Improve flexibility with build-in controls localization (#13773)

* Avoid hardcoding strings in DateTimePicker cs files

* Add invariant resources

* Implement ResourceProvider for flexibility of localization with custom resource provider

* Fix these weird tests

* Seal some ResourceDictionary extension points

* Replace "Locale" with "String"

src/Avalonia.Base/Controls/ResourceDictionary.cs

@@ -2,6 +2,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Avalonia.Collections;
 using Avalonia.Controls.Templates;
@@ -13,11 +14,10 @@ namespace Avalonia.Controls
     /// <summary>
     /// An indexed dictionary of resources.
     /// </summary>
-    public class ResourceDictionary : IResourceDictionary, IThemeVariantProvider
+    public class ResourceDictionary : ResourceProvider, IResourceDictionary, IThemeVariantProvider
     {
         private object? lastDeferredItemKey;
         private Dictionary<object, object?>? _inner;
-        private IResourceHost? _owner;
         private AvaloniaList<IResourceProvider>? _mergedDictionaries;
         private AvaloniaDictionary<ThemeVariant, IThemeVariantProvider>? _themeDictionary;
 
@@ -29,7 +29,7 @@ public ResourceDictionary() { }
         /// <summary>
         /// Initializes a new instance of the <see cref="ResourceDictionary"/> class.
         /// </summary>
-        public ResourceDictionary(IResourceHost owner) => Owner = owner;
+        public ResourceDictionary(IResourceHost owner) : base(owner) { }
 
         public int Count => _inner?.Count ?? 0;
 
@@ -50,19 +50,6 @@ public object? this[object key]
         public ICollection<object> Keys => (ICollection<object>?)_inner?.Keys ?? Array.Empty<object>();
         public ICollection<object?> Values => (ICollection<object?>?)_inner?.Values ?? Array.Empty<object?>();
 
-        public IResourceHost? Owner
-        {
-            get => _owner;
-            private set
-            {
-                if (_owner != value)
-                {
-                    _owner = value;
-                    OwnerChanged?.Invoke(this, EventArgs.Empty);
-                }
-            }
-        }
-
         public IList<IResourceProvider> MergedDictionaries
         {
             get
@@ -123,7 +110,7 @@ public IDictionary<ThemeVariant, IThemeVariantProvider> ThemeDictionaries
 
         ThemeVariant? IThemeVariantProvider.Key { get; set; }
 
-        bool IResourceNode.HasResources
+        public sealed override bool HasResources
         {
             get
             {
@@ -150,9 +137,7 @@ bool IResourceNode.HasResources
         bool ICollection<KeyValuePair<object, object?>>.IsReadOnly => false;
 
         private Dictionary<object, object?> Inner => _inner ??= new();
-
-        public event EventHandler? OwnerChanged;
-
+
         public void Add(object key, object? value)
         {
             Inner.Add(key, value);
@@ -187,7 +172,7 @@ public bool Remove(object key)
             return false;
         }
 
-        public bool TryGetResource(object key, ThemeVariant? theme, out object? value)
+        public sealed override bool TryGetResource(object key, ThemeVariant? theme, out object? value)
         {
             if (TryGetValue(key, out value))
                 return true;
@@ -316,17 +301,8 @@ internal bool ContainsDeferredKey(object key)
             return false;
         }
 
-        void IResourceProvider.AddOwner(IResourceHost owner)
+        protected sealed override void OnAddOwner(IResourceHost owner)
         {
-            owner = owner ?? throw new ArgumentNullException(nameof(owner));
-
-            if (Owner != null)
-            {
-                throw new InvalidOperationException("The ResourceDictionary already has a parent.");
-            }
-
-            Owner = owner;
-
             var hasResources = _inner?.Count > 0;
 
             if (_mergedDictionaries is not null)
@@ -352,37 +328,30 @@ void IResourceProvider.AddOwner(IResourceHost owner)
             }
         }
 
-        void IResourceProvider.RemoveOwner(IResourceHost owner)
+        protected sealed override void OnRemoveOwner(IResourceHost owner)
         {
-            owner = owner ?? throw new ArgumentNullException(nameof(owner));
+            var hasResources = _inner?.Count > 0;
 
-            if (Owner == owner)
+            if (_mergedDictionaries is not null)
             {
-                Owner = null;
-
-                var hasResources = _inner?.Count > 0;
-
-                if (_mergedDictionaries is not null)
+                foreach (var i in _mergedDictionaries)
                 {
-                    foreach (var i in _mergedDictionaries)
-                    {
-                        i.RemoveOwner(owner);
-                        hasResources |= i.HasResources;
-                    }
+                    i.RemoveOwner(owner);
+                    hasResources |= i.HasResources;
                 }
-                if (_themeDictionary is not null)
+            }
+            if (_themeDictionary is not null)
+            {
+                foreach (var i in _themeDictionary.Values)
                 {
-                    foreach (var i in _themeDictionary.Values)
-                    {
-                        i.RemoveOwner(owner);
-                        hasResources |= i.HasResources;
-                    }
+                    i.RemoveOwner(owner);
+                    hasResources |= i.HasResources;
                 }
+            }
 
-                if (hasResources)
-                {
-                    owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
-                }
+            if (hasResources)
+            {
+                owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
             }
         }
 

src/Avalonia.Base/Controls/ResourceProvider.cs

@@ -0,0 +1,102 @@
+using System;
+using Avalonia.Styling;
+
+namespace Avalonia.Controls;
+
+/// <summary>
+/// Base implementation for IResourceProvider interface.
+/// Includes Owner property management.
+/// </summary>
+public abstract class ResourceProvider : IResourceProvider
+{
+    private IResourceHost? _owner;
+
+    public ResourceProvider()
+    {
+    }
+
+    public ResourceProvider(IResourceHost owner)
+    {
+        _owner = owner;
+    }
+
+    /// <inheritdoc/>
+    public abstract bool HasResources { get; }
+
+    /// <inheritdoc/>
+    public abstract bool TryGetResource(object key, ThemeVariant? theme, out object? value);
+
+    /// <inheritdoc/>
+    public IResourceHost? Owner
+    {
+        get => _owner;
+        private set
+        {
+            if (_owner != value)
+            {
+                _owner = value;
+                OwnerChanged?.Invoke(this, EventArgs.Empty);
+            }
+        }
+    }
+
+    /// <inheritdoc/>
+    public event EventHandler? OwnerChanged;
+
+    protected void RaiseResourcesChanged()
+    {
+        Owner?.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
+    }
+
+    /// <summary>
+    /// Handles when owner was added.
+    /// Base method implementation raises <see cref="IResourceHost.NotifyHostedResourcesChanged"/>, if this provider has any resources.
+    /// </summary>
+    /// <param name="owner">New owner.</param>
+    protected virtual void OnAddOwner(IResourceHost owner)
+    {
+        if (HasResources)
+        {
+            owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
+        }
+    }
+
+    /// <summary>
+    /// Handles when owner was removed.
+    /// Base method implementation raises <see cref="IResourceHost.NotifyHostedResourcesChanged"/>, if this provider has any resources.
+    /// </summary>
+    /// <param name="owner">Old owner.</param>
+    protected virtual void OnRemoveOwner(IResourceHost owner)
+    {
+        if (HasResources)
+        {
+            owner.NotifyHostedResourcesChanged(ResourcesChangedEventArgs.Empty);
+        }
+    }
+
+    void IResourceProvider.AddOwner(IResourceHost owner)
+    {
+        owner = owner ?? throw new ArgumentNullException(nameof(owner));
+
+        if (Owner != null)
+        {
+            throw new InvalidOperationException("The ResourceDictionary already has a parent.");
+        }
+
+        Owner = owner;
+
+        OnAddOwner(owner);
+    }
+
+    void IResourceProvider.RemoveOwner(IResourceHost owner)
+    {
+        owner = owner ?? throw new ArgumentNullException(nameof(owner));
+
+        if (Owner == owner)
+        {
+            Owner = null;
+
+            OnRemoveOwner(owner);
+        }
+    }
+}

src/Avalonia.Controls/DateTimePickers/DatePicker.cs

@@ -373,10 +373,11 @@ private void SetSelectedDateText()
             }
             else
             {
+                // By clearing local value, we reset text property to the value from the template.
+                _monthText!.ClearValue(TextBlock.TextProperty);
+                _yearText!.ClearValue(TextBlock.TextProperty);
+                _dayText!.ClearValue(TextBlock.TextProperty);
                 PseudoClasses.Set(":hasnodate", true);
-                _monthText!.Text = "month";
-                _yearText!.Text = "year";
-                _dayText!.Text = "day";
             }
         }
 

src/Avalonia.Controls/DateTimePickers/TimePicker.cs

@@ -190,10 +190,19 @@ private void SetGrid()
             if (_contentGrid == null)
                 return;
 
-            bool use24HourClock = ClockIdentifier == "24HourClock";
+            var use24HourClock = ClockIdentifier == "24HourClock";
 
-            var columnsD = use24HourClock ? "*, Auto, *" : "*, Auto, *, Auto, *";
-            _contentGrid.ColumnDefinitions = new ColumnDefinitions(columnsD);
+            var columnsD = new ColumnDefinitions();
+            columnsD.Add(new ColumnDefinition(GridLength.Star));
+            columnsD.Add(new ColumnDefinition(GridLength.Auto));
+            columnsD.Add(new ColumnDefinition(GridLength.Star));
+            if (!use24HourClock)
+            {
+                columnsD.Add(new ColumnDefinition(GridLength.Auto));
+                columnsD.Add(new ColumnDefinition(GridLength.Star));
+            }
+
+            _contentGrid.ColumnDefinitions = columnsD;
 
             _thirdPickerHost!.IsVisible = !use24HourClock;
             _secondSplitter!.IsVisible = !use24HourClock;
@@ -232,8 +241,9 @@ private void SetSelectedTimeText()
             }
             else
             {
-                _hourText.Text = "hour";
-                _minuteText.Text = "minute";
+                // By clearing local value, we reset text property to the value from the template.
+                _hourText.ClearValue(TextBlock.TextProperty);
+                _minuteText.ClearValue(TextBlock.TextProperty);
                 PseudoClasses.Set(":hasnotime", true);
 
                 _periodText.Text = DateTime.Now.Hour >= 12 ?  TimeUtils.GetPMDesignator() :  TimeUtils.GetAMDesignator();

src/Avalonia.Themes.Fluent/Accents/SystemAccentColors.cs

@@ -6,7 +6,7 @@
 
 namespace Avalonia.Themes.Fluent.Accents;
 
-internal class SystemAccentColors : IResourceProvider
+internal sealed class SystemAccentColors : ResourceProvider
 {
     public const string AccentKey = "SystemAccentColor";
     public const string AccentDark1Key = "SystemAccentColorDark1";
@@ -22,8 +22,8 @@ internal class SystemAccentColors : IResourceProvider
     private Color _systemAccentColorDark1, _systemAccentColorDark2, _systemAccentColorDark3;
     private Color _systemAccentColorLight1, _systemAccentColorLight2, _systemAccentColorLight3;
 
-    public bool HasResources => true;
-    public bool TryGetResource(object key, ThemeVariant? theme, out object? value)
+    public override bool HasResources => true;
+    public override bool TryGetResource(object key, ThemeVariant? theme, out object? value)
     {
         if (key is string strKey)
         {
@@ -81,38 +81,24 @@ public bool TryGetResource(object key, ThemeVariant? theme, out object? value)
         return false;
     }
 
-    public IResourceHost? Owner { get; private set; }
-    public event EventHandler? OwnerChanged;
-    public void AddOwner(IResourceHost owner)
+    protected override void OnAddOwner(IResourceHost owner)
     {
-        if (Owner != owner)
+        if (GetFromOwner(owner) is { } platformSettings)
         {
-            Owner = owner;
-            OwnerChanged?.Invoke(this, EventArgs.Empty);
-
-            if (GetFromOwner(owner) is { } platformSettings)
-            {
-                platformSettings.ColorValuesChanged += PlatformSettingsOnColorValuesChanged;
-            }
-
-            _invalidateColors = true;
+            platformSettings.ColorValuesChanged += PlatformSettingsOnColorValuesChanged;
         }
+
+        _invalidateColors = true;
     }
 
-    public void RemoveOwner(IResourceHost owner)
+    protected override void OnRemoveOwner(IResourceHost owner)
     {
-        if (Owner == owner)
+        if (GetFromOwner(owner) is { } platformSettings)
         {
-            Owner = null;
-            OwnerChanged?.Invoke(this, EventArgs.Empty);
-
-            if (GetFromOwner(owner) is { } platformSettings)
-            {
-                platformSettings.ColorValuesChanged -= PlatformSettingsOnColorValuesChanged;
-            }
-
-            _invalidateColors = true;
+            platformSettings.ColorValuesChanged -= PlatformSettingsOnColorValuesChanged;
         }
+
+        _invalidateColors = true;
     }
 
     private void EnsureColors()

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

@@ -97,12 +97,12 @@
                     VerticalAlignment="Stretch"
                     TemplatedControl.IsTemplateFocusTarget="True">
               <Grid Name="PART_ButtonContentGrid" ColumnDefinitions="78*,Auto,132*,Auto,78*">
-                <TextBlock Name="PART_DayTextBlock" Text="day" HorizontalAlignment="Center"
-                           Padding="{DynamicResource DatePickerHostPadding}"/>
-                <TextBlock Name="PART_MonthTextBlock" Text="month" TextAlignment="Left"
-                           Padding="{DynamicResource DatePickerHostMonthPadding}"/>
-                <TextBlock Name="PART_YearTextBlock" Text="year" HorizontalAlignment="Center"
-                           Padding="{DynamicResource DatePickerHostPadding}"/>
+                <TextBlock Name="PART_DayTextBlock" Text="{DynamicResource StringDatePickerDayText}" HorizontalAlignment="Center"
+                           Padding="{DynamicResource DatePickerHostPadding}" />
+                <TextBlock Name="PART_MonthTextBlock" Text="{DynamicResource StringDatePickerMonthText}" TextAlignment="Left"
+                           Padding="{DynamicResource DatePickerHostMonthPadding}" />
+                <TextBlock Name="PART_YearTextBlock" Text="{DynamicResource StringDatePickerYearText}" HorizontalAlignment="Center"
+                           Padding="{DynamicResource DatePickerHostPadding}" />
                 <Rectangle x:Name="PART_FirstSpacer"
                       Fill="{DynamicResource DatePickerSpacerFill}"
                       HorizontalAlignment="Center"