Clean up screen saver inhibition and apply setting change immediately.

Source/Core/DolphinNoGUI/PlatformWin32.cpp

@@ -107,6 +107,9 @@ bool PlatformWin32::Init()
     ProcessEvents();
   }
 
+  if (Config::Get(Config::MAIN_DISABLE_SCREENSAVER))
+    SetThreadExecutionState(ES_CONTINUOUS | ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED);
+
   UpdateWindowPosition();
   return true;
 }

Source/Core/DolphinQt/MainWindow.cpp

@@ -737,7 +737,6 @@ void MainWindow::Play(const std::optional<std::string>& savestate_path)
     if (selection)
     {
       StartGame(selection->GetFilePath(), ScanForSecondDisc::Yes, savestate_path);
-      EnableScreenSaver(false);
     }
     else
     {
@@ -745,7 +744,6 @@ void MainWindow::Play(const std::optional<std::string>& savestate_path)
       if (!default_path.isEmpty() && QFile::exists(default_path))
       {
         StartGame(default_path, ScanForSecondDisc::Yes, savestate_path);
-        EnableScreenSaver(false);
       }
       else
       {
@@ -776,7 +774,6 @@ void MainWindow::OnStopComplete()
 {
   m_stop_requested = false;
   HideRenderWidget();
-  EnableScreenSaver(true);
 #ifdef USE_DISCORD_PRESENCE
   if (!m_netplay_dialog->isVisible())
     Discord::UpdateDiscordPresence();
@@ -993,13 +990,6 @@ void MainWindow::StartGame(std::unique_ptr<BootParameters>&& parameters)
 
   if (Config::Get(Config::MAIN_FULLSCREEN))
     m_fullscreen_requested = true;
-
-#ifdef Q_OS_WIN
-  // Prevents Windows from sleeping, turning off the display, or idling
-  EXECUTION_STATE shouldScreenSave =
-      Config::Get(Config::MAIN_DISABLE_SCREENSAVER) ? ES_DISPLAY_REQUIRED : 0;
-  SetThreadExecutionState(ES_CONTINUOUS | shouldScreenSave | ES_SYSTEM_REQUIRED);
-#endif
 }
 
 void MainWindow::SetFullScreenResolution(bool fullscreen)
@@ -1304,6 +1294,10 @@ void MainWindow::NetPlayInit()
   Discord::InitNetPlayFunctionality(*m_netplay_discord);
   m_netplay_discord->Start();
 #endif
+  connect(&Settings::Instance(), &Settings::ConfigChanged, this,
+          &MainWindow::UpdateScreenSaverInhibition);
+  connect(&Settings::Instance(), &Settings::EmulationStateChanged, this,
+          &MainWindow::UpdateScreenSaverInhibition);
 }
 
 bool MainWindow::NetPlayJoin()
@@ -1435,13 +1429,16 @@ void MainWindow::NetPlayQuit()
 #endif
 }
 
-void MainWindow::EnableScreenSaver(bool enable)
+void MainWindow::UpdateScreenSaverInhibition()
 {
+  const bool inhibit =
+      Config::Get(Config::MAIN_DISABLE_SCREENSAVER) && (Core::GetState() == Core::State::Running);
+
 #if defined(HAVE_XRANDR) && HAVE_XRANDR
   if (GetWindowSystemType() == WindowSystemType::X11)
-    UICommon::EnableScreenSaver(winId(), enable);
+    UICommon::InhibitScreenSaver(winId(), inhibit);
 #else
-  UICommon::EnableScreenSaver(enable);
+  UICommon::InhibitScreenSaver(inhibit);
 #endif
 }
 

Source/Core/DolphinQt/MainWindow.h

@@ -182,7 +182,7 @@ private:
 
   QStringList PromptFileNames();
 
-  void EnableScreenSaver(bool enable);
+  void UpdateScreenSaverInhibition();
 
   void OnStopComplete();
   void dragEnterEvent(QDragEnterEvent* event) override;

Source/Core/UICommon/UICommon.cpp

@@ -397,57 +397,42 @@ bool TriggerSTMPowerEvent()
 }
 
 #if defined(HAVE_XRANDR) && HAVE_XRANDR
-void EnableScreenSaver(Window win, bool enable)
+void InhibitScreenSaver(Window win, bool inhibit)
 #else
-void EnableScreenSaver(bool enable)
+void InhibitScreenSaver(bool inhibit)
 #endif
 {
   // Inhibit the screensaver. Depending on the operating system this may also
   // disable low-power states and/or screen dimming.
 
 #if defined(HAVE_X11) && HAVE_X11
-  if (Config::Get(Config::MAIN_DISABLE_SCREENSAVER))
+  X11Utils::InhibitScreensaver(win, inhibit);
-  {
-    X11Utils::InhibitScreensaver(win, !enable);
-  }
 #endif
 
 #ifdef _WIN32
   // Prevents Windows from sleeping, turning off the display, or idling
-  if (enable)
+  SetThreadExecutionState(ES_CONTINUOUS |
-  {
+                          (inhibit ? (ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED) : 0));
-    SetThreadExecutionState(ES_CONTINUOUS);
-  }
-  else
-  {
-    EXECUTION_STATE should_screen_save =
-        Config::Get(Config::MAIN_DISABLE_SCREENSAVER) ? ES_DISPLAY_REQUIRED : 0;
-    SetThreadExecutionState(ES_CONTINUOUS | should_screen_save | ES_SYSTEM_REQUIRED);
-  }
 #endif
 
 #ifdef __APPLE__
   static IOPMAssertionID s_power_assertion = kIOPMNullAssertionID;
-
+  if (inhibit)
-  if (Config::Get(Config::MAIN_DISABLE_SCREENSAVER))
   {
-    if (enable)
+    CFStringRef reason_for_activity = CFSTR("Emulation Running");
+    if (IOPMAssertionCreateWithName(kIOPMAssertionTypePreventUserIdleDisplaySleep,
+                                    kIOPMAssertionLevelOn, reason_for_activity,
+                                    &s_power_assertion) != kIOReturnSuccess)
     {
-      if (s_power_assertion != kIOPMNullAssertionID)
+      s_power_assertion = kIOPMNullAssertionID;
-      {
-        IOPMAssertionRelease(s_power_assertion);
-        s_power_assertion = kIOPMNullAssertionID;
-      }
     }
-    else
+  }
+  else
+  {
+    if (s_power_assertion != kIOPMNullAssertionID)
     {
-      CFStringRef reason_for_activity = CFSTR("Emulation Running");
+      IOPMAssertionRelease(s_power_assertion);
-      if (IOPMAssertionCreateWithName(kIOPMAssertionTypePreventUserIdleDisplaySleep,
+      s_power_assertion = kIOPMNullAssertionID;
-                                      kIOPMAssertionLevelOn, reason_for_activity,
-                                      &s_power_assertion) != kIOReturnSuccess)
-      {
-        s_power_assertion = kIOPMNullAssertionID;
-      }
     }
   }
 #endif

Source/Core/UICommon/UICommon.h

@@ -14,9 +14,9 @@ void Init();
 void Shutdown();
 
 #if defined(HAVE_XRANDR) && HAVE_XRANDR
-void EnableScreenSaver(unsigned long win, bool enable);
+void InhibitScreenSaver(unsigned long win, bool enable);
 #else
-void EnableScreenSaver(bool enable);
+void InhibitScreenSaver(bool enable);
 #endif
 
 // Calls std::locale::global, selecting a fallback locale if the