From d4b96557b8ee95520e44dfcf2329026779cf63bb Mon Sep 17 00:00:00 2001
From: Kleidis <167202775+kleidis@users.noreply.github.com>
Date: Thu, 24 Oct 2024 03:41:41 +0200
Subject: [PATCH 1/2] lime_qt: Switch to `GetUserDefaultUILanguage` to fetch
 active display language on Windows

---
 src/citra_qt/citra_qt.cpp | 30 +++++++++++++++++++++++-------
 src/citra_qt/citra_qt.h   |  3 +++
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/citra_qt/citra_qt.cpp b/src/citra_qt/citra_qt.cpp
index 487f38587..89458e153 100644
--- a/src/citra_qt/citra_qt.cpp
+++ b/src/citra_qt/citra_qt.cpp
@@ -3515,16 +3515,32 @@ void GMainWindow::LoadTranslation() {
         return;
     }
 
-    bool loaded;
+    QString language = UISettings::values.language;
 
-    if (UISettings::values.language.isEmpty()) {
-        // Use the system's default locale
-        loaded = translator.load(QLocale::system(), {}, {}, QStringLiteral(":/languages/"));
-    } else {
-        // Otherwise load from the specified file
-        loaded = translator.load(UISettings::values.language, QStringLiteral(":/languages/"));
+    if (language.isEmpty()) {
+#ifdef _WIN32
+        // Use Windows API to get the active display language
+        LANGID lang_id = GetUserDefaultUILanguage();
+        wchar_t locale_name[LOCALE_NAME_MAX_LENGTH];
+
+        if (LCIDToLocaleName(MAKELCID(lang_id, SORT_DEFAULT), locale_name, LOCALE_NAME_MAX_LENGTH,
+                             0)) {
+            char locale_name_str[LOCALE_NAME_MAX_LENGTH];
+            WideCharToMultiByte(CP_UTF8, 0, locale_name, -1, locale_name_str,
+                                LOCALE_NAME_MAX_LENGTH, nullptr, nullptr);
+            language = QString::fromUtf8(locale_name_str);
+        } else {
+            language = QLocale::system().name();
+        }
+#else
+        language = QLocale::system().name();
+#endif
     }
 
+    // Replace dashes with underscores for compatibility with translation files
+    language.replace(QLatin1Char('-'), QLatin1Char('_'));
+
+    bool loaded = translator.load(language, QStringLiteral(":/languages/"));
     if (loaded) {
         qApp->installTranslator(&translator);
     } else {
diff --git a/src/citra_qt/citra_qt.h b/src/citra_qt/citra_qt.h
index 078d254b5..161dc2b46 100644
--- a/src/citra_qt/citra_qt.h
+++ b/src/citra_qt/citra_qt.h
@@ -321,6 +321,9 @@ private:
     GameListPlaceholder* game_list_placeholder;
     LoadingScreen* loading_screen;
 
+    // General
+    QString current_language;
+
     // Status bar elements
     QProgressBar* progress_bar = nullptr;
     QLabel* message_label = nullptr;

From 4d1a2c75c6c205601763aac07085f58cacb7f5be Mon Sep 17 00:00:00 2001
From: Kleidis <167202775+kleidis@users.noreply.github.com>
Date: Thu, 24 Oct 2024 15:17:55 +0200
Subject: [PATCH 2/2] Remove useless variable and cleanup comments

---
 src/citra_qt/citra_qt.cpp | 3 +--
 src/citra_qt/citra_qt.h   | 3 ---
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/citra_qt/citra_qt.cpp b/src/citra_qt/citra_qt.cpp
index 89458e153..a4264f51b 100644
--- a/src/citra_qt/citra_qt.cpp
+++ b/src/citra_qt/citra_qt.cpp
@@ -3519,7 +3519,6 @@ void GMainWindow::LoadTranslation() {
 
     if (language.isEmpty()) {
 #ifdef _WIN32
-        // Use Windows API to get the active display language
         LANGID lang_id = GetUserDefaultUILanguage();
         wchar_t locale_name[LOCALE_NAME_MAX_LENGTH];
 
@@ -3537,7 +3536,7 @@ void GMainWindow::LoadTranslation() {
 #endif
     }
 
-    // Replace dashes with underscores for compatibility with translation files
+    // For compatibility with translation files
     language.replace(QLatin1Char('-'), QLatin1Char('_'));
 
     bool loaded = translator.load(language, QStringLiteral(":/languages/"));
diff --git a/src/citra_qt/citra_qt.h b/src/citra_qt/citra_qt.h
index 161dc2b46..078d254b5 100644
--- a/src/citra_qt/citra_qt.h
+++ b/src/citra_qt/citra_qt.h
@@ -321,9 +321,6 @@ private:
     GameListPlaceholder* game_list_placeholder;
     LoadingScreen* loading_screen;
 
-    // General
-    QString current_language;
-
     // Status bar elements
     QProgressBar* progress_bar = nullptr;
     QLabel* message_label = nullptr;