First pass localisation where buttons can self-retranslate.

Keflon · Feb 25, 2024 · 7e24d8f · 7e24d8f
1 parent f848cc8
commit 7e24d8f
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Showing 9 changed files with 99 additions and 53 deletions.
diff --git a/FunctionZero.Maui.Controls/MarkupExtensions/TranslationService.cs b/FunctionZero.Maui.Controls/MarkupExtensions/TranslationService.cs
diff --git a/...i.Controls/Services/TranslationService.cs → ....Controls/Services/BaseLanguageService.cs b/...i.Controls/Services/TranslationService.cs → ....Controls/Services/BaseLanguageService.cs
@@ -1,4 +1,5 @@
-using System;
+using FunctionZero.Maui.MarkupExtensions;
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
@@ -11,30 +12,31 @@ namespace FunctionZero.Maui.Services
     /// <summary>
     /// Goal. To be decoupled enough to allow downloading and selection of new or updated language packs on the fly.
     /// </summary>
-    public class TranslationService : INotifyPropertyChanged
+    public abstract partial class BaseLanguageService<TEnum> : INotifyPropertyChanged where TEnum : Enum
     {
         private readonly string _resourceKey;
         private ResourceDictionary _resourceHost;
         private Dictionary<string, LanguageProvider> _languages;
         public event EventHandler<LanguageChangedEventArgs> LanguageChanged;
 
         // INPC raised by SetLanguage(..)
-        public string CurrentLanguageId => _resourceHost[_resourceKey] as string;
+        public string CurrentLanguageId { get; protected set; }
 
 
         public event PropertyChangedEventHandler PropertyChanged;
 
 
         // TODO: Expose an ObsColl of languages, so the app can e.g. download new language packs and the UI can bind to it all.
-        public TranslationService(string resourceKey = "LocalisedStrings")
+        public BaseLanguageService(string resourceKey = "languageResource")
         {
             _resourceKey = resourceKey;
             _languages = new();
         }
 
-        public void Init(ResourceDictionary resourceHost)
+        public void Init(ResourceDictionary resourceHost, string initialLanguage)
         {
             _resourceHost = resourceHost;
+            SetLanguage(initialLanguage);
         }
 
         public void RegisterLanguage(string id, LanguageProvider language)
@@ -51,27 +53,25 @@ public void RegisterLanguage(string id, LanguageProvider language)
         public void SetLanguage(string id)
         {
             if (_resourceHost == null)
-                throw new InvalidOperationException("You must call Init on the TranslationService before you call SetLanguage(string id), e.g. Init(Application.Current.Resources);");
+                throw new InvalidOperationException("You must call Init on the LanguageService before you call SetLanguage(string id), e.g. Init(Application.Current.Resources);");
 
             if (_languages.TryGetValue(id, out var languageService))
                 _resourceHost[_resourceKey] = languageService.GetLookup();
             else
                 throw new Exception($"Register a language before trying to set it. Language: '{id}' ");
 
+            CurrentLanguageId = id;
+
             LanguageChanged?.Invoke(this, new LanguageChangedEventArgs(id));
             PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(CurrentLanguageId)));
         }
 
         public string[] CurrentLookup => _resourceHost[_resourceKey] as string[];
-        public class LanguageProvider
+
+        public string GetText(TEnum textId)
         {
-            public LanguageProvider(Func<string[]> getLookup, string languageName)
-            {
-                GetLookup = getLookup;
-                LanguageName = languageName;
-            }
-            public Func<string[]> GetLookup { get; }
-            public string LanguageName { get; }
+            var retval = _languages[CurrentLanguageId].GetLookup()[(int)(object)textId];
+            return retval;
         }
     }
 }
diff --git a/FunctionZero.Maui.Controls/Services/LanguageProvider.cs b/FunctionZero.Maui.Controls/Services/LanguageProvider.cs
@@ -0,0 +1,13 @@
+namespace FunctionZero.Maui.Services
+{
+    public class LanguageProvider
+    {
+        public LanguageProvider(Func<string[]> getLookup, string languageName)
+        {
+            GetLookup = getLookup;
+            LanguageName = languageName;
+        }
+        public Func<string[]> GetLookup { get; }
+        public string LanguageName { get; }
+    }
+}
diff --git a/SampleApp/App.xaml.cs b/SampleApp/App.xaml.cs
@@ -2,19 +2,21 @@
 using FunctionZero.Maui.MvvmZero;
 using Microsoft.Maui.Platform;
 using SampleApp.Mvvm.PageViewModels;
+using SampleApp.Translations;
 using SampleApp.Widgets;
 using System.Diagnostics;
 
 namespace SampleApp
 {
     public partial class App : Application
     {
-        public App(IPageServiceZero pageService)
+        public App(IPageServiceZero pageService, LangService langService)
         {
             var temp = new WidgetContainer("", "", "");
             InitializeComponent();
 
             pageService.Init(this);
+            langService.Init(this.Resources, "english");
 
             // Uses AdaptedFlyoutPage because https://github.com/dotnet/maui/issues/13496
             var flyoutPage = pageService.GetFlyoutPage<AppFlyoutPageVm>();

diff --git a/SampleApp/MauiProgram.cs b/SampleApp/MauiProgram.cs
@@ -1,5 +1,6 @@
 using FunctionZero.Maui.Controls;
 using FunctionZero.Maui.MvvmZero;
+using FunctionZero.Maui.Services;
 using SampleApp.Mvvm.Pages;
 using SampleApp.Mvvm.Pages.Expander;
 using SampleApp.Mvvm.Pages.List;
@@ -14,6 +15,7 @@
 using SampleApp.Mvvm.PageViewModels.MultiView;
 using SampleApp.Mvvm.PageViewModels.Translations;
 using SampleApp.Mvvm.PageViewModels.Tree;
+using SampleApp.Translations;
 
 namespace SampleApp
 {
@@ -98,10 +100,27 @@ public static MauiApp CreateMauiApp()
                 .AddSingleton<TranslationHomePage>()
                 .AddSingleton<TranslationHomePageVm>()
 
+                .AddSingleton<LangService>(GetConfiguredLanguageService)
 
                ;
 
             return builder.Build();
         }
+
+        #region Language translation setup
+        private static LangService GetConfiguredLanguageService(IServiceProvider provider)
+        {
+            var translationService = new LangService();
+            translationService.RegisterLanguage("english", new LanguageProvider(GetEnglish, "English"));
+            translationService.RegisterLanguage("german", new LanguageProvider(GetGerman, "Deutsch"));
+
+            return translationService;
+        }
+
+        // Example
+        private static string[] GetEnglish() => new string[] { "Hello", "World", "Welcome to the Moasure Playground!" };
+        private static string[] GetGerman() => new string[] { "Hallo", "Welt", "Willkommen auf dem Moasure Spielplatz!" };
+
+        #endregion
     }
 }
diff --git a/SampleApp/Mvvm/PageViewModels/Translations/TranslationHomePageVm.cs b/SampleApp/Mvvm/PageViewModels/Translations/TranslationHomePageVm.cs
@@ -2,8 +2,10 @@
 using FunctionZero.Maui.MvvmZero;
 using FunctionZero.Maui.Services;
 using SampleApp.Mvvm.ViewModels;
+using SampleApp.Translations;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -13,19 +15,35 @@ namespace SampleApp.Mvvm.PageViewModels.Translations
 {
     public class TranslationHomePageVm : BasePageVm
     {
-        private string _selectedLanguage;
-
-        public IList<KeyValuePair<string, string>> AvailableLanguages { get; }
-
-        public string SelectedLanguage { get => _selectedLanguage; set => SetProperty(ref _selectedLanguage, value); }
+        private readonly LangService _langService;
 
         public ICommand SetLanguageCommand { get; }
-        public TranslationHomePageVm(TranslationService translationService)
+        public ICommand DoTheThingCommand { get; }
+        public TranslationHomePageVm(LangService langService)
         {
-            AvailableLanguages = [new KeyValuePair<string, string>("English", "english"), new KeyValuePair<string, string>("Deutsch", "german")];
+            _langService = langService;
 
             SetLanguageCommand = new CommandBuilder()
-                .SetText()=>translationService.
+                .AddGuard(this)
+                .SetExecute(SetLanguageCommandExecute)
+                .Build();
+
+            DoTheThingCommand = new CommandBuilder()
+                .AddGuard(this)
+                .SetExecute(DoTheThingCommandExecute)
+                .SetName(() => langService.GetText(LangStrings.E_World))
+                .AddObservedProperty(langService, nameof(LangService.CurrentLanguageId))
+                .Build();
+        }
+
+        private void DoTheThingCommandExecute()
+        {
+            Debug.WriteLine($"New language: {_langService.CurrentLanguageId}");
+        }
+
+        private void SetLanguageCommandExecute(object arg)
+        {
+            _langService.SetLanguage((string)arg);
         }
     }
 }
diff --git a/SampleApp/Mvvm/Pages/Translations/TranslationHomePage.xaml b/SampleApp/Mvvm/Pages/Translations/TranslationHomePage.xaml
@@ -1,15 +1,16 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:tz="clr-namespace:SampleApp.Translations"
              x:Class="SampleApp.Mvvm.Pages.Translations.TranslationHomePage"
              Title="TranslationHomePage">
     <VerticalStackLayout>
-        <CollectionView ItemsSource="{Binding AvailableLanguages}" SelectionMode="Single">
-            <CollectionView.ItemTemplate>
-                <DataTemplate>
-                    <Label Text="{Binding Key}"/>
-                </DataTemplate>
-            </CollectionView.ItemTemplate>
-        </CollectionView>
+        <HorizontalStackLayout>
+            <Button Text="English" Command="{Binding SetLanguageCommand}" CommandParameter="english"/>
+            <Button Text="German" Command="{Binding SetLanguageCommand}" CommandParameter="german"/>
+        </HorizontalStackLayout>
+        <Label Text="{tz:Lang TextId=E_Welcome}"/>
+        <Button Text="{Binding DoTheThingCommand.Text}" Command="{Binding DoTheThingCommand}"/>
+
     </VerticalStackLayout>
 </ContentPage>
diff --git a/SampleApp/Translations/LangExtension.cs b/SampleApp/Translations/LangExtension.cs
@@ -7,14 +7,11 @@
 
 namespace SampleApp.Translations
 {
-    public class LanguageService<TEnum> where TEnum : Enum
+    public class LangExtension : BaseLanguageExtension<LangStrings>
     {
-        public class LangExtension : BaseLanguageExtension<TEnum>
+        public LangExtension() : base("languageResource")
         {
-            public LangExtension() : base("languageResource")
-            {
 
-            }
         }
     }
 }
diff --git a/SampleApp/Translations/LangService.cs b/SampleApp/Translations/LangService.cs
@@ -0,0 +1,14 @@
+using FunctionZero.Maui.MarkupExtensions;
+using FunctionZero.Maui.Services;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SampleApp.Translations
+{
+    public class LangService : BaseLanguageService<LangStrings>
+    {
+    }
+}