Merge 7b4eda133a into 3068850405

samples/ControlCatalog/MainView.xaml

@@ -174,6 +174,9 @@
       <TabItem Header="Platform Information">
         <pages:PlatformInfoPage />
       </TabItem>
+      <TabItem Header="Platform Settings">
+        <pages:PlatformSettingsPage />
+      </TabItem>
       <TabItem Header="Pointers">
         <pages:PointersPage />
       </TabItem>

samples/ControlCatalog/Pages/PlatformSettingsPage.xaml

@@ -0,0 +1,142 @@
+<UserControl x:Class="ControlCatalog.Pages.PlatformSettingsPage"
+             xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:viewModels="using:ControlCatalog.ViewModels"
+             d:DesignHeight="800"
+             d:DesignWidth="600"
+             mc:Ignorable="d"
+             x:DataType="viewModels:PlatformSettingsViewModel">
+  
+  <ScrollViewer>
+    <StackPanel Spacing="20" Margin="20">
+      
+      <TextBlock Text="Platform Settings Information" 
+                 FontSize="20" 
+                 FontWeight="Bold" />
+
+      <TextBlock Text="This page displays IPlatformSettings values which may change at runtime based on system settings."
+                 TextWrapping="Wrap"
+                 Opacity="0.7" />
+
+      <GroupBox Header="System Color Values">
+        <StackPanel Spacing="15">
+          <Grid ColumnDefinitions="180,*" RowDefinitions="Auto,Auto,Auto">
+            <TextBlock Grid.Column="0" Grid.Row="0" Text="Theme Variant:" VerticalAlignment="Center" />
+            <TextBlock Grid.Column="1" Grid.Row="0" Text="{Binding ThemeVariant}" FontWeight="Bold" VerticalAlignment="Center" />
+
+            <TextBlock Grid.Column="0" Grid.Row="1" Text="Contrast Preference:" VerticalAlignment="Center" Margin="0,10,0,0" />
+            <TextBlock Grid.Column="1" Grid.Row="1" Text="{Binding ContrastPreference}" FontWeight="Bold" VerticalAlignment="Center" Margin="0,10,0,0" />
+          </Grid>
+
+          <StackPanel Spacing="10">
+            <Grid ColumnDefinitions="180,120,*">
+              <TextBlock Grid.Column="0" Text="Accent Color 1:" VerticalAlignment="Center" />
+              <Border Grid.Column="1" 
+                      Width="100" 
+                      Height="40"
+                      BorderBrush="Black"
+                      BorderThickness="1"
+                      CornerRadius="4"
+                      HorizontalAlignment="Left">
+                <Border.Background>
+                  <SolidColorBrush Color="{Binding AccentColor1}" />
+                </Border.Background>
+              </Border>
+              <TextBlock Grid.Column="2" 
+                         Text="{Binding AccentColor1}" 
+                         VerticalAlignment="Center"
+                         Margin="10,0,0,0" />
+            </Grid>
+
+            <Grid ColumnDefinitions="180,120,*">
+              <TextBlock Grid.Column="0" Text="Accent Color 2:" VerticalAlignment="Center" />
+              <Border Grid.Column="1" 
+                      Width="100" 
+                      Height="40" 
+                      BorderBrush="Black"
+                      BorderThickness="1"
+                      CornerRadius="4"
+                      HorizontalAlignment="Left">
+                <Border.Background>
+                  <SolidColorBrush Color="{Binding AccentColor2}" />
+                </Border.Background>
+              </Border>
+              <TextBlock Grid.Column="2" 
+                         Text="{Binding AccentColor2}" 
+                         VerticalAlignment="Center"
+                         Margin="10,0,0,0" />
+            </Grid>
+
+            <Grid ColumnDefinitions="180,120,*">
+              <TextBlock Grid.Column="0" Text="Accent Color 3:" VerticalAlignment="Center" />
+              <Border Grid.Column="1" 
+                      Width="100" 
+                      Height="40" 
+                      BorderBrush="Black"
+                      BorderThickness="1"
+                      CornerRadius="4"
+                      HorizontalAlignment="Left">
+                <Border.Background>
+                  <SolidColorBrush Color="{Binding AccentColor3}" />
+                </Border.Background>
+              </Border>
+              <TextBlock Grid.Column="2" 
+                         Text="{Binding AccentColor3}" 
+                         VerticalAlignment="Center"
+                         Margin="10,0,0,0" />
+            </Grid>
+          </StackPanel>
+        </StackPanel>
+      </GroupBox>
+
+      <GroupBox Header="Language Settings">
+        <StackPanel Spacing="10">
+          <TextBlock Text="This reflects the preferred application language as specified in OS settings."
+                     TextWrapping="Wrap"
+                     Opacity="0.7"
+                     FontSize="12" />
+          <Grid ColumnDefinitions="180,*">
+            <TextBlock Grid.Column="0" Text="Preferred Language:" VerticalAlignment="Center" />
+            <TextBlock Grid.Column="1" Text="{Binding PreferredLanguage}" FontWeight="Bold" VerticalAlignment="Center" />
+          </Grid>
+        </StackPanel>
+      </GroupBox>
+
+      <GroupBox Header="Other Platform Settings">
+        <StackPanel Spacing="10">
+          <TextBlock Text="These settings are less commonly changed and are platform-specific."
+                     TextWrapping="Wrap"
+                     Opacity="0.7"
+                     FontSize="12" />
+          
+          <Grid ColumnDefinitions="180,*" RowDefinitions="Auto,Auto,Auto,Auto,Auto,Auto,Auto">
+            <TextBlock Grid.Column="0" Grid.Row="0" Text="Hold Wait Duration:" VerticalAlignment="Center" />
+            <TextBlock Grid.Column="1" Grid.Row="0" Text="{Binding HoldWaitDuration}" VerticalAlignment="Center" />
+
+            <TextBlock Grid.Column="0" Grid.Row="1" Text="Tap Size (Touch):" VerticalAlignment="Center" Margin="0,5,0,0" />
+            <TextBlock Grid.Column="1" Grid.Row="1" Text="{Binding TapSizeTouch}" VerticalAlignment="Center" Margin="0,5,0,0" />
+
+            <TextBlock Grid.Column="0" Grid.Row="2" Text="Tap Size (Mouse):" VerticalAlignment="Center" Margin="0,5,0,0" />
+            <TextBlock Grid.Column="1" Grid.Row="2" Text="{Binding TapSizeMouse}" VerticalAlignment="Center" Margin="0,5,0,0" />
+
+            <TextBlock Grid.Column="0" Grid.Row="3" Text="Double-Tap Size (Touch):" VerticalAlignment="Center" Margin="0,5,0,0" />
+            <TextBlock Grid.Column="1" Grid.Row="3" Text="{Binding DoubleTapSizeTouch}" VerticalAlignment="Center" Margin="0,5,0,0" />
+
+            <TextBlock Grid.Column="0" Grid.Row="4" Text="Double-Tap Size (Mouse):" VerticalAlignment="Center" Margin="0,5,0,0" />
+            <TextBlock Grid.Column="1" Grid.Row="4" Text="{Binding DoubleTapSizeMouse}" VerticalAlignment="Center" Margin="0,5,0,0" />
+
+            <TextBlock Grid.Column="0" Grid.Row="5" Text="Double-Tap Time (Touch):" VerticalAlignment="Center" Margin="0,5,0,0" />
+            <TextBlock Grid.Column="1" Grid.Row="5" Text="{Binding DoubleTapTimeTouch}" VerticalAlignment="Center" Margin="0,5,0,0" />
+
+            <TextBlock Grid.Column="0" Grid.Row="6" Text="Double-Tap Time (Mouse):" VerticalAlignment="Center" Margin="0,5,0,0" />
+            <TextBlock Grid.Column="1" Grid.Row="6" Text="{Binding DoubleTapTimeMouse}" VerticalAlignment="Center" Margin="0,5,0,0" />
+          </Grid>
+        </StackPanel>
+      </GroupBox>
+
+    </StackPanel>
+  </ScrollViewer>
+</UserControl>
+

samples/ControlCatalog/Pages/PlatformSettingsPage.xaml.cs

@@ -0,0 +1,15 @@
+using Avalonia.Controls;
+using ControlCatalog.ViewModels;
+
+namespace ControlCatalog.Pages
+{
+    public partial class PlatformSettingsPage : UserControl
+    {
+        public PlatformSettingsPage()
+        {
+            InitializeComponent();
+            DataContext = new PlatformSettingsViewModel();
+        }
+    }
+}
+

samples/ControlCatalog/ViewModels/PlatformSettingsViewModel.cs

@@ -0,0 +1,77 @@
+using System;
+using Avalonia;
+using Avalonia.Input;
+using Avalonia.Media;
+using Avalonia.Platform;
+using MiniMvvm;
+
+namespace ControlCatalog.ViewModels;
+
+public class PlatformSettingsViewModel : ViewModelBase
+{
+    private readonly IPlatformSettings? _platformSettings;
+    private PlatformColorValues? _colorValues;
+    private string? _preferredLanguage;
+
+    public PlatformSettingsViewModel()
+    {
+        _platformSettings = AvaloniaLocator.Current.GetService<IPlatformSettings>();
+        
+        if (_platformSettings != null)
+        {
+            _colorValues = _platformSettings.GetColorValues();
+            _preferredLanguage = _platformSettings.PreferredApplicationLanguage;
+            
+            _platformSettings.ColorValuesChanged += OnColorValuesChanged;
+            _platformSettings.PreferredApplicationLanguageChanged += OnPreferredLanguageChanged;
+        }
+    }
+
+    private void OnColorValuesChanged(object? sender, PlatformColorValues e)
+    {
+        _colorValues = e;
+        RaisePropertyChanged(nameof(ThemeVariant));
+        RaisePropertyChanged(nameof(ContrastPreference));
+        RaisePropertyChanged(nameof(AccentColor1));
+        RaisePropertyChanged(nameof(AccentColor2));
+        RaisePropertyChanged(nameof(AccentColor3));
+    }
+
+    private void OnPreferredLanguageChanged(object? sender, EventArgs e)
+    {
+        if (_platformSettings != null)
+        {
+            _preferredLanguage = _platformSettings.PreferredApplicationLanguage;
+            RaisePropertyChanged(nameof(PreferredLanguage));
+        }
+    }
+
+    public bool IsAvailable => _platformSettings != null;
+
+    public string PreferredLanguage => _preferredLanguage ?? "Not available";
+
+    public string ThemeVariant => _colorValues?.ThemeVariant.ToString() ?? "Not available";
+
+    public string ContrastPreference => _colorValues?.ContrastPreference.ToString() ?? "Not available";
+
+    public Color AccentColor1 => _colorValues?.AccentColor1 ?? Colors.Gray;
+
+    public Color AccentColor2 => _colorValues?.AccentColor2 ?? Colors.Gray;
+
+    public Color AccentColor3 => _colorValues?.AccentColor3 ?? Colors.Gray;
+
+    public string HoldWaitDuration => _platformSettings?.HoldWaitDuration.ToString() ?? "Not available";
+
+    public string TapSizeTouch => _platformSettings?.GetTapSize(PointerType.Touch).ToString() ?? "Not available";
+
+    public string TapSizeMouse => _platformSettings?.GetTapSize(PointerType.Mouse).ToString() ?? "Not available";
+
+    public string DoubleTapSizeTouch => _platformSettings?.GetDoubleTapSize(PointerType.Touch).ToString() ?? "Not available";
+
+    public string DoubleTapSizeMouse => _platformSettings?.GetDoubleTapSize(PointerType.Mouse).ToString() ?? "Not available";
+
+    public string DoubleTapTimeTouch => _platformSettings?.GetDoubleTapTime(PointerType.Touch).ToString() ?? "Not available";
+
+    public string DoubleTapTimeMouse => _platformSettings?.GetDoubleTapTime(PointerType.Mouse).ToString() ?? "Not available";
+}
+

src/Avalonia.Base/Platform/DefaultPlatformSettings.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Globalization;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.Media;
@@ -39,6 +40,9 @@ namespace Avalonia.Platform
         public PlatformHotkeyConfiguration HotkeyConfiguration =>
             AvaloniaLocator.Current.GetRequiredService<PlatformHotkeyConfiguration>();
 
+        public virtual string PreferredApplicationLanguage =>
+            CultureInfo.CurrentUICulture.Name;
+
         public virtual PlatformColorValues GetColorValues()
         {
             return new PlatformColorValues
@@ -48,11 +52,18 @@ namespace Avalonia.Platform
         }
 
         public virtual event EventHandler<PlatformColorValues>? ColorValuesChanged;
+        public virtual event EventHandler? PreferredApplicationLanguageChanged;
 
         protected void OnColorValuesChanged(PlatformColorValues colorValues)
         {
             Dispatcher.UIThread.Send(
                 _ => ColorValuesChanged?.Invoke(this, colorValues));
         }
+
+        protected void OnPreferredApplicationLanguageChanged()
+        {
+            Dispatcher.UIThread.Send(
+                _ => PreferredApplicationLanguageChanged?.Invoke(this, EventArgs.Empty));
+        }
     }
 }

src/Avalonia.Base/Platform/IPlatformSettings.cs

@@ -37,12 +37,17 @@ namespace Avalonia.Platform
         /// Holding duration between pointer press and when event is fired.
         /// </summary>
         TimeSpan HoldWaitDuration { get; }
-        
+
         /// <summary>
         /// Get a configuration for platform-specific hotkeys in an Avalonia application.
         /// </summary>
         PlatformHotkeyConfiguration HotkeyConfiguration { get; }
-        
+
+        /// <summary>
+        /// Gets the preferred application language as specified in the operating system settings.
+        /// </summary>
+        string PreferredApplicationLanguage { get; }
+
         /// <summary>
         /// Gets current system color values including dark mode and accent colors.
         /// </summary>
@@ -52,5 +57,10 @@ namespace Avalonia.Platform
         /// Raises when current system color values are changed. Including changing of a dark mode and accent colors.
         /// </summary>
         event EventHandler<PlatformColorValues>? ColorValuesChanged;
+
+        /// <summary>
+        /// Raises when the preferred application language is changed in the operating system settings.
+        /// </summary>
+        event EventHandler? PreferredApplicationLanguageChanged;
     }
 }

src/Browser/Avalonia.Browser/BrowserPlatformSettings.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using Avalonia.Browser.Interop;
 using Avalonia.Platform;
 
@@ -9,20 +10,41 @@ internal class BrowserPlatformSettings : DefaultPlatformSettings
     private bool _isDarkMode;
     private bool _isHighContrast;
     private bool _isInitialized;
+    private string? _lastLanguage;
 
     public override event EventHandler<PlatformColorValues>? ColorValuesChanged
     {
         add
         {
-            EnsureBackend();
+            EnsureSettings();
             base.ColorValuesChanged += value;
         }
         remove => base.ColorValuesChanged -= value;
     }
 
+    public override event EventHandler? PreferredApplicationLanguageChanged
+    {
+        add
+        {
+            EnsureSettings();
+            base.PreferredApplicationLanguageChanged += value;
+        }
+        remove => base.PreferredApplicationLanguageChanged -= value;
+    }
+
+    public override string PreferredApplicationLanguage
+    {
+        get
+        {
+            EnsureSettings();
+
+            return _lastLanguage ?? base.PreferredApplicationLanguage;
+        }
+    }
+
     public override PlatformColorValues GetColorValues()
     {
-        EnsureBackend();
+        EnsureSettings();
 
         return base.GetColorValues() with
         {
@@ -31,18 +53,27 @@ internal class BrowserPlatformSettings : DefaultPlatformSettings
         };
     }
 
-    public void OnValuesChanged(bool isDarkMode, bool isHighContrast)
+    public void OnColorValuesChanged(bool isDarkMode, bool isHighContrast)
     {
         _isDarkMode = isDarkMode;
         _isHighContrast = isHighContrast;
         OnColorValuesChanged(GetColorValues());
     }
-    
+
-    private void EnsureBackend()
+    public void OnPreferredLanguageChanged(string? language)
+    {
+        if (language is not null && _lastLanguage != language)
+        {
+            _lastLanguage = language;
+            OnPreferredApplicationLanguageChanged();   
+        }
+    }
+
+    private void EnsureSettings()
     {
         if (!_isInitialized)
         {
-            // WASM module has async nature of initialization. We can't native code right away during components registration. 
+            // WASM module has async nature of initialization. We can't call platform code right away during components registration. 
             _isInitialized = true;
             var values = DomHelper.GetDarkMode(BrowserWindowingPlatform.GlobalThis);
             if (values.Length == 2)
@@ -50,6 +81,8 @@ internal class BrowserPlatformSettings : DefaultPlatformSettings
                 _isDarkMode = values[0] > 0;
                 _isHighContrast = values[1] > 0;
             }
+
+            _lastLanguage = DomHelper.GetNavigatorLanguage(BrowserWindowingPlatform.GlobalThis);
         }
     }
 }

src/Browser/Avalonia.Browser/Interop/DomHelper.cs

@@ -1,4 +1,4 @@
-using System.Runtime.InteropServices.JavaScript;
+using System.Runtime.InteropServices.JavaScript;
 using System.Threading.Tasks;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Platform;
@@ -31,6 +31,9 @@ internal static partial class DomHelper
     [JSImport("AvaloniaDOM.getDarkMode", AvaloniaModule.MainModuleName)]
     public static partial int[] GetDarkMode(JSObject globalThis);
 
+    [JSImport("AvaloniaDOM.getNavigatorLanguage", AvaloniaModule.MainModuleName)]
+    public static partial string? GetNavigatorLanguage(JSObject globalThis);
+
     [JSImport("AvaloniaDOM.addClass", AvaloniaModule.MainModuleName)]
     public static partial void AddCssClass(JSObject element, string className);
 
@@ -40,7 +43,7 @@ internal static partial class DomHelper
     [JSExport]
     public static Task DarkModeChanged(bool isDarkMode, bool isHighContrast)
     {
-        (AvaloniaLocator.Current.GetService<IPlatformSettings>() as BrowserPlatformSettings)?.OnValuesChanged(isDarkMode, isHighContrast);
+        (AvaloniaLocator.Current.GetService<IPlatformSettings>() as BrowserPlatformSettings)?.OnColorValuesChanged(isDarkMode, isHighContrast);
         return Task.CompletedTask;
     }
 
@@ -51,6 +54,13 @@ internal static partial class DomHelper
         return Task.CompletedTask;
     }
 
+    [JSExport]
+    public static Task LanguageChanged(string language)
+    {
+        (AvaloniaLocator.Current.GetService<IPlatformSettings>() as BrowserPlatformSettings)?.OnPreferredLanguageChanged(language);
+        return Task.CompletedTask;
+    }
+
     [JSExport]
     public static Task ScreensChanged()
     {

src/Browser/Avalonia.Browser/webapp/modules/avalonia/dom.ts

@@ -136,6 +136,10 @@ export class AvaloniaDOM {
             });
         }
 
+        globalThis.addEventListener("languagechange", () => {
+            JsExports.DomHelper.LanguageChanged(globalThis.navigator.language);
+        });
+
         globalThis.document.addEventListener("visibilitychange", () => {
             JsExports.DomHelper.DocumentVisibilityChanged(globalThis.document.visibilityState);
         });
@@ -167,4 +171,8 @@ export class AvaloniaDOM {
             prefersContrastMedia.matches ? 1 : 0
         ];
     }
+
+    public static getNavigatorLanguage(globalThis: Window): string | null {
+        return globalThis.navigator?.language ?? null;
+    }
 }

src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs

@@ -1334,6 +1334,9 @@ namespace Avalonia.Win32.Interop
         [DllImport("kernel32.dll", CharSet = CharSet.Unicode, EntryPoint = "GetModuleHandleW", ExactSpelling = true)]
         public static extern IntPtr GetModuleHandle(string? lpModuleName);
 
+        [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+        public static extern int GetUserDefaultLocaleName(char* lpLocaleName, int cchLocaleName);
+
         [DllImport("user32.dll")]
         public static extern int GetSystemMetrics(SystemMetric smIndex);
 

src/Windows/Avalonia.Win32/Win32Platform.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
@@ -183,6 +183,10 @@ namespace Avalonia.Win32
                 {
                     win32PlatformSettings.OnColorValuesChanged();   
                 }
+                else if (changedSetting == "intl") // language/locale change
+                {
+                    win32PlatformSettings.OnLanguageChanged();
+                }
             }
 
             if (msg == (uint)WindowsMessage.WM_TIMER)

src/Windows/Avalonia.Win32/Win32PlatformSettings.cs

@@ -13,6 +13,7 @@ internal class Win32PlatformSettings : DefaultPlatformSettings
         && WinRTApiInformation.IsTypePresent("Windows.UI.ViewManagement.AccessibilitySettings")); 
 
     private PlatformColorValues? _lastColorValues;
+    private string? _lastLanguage;
 
     public override Size GetTapSize(PointerType type)
     {
@@ -33,6 +34,27 @@ internal class Win32PlatformSettings : DefaultPlatformSettings
     }
 
     public override TimeSpan GetDoubleTapTime(PointerType type) => TimeSpan.FromMilliseconds(GetDoubleClickTime());
+
+    public override string PreferredApplicationLanguage
+    {
+        get
+        {
+            if (_lastLanguage is null)
+            {
+                unsafe
+                {
+                    const int LOCALE_NAME_MAX_LENGTH = 85;
+                    var buffer = stackalloc char[LOCALE_NAME_MAX_LENGTH];
+                    var length = GetUserDefaultLocaleName(buffer, LOCALE_NAME_MAX_LENGTH);
+                    _lastLanguage = length > 0
+                        ? new string(buffer, 0, length - 1)
+                        : base.PreferredApplicationLanguage;
+                }
+            }
+
+            return _lastLanguage;
+        }
+    }
     
     public override PlatformColorValues GetColorValues()
     {
@@ -88,4 +110,16 @@ internal class Win32PlatformSettings : DefaultPlatformSettings
             OnColorValuesChanged(colorValues);
         }
     }
+
+    internal void OnLanguageChanged()
+    {
+        var oldLanguage = _lastLanguage;
+        _lastLanguage = null;
+        var newLanguage = PreferredApplicationLanguage;
+
+        if (oldLanguage != newLanguage)
+        {
+            OnPreferredApplicationLanguageChanged();
+        }
+    }
 }