preferencesdialog: Suffix to identify system and default languages

Also, move the selected language to the top of the language
combo box.

src/PreferencesDialog.cpp

@@ -259,20 +259,28 @@ void PreferencesDialog::fillLanguageBox()
     QDir translationsDir(QCoreApplication::applicationDirPath() + "/translations",
                          "sqlb_*.qm");
 
+    QLocale systemLocale = QLocale::system();
+
     // Add default language
-    ui->languageComboBox->addItem("English (United States)", "en_US");
+    if (systemLocale.name() == "en_US")
+        ui->languageComboBox->addItem("English (United States) [System Language]","en_US");
+    else
+        ui->languageComboBox->addItem("English (United States) [Default Language]","en_US");
 
     foreach(const QFileInfo &file, translationsDir.entryInfoList())
     {
         QLocale locale(file.baseName().remove("sqlb_"));
 
-        // Prevent invalid locales from being added to the box
+        // Skip invalid locales
         if(locale.name() == "C")
             continue;
 
         QString language = QLocale::languageToString(locale.language()) + " (" +
                            QLocale::countryToString(locale.country()) + ")";
 
+        if (locale == systemLocale)
+            language += " [System language]";
+
         ui->languageComboBox->addItem(language, locale.name());
     }
 
@@ -286,5 +294,11 @@ void PreferencesDialog::fillLanguageBox()
     if(index < 0)
         index = ui->languageComboBox->findData("en_US", Qt::UserRole, Qt::MatchExactly);
 
-    ui->languageComboBox->setCurrentIndex(index);
+    QString chosenLanguage = ui->languageComboBox->itemText(index);
+    QVariant chosenLocale = ui->languageComboBox->itemData(index);
+
+    // There's no "move" method, so we remove and add the chosen language again at the top
+    ui->languageComboBox->removeItem(index);
+    ui->languageComboBox->insertItem(0, chosenLanguage, chosenLocale);
+    ui->languageComboBox->setCurrentIndex(0);
 }

src/PreferencesDialog.ui

@@ -42,7 +42,7 @@
            </property>
            <property name="minimumSize">
             <size>
-             <width>200</width>
+             <width>290</width>
              <height>0</height>
             </size>
            </property>
@@ -86,7 +86,7 @@
           <enum>QComboBox::AdjustToMinimumContentsLength</enum>
          </property>
          <property name="minimumContentsLength">
-          <number>20</number>
+          <number>35</number>
          </property>
         </widget>
        </item>