Qt: Make ALT+F4 while fullscreen exit DuckStation

src/duckstation-qt/displaywidget.cpp

@@ -135,7 +135,9 @@ void DisplayWidget::handleCloseEvent(QCloseEvent* event)
 {
   // Closing the separate widget will either cancel the close, or trigger shutdown.
   // In the latter case, it's going to destroy us, so don't let Qt do it first.
-  if (QtHost::IsSystemValid())
+  // Treat a close event while fullscreen as an exit, that way ALT+F4 closes DuckStation,
+  // rather than just the game.
+  if (QtHost::IsSystemValid() && !isActuallyFullscreen())
   {
     QMetaObject::invokeMethod(g_main_window, "requestShutdown", Q_ARG(bool, true), Q_ARG(bool, true),
                               Q_ARG(bool, false));
@@ -156,12 +158,19 @@ void DisplayWidget::destroy()
   // See Qt documentation, entire application is in full screen state, and the main
   // window will get reopened fullscreen instead of windowed if we don't close the
   // fullscreen window first.
-  if (isFullScreen())
+  if (isActuallyFullscreen())
     close();
 #endif
   deleteLater();
 }
 
+bool DisplayWidget::isActuallyFullscreen() const
+{
+  // I hate you QtWayland... have to check the parent, not ourselves.
+  QWidget* container = qobject_cast<QWidget*>(parent());
+  return container ? container->isFullScreen() : isFullScreen();
+}
+
 void DisplayWidget::updateCenterPos()
 {
 #ifdef _WIN32

src/duckstation-qt/displaywidget.h

@@ -46,6 +46,7 @@ protected:
   bool event(QEvent* event) override;
 
 private:
+  bool isActuallyFullscreen() const;
   void updateCenterPos();
 
   QPoint m_relative_mouse_start_pos{};