Ensure settings updates trigger main UI recreation

Author: MihaiCristianCondrea

app/src/main/java/com/d4rk/androidtutorials/java/data/repository/DefaultMainRepository.java

@@ -100,12 +100,23 @@ public void markStartupScreenShown() {
     /**
      * Applies the language setting from SharedPreferences.
      */
-    public void applyLanguageSettings() {
+    public boolean applyLanguageSettings() {
         String languageKey = context.getString(R.string.key_language);
         String defaultLanguageValue = context.getString(R.string.default_value_language);
         String languageCode = defaultSharedPrefs.getString(languageKey, defaultLanguageValue);
 
+        if (languageCode == null) {
+            languageCode = defaultLanguageValue;
+        }
+
+        LocaleListCompat currentLocales = AppCompatDelegate.getApplicationLocales();
+        String currentLanguageTags = currentLocales.toLanguageTags();
+        if (languageCode.equals(currentLanguageTags)) {
+            return false;
+        }
+
         AppCompatDelegate.setApplicationLocales(LocaleListCompat.forLanguageTags(languageCode));
+        return true;
     }
 
     /**

app/src/main/java/com/d4rk/androidtutorials/java/data/repository/MainRepository.java

@@ -13,7 +13,7 @@ public interface MainRepository {
 
     void markStartupScreenShown();
 
-    void applyLanguageSettings();
+    boolean applyLanguageSettings();
 
     AppUpdateManager getAppUpdateManager();
 }

app/src/main/java/com/d4rk/androidtutorials/java/domain/main/ApplyLanguageSettingsUseCase.java

@@ -12,7 +12,7 @@ public ApplyLanguageSettingsUseCase(MainRepository repository) {
         this.repository = repository;
     }
 
-    public void invoke() {
-        repository.applyLanguageSettings();
+    public boolean invoke() {
+        return repository.applyLanguageSettings();
     }
 }

app/src/main/java/com/d4rk/androidtutorials/java/ui/screens/main/MainUiState.java

@@ -4,8 +4,8 @@
 
 /**
  * UI state for {@link MainActivity}. Holds values related to the main screen such as
- * bottom navigation visibility, the default navigation destination, and whether the theme
- * has changed requiring a recreation of the activity.
+ * bottom navigation visibility, the default navigation destination, and whether the configuration
+ * has changed (e.g., theme or language) requiring a recreation of the activity.
  */
 public record MainUiState(@NavigationBarView.LabelVisibility int bottomNavVisibility,
                           int defaultNavDestination, boolean themeChanged) {

app/src/main/java/com/d4rk/androidtutorials/java/ui/screens/main/MainViewModel.java

@@ -91,8 +91,10 @@ public void applySettings(String[] themeValues,
             startFragmentId = R.id.navigation_home;
         }
 
-        uiState.setValue(new MainUiState(visibilityMode, startFragmentId, changedTheme));
-        applyLanguageSettingsUseCase.invoke();
+        boolean changedLanguage = applyLanguageSettingsUseCase.invoke();
+        boolean requiresRecreation = changedTheme || changedLanguage;
+
+        uiState.setValue(new MainUiState(visibilityMode, startFragmentId, requiresRecreation));
         isLoading.setValue(false);
     }