Android: Add support for getting the UiLanguages

From API 24 it is possible to get the UiLanguages correctly from
Android so if API 24 or later is available we should use this. If it is
not available, then it will fallback to the original behavior of using
the system language.

Fixes: QTBUG-68019
Change-Id: I4cfbc2b807b361c08da56a74100ba59abf5f2d0f
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/plugins/platforms/android/qandroidsystemlocale.cpp b/src/plugins/platforms/android/qandroidsystemlocale.cpp
index 7fe36aa9bc..f9d566ff1a 100644
--- a/src/plugins/platforms/android/qandroidsystemlocale.cpp
+++ b/src/plugins/platforms/android/qandroidsystemlocale.cpp
@@ -40,6 +40,7 @@
 #include "qandroidsystemlocale.h"
 #include "androidjnimain.h"
 #include <QtCore/private/qjni_p.h>
+#include <QtCore/private/qjnihelpers_p.h>
 #include "qdatetime.h"
 #include "qstringlist.h"
 #include "qvariant.h"
@@ -162,6 +163,23 @@ QVariant QAndroidSystemLocale::query(QueryType type, QVariant in) const
         return m_locale.createSeparatedList(in.value<QStringList>());
     case LocaleChanged:
         Q_ASSERT_X(false, Q_FUNC_INFO, "This can't happen.");
+    case UILanguages: {
+        if (QtAndroidPrivate::androidSdkVersion() >= 24) {
+            QJNIObjectPrivate localeListObject =
+                QJNIObjectPrivate::callStaticObjectMethod("android/os/LocaleList", "getDefault",
+                                                          "()Landroid/os/LocaleList;");
+            if (localeListObject.isValid()) {
+                QString lang = localeListObject.callObjectMethod("toLanguageTags",
+                                                                 "()Ljava/lang/String;").toString();
+                // Some devices return with it enclosed in []'s so check if both exists before
+                // removing to ensure it is formatted correctly
+                if (lang.startsWith(QChar('[')) && lang.endsWith(QChar(']')))
+                    lang = lang.mid(1, lang.length() - 2);
+                return lang.split(QChar(','));
+            }
+        }
+        return QVariant();
+    }
     default:
         break;
     }