Qt: Drop Qt 6.1 workaround in Host::GetTopLevelWindowInfo()

src/duckstation-qt/mainwindow.cpp

@@ -2645,11 +2645,14 @@ void MainWindow::checkForSettingChanges()
   updateWindowState();
 }
 
-void MainWindow::getWindowInfo(WindowInfo* wi)
+std::optional<WindowInfo> MainWindow::getWindowInfo()
 {
-  std::optional<WindowInfo> opt_wi(QtUtils::GetWindowInfoForWidget(this));
-  if (opt_wi.has_value())
-    *wi = opt_wi.value();
+  if (!m_display_widget || isRenderingToMain())
+    return QtUtils::GetWindowInfoForWidget(this);
+  else if (QWidget* widget = getDisplayContainer())
+    return QtUtils::GetWindowInfoForWidget(widget);
+  else
+    return std::nullopt;
 }
 
 void MainWindow::onCheckForUpdatesActionTriggered()

src/duckstation-qt/mainwindow.h

@@ -104,7 +104,7 @@ public Q_SLOTS:
   bool requestShutdown(bool allow_confirm = true, bool allow_save_to_state = true, bool save_state = true);
   void requestExit(bool allow_confirm = true);
   void checkForSettingChanges();
-  void getWindowInfo(WindowInfo* wi);
+  std::optional<WindowInfo> getWindowInfo();
 
   void checkForUpdates(bool display_message);
 

src/duckstation-qt/qthost.cpp

@@ -118,6 +118,7 @@ EmuThread::~EmuThread() = default;
 void QtHost::RegisterTypes()
 {
   // Register any standard types we need elsewhere
+  qRegisterMetaType<std::optional<WindowInfo>>("std::optional<WindowInfo>()");
   qRegisterMetaType<std::optional<bool>>();
   qRegisterMetaType<std::function<void()>>("std::function<void()>");
   qRegisterMetaType<std::shared_ptr<SystemBootParameters>>();
@@ -1632,11 +1633,8 @@ void Host::RequestExit(bool allow_confirm)
 
 std::optional<WindowInfo> Host::GetTopLevelWindowInfo()
 {
-  // Normally we'd just feed the std::optional all the way through here. But that won't work because of some bug
-  // in Qt 6.1, and we can't upgrade that because of raging/abusive Win7 users... to anyone still using that dead
-  // OS, this is a passive-aggressive "screw you".
-  WindowInfo ret;
-  QMetaObject::invokeMethod(g_main_window, "getWindowInfo", Qt::BlockingQueuedConnection, Q_ARG(WindowInfo*, &ret));
+  std::optional<WindowInfo> ret;
+  QMetaObject::invokeMethod(g_main_window, &MainWindow::getWindowInfo, Qt::BlockingQueuedConnection, &ret);
   return ret;
 }