Merge branch 'master' into remove_header

.editorconfig

@@ -137,6 +137,11 @@ space_within_single_line_array_initializer_braces = true
 #Net Analyzer
 dotnet_analyzer_diagnostic.category-Performance.severity = none #error - Uncomment when all violations are fixed.
 
+# CA1802: Use literals where appropriate
+dotnet_diagnostic.CA1802.severity = warning
+# CA1825: Avoid zero-length array allocations
+dotnet_diagnostic.CA1825.severity = warning
+
 # Wrapping preferences
 csharp_wrap_before_ternary_opsigns = false
 

NOTICE.md

@@ -111,7 +111,7 @@ DEALINGS IN THE SOFTWARE.
 
 # Metsys.Bson
 
-Copyright (c) 2010, Karl Seguin - http://www.openmymind.net/
+Copyright (c) 2010, Karl Seguin - https://www.openmymind.net/
 All rights reserved.
  
 Redistribution and use in source and binary forms, with or without
@@ -302,4 +302,4 @@ https://github.com/chromium/chromium
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

samples/ControlCatalog.Android/MainActivity.cs

@@ -5,16 +5,8 @@ using Avalonia.Android;
 
 namespace ControlCatalog.Android
 {
-    [Activity(Label = "ControlCatalog.Android", Theme = "@style/MyTheme.NoActionBar", Icon = "@drawable/icon", LaunchMode = LaunchMode.SingleInstance, ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize)]
+    [Activity(Label = "ControlCatalog.Android", Theme = "@style/MyTheme.NoActionBar", Icon = "@drawable/icon", LaunchMode = LaunchMode.SingleTop, ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize)]
-    public class MainActivity : AvaloniaActivity<App>
+    public class MainActivity : AvaloniaMainActivity
     {
-        protected override AppBuilder CustomizeAppBuilder(AppBuilder builder)
-        {
-            return base.CustomizeAppBuilder(builder)
-                .AfterSetup(_ =>
-                {
-                    Pages.EmbedSample.Implementation = new EmbedSampleAndroid();
-                });
-        }
     }
 }

samples/ControlCatalog.Android/SplashActivity.cs

@@ -1,12 +1,23 @@
 using Android.App;
 using Android.Content;
+using Android.Content.PM;
 using Android.OS;
+using Avalonia.Android;
 
 namespace ControlCatalog.Android
 {
     [Activity(Theme = "@style/MyTheme.Splash", MainLauncher = true, NoHistory = true)]
-    public class SplashActivity : Activity
+    public class SplashActivity : AvaloniaSplashActivity<App>
     {
+        protected override Avalonia.AppBuilder CustomizeAppBuilder(Avalonia.AppBuilder builder)
+        {
+            return base.CustomizeAppBuilder(builder)
+                 .AfterSetup(_ =>
+                 {
+                     Pages.EmbedSample.Implementation = new EmbedSampleAndroid();
+                 });
+        }
+
         protected override void OnCreate(Bundle? savedInstanceState)
         {
             base.OnCreate(savedInstanceState);

samples/MobileSandbox.Android/MainActivity.cs

@@ -5,8 +5,8 @@ using Avalonia.Android;
 
 namespace MobileSandbox.Android
 {
-    [Activity(Label = "MobileSandbox.Android", Theme = "@style/MyTheme.NoActionBar", Icon = "@drawable/icon", LaunchMode = LaunchMode.SingleInstance, ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize)]
+    [Activity(Label = "MobileSandbox.Android", Theme = "@style/MyTheme.NoActionBar", Icon = "@drawable/icon", LaunchMode = LaunchMode.SingleTop, ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize)]
-    public class MainActivity : AvaloniaActivity<App>
+    public class MainActivity : AvaloniaMainActivity
     {
     }
 }

samples/MobileSandbox.Android/SplashActivity.cs

@@ -1,11 +1,11 @@
 using Android.App;
 using Android.Content;
-using Android.OS;
+using Avalonia.Android;
 
 namespace MobileSandbox.Android
 {
     [Activity(Theme = "@style/MyTheme.Splash", MainLauncher = true, NoHistory = true)]
-    public class SplashActivity : Activity
+    public class SplashActivity : AvaloniaSplashActivity<App>
     {
         protected override void OnResume()
         {

src/Android/Avalonia.Android/AvaloniaActivity.cs

@@ -1,105 +0,0 @@
-using Android.OS;
-using AndroidX.AppCompat.App;
-using Android.Content.Res;
-using AndroidX.Lifecycle;
-using Avalonia.Controls.ApplicationLifetimes;
-using Avalonia.Controls;
-using Android.Runtime;
-using Android.App;
-using Android.Content;
-using System;
-
-namespace Avalonia.Android
-{
-    public abstract class AvaloniaActivity : AppCompatActivity
-    {
-        internal class SingleViewLifetime : ISingleViewApplicationLifetime
-        {
-            public AvaloniaView View { get; internal set; }
-
-            public Control MainView
-            {
-                get => (Control)View.Content;
-                set => View.Content = value;
-            }
-        }
-
-        internal Action<int, Result, Intent> ActivityResult;
-        internal AvaloniaView View;
-        internal AvaloniaViewModel _viewModel;
-
-        protected abstract AppBuilder CreateAppBuilder();
-
-        protected override void OnCreate(Bundle savedInstanceState)
-        {
-            var builder = CreateAppBuilder();
-
-
-            var lifetime = new SingleViewLifetime();
-
-            builder.AfterSetup(x =>
-            {
-                _viewModel = new ViewModelProvider(this).Get(Java.Lang.Class.FromType(typeof(AvaloniaViewModel))) as AvaloniaViewModel;
-
-                View = new AvaloniaView(this);
-                if (_viewModel.Content != null)
-                {
-                    View.Content = _viewModel.Content;
-                }
-
-                SetContentView(View);
-                lifetime.View = View;
-
-                View.Prepare();
-            });
-
-            builder.SetupWithLifetime(lifetime);
-
-            base.OnCreate(savedInstanceState);
-        }
-        public object Content
-        {
-            get
-            {
-                return _viewModel.Content;
-            }
-            set
-            {
-                _viewModel.Content = value;
-                if (View != null)
-                    View.Content = value;
-            }
-        }
-
-        public override void OnConfigurationChanged(Configuration newConfig)
-        {
-            base.OnConfigurationChanged(newConfig);
-        }
-
-        protected override void OnDestroy()
-        {
-            View.Content = null;
-
-            base.OnDestroy();
-        }
-
-        protected override void OnActivityResult(int requestCode, [GeneratedEnum] Result resultCode, Intent data)
-        {
-            base.OnActivityResult(requestCode, resultCode, data);
-
-            ActivityResult?.Invoke(requestCode, resultCode, data);
-        }
-    }
-
-    public abstract class AvaloniaActivity<TApp> : AvaloniaActivity where TApp : Application, new()
-    {
-        protected virtual AppBuilder CustomizeAppBuilder(AppBuilder builder) => builder.UseAndroid();
-
-        protected override AppBuilder CreateAppBuilder()
-        {
-            var builder = AppBuilder.Configure<TApp>();
-
-            return CustomizeAppBuilder(builder);
-        }
-    }
-}

src/Android/Avalonia.Android/AvaloniaMainActivity.cs

@@ -0,0 +1,72 @@
+using System;
+using Android.App;
+using Android.Content;
+using Android.Content.Res;
+using Android.OS;
+using Android.Runtime;
+using AndroidX.AppCompat.App;
+using AndroidX.Lifecycle;
+
+namespace Avalonia.Android
+{
+    public abstract class AvaloniaMainActivity : AppCompatActivity
+    {
+        internal static object ViewContent;
+
+        internal Action<int, Result, Intent> ActivityResult;
+        internal AvaloniaView View;
+
+        protected override void OnCreate(Bundle savedInstanceState)
+        {
+            View = new AvaloniaView(this);
+            if (ViewContent != null)
+            {
+                View.Content = ViewContent;
+            }
+
+            View.Prepare();
+
+            if (Avalonia.Application.Current.ApplicationLifetime is SingleViewLifetime lifetime)
+            {
+                lifetime.View = View;
+            }
+
+            base.OnCreate(savedInstanceState);
+
+            SetContentView(View);
+        }
+
+        public object Content
+        {
+            get
+            {
+                return ViewContent;
+            }
+            set
+            {
+                ViewContent = value;
+                if (View != null)
+                    View.Content = value;
+            }
+        }
+
+        public override void OnConfigurationChanged(Configuration newConfig)
+        {
+            base.OnConfigurationChanged(newConfig);
+        }
+
+        protected override void OnDestroy()
+        {
+            View.Content = null;
+
+            base.OnDestroy();
+        }
+
+        protected override void OnActivityResult(int requestCode, [GeneratedEnum] Result resultCode, Intent data)
+        {
+            base.OnActivityResult(requestCode, resultCode, data);
+
+            ActivityResult?.Invoke(requestCode, resultCode, data);
+        }
+    }
+}

src/Android/Avalonia.Android/AvaloniaSplashActivity.cs

@@ -0,0 +1,34 @@
+using Android.OS;
+using AndroidX.AppCompat.App;
+using AndroidX.Lifecycle;
+
+namespace Avalonia.Android
+{
+    public abstract class AvaloniaSplashActivity : AppCompatActivity
+    {
+        protected abstract AppBuilder CreateAppBuilder();
+
+        protected override void OnCreate(Bundle? savedInstanceState)
+        {
+            base.OnCreate(savedInstanceState);
+
+            var builder = CreateAppBuilder();
+
+            var lifetime = new SingleViewLifetime();
+
+            builder.SetupWithLifetime(lifetime);
+        }
+    }
+
+    public abstract class AvaloniaSplashActivity<TApp> : AvaloniaSplashActivity where TApp : Application, new()
+    {
+        protected virtual AppBuilder CustomizeAppBuilder(AppBuilder builder) => builder.UseAndroid();
+
+        protected override AppBuilder CreateAppBuilder()
+        {
+            var builder = AppBuilder.Configure<TApp>();
+
+            return CustomizeAppBuilder(builder);
+        }
+    }
+}

src/Android/Avalonia.Android/AvaloniaViewModel.cs

@@ -1,11 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace Avalonia.Android
-{
-    internal class AvaloniaViewModel : AndroidX.Lifecycle.ViewModel
-    {
-        public object Content { get; set; }
-    }
-}

src/Android/Avalonia.Android/OpenGL/GlPlatformSurface.cs

@@ -1,4 +1,5 @@
-using Avalonia.OpenGL.Egl;
+using Avalonia.OpenGL;
+using Avalonia.OpenGL.Egl;
 using Avalonia.OpenGL.Surfaces;
 
 namespace Avalonia.Android.OpenGL
@@ -19,7 +20,8 @@ namespace Avalonia.Android.OpenGL
 
         public static GlPlatformSurface TryCreate(IEglWindowGlPlatformSurfaceInfo info)
         {
-            if (EglPlatformOpenGlInterface.TryCreate() is EglPlatformOpenGlInterface egl)
+            var feature = AvaloniaLocator.Current.GetService<IPlatformOpenGlInterface>();
+            if (feature is EglPlatformOpenGlInterface egl)
             {
                 return new GlPlatformSurface(egl, info);
             }

src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs

@@ -3,20 +3,14 @@ using System.Collections.Generic;
 
 using Android.Content;
 using Android.Graphics;
-using Android.Media.TV;
-using Android.OS;
 using Android.Runtime;
-using Android.Text;
 using Android.Views;
 using Android.Views.InputMethods;
-using Android.Widget;
 using Avalonia.Android.OpenGL;
-using Avalonia.Android.Platform.Input;
 using Avalonia.Android.Platform.Specific;
 using Avalonia.Android.Platform.Specific.Helpers;
 using Avalonia.Android.Platform.Storage;
 using Avalonia.Controls;
-using Avalonia.Controls.Documents;
 using Avalonia.Controls.Platform;
 using Avalonia.Controls.Platform.Surfaces;
 using Avalonia.Input;
@@ -29,7 +23,6 @@ using Avalonia.Platform.Storage;
 using Avalonia.Rendering;
 using Avalonia.Rendering.Composition;
 using Java.Lang;
-using static System.Net.Mime.MediaTypeNames;
 
 namespace Avalonia.Android.Platform.SkiaPlatform
 {
@@ -59,7 +52,7 @@ namespace Avalonia.Android.Platform.SkiaPlatform
                 _view.Resources.DisplayMetrics.HeightPixels).ToSize(RenderScaling);
 
             NativeControlHost = new AndroidNativeControlHostImpl(avaloniaView);
-            StorageProvider = new AndroidStorageProvider((AvaloniaActivity)avaloniaView.Context);
+            StorageProvider = new AndroidStorageProvider((AvaloniaMainActivity)avaloniaView.Context);
         }
 
         public virtual Point GetAvaloniaPointFromEvent(MotionEvent e, int pointerIndex) =>
@@ -301,7 +294,7 @@ namespace Avalonia.Android.Platform.SkiaPlatform
 
             IsComposing = true;
 
-            _inputMethod.Client.SetPreeditText(ComposingText);
+            _inputMethod.Client?.SetPreeditText(ComposingText);
 
             return base.SetComposingText(text, newCursorPosition);
         }

src/Android/Avalonia.Android/Platform/Storage/AndroidStorageProvider.cs

@@ -14,10 +14,10 @@ namespace Avalonia.Android.Platform.Storage;
 
 internal class AndroidStorageProvider : IStorageProvider
 {
-    private readonly AvaloniaActivity _activity;
+    private readonly AvaloniaMainActivity _activity;
     private int _lastRequestCode = 20000;
 
-    public AndroidStorageProvider(AvaloniaActivity activity)
+    public AndroidStorageProvider(AvaloniaMainActivity activity)
     {
         _activity = activity;
     }

src/Android/Avalonia.Android/SingleViewLifetime.cs

@@ -0,0 +1,26 @@
+using Avalonia.Controls;
+using Avalonia.Controls.ApplicationLifetimes;
+
+namespace Avalonia.Android
+{
+    internal class SingleViewLifetime : ISingleViewApplicationLifetime
+    {
+        private AvaloniaView _view;
+
+        public AvaloniaView View
+        {
+            get => _view; internal set
+            {
+                if (_view != null)
+                {
+                    _view.Content = null;
+                    _view.Dispose();
+                }
+                _view = value;
+                _view.Content = MainView;
+            }
+        }
+
+        public Control MainView { get; set; }
+    }
+}

src/Avalonia.Base/Media/TextFormatting/Unicode/GraphemeBreak.cs

@@ -2,6 +2,6 @@ namespace Avalonia.Media.TextFormatting.Unicode
 {
     internal static class GraphemeBreak
     {
-        public static byte[] Data => new byte[0];
+        public static byte[] Data => System.Array.Empty<byte>();
     }
 }

src/Avalonia.Build.Tasks/Avalonia.Build.Tasks.csproj

@@ -9,6 +9,11 @@
         <NoWarn>NU1605;CS8632</NoWarn>
     </PropertyGroup>
 
+    <!--Disable Net Perf. analyzer for submodule to avoid commit issue -->
+    <PropertyGroup>
+      <EnableNETAnalyzers>false</EnableNETAnalyzers>
+    </PropertyGroup>
+
     <ItemGroup>
       <Compile Include="../Avalonia.Base/Utilities/AvaloniaResourcesIndex.cs">
         <Link>Shared/AvaloniaResourcesIndex.cs</Link>

src/Avalonia.Controls.ColorPicker/Helpers/ColorPickerHelpers.cs

@@ -49,7 +49,7 @@ namespace Avalonia.Controls.Primitives
         {
             if (width == 0 || height == 0)
             {
-                return new byte[0];
+                return Array.Empty<byte>();
             }
 
             var bitmap = await Task.Run<byte[]>(() =>

src/Avalonia.Controls/TextBox.cs

@@ -18,6 +18,7 @@ using Avalonia.Media.TextFormatting;
 using Avalonia.Media.TextFormatting.Unicode;
 using Avalonia.Automation.Peers;
 using System.Diagnostics;
+using Avalonia.Threading;
 
 namespace Avalonia.Controls
 {
@@ -159,18 +160,41 @@ namespace Avalonia.Controls
                 (o, v) => o.UndoLimit = v,
                 unsetValue: -1);
 
+        /// <summary>
+        /// Defines the <see cref="CopyingToClipboard"/> event.
+        /// </summary>
         public static readonly RoutedEvent<RoutedEventArgs> CopyingToClipboardEvent =
             RoutedEvent.Register<TextBox, RoutedEventArgs>(
                 nameof(CopyingToClipboard), RoutingStrategies.Bubble);
 
+        /// <summary>
+        /// Defines the <see cref="CuttingToClipboard"/> event.
+        /// </summary>
         public static readonly RoutedEvent<RoutedEventArgs> CuttingToClipboardEvent =
             RoutedEvent.Register<TextBox, RoutedEventArgs>(
                 nameof(CuttingToClipboard), RoutingStrategies.Bubble);
 
+        /// <summary>
+        /// Defines the <see cref="PastingFromClipboard"/> event.
+        /// </summary>
         public static readonly RoutedEvent<RoutedEventArgs> PastingFromClipboardEvent =
             RoutedEvent.Register<TextBox, RoutedEventArgs>(
                 nameof(PastingFromClipboard), RoutingStrategies.Bubble);
 
+        /// <summary>
+        /// Defines the <see cref="TextChanged"/> event.
+        /// </summary>
+        public static readonly RoutedEvent<TextChangedEventArgs> TextChangedEvent =
+            RoutedEvent.Register<TextBox, TextChangedEventArgs>(
+                nameof(TextChanged), RoutingStrategies.Bubble);
+
+        /// <summary>
+        /// Defines the <see cref="TextChanging"/> event.
+        /// </summary>
+        public static readonly RoutedEvent<TextChangingEventArgs> TextChangingEvent =
+            RoutedEvent.Register<TextBox, TextChangingEventArgs>(
+                nameof(TextChanging), RoutingStrategies.Bubble);
+
         readonly struct UndoRedoState : IEquatable<UndoRedoState>
         {
             public string? Text { get; }
@@ -359,8 +383,8 @@ namespace Avalonia.Controls
         /// </summary>
         public double LineHeight
         {
-            get { return GetValue(LineHeightProperty); }
+            get => GetValue(LineHeightProperty);
-            set { SetValue(LineHeightProperty, value); }
+            set => SetValue(LineHeightProperty, value);
         }
 
         [Content]
@@ -376,11 +400,19 @@ namespace Avalonia.Controls
                 CaretIndex = CoerceCaretIndex(caretIndex, value);
                 SelectionStart = CoerceCaretIndex(selectionStart, value);
                 SelectionEnd = CoerceCaretIndex(selectionEnd, value);
-                if (SetAndRaise(TextProperty, ref _text, value) && IsUndoEnabled && !_isUndoingRedoing)
+
+                var textChanged = SetAndRaise(TextProperty, ref _text, value);
+
+                if (textChanged && IsUndoEnabled && !_isUndoingRedoing)
                 {
                     _undoRedoHelper.Clear();
                     SnapshotUndoRedo(); // so we always have an initial state
                 }
+
+                if (textChanged)
+                {
+                    RaiseTextChangeEvents();
+                }
             }
         }
 
@@ -564,6 +596,27 @@ namespace Avalonia.Controls
             remove => RemoveHandler(PastingFromClipboardEvent, value);
         }
 
+        /// <summary>
+        /// Occurs asynchronously after text changes and the new text is rendered.
+        /// </summary>
+        public event EventHandler<TextChangedEventArgs>? TextChanged
+        {
+            add => AddHandler(TextChangedEvent, value);
+            remove => RemoveHandler(TextChangedEvent, value);
+        }
+
+        /// <summary>
+        /// Occurs synchronously when text starts to change but before it is rendered.
+        /// </summary>
+        /// <remarks>
+        /// This event occurs just after the <see cref="Text"/> property value has been updated.
+        /// </remarks>
+        public event EventHandler<TextChangingEventArgs>? TextChanging
+        {
+            add => AddHandler(TextChangingEvent, value);
+            remove => RemoveHandler(TextChangingEvent, value);
+        }
+
         protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
         {
             _presenter = e.NameScope.Get<TextPresenter>("PART_TextPresenter");
@@ -1252,7 +1305,7 @@ namespace Avalonia.Controls
 
                 if (text != null && _wordSelectionStart >= 0)
                 {
-                    var distance = caretIndex - _wordSelectionStart;                 
+                    var distance = caretIndex - _wordSelectionStart;
 
                     if (distance <= 0)
                     {
@@ -1539,11 +1592,39 @@ namespace Avalonia.Controls
             return text.Substring(start, end - start);
         }
 
+        /// <summary>
+        /// Raises both the <see cref="TextChanging"/> and <see cref="TextChanged"/> events.
+        /// </summary>
+        /// <remarks>
+        /// This must be called after the <see cref="Text"/> property is set.
+        /// </remarks>
+        private void RaiseTextChangeEvents()
+        {
+            // Note the following sequence of these events (following WinUI)
+            // 1. TextChanging occurs synchronously when text starts to change but before it is rendered.
+            //    This occurs after the Text property is set.
+            // 2. TextChanged occurs asynchronously after text changes and the new text is rendered.
+
+            var textChangingEventArgs = new TextChangingEventArgs(TextChangingEvent);
+            RaiseEvent(textChangingEventArgs);
+
+            Dispatcher.UIThread.Post(() =>
+            {
+                var textChangedEventArgs = new TextChangedEventArgs(TextChangedEvent);
+                RaiseEvent(textChangedEventArgs);
+            }, DispatcherPriority.Normal);
+        }
+
         private void SetTextInternal(string value, bool raiseTextChanged = true)
         {
             if (raiseTextChanged)
             {
-                SetAndRaise(TextProperty, ref _text, value);
+                bool textChanged = SetAndRaise(TextProperty, ref _text, value);
+
+                if (textChanged)
+                {
+                    RaiseTextChangeEvents();
+                }
             }
             else
             {

src/Avalonia.Controls/TextBoxTextInputMethodClient.cs

@@ -64,7 +64,7 @@ namespace Avalonia.Controls
 
                 return new TextInputMethodSurroundingText
                 {
-                    Text = lineText ?? "",                   
+                    Text = lineText ?? "",
                     AnchorOffset = anchorOffset,
                     CursorOffset = cursorOffset
                 };

src/Avalonia.Controls/TextChangedEventArgs.cs

@@ -0,0 +1,20 @@
+using Avalonia.Interactivity;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Provides data specific to a TextChanged event.
+    /// </summary>
+    public class TextChangedEventArgs : RoutedEventArgs
+    {
+        public TextChangedEventArgs(RoutedEvent? routedEvent)
+            : base (routedEvent)
+        {
+        }
+
+        public TextChangedEventArgs(RoutedEvent? routedEvent, IInteractive? source)
+            : base(routedEvent, source)
+        {
+        }
+    }
+}

src/Avalonia.Controls/TextChangingEventArgs.cs

@@ -0,0 +1,20 @@
+using Avalonia.Interactivity;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Provides data specific to a TextChanging event.
+    /// </summary>
+    public class TextChangingEventArgs : RoutedEventArgs
+    {
+        public TextChangingEventArgs(RoutedEvent? routedEvent)
+            : base (routedEvent)
+        {
+        }
+
+        public TextChangingEventArgs(RoutedEvent? routedEvent, IInteractive? source)
+            : base(routedEvent, source)
+        {
+        }
+    }
+}

src/Avalonia.DesignerSupport/Remote/HtmlTransport/SimpleWebSocketHttpServer.cs

@@ -140,7 +140,7 @@ namespace Avalonia.DesignerSupport.Remote.HtmlTransport
                 IsWebsocketRequest = true;
                 if (headers.TryGetValue("Sec-WebSocket-Protocol", out h))
                     WebSocketProtocols = h.Split(',').Select(x => x.Trim()).ToArray();
-                else WebSocketProtocols = new string[0];
+                else WebSocketProtocols = Array.Empty<string>();
             }
         }
 

src/Avalonia.FreeDesktop/DBusMenuExporter.cs

@@ -340,7 +340,7 @@ namespace Avalonia.FreeDesktop
             {
                 var id = item == null ? 0 : GetId(item);
                 var props = GetProperties((item, menu), propertyNames);
-                var children = (depth == 0 || menu == null) ? new object[0] : new object[menu.Items.Count];
+                var children = (depth == 0 || menu == null) ? Array.Empty<object>() : new object[menu.Items.Count];
                 if(menu != null)
                     for (var c = 0; c < children.Length; c++)
                     {
@@ -397,7 +397,7 @@ namespace Avalonia.FreeDesktop
             {
                 foreach (var e in Events)
                     HandleEvent(e.id, e.eventId, e.data, e.timestamp);
-                return Task.FromResult(new int[0]);
+                return Task.FromResult(Array.Empty<int>());
             }
 
             public async Task<bool> AboutToShowAsync(int Id)
@@ -407,7 +407,7 @@ namespace Avalonia.FreeDesktop
 
             public async Task<(int[] updatesNeeded, int[] idErrors)> AboutToShowGroupAsync(int[] Ids)
             {
-                return (new int[0], new int[0]);
+                return (Array.Empty<int>(), Array.Empty<int>());
             }
 
             #region Events

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

@@ -99,7 +99,7 @@ namespace Avalonia.LinuxFramebuffer.Output
             // prepare for the new ioctl call
             var handles = new uint[] {handle, 0, 0, 0};
             var pitches = new uint[] {stride, 0, 0, 0};
-            var offsets = new uint[] {};
+            var offsets = Array.Empty<uint>();
 
             var ret = drmModeAddFB2(_card.Fd, w, h, format, handles, pitches,
                                     offsets, out var fbHandle, 0);

src/Windows/Avalonia.Win32/Win32Platform.cs

@@ -241,8 +241,8 @@ namespace Avalonia.Win32
             });
         }
 
-        private static readonly int SignalW = unchecked((int) 0xdeadbeaf);
+        private const int SignalW = unchecked((int)0xdeadbeaf);
-        private static readonly int SignalL = unchecked((int)0x12345678);
+        private const int SignalL = unchecked((int)0x12345678);
 
         public void Signal(DispatcherPriority prio)
         {

tests/Avalonia.Base.UnitTests/VisualTree/MockRenderInterface.cs

@@ -235,7 +235,7 @@ namespace Avalonia.Base.UnitTests.VisualTree
 
                 public bool FillContains(Point point)
                 {
-                    // Use the algorithm from http://www.blackpawn.com/texts/pointinpoly/default.html
+                    // Use the algorithm from https://www.blackpawn.com/texts/pointinpoly/default.html
                     // to determine if the point is in the geometry (since it will always be convex in this situation)
                     for (int i = 0; i < points.Count; i++)
                     {

tests/Avalonia.UnitTests/MockStreamGeometryImpl.cs

@@ -148,7 +148,7 @@ namespace Avalonia.UnitTests
 
             public bool FillContains(Point point)
             {
-                // Use the algorithm from http://www.blackpawn.com/texts/pointinpoly/default.html
+                // Use the algorithm from https://www.blackpawn.com/texts/pointinpoly/default.html
                 // to determine if the point is in the geometry (since it will always be convex in this situation)
                 for (int i = 0; i < points.Count; i++)
                 {