Clean up/update translation code and made language selectable in the settings dialog

gui/dialogs/SettingsDialog.cpp

@@ -219,6 +219,9 @@ void SettingsDialog::applySettings(SettingsObject *s)
 		}
 	}
 
+	// Language
+	s->set("Language", ui->languageBox->currentData().toLocale().bcp47Name());
+
 	// Updates
 	s->set("AutoUpdate", ui->autoUpdateCheckBox->isChecked());
 
@@ -286,6 +289,19 @@ void SettingsDialog::applySettings(SettingsObject *s)
 
 void SettingsDialog::loadSettings(SettingsObject *s)
 {
+	// Language
+	ui->languageBox->clear();
+	ui->languageBox->addItem(tr("English"), QLocale(QLocale::English));
+	foreach(const QString & lang,
+			QDir(MMC->root() + "/translations").entryList(QStringList() << "*.qm", QDir::Files))
+	{
+		QLocale locale(lang.section(QRegExp("[_\.]"), 1));
+		ui->languageBox->addItem(
+			QLocale::languageToString(locale.language()),
+			locale);
+	}
+	ui->languageBox->setCurrentIndex(ui->languageBox->findData(QLocale(s->get("Language").toString())));
+
 	// Updates
 	ui->autoUpdateCheckBox->setChecked(s->get("AutoUpdate").toBool());
 	ui->devBuildsCheckBox->setChecked(s->get("UseDevBuilds").toBool());

gui/dialogs/SettingsDialog.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>526</width>
-    <height>628</height>
+    <height>701</height>
    </rect>
   </property>
   <property name="sizePolicy">
@@ -40,6 +40,20 @@
        <string>General</string>
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout">
+       <item>
+        <layout class="QHBoxLayout" name="horizontalLayout_2" stretch="0,1">
+         <item>
+          <widget class="QLabel" name="label_3">
+           <property name="text">
+            <string>Language (needs restart):</string>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QComboBox" name="languageBox"/>
+         </item>
+        </layout>
+       </item>
        <item>
         <widget class="QGroupBox" name="sortingModeBox">
          <property name="enabled">
@@ -644,7 +658,6 @@
   </layout>
  </widget>
  <tabstops>
-  <tabstop>settingsTab</tabstop>
   <tabstop>buttonBox</tabstop>
   <tabstop>sortLastLaunchedBtn</tabstop>
   <tabstop>sortByNameBtn</tabstop>