Qt: Respond to QScreen refresh rate changes

src/duckstation-qt/displaywidget.cpp

@@ -51,7 +51,7 @@ DisplayWidget::DisplayWidget(QWidget* parent) : QWidget(parent)
 
 DisplayWidget::~DisplayWidget() = default;
 
-void DisplayWidget::registerScreenChangeEvent()
+void DisplayWidget::connectScreenChangedEvent()
 {
   DebugAssert(!m_screen_change_registered);
 
@@ -60,9 +60,36 @@ void DisplayWidget::registerScreenChangeEvent()
     parent_widget = this;
   QWindow* parent_window_handle = parent_widget->windowHandle();
   if (parent_window_handle)
-    connect(parent_window_handle, &QWindow::screenChanged, this, [this]() { checkForSizeChange(true); });
+    connect(parent_window_handle, &QWindow::screenChanged, this, &DisplayWidget::onScreenChanged);
 
   m_screen_change_registered = true;
+  connectScreenRefreshRateChangedEvent();
+}
+
+void DisplayWidget::connectScreenRefreshRateChangedEvent()
+{
+  if (m_screen_refresh_rate_changed_connection)
+  {
+    disconnect(m_screen_refresh_rate_changed_connection);
+    m_screen_refresh_rate_changed_connection = {};
+  }
+
+  if (QScreen* const widget_screen = screen())
+  {
+    m_screen_refresh_rate_changed_connection =
+      connect(widget_screen, &QScreen::refreshRateChanged, this, &DisplayWidget::onScreenRefreshRateChanged);
+  }
+}
+
+void DisplayWidget::onScreenChanged()
+{
+  connectScreenRefreshRateChangedEvent();
+  checkForSizeChange(true);
+}
+
+void DisplayWidget::onScreenRefreshRateChanged()
+{
+  checkForSizeChange(true);
 }
 
 const std::optional<WindowInfo>& DisplayWidget::getWindowInfo(RenderAPI render_api, Error* error)
@@ -72,7 +99,7 @@ const std::optional<WindowInfo>& DisplayWidget::getWindowInfo(RenderAPI render_a
     m_window_info = QtUtils::GetWindowInfoForWidget(this, render_api, error);
 
     if (m_window_info.has_value() && !m_screen_change_registered)
-      registerScreenChangeEvent();
+      connectScreenChangedEvent();
   }
 
   m_render_api = m_window_info.has_value() ? render_api : RenderAPI::None;

src/duckstation-qt/displaywidget.h

@@ -56,7 +56,10 @@ protected:
   bool event(QEvent* event) override;
 
 private:
-  void registerScreenChangeEvent();
+  void connectScreenChangedEvent();
+  void connectScreenRefreshRateChangedEvent();
+  void onScreenChanged();
+  void onScreenRefreshRateChanged();
   bool isActuallyFullscreen() const;
   void updateCenterPos();
 
@@ -76,6 +79,7 @@ private:
   RenderAPI m_render_api = RenderAPI::None;
   std::optional<WindowInfo> m_window_info;
 
+  QMetaObject::Connection m_screen_refresh_rate_changed_connection;
   const char* m_window_position_key = nullptr;
 };