Qt: Further eliminate redundant window shows

And remove a couple of hacks.

src/duckstation-qt/displaywidget.cpp

@@ -142,10 +142,6 @@ void DisplayWidget::handleCloseEvent(QCloseEvent* event)
     QMetaObject::invokeMethod(g_main_window, "requestShutdown", Qt::QueuedConnection, Q_ARG(bool, true),
                               Q_ARG(bool, true), Q_ARG(bool, false), Q_ARG(bool, true));
   }
-  else if (QtHost::IsFullscreenUIStarted())
-  {
-    g_emu_thread->stopFullscreenUI();
-  }
   else
   {
     QMetaObject::invokeMethod(g_main_window, "requestExit", Qt::QueuedConnection);

src/duckstation-qt/mainwindow.cpp

@@ -338,6 +338,11 @@ bool MainWindow::wantsDisplayWidget() const
   return (s_system_starting || s_system_valid || s_fullscreen_ui_started);
 }
 
+bool MainWindow::hasDisplayWidget() const
+{
+  return m_display_widget != nullptr;
+}
+
 void MainWindow::createDisplayWidget(bool fullscreen, bool render_to_main, bool use_main_window_pos)
 {
   // If we're rendering to main and were hidden (e.g. coming back from fullscreen),
@@ -434,6 +439,8 @@ void MainWindow::releaseRenderWindow()
 {
   // Now we can safely destroy the display window.
   destroyDisplayWidget(true);
+  updateWindowTitle();
+  updateWindowState(false);
 }
 
 void MainWindow::destroyDisplayWidget(bool show_game_list)
@@ -824,11 +831,6 @@ void MainWindow::recreate()
   notifyRAIntegrationOfWindowChange();
 }
 
-void MainWindow::ensureVisible()
-{
-  updateWindowState(true);
-}
-
 void MainWindow::destroySubWindows()
 {
   QtUtils::CloseAndDeleteWindow(m_memory_scanner_window);
@@ -2051,7 +2053,7 @@ void MainWindow::updateWindowState(bool force_visible)
     return;
 
   const bool hide_window = shouldHideMainWindow();
-  const bool disable_resize = Host::GetBoolSettingValue("Main", "DisableWindowResize", false);
+  const bool disable_resize = (Host::GetBoolSettingValue("Main", "DisableWindowResize", false) && wantsDisplayWidget());
 
   // Need to test both valid and display widget because of startup (vm invalid while window is created).
   const bool visible = force_visible || !hide_window;
@@ -2793,14 +2795,6 @@ bool MainWindow::requestShutdown(bool allow_confirm, bool allow_save_to_state, b
       lock.cancelResume();
   }
 
-  // This is a little bit annoying. Qt will close everything down if we don't have at least one window visible,
-  // but we might not be visible because the user is using render-to-separate and hide. We don't want to always
-  // reshow the main window during display updates, because otherwise fullscreen transitions and renderer switches
-  // would briefly show and then hide the main window. So instead, we do it on shutdown, here. Except if we're in
-  // batch mode, when we're going to exit anyway.
-  if (!isRenderingToMain() && isHidden() && !QtHost::InBatchMode() && !s_fullscreen_ui_started)
-    updateWindowState(true);
-
   // Now we can actually shut down the VM.
   g_emu_thread->shutdownSystem(save_state, check_memcard_busy);
   return true;
@@ -2814,10 +2808,14 @@ void MainWindow::requestExit(bool allow_confirm /* = true */)
 
   // VM stopped signal won't have fired yet, so queue an exit if we still have one.
   // Otherwise, immediately exit, because there's no VM to exit us later.
+  m_is_closing = true;
   if (s_system_valid)
-    m_is_closing = true;
-  else
-    quit();
+    return;
+
+  if (s_fullscreen_ui_started)
+    g_emu_thread->stopFullscreenUI();
+
+  quit();
 }
 
 void MainWindow::checkForSettingChanges()
@@ -3203,7 +3201,6 @@ MainWindow::SystemLock MainWindow::pauseAndLockSystem()
   if (dialog_parent->parent())
     dialog_parent = this;
 
-
   return SystemLock(dialog_parent, was_paused, was_fullscreen);
 }
 

src/duckstation-qt/mainwindow.h

@@ -95,6 +95,9 @@ public:
   /// Force quits the application.
   void quit();
 
+  /// Returns true if there is any display widget, main or otherwise.
+  bool hasDisplayWidget() const;
+
   /// Accessors for the status bar widgets, updated by the emulation thread.
   ALWAYS_INLINE QLabel* getStatusRendererWidget() const { return m_status_renderer_widget; }
   ALWAYS_INLINE QLabel* getStatusResolutionWidget() const { return m_status_resolution_widget; }
@@ -125,7 +128,6 @@ public Q_SLOTS:
 
   void checkForUpdates(bool display_message);
   void recreate();
-  void ensureVisible();
 
   void* getNativeWindowId();
 

src/duckstation-qt/qthost.cpp

@@ -723,21 +723,17 @@ void EmuThread::stopFullscreenUI()
     QMetaObject::invokeMethod(this, &EmuThread::stopFullscreenUI, Qt::QueuedConnection);
 
     // wait until the host display is gone
-    QtUtils::ProcessEventsWithSleep(QEventLoop::ExcludeUserInputEvents,
-                                    []() { return QtHost::IsFullscreenUIStarted(); });
+    QtUtils::ProcessEventsWithSleep(QEventLoop::ExcludeUserInputEvents, []() {
+      return QtHost::IsFullscreenUIStarted() || g_main_window->hasDisplayWidget();
+    });
     return;
   }
 
   if (m_is_fullscreen_ui_started)
   {
-    // Need to switch out of fullscreen before stopping the fullscreen UI, otherwise Qt
-    // terminates the applcation because briefly there are no windows remaining.
-    if (m_is_fullscreen)
-      setFullscreen(false, true);
-
-    GPUThread::StopFullscreenUI();
     m_is_fullscreen_ui_started = false;
     emit fullscreenUIStartedOrStopped(false);
+    GPUThread::StopFullscreenUI();
   }
 }
 
@@ -751,10 +747,6 @@ void EmuThread::exitFullscreenUI()
 
   const bool was_in_nogui_mode = std::exchange(s_nogui_mode, false);
 
-  // force the main window to be visible, otherwise qt will terminate the application
-  QMetaObject::invokeMethod(g_main_window, &MainWindow::ensureVisible, Qt::QueuedConnection);
-  
-  // then stop as normal
   stopFullscreenUI();
 
   // if we were in nogui mode, the game list won't have been populated yet. do it now.
@@ -2909,8 +2901,8 @@ bool QtHost::ParseCommandLineParametersAndInitializeConfig(QApplication& app,
   if (autoboot && autoboot->path.empty() && autoboot->save_state.empty() && !starting_bios)
     autoboot.reset();
 
-  // nogui implies batch mode if autobooting and not running big picture mode
-  s_batch_mode = (s_batch_mode || (autoboot && !s_start_fullscreen_ui));
+  // nogui implies batch mode if not running big picture mode
+  s_batch_mode = (s_batch_mode || (s_nogui_mode && !s_start_fullscreen_ui));
 
   // if we don't have autoboot, we definitely don't want batch mode (because that'll skip
   // scanning the game list).