[TextExtractor] Extend settings with preferred language (#22901)

* [TextExtractor] Extend settings with preferred language

* TextExtractor simplifying code, adding update languages on dropdown opening

* fix typo

* TextExtractor fixing bug with order of languages

src/settings-ui/Settings.UI.Library/PowerOcrProperties.cs

@@ -15,6 +15,8 @@ namespace Microsoft.PowerToys.Settings.UI.Library
 
         public HotkeySettings ActivationShortcut { get; set; }
 
+        public string PreferredLanguage { get; set; }
+
         public override string ToString()
             => JsonSerializer.Serialize(this);
     }

src/settings-ui/Settings.UI/Strings/en-us/Resources.resw

@@ -2855,4 +2855,7 @@ Activate by holding the key for the character you want to add an accent to, then
   <data name="Hosts_AdditionalLinesPosition.Description" xml:space="preserve">
     <value>Additional content includes the file header and lines that can't parse</value>
   </data>
+  <data name="TextExtractor_Languages.Header" xml:space="preserve">
+    <value>Preferred language</value>
+  </data>
 </root>

src/settings-ui/Settings.UI/ViewModels/PowerOcrViewModel.cs

@@ -3,13 +3,18 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Globalization;
+using System.Linq;
 using System.Text.Json;
 using System.Timers;
 using global::PowerToys.GPOWrapper;
 using Microsoft.PowerToys.Settings.UI.Library;
 using Microsoft.PowerToys.Settings.UI.Library.Helpers;
 using Microsoft.PowerToys.Settings.UI.Library.Interfaces;
+using Windows.Globalization;
+using Windows.Media.Ocr;
 
 namespace Microsoft.PowerToys.Settings.UI.ViewModels
 {
@@ -31,6 +36,33 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
         private GpoRuleConfigured _enabledGpoRuleConfiguration;
         private bool _enabledStateIsGPOConfigured;
         private bool _isEnabled;
+        private int _languageIndex;
+        private List<Language> possibleOcrLanguages;
+
+        public ObservableCollection<string> AvailableLanguages { get; } = new ObservableCollection<string>();
+
+        public int LanguageIndex
+        {
+            get
+            {
+                return _languageIndex;
+            }
+
+            set
+            {
+                if (value != _languageIndex)
+                {
+                    _languageIndex = value;
+                    if (_powerOcrSettings != null && _languageIndex < possibleOcrLanguages.Count && _languageIndex >= 0)
+                    {
+                        _powerOcrSettings.Properties.PreferredLanguage = possibleOcrLanguages[_languageIndex].DisplayName;
+                        NotifySettingsChanged();
+                    }
+
+                    OnPropertyChanged(nameof(LanguageIndex));
+                }
+            }
+        }
 
         private Func<string, int> SendConfigMSG { get; }
 
@@ -130,6 +162,48 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
             }
         }
 
+        internal void UpdateLanguages()
+        {
+            int preferredLanguageIndex = -1;
+            int systemLanguageIndex = -1;
+            CultureInfo systemCulture = CultureInfo.CurrentUICulture;
+
+            // get the list of all installed OCR languages. While processing them, search for the previously preferred language and also for the current ui language
+            possibleOcrLanguages = OcrEngine.AvailableRecognizerLanguages.OrderBy(x => x.NativeName).ToList();
+            AvailableLanguages.Clear();
+            foreach (Language language in possibleOcrLanguages)
+            {
+                if (_powerOcrSettings.Properties.PreferredLanguage?.Equals(language.DisplayName) == true)
+                {
+                    preferredLanguageIndex = AvailableLanguages.Count;
+                }
+
+                if (systemCulture.DisplayName.Equals(language.DisplayName) || systemCulture.Parent.DisplayName.Equals(language.DisplayName))
+                {
+                    systemLanguageIndex = AvailableLanguages.Count;
+                }
+
+                AvailableLanguages.Add(language.NativeName);
+            }
+
+            // if the previously stored preferred language is not available (has been deleted or this is the first run with language preference)
+            if (preferredLanguageIndex == -1)
+            {
+                // try to use the current ui language. If it is also not available, set the first language as preferred (to have any selected language)
+                if (systemLanguageIndex >= 0)
+                {
+                    preferredLanguageIndex = systemLanguageIndex;
+                }
+                else
+                {
+                    preferredLanguageIndex = 0;
+                }
+            }
+
+            // set the language index -> the preferred language gets selected in the combo box
+            LanguageIndex = preferredLanguageIndex;
+        }
+
         private void ScheduleSavingOfSettings()
         {
             lock (_delayedActionLock)

src/settings-ui/Settings.UI/Views/PowerOcrPage.xaml

@@ -55,6 +55,18 @@
                             MinWidth="{StaticResource SettingActionControlMinWidth}"
                             HotkeySettings="{x:Bind Path=ViewModel.ActivationShortcut, Mode=TwoWay}" />
                     </labs:SettingsCard>
+                    <labs:SettingsCard
+                        x:Uid="TextExtractor_Languages">
+                        <ComboBox
+                            x:Name="TextExtractor_ComboBox"
+                            MinWidth="{StaticResource SettingActionControlMinWidth}"
+                            ItemsSource="{x:Bind Path=ViewModel.AvailableLanguages, Mode=OneWay}"
+                            SelectedIndex="{x:Bind Path=ViewModel.LanguageIndex, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
+                            SelectedValue="{Binding SelectedColorRepresentationValue, Mode=TwoWay}"
+                            Loaded="TextExtractor_ComboBox_Loaded"
+                            DropDownOpened="TextExtractor_ComboBox_DropDownOpened">
+                        </ComboBox>
+                    </labs:SettingsCard>
                 </controls:SettingsGroup>
             </StackPanel>
         </controls:SettingsPageControl.ModuleContent>

src/settings-ui/Settings.UI/Views/PowerOcrPage.xaml.cs

@@ -23,5 +23,21 @@ namespace Microsoft.PowerToys.Settings.UI.Views
             DataContext = ViewModel;
             InitializeComponent();
         }
+
+        private void TextExtractor_ComboBox_Loaded(object sender, Microsoft.UI.Xaml.RoutedEventArgs e)
+        {
+            /**
+          * UWP hack
+          * because UWP load the bound ItemSource of the ComboBox asynchronous,
+          * so after InitializeComponent() the ItemSource is still empty and can't automatically select a entry.
+          * Selection via SelectedItem and SelectedValue is still not working too
+          */
+            ViewModel.UpdateLanguages();
+        }
+
+        private void TextExtractor_ComboBox_DropDownOpened(object sender, object e)
+        {
+            ViewModel.UpdateLanguages();
+        }
     }
 }