citra-qt: add new uisetting->theme

src/citra_qt/configuration/config.cpp

@@ -134,6 +134,7 @@ void Config::ReadValues() {
     qt_config->endGroup();
 
     qt_config->beginGroup("UI");
+    UISettings::values.theme = qt_config->value("theme", UISettings::themes[0].second).toString();
 
     qt_config->beginGroup("UILayout");
     UISettings::values.geometry = qt_config->value("geometry").toByteArray();
@@ -269,6 +270,7 @@ void Config::SaveValues() {
     qt_config->endGroup();
 
     qt_config->beginGroup("UI");
+    qt_config->setValue("theme", UISettings::values.theme);
 
     qt_config->beginGroup("UILayout");
     qt_config->setValue("geometry", UISettings::values.geometry);

src/citra_qt/ui_settings.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <array>
 #include <vector>
 #include <QByteArray>
 #include <QString>
@@ -14,6 +15,10 @@ namespace UISettings {
 using ContextualShortcut = std::pair<QString, int>;
 using Shortcut = std::pair<QString, ContextualShortcut>;
 
+static const std::array<std::pair<QString, QString>, 2> themes = {
+    {std::make_pair(QString("Default"), QString("default")),
+     std::make_pair(QString("Dark"), QString("qdarkstyle"))}};
+
 struct Values {
     QByteArray geometry;
     QByteArray state;
@@ -39,6 +44,8 @@ struct Values {
     bool gamedir_deepscan;
     QStringList recent_files;
 
+    QString theme;
+
     // Shortcut name <Shortcut, context>
     std::vector<Shortcut> shortcuts;
 };