Add Platform.GetUserLanguage for text localization, separate from locale used for numbers, currency and dates

Source/Engine/Engine/Engine.cpp

@@ -622,7 +622,7 @@ void EngineImpl::InitLog()
 
     // Log product info
     LOG(Info, "Product: {0}, Company: {1}", Globals::ProductName, Globals::CompanyName);
-    LOG(Info, "Current culture: {0}", Platform::GetUserLocaleName());
+    LOG(Info, "Current language: {}, culture: {}", Platform::GetUserLanguage(), Platform::GetUserLocaleName());
     LOG(Info, "Command line: {0}", CommandLine);
     LOG(Info, "Base folder: {0}", Globals::StartupFolder);
     LOG(Info, "Binaries folder: {0}", Globals::BinariesFolder);

Source/Engine/Localization/Localization.cpp

@@ -328,7 +328,8 @@ bool LocalizationService::Init()
     PROFILE_MEM(Localization);
 
     // Use system language as default
-    CurrentLanguage = CurrentCulture = CultureInfo(Platform::GetUserLocaleName());
+    CurrentLanguage = CultureInfo(Platform::GetUserLanguage());
+    CurrentCulture = CultureInfo(Platform::GetUserLocaleName());
 
     // Setup localization
     Instance.OnLocalizationChanged();

Source/Engine/Platform/Base/PlatformBase.cpp

@@ -595,6 +595,11 @@ ScreenOrientationType PlatformBase::GetScreenOrientationType()
     return ScreenOrientationType::Unknown;
 }
 
+String PlatformBase::GetUserLanguage()
+{
+    return Platform::GetUserLocaleName();
+}
+
 String PlatformBase::GetUserName()
 {
     return Users.Count() != 0 ? Users[0]->GetName() : String::Empty;

Source/Engine/Platform/Base/PlatformBase.h

@@ -613,7 +613,12 @@ public:
     API_PROPERTY() static ScreenOrientationType GetScreenOrientationType();
 
     /// <summary>
-    /// Gets the current locale culture (eg. "pl-PL" or "en-US").
+    /// Gets the current user display language used to localize texts. Returns name of the culture (eg. "pl-PL" or "en-US"), use CultureInfo for display name of the language.
+    /// </summary>
+    API_PROPERTY() static String GetUserLanguage();
+
+    /// <summary>
+    /// Gets the current user locale culture used to localize numbers, currency and dates. Returns name of the culture (eg. "pl-PL" or "en-US"), use CultureInfo for display name of the language.
     /// </summary>
     API_PROPERTY() static String GetUserLocaleName() = delete;
 

Source/Engine/Platform/Windows/WindowsPlatform.cpp

@@ -61,7 +61,7 @@ void FlaxDbgHelpUnlock()
 
 namespace
 {
-    String UserLocale, ComputerName, WindowsName;
+    String UserLanguage, UserLocale, ComputerName, WindowsName;
     HANDLE EngineMutex = nullptr;
     Rectangle VirtualScreenBounds(0.0f, 0.0f, 0.0f, 0.0f);
     int32 VersionMajor = 0;
@@ -766,12 +766,18 @@ bool WindowsPlatform::Init()
 
     DWORD tmp;
     Char buffer[256];
+    ULONG bufferSize = ARRAY_COUNT(buffer), languagesCount = 0;
 
-    // Get user locale string
-    if (GetUserDefaultLocaleName(buffer, LOCALE_NAME_MAX_LENGTH))
+    // Get user locale strings
+    if (GetUserDefaultLocaleName(buffer, (int)bufferSize))
     {
         UserLocale = String(buffer);
     }
+    if (GetUserPreferredUILanguages(MUI_LANGUAGE_NAME, &languagesCount, buffer, &bufferSize))
+    {
+        // Get the first language
+        UserLanguage = String(buffer);
+    }
 
     // Get computer name string
     if (GetComputerNameW(buffer, &tmp))
@@ -935,6 +941,11 @@ int32 WindowsPlatform::GetDpi()
     return SystemDpi;
 }
 
+String WindowsPlatform::GetUserLanguage()
+{
+    return UserLanguage.HasChars() ? UserLanguage : UserLocale;
+}
+
 String WindowsPlatform::GetUserLocaleName()
 {
     return UserLocale;

Source/Engine/Platform/Windows/WindowsPlatform.h

@@ -71,6 +71,7 @@ public:
     static Version GetSystemVersion();
     static BatteryInfo GetBatteryInfo();
     static int32 GetDpi();
+    static String GetUserLanguage();
     static String GetUserLocaleName();
     static String GetComputerName();
     static bool GetHasFocus();