Stopwatch _sw = Stopwatch.StartNew();
         private readonly ITextInputMethodImpl _textInputMethod;
         private readonly TouchDevice _touchDevice;
 
         public RazorViewTopLevelImpl(ITextInputMethodImpl textInputMethod)
         {
             _textInputMethod = textInputMethod;
+            TransparencyLevel = WindowTransparencyLevel.None;
+            AcrylicCompensationLevels = new AcrylicPlatformCompensationLevels(1, 1, 1);
             _touchDevice = new TouchDevice();
         }
 
@@ -31,15 +35,8 @@ namespace Avalonia.Web.Blazor
 
         internal void SetSurface(GRContext context, SKHtmlCanvasInterop.GLInfo glInfo, SKColorType colorType, PixelSize size, double scaling)
         {
-            _currentSurface = new BlazorSkiaSurface
-            {
-                Context = context,
-                GlInfo = glInfo,
-                ColorType = colorType,
-                Size = size,
-                Scaling = scaling,
-                Origin = GRSurfaceOrigin.BottomLeft
-            };
+            _currentSurface =
+                new BlazorSkiaSurface(context, glInfo, colorType, size, scaling, GRSurfaceOrigin.BottomLeft);
         }
 
         public void SetClientSize(SKSize size, double dpi)
@@ -63,7 +60,7 @@ namespace Avalonia.Web.Blazor
         {
             if (_inputRoot is { })
             {
-                Input.Invoke(new RawTouchEventArgs(_touchDevice, Timestamp, _inputRoot, type, p, modifiers, touchPointId));
+                Input?.Invoke(new RawTouchEventArgs(_touchDevice, Timestamp, _inputRoot, type, p, modifiers, touchPointId));
             }
         }
 
@@ -102,8 +99,6 @@ namespace Avalonia.Web.Blazor
             }
         }
 
-
-
         public void Dispose()
         {
 
@@ -136,7 +131,7 @@ namespace Avalonia.Web.Blazor
 
         }
 
-        public IPopupImpl CreatePopup()
+        public IPopupImpl? CreatePopup()
         {
             return null;
         }
@@ -150,17 +145,15 @@ namespace Avalonia.Web.Blazor
         public Size? FrameSize => null;
         public double RenderScaling => 1;
 
-        public IEnumerable<object> Surfaces => new[] { _currentSurface };
-
-        internal BlazorSkiaSurface Surface => _currentSurface;
+        public IEnumerable<object> Surfaces => new object[] { _currentSurface! };
 
-        public Action<RawInputEventArgs> Input { get; set; }
-        public Action<Rect> Paint { get; set; }
-        public Action<Size, PlatformResizeReason> Resized { get; set; }
-        public Action<double> ScalingChanged { get; set; }
-        public Action<WindowTransparencyLevel> TransparencyLevelChanged { get; set; }
-        public Action Closed { get; set; }
-        public Action LostFocus { get; set; }
+        public Action<RawInputEventArgs>? Input { get; set; }
+        public Action<Rect>? Paint { get; set; }
+        public Action<Size, PlatformResizeReason>? Resized { get; set; }
+        public Action<double>? ScalingChanged { get; set; }
+        public Action<WindowTransparencyLevel>? TransparencyLevelChanged { get; set; }
+        public Action? Closed { get; set; }
+        public Action? LostFocus { get; set; }
         public IMouseDevice MouseDevice { get; } = new MouseDevice();
 
         public IKeyboardDevice KeyboardDevice { get; } = BlazorWindowingPlatform.Keyboard;

src/Web/Avalonia.Web.Blazor/WinStubs.cs

@@ -1,17 +1,14 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading.Tasks;
 using Avalonia.Controls;
 using Avalonia.Controls.Platform;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.Platform;
 
+#nullable enable
+
 namespace Avalonia.Web.Blazor
 {
-    class ClipboardStub : IClipboard
+    internal class ClipboardStub : IClipboard
     {
         public Task<string> GetTextAsync() => Task.FromResult("");
 
@@ -23,10 +20,10 @@ namespace Avalonia.Web.Blazor
 
         public Task<string[]> GetFormatsAsync() => Task.FromResult(Array.Empty<string>());
 
-        public Task<object> GetDataAsync(string format) => Task.FromResult<object>(null);
+        public Task<object> GetDataAsync(string format) => Task.FromResult<object>(new ());
     }
 
-    class CursorStub : ICursorImpl
+    internal class CursorStub : ICursorImpl
     {
         public void Dispose()
         {
@@ -34,7 +31,7 @@ namespace Avalonia.Web.Blazor
         }
     }
 
-    class CursorFactoryStub : ICursorFactory
+    internal class CursorFactoryStub : ICursorFactory
     {
         public ICursorImpl CreateCursor(IBitmapImpl cursor, PixelPoint hotSpot)
         {
@@ -47,9 +44,9 @@ namespace Avalonia.Web.Blazor
         }
     }
 
-    class IconLoaderStub : IPlatformIconLoader
+    internal class IconLoaderStub : IPlatformIconLoader
     {
-        class IconStub : IWindowIconImpl
+        private class IconStub : IWindowIconImpl
         {
             public void Save(Stream outputStream)
             {
@@ -64,20 +61,20 @@ namespace Avalonia.Web.Blazor
         public IWindowIconImpl LoadIcon(IBitmapImpl bitmap) => new IconStub();
     }
 
-    class SystemDialogsStub : ISystemDialogImpl
+    internal class SystemDialogsStub : ISystemDialogImpl
     {
-        public Task<string[]> ShowFileDialogAsync(FileDialog dialog, Window parent) =>
-            Task.FromResult((string[])null);
+        public Task<string[]?> ShowFileDialogAsync(FileDialog dialog, Window parent) =>
+            Task.FromResult((string[]?)null);
 
-        public Task<string> ShowFolderDialogAsync(OpenFolderDialog dialog, Window parent) =>
-            Task.FromResult((string)null);
+        public Task<string?> ShowFolderDialogAsync(OpenFolderDialog dialog, Window parent) =>
+            Task.FromResult((string?)null);
     }
 
-    class ScreenStub : IScreenImpl
+    internal class ScreenStub : IScreenImpl
     {
         public int ScreenCount => 1;
 
         public IReadOnlyList<Screen> AllScreens { get; } =
-            new Screen[] { new Screen(96, new PixelRect(0, 0, 4000, 4000), new PixelRect(0, 0, 4000, 4000), true) };
+            new[] { new Screen(96, new PixelRect(0, 0, 4000, 4000), new PixelRect(0, 0, 4000, 4000), true) };
     }
-}
+}

src/Web/Avalonia.Web.Blazor/WindowingPlatform.cs

@@ -5,15 +5,14 @@ using Avalonia.Platform;
 using Avalonia.Rendering;
 using Avalonia.Threading;
 
+#nullable enable
+
 namespace Avalonia.Web.Blazor
 {
     public class BlazorWindowingPlatform : IWindowingPlatform, IPlatformSettings, IPlatformThreadingInterface
     {
-        private static object _uiLock = new object();
-        private static object _syncRootLock = new object();
-        private bool _signaled = false;
-        private static int _uiThreadId = -1;
-        private static int _lockNesting = 0;
+        private bool _signaled;
+        private static int s_uiThreadId = -1;
 
         public IWindowImpl CreateWindow() => throw new NotSupportedException();
 
@@ -22,7 +21,7 @@ namespace Avalonia.Web.Blazor
             throw new NotImplementedException();
         }
 
-        public ITrayIconImpl CreateTrayIcon()
+        public ITrayIconImpl? CreateTrayIcon()
         {
             return null;
         }
@@ -61,36 +60,29 @@ namespace Avalonia.Web.Blazor
             return AvaloniaLocator.Current.GetService<IRuntimePlatform>()
                 .StartSystemTimer(interval, () =>
                 {
-                    using (Lock())
-                    {
-                        Dispatcher.UIThread.RunJobs(priority);
-                        tick();
-                    }
+                    Dispatcher.UIThread.RunJobs(priority);
+                    tick();
                 });
         }
 
         public void Signal(DispatcherPriority priority)
         {
-            lock (_syncRootLock)
-            {
-                if (_signaled)
-                    return;
-                _signaled = true;
-                IDisposable disp = null;
-                disp = AvaloniaLocator.Current.GetService<IRuntimePlatform>()
-                    .StartSystemTimer(TimeSpan.FromMilliseconds(1),
-                        () =>
-                        {
-                            lock (_syncRootLock)
-                            {
-                                _signaled = false;
-                                disp.Dispose();
-                            }
-
-                            using (Lock())
-                                Signaled?.Invoke(null);
-                        });
-            }
+            if (_signaled)
+                return;
+            
+            _signaled = true;
+            
+            IDisposable? disp = null;
+            
+            disp = AvaloniaLocator.Current.GetService<IRuntimePlatform>()
+                .StartSystemTimer(TimeSpan.FromMilliseconds(1),
+                    () =>
+                    {
+                        _signaled = false;
+                        disp?.Dispose();
+
+                        Signaled?.Invoke(null);
+                    });
         }
 
         public bool CurrentThreadIsLoopThread
@@ -101,33 +93,8 @@ namespace Avalonia.Web.Blazor
             }
         }
 
-        public event Action<DispatcherPriority?> Signaled;
-
-        class LockDisposable : IDisposable
-        {
-            public void Dispose()
-            {
-                lock (_syncRootLock)
-                {
-                    _lockNesting--;
-                    if (_lockNesting == 0)
-                        _uiThreadId = -1;
-                }
-
-                Monitor.Exit(_uiLock);
-            }
-        }
-
-        public static IDisposable Lock()
-        {
-            Monitor.Enter(_uiLock);
-            lock (_syncRootLock)
-            {
-                _lockNesting++;
-                _uiThreadId = Thread.CurrentThread.ManagedThreadId;
-            }
+        public event Action<DispatcherPriority?>? Signaled;
 
-            return new LockDisposable();
-        }
+        
     }
 }