fix(translator): Added layout direction reset on translation.

Fix #3542.

src/widget/translator.cpp

@@ -55,7 +55,8 @@ void Translator::translate()
             // system menu translation
             QTranslator *qtTranslator = new QTranslator();
             QString s_locale = "qt_"+locale;
-            if (qtTranslator->load(s_locale, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
+            QString location = QLibraryInfo::location(QLibraryInfo::TranslationsPath);
+            if (qtTranslator->load(s_locale, location))
             {
                 QApplication::installTranslator(qtTranslator);
                 qDebug() << "System translation loaded" << locale;
@@ -72,6 +73,16 @@ void Translator::translate()
         QCoreApplication::installTranslator(translator);
     }
 
+    // After the language is changed from RTL to LTR, the layout direction isn't
+    // always restored
+    const QString direction = QApplication::tr("LTR",
+                 "Translate this string to the string 'RTL' in"
+                 " right-to-left languages (for example Hebrew and"
+                 " Arabic) to get proper widget layout");
+
+    QGuiApplication::setLayoutDirection(
+                direction == "RTL" ? Qt::RightToLeft : Qt::LeftToRight);
+
     for (auto pair : callbacks)
         pair.second();
 }

translations/ar.ts

@@ -1934,6 +1934,14 @@ Share it with your friends to communicate.</source>
         <translation>إسم الملف الشخصي &quot;%1&quot; موجود مسبقاً . هل تود إزاته؟</translation>
     </message>
 </context>
+<context>
+    <name>QApplication</name>
+    <message>
+        <source>LTR</source>
+        <comment>Translate this string to the string &apos;RTL&apos; in right-to-left languages (for example Hebrew and Arabic) to get proper widget layout</comment>
+        <translation>RTL</translation>
+    </message>
+</context>
 <context>
     <name>QObject</name>
     <message>

translations/he.ts

@@ -1929,6 +1929,14 @@ Share it with your friends to communicate.</source>
         <translation type="unfinished"></translation>
     </message>
 </context>
+<context>
+    <name>QApplication</name>
+    <message>
+        <source>LTR</source>
+        <comment>Translate this string to the string &apos;RTL&apos; in right-to-left languages (for example Hebrew and Arabic) to get proper widget layout</comment>
+        <translation>RTL</translation>
+    </message>
+</context>
 <context>
     <name>QObject</name>
     <message>

translations/ug.ts

@@ -1935,6 +1935,14 @@ Share it with your friends to communicate.</source>
         <translation type="unfinished"></translation>
     </message>
 </context>
+<context>
+    <name>QApplication</name>
+    <message>
+        <source>LTR</source>
+        <comment>Translate this string to the string &apos;RTL&apos; in right-to-left languages (for example Hebrew and Arabic) to get proper widget layout</comment>
+        <translation>RTL</translation>
+    </message>
+</context>
 <context>
     <name>QObject</name>
     <message>