Move most helper logic from base HostInterface to FrontendCommon

src/core/host_interface.h

@@ -28,12 +28,6 @@ class HostInterface
   friend System;
 
 public:
-  enum : s32
-  {
-    PER_GAME_SAVE_STATE_SLOTS = 10,
-    GLOBAL_SAVE_STATE_SLOTS = 10
-  };
-
   enum : u32
   {
     AUDIO_SAMPLE_RATE = 44100,
@@ -41,29 +35,6 @@ public:
     DEFAULT_AUDIO_BUFFER_SIZE = 2048
   };
 
-  struct SaveStateInfo
-  {
-    std::string path;
-    u64 timestamp;
-    s32 slot;
-    bool global;
-  };
-
-  struct ExtendedSaveStateInfo
-  {
-    std::string path;
-    u64 timestamp;
-    s32 slot;
-    bool global;
-
-    std::string title;
-    std::string game_code;
-
-    u32 screenshot_width;
-    u32 screenshot_height;
-    std::vector<u32> screenshot_data;
-  };
-
   HostInterface();
   virtual ~HostInterface();
 
@@ -76,9 +47,6 @@ public:
   /// Returns a settings object which can be modified.
   ALWAYS_INLINE Settings& GetSettings() { return m_settings; }
 
-  /// Returns the game list.
-  ALWAYS_INLINE const GameList* GetGameList() const { return m_game_list.get(); }
-
   /// Access to emulated system.
   ALWAYS_INLINE System* GetSystem() const { return m_system.get(); }
 
@@ -91,41 +59,12 @@ public:
   virtual bool BootSystem(const SystemBootParameters& parameters);
   virtual void PowerOffSystem();
 
-  void PauseSystem(bool paused);
-  void ResetSystem();
-  void DestroySystem();
+  virtual void ResetSystem();
+  virtual void DestroySystem();
 
   /// Loads state from the specified filename.
   bool LoadState(const char* filename);
 
-  /// Loads the current emulation state from file. Specifying a slot of -1 loads the "resume" game state.
-  bool LoadState(bool global, s32 slot);
-
-  /// Saves the current emulation state to a file. Specifying a slot of -1 saves the "resume" save state.
-  bool SaveState(bool global, s32 slot);
-
-  /// Loads the resume save state for the given game. Optionally boots the game anyway if loading fails.
-  bool ResumeSystemFromState(const char* filename, bool boot_on_failure);
-
-  /// Loads the most recent resume save state. This may be global or per-game.
-  bool ResumeSystemFromMostRecentState();
-
-  /// Saves the resume save state, call when shutting down. Not called automatically on DestroySystem() since that can
-  /// be called as a result of an error.
-  bool SaveResumeSaveState();
-
-  /// Returns true if currently dumping audio.
-  bool IsDumpingAudio() const;
-
-  /// Starts dumping audio to a file. If no file name is provided, one will be generated automatically.
-  bool StartDumpingAudio(const char* filename = nullptr);
-
-  /// Stops dumping audio to file if it has been started.
-  void StopDumpingAudio();
-
-  /// Saves a screenshot to the specified file. IF no file name is provided, one will be generated automatically.
-  bool SaveScreenshot(const char* filename = nullptr, bool full_resolution = true, bool apply_aspect_ratio = true);
-
   virtual void ReportError(const char* message);
   virtual void ReportMessage(const char* message);
   virtual bool ConfirmMessage(const char* message);
@@ -135,7 +74,7 @@ public:
   bool ConfirmFormattedMessage(const char* format, ...);
 
   /// Adds OSD messages, duration is in seconds.
-  void AddOSDMessage(const char* message, float duration = 2.0f);
+  virtual void AddOSDMessage(std::string message, float duration = 2.0f);
   void AddFormattedOSDMessage(float duration, const char* format, ...);
 
   /// Returns the base user directory path.
@@ -152,19 +91,10 @@ public:
 
   /// Displays a loading screen with the logo, rendered with ImGui. Use when executing possibly-time-consuming tasks
   /// such as compiling shaders when starting up.
-  void DisplayLoadingScreen(const char* message, int progress_min = -1, int progress_max = -1, int progress_value = -1);
+  virtual void DisplayLoadingScreen(const char* message, int progress_min = -1, int progress_max = -1, int progress_value = -1);
 
-  /// Returns a list of save states for the specified game code.
-  std::vector<SaveStateInfo> GetAvailableSaveStates(const char* game_code) const;
-
-  /// Returns save state info if present. If game_code is null or empty, assumes global state.
-  std::optional<SaveStateInfo> GetSaveStateInfo(const char* game_code, s32 slot);
-
-  /// Returns save state info if present. If game_code is null or empty, assumes global state.
-  std::optional<ExtendedSaveStateInfo> GetExtendedSaveStateInfo(const char* game_code, s32 slot);
-
-  /// Deletes save states for the specified game code. If resume is set, the resume state is deleted too.
-  void DeleteSaveStates(const char* game_code, bool resume);
+  /// Retrieves information about specified game from game list.
+  virtual void GetGameInfo(const char* path, CDImage* image, std::string* code, std::string* title);
 
   /// Enables the software cursor. Can be called multiple times, but must be matched by a call to DisableSoftwareCursor().
   void EnableSoftwareCursor();
@@ -173,118 +103,59 @@ public:
   void DisableSoftwareCursor();
 
 protected:
-  enum : u32
-  {
-    SETTINGS_VERSION = 2
-  };
-
-  struct OSDMessage
-  {
-    std::string text;
-    Common::Timer time;
-    float duration;
-  };
-
   virtual bool AcquireHostDisplay() = 0;
   virtual void ReleaseHostDisplay() = 0;
   virtual std::unique_ptr<AudioStream> CreateAudioStream(AudioBackend backend) = 0;
 
   virtual void OnSystemCreated();
-  virtual void OnSystemPaused(bool paused);
   virtual void OnSystemDestroyed();
   virtual void OnSystemPerformanceCountersUpdated();
   virtual void OnSystemStateSaved(bool global, s32 slot);
   virtual void OnRunningGameChanged();
   virtual void OnControllerTypeChanged(u32 slot);
-  virtual void DrawImGuiWindows();
 
-  /// Sets the base path for the user directory. Can be overridden by platform/frontend/command line.
-  virtual void SetUserDirectory();
+  /// Restores all settings to defaults.
+  virtual void SetDefaultSettings(SettingsInterface& si);
+
+  /// Loads settings to m_settings and any frontend-specific parameters.
+  virtual void LoadSettings(SettingsInterface& si);
+
+  /// Saves current settings variables to ini.
+  virtual void SaveSettings(SettingsInterface& si);
+
+  /// Checks for settings changes, std::move() the old settings away for comparing beforehand.
+  virtual void CheckForSettingsChanges(const Settings& old_settings);
+
+  /// Switches the GPU renderer by saving state, recreating the display window, and restoring state (if needed).
+  virtual void RecreateSystem();
 
   /// Sets the user directory to the program directory, i.e. "portable mode".
   void SetUserDirectoryToProgramDirectory();
 
-  /// Performs the initial load of settings. Should call CheckSettings() and ApplySettings().
-  virtual void LoadSettings() = 0;
-
-  /// Updates logging settings.
-  virtual void UpdateLogSettings(LOGLEVEL level, const char* filter, bool log_to_console, bool log_to_debug,
-                                 bool log_to_window, bool log_to_file);
-
-  /// Returns the path of the settings file.
-  std::string GetSettingsFileName() const;
-
-  /// Returns the path to a save state file. Specifying an index of -1 is the "resume" save state.
-  std::string GetGameSaveStateFileName(const char* game_code, s32 slot) const;
-
-  /// Returns the path to a save state file. Specifying an index of -1 is the "resume" save state.
-  std::string GetGlobalSaveStateFileName(s32 slot) const;
-
   /// Returns the default path to a memory card.
   std::string GetSharedMemoryCardPath(u32 slot) const;
 
   /// Returns the default path to a memory card for a specific game.
   std::string GetGameMemoryCardPath(const char* game_code, u32 slot) const;
 
-  /// Returns the most recent resume save state.
-  std::string GetMostRecentResumeSaveStatePath() const;
-
   /// Loads the BIOS image for the specified region.
   std::optional<std::vector<u8>> GetBIOSImage(ConsoleRegion region);
 
-  /// Ensures the settings is valid and the correct version. If not, resets to defaults.
-  void CheckSettings(SettingsInterface& si);
-
-  /// Restores all settings to defaults.
-  virtual void SetDefaultSettings(SettingsInterface& si);
-
-  /// Loads settings to m_settings and any frontend-specific parameters.
-  virtual void ApplySettings(SettingsInterface& si);
-
-  /// Saves current settings variables to ini.
-  virtual void ExportSettings(SettingsInterface& si);
-
-  /// Applies new settings, updating internal state as needed.
-  virtual void UpdateSettings(SettingsInterface& si);
-
   /// Quick switch between software and hardware rendering.
   void ToggleSoftwareRendering();
 
   /// Adjusts the internal (render) resolution of the hardware backends.
   void ModifyResolutionScale(s32 increment);
 
-  /// Switches the GPU renderer by saving state, recreating the display window, and restoring state (if needed).
-  void RecreateSystem();
-
-  /// Increases timer resolution when supported by the host OS.
-  void SetTimerResolutionIncreased(bool enabled);
-
-  void UpdateSpeedLimiterState();
-
-  void DrawFPSWindow();
-  void DrawOSDMessages();
-  void DrawDebugWindows();
+  bool SaveState(const char* filename);
+  void CreateAudioStream();
 
   HostDisplay* m_display = nullptr;
   std::unique_ptr<AudioStream> m_audio_stream;
   std::unique_ptr<System> m_system;
-  std::unique_ptr<GameList> m_game_list;
   Settings m_settings;
   std::string m_program_directory;
   std::string m_user_directory;
 
-  std::deque<OSDMessage> m_osd_messages;
-  std::mutex m_osd_messages_lock;
-
   u32 m_software_cursor_use_count = 0;
-
-  bool m_paused = false;
-  bool m_speed_limiter_temp_disabled = false;
-  bool m_speed_limiter_enabled = false;
-  bool m_timer_resolution_increased = false;
-
-private:
-  void InitializeUserDirectory();
-  void CreateAudioStream();
-  bool SaveState(const char* filename);
 };

src/core/memory_card.cpp

@@ -1,6 +1,7 @@
 #include "memory_card.h"
 #include "common/byte_stream.h"
 #include "common/file_system.h"
+#include "common/string_util.h"
 #include "common/log.h"
 #include "common/state_wrapper.h"
 #include "host_interface.h"
@@ -254,7 +255,7 @@ std::unique_ptr<MemoryCard> MemoryCard::Open(System* system, std::string_view fi
     message.AppendString(filename.data(), static_cast<u32>(filename.length()));
     message.AppendString("' could not be read, formatting.");
     Log_ErrorPrint(message);
-    system->GetHostInterface()->AddOSDMessage(message, 5.0f);
+    system->GetHostInterface()->AddOSDMessage(message.GetCharArray(), 5.0f);
     mc->Format();
   }
 
@@ -385,7 +386,7 @@ bool MemoryCard::SaveIfChanged(bool display_osd_message)
   if (display_osd_message)
   {
     m_system->GetHostInterface()->AddOSDMessage(
-      SmallString::FromFormat("Saved memory card to '%s'", m_filename.c_str()));
+      StringUtil::StdStringFromFormat("Saved memory card to '%s'", m_filename.c_str()));
   }
 
   return true;

src/core/settings.cpp

@@ -73,7 +73,7 @@ void Settings::Load(SettingsInterface& si)
   gpu_max_run_ahead = si.GetIntValue("Hacks", "GPUMaxRunAhead", DEFAULT_GPU_MAX_RUN_AHEAD);
 
   bios_path = si.GetStringValue("BIOS", "Path", "bios/scph1001.bin");
-  bios_patch_tty_enable = si.GetBoolValue("BIOS", "PatchTTYEnable", true);
+  bios_patch_tty_enable = si.GetBoolValue("BIOS", "PatchTTYEnable", false);
   bios_patch_fast_boot = si.GetBoolValue("BIOS", "PatchFastBoot", false);
 
   controller_types[0] = ParseControllerTypeName(si.GetStringValue("Controller1", "Type", "DigitalController").c_str())

src/core/system.cpp

@@ -1133,26 +1133,7 @@ void System::UpdateRunningGame(const char* path, CDImage* image)
   if (path && std::strlen(path) > 0)
   {
     m_running_game_path = path;
-
-    const GameListEntry* list_entry = m_host_interface->GetGameList()->GetEntryForPath(path);
-    if (list_entry)
-    {
-      m_running_game_code = list_entry->code;
-      m_running_game_title = list_entry->title;
-    }
-    else
-    {
-      if (image)
-        m_running_game_code = GameList::GetGameCodeForImage(image);
-
-      const GameListDatabaseEntry* db_entry =
-        (!m_running_game_code.empty()) ? m_host_interface->GetGameList()->GetDatabaseEntryForCode(m_running_game_code) :
-                                         nullptr;
-      if (db_entry)
-        m_running_game_title = db_entry->title;
-      else
-        m_running_game_title = GameList::GetTitleForPath(path);
-    }
+    m_host_interface->GetGameInfo(path, image, &m_running_game_code, &m_running_game_title);
   }
 
   m_host_interface->OnRunningGameChanged();

src/core/system.h

@@ -90,6 +90,7 @@ public:
   float GetEmulationSpeed() const { return m_speed; }
   float GetAverageFrameTime() const { return m_average_frame_time; }
   float GetWorstFrameTime() const { return m_worst_frame_time; }
+  float GetThrottleFrequency() const { return m_throttle_frequency; }
 
   bool Boot(const SystemBootParameters& params);
   void Reset();

src/duckstation-qt/qthostinterface.cpp

@@ -144,13 +144,15 @@ void QtHostInterface::setDefaultSettings()
     return;
   }
 
-  QtSettingsInterface si(m_qsettings.get());
+  Settings old_settings(std::move(m_settings));
   {
+    QtSettingsInterface si(m_qsettings.get());
     std::lock_guard<std::recursive_mutex> guard(m_qsettings_mutex);
     SetDefaultSettings(si);
+    CommonHostInterface::LoadSettings(si);
   }
-  UpdateSettings(si);
-  CommonHostInterface::UpdateInputMap(si);
+
+  CheckForSettingsChanges(old_settings);
 }
 
 void QtHostInterface::applySettings()
@@ -161,15 +163,19 @@ void QtHostInterface::applySettings()
     return;
   }
 
-  std::lock_guard<std::recursive_mutex> guard(m_qsettings_mutex);
-  QtSettingsInterface si(m_qsettings.get());
-  UpdateSettings(si);
-  CommonHostInterface::UpdateInputMap(si);
+  Settings old_settings(std::move(m_settings));
+  {
+    QtSettingsInterface si(m_qsettings.get());
+    std::lock_guard<std::recursive_mutex> guard(m_qsettings_mutex);
+    CommonHostInterface::LoadSettings(si);
+  }
+
+  CheckForSettingsChanges(old_settings);
 
   // detect when render-to-main flag changes
   if (m_system)
   {
-    const bool render_to_main = m_qsettings->value("Main/RenderToMainWindow", true).toBool();
+    const bool render_to_main = getSettingValue("Main/RenderToMainWindow", true).toBool();
     if (getHostDisplay() && !m_is_fullscreen && render_to_main != m_is_rendering_to_main)
     {
       m_is_rendering_to_main = render_to_main;
@@ -224,9 +230,9 @@ void QtHostInterface::resumeSystemFromState(const QString& filename, bool boot_o
 
   emit emulationStarting();
   if (filename.isEmpty())
-    HostInterface::ResumeSystemFromMostRecentState();
+    ResumeSystemFromMostRecentState();
   else
-    HostInterface::ResumeSystemFromState(filename.toStdString().c_str(), boot_on_failure);
+    ResumeSystemFromState(filename.toStdString().c_str(), boot_on_failure);
 }
 
 void QtHostInterface::resumeSystemFromMostRecentState()
@@ -238,7 +244,7 @@ void QtHostInterface::resumeSystemFromMostRecentState()
   }
 
   emit emulationStarting();
-  HostInterface::ResumeSystemFromMostRecentState();
+  ResumeSystemFromMostRecentState();
 }
 
 void QtHostInterface::onDisplayWindowKeyEvent(int key, bool pressed)
@@ -510,8 +516,8 @@ void QtHostInterface::LoadSettings()
   }
 
   // load in settings
-  CheckSettings(si);
-  ApplySettings(si);
+  CommonHostInterface::CheckSettings(si);
+  CommonHostInterface::LoadSettings(si);
 }
 
 void QtHostInterface::SetDefaultSettings(SettingsInterface& si)
@@ -521,12 +527,6 @@ void QtHostInterface::SetDefaultSettings(SettingsInterface& si)
   si.SetBoolValue("Main", "RenderToMainWindow", true);
 }
 
-void QtHostInterface::ApplySettings(SettingsInterface& si)
-{
-  std::lock_guard<std::recursive_mutex> lock(m_qsettings_mutex);
-  CommonHostInterface::ApplySettings(si);
-}
-
 void QtHostInterface::UpdateInputMap()
 {
   updateInputMap();

src/duckstation-qt/qthostinterface.h

@@ -158,7 +158,6 @@ protected:
 
   void LoadSettings() override;
   void SetDefaultSettings(SettingsInterface& si) override;
-  void ApplySettings(SettingsInterface& si) override;
   void UpdateInputMap() override;
 
 private:

src/duckstation-sdl/sdl_host_interface.cpp

@@ -299,7 +299,11 @@ void SDLHostInterface::RunLater(std::function<void()> callback)
 void SDLHostInterface::SaveAndUpdateSettings()
 {
   m_settings_copy.Save(*m_settings_interface.get());
-  UpdateSettings(*m_settings_interface.get());
+
+  Settings old_settings(std::move(m_settings));
+  CommonHostInterface::LoadSettings(*m_settings_interface.get());
+  CheckForSettingsChanges(old_settings);
+
   m_settings_interface->Save();
 }
 
@@ -382,7 +386,7 @@ void SDLHostInterface::LoadSettings()
 {
   // Settings need to be loaded prior to creating the window for OpenGL bits.
   m_settings_interface = std::make_unique<INISettingsInterface>(GetSettingsFileName());
-  ApplySettings(*m_settings_interface.get());
+  CommonHostInterface::LoadSettings(*m_settings_interface.get());
   m_settings_copy = m_settings;
 }
 

src/frontend-common/common_host_interface.h

@@ -22,6 +22,12 @@ class CommonHostInterface : public HostInterface
 public:
   friend ControllerInterface;
 
+  enum : s32
+  {
+    PER_GAME_SAVE_STATE_SLOTS = 10,
+    GLOBAL_SAVE_STATE_SLOTS = 10
+  };
+
   using HostKeyCode = s32;
   using HostMouseButton = s32;
 
@@ -39,6 +45,32 @@ public:
 
   using HotkeyInfoList = std::vector<HotkeyInfo>;
 
+  struct SaveStateInfo
+  {
+    std::string path;
+    u64 timestamp;
+    s32 slot;
+    bool global;
+  };
+
+  struct ExtendedSaveStateInfo
+  {
+    std::string path;
+    u64 timestamp;
+    s32 slot;
+    bool global;
+
+    std::string title;
+    std::string game_code;
+
+    u32 screenshot_width;
+    u32 screenshot_height;
+    std::vector<u32> screenshot_data;
+  };
+
+  using HostInterface::LoadState;
+  using HostInterface::SaveState;
+
   /// Returns the name of the frontend.
   virtual const char* GetFrontendName() const = 0;
 
@@ -47,6 +79,10 @@ public:
 
   virtual bool BootSystem(const SystemBootParameters& parameters) override;
   virtual void PowerOffSystem() override;
+  virtual void DestroySystem() override;
+
+  /// Returns the game list.
+  ALWAYS_INLINE const GameList* GetGameList() const { return m_game_list.get(); }
 
   /// Returns a list of all available hotkeys.
   ALWAYS_INLINE const HotkeyInfoList& GetHotkeyInfoList() const { return m_hotkeys; }
@@ -57,10 +93,75 @@ public:
   /// Returns true if running in batch mode, i.e. exit after emulation.
   ALWAYS_INLINE bool InBatchMode() const { return m_batch_mode; }
 
+  void PauseSystem(bool paused);
+
   /// Parses command line parameters for all frontends.
   bool ParseCommandLineParameters(int argc, char* argv[], std::unique_ptr<SystemBootParameters>* out_boot_params);
 
+  /// Loads the current emulation state from file. Specifying a slot of -1 loads the "resume" game state.
+  bool LoadState(bool global, s32 slot);
+
+  /// Saves the current emulation state to a file. Specifying a slot of -1 saves the "resume" save state.
+  bool SaveState(bool global, s32 slot);
+
+  /// Loads the resume save state for the given game. Optionally boots the game anyway if loading fails.
+  bool ResumeSystemFromState(const char* filename, bool boot_on_failure);
+
+  /// Loads the most recent resume save state. This may be global or per-game.
+  bool ResumeSystemFromMostRecentState();
+
+  /// Saves the resume save state, call when shutting down. Not called automatically on DestroySystem() since that can
+  /// be called as a result of an error.
+  bool SaveResumeSaveState();
+
+  /// Returns a list of save states for the specified game code.
+  std::vector<SaveStateInfo> GetAvailableSaveStates(const char* game_code) const;
+
+  /// Returns save state info if present. If game_code is null or empty, assumes global state.
+  std::optional<SaveStateInfo> GetSaveStateInfo(const char* game_code, s32 slot);
+
+  /// Returns save state info if present. If game_code is null or empty, assumes global state.
+  std::optional<ExtendedSaveStateInfo> GetExtendedSaveStateInfo(const char* game_code, s32 slot);
+
+  /// Deletes save states for the specified game code. If resume is set, the resume state is deleted too.
+  void DeleteSaveStates(const char* game_code, bool resume);
+
+  /// Adds OSD messages, duration is in seconds.
+  void AddOSDMessage(std::string message, float duration = 2.0f) override;
+
+  /// Displays a loading screen with the logo, rendered with ImGui. Use when executing possibly-time-consuming tasks
+  /// such as compiling shaders when starting up.
+  void DisplayLoadingScreen(const char* message, int progress_min = -1, int progress_max = -1,
+                            int progress_value = -1) override;
+
+  /// Retrieves information about specified game from game list.
+  void GetGameInfo(const char* path, CDImage* image, std::string* code, std::string* title) override;
+
+  /// Returns true if currently dumping audio.
+  bool IsDumpingAudio() const;
+
+  /// Starts dumping audio to a file. If no file name is provided, one will be generated automatically.
+  bool StartDumpingAudio(const char* filename = nullptr);
+
+  /// Stops dumping audio to file if it has been started.
+  void StopDumpingAudio();
+
+  /// Saves a screenshot to the specified file. IF no file name is provided, one will be generated automatically.
+  bool SaveScreenshot(const char* filename = nullptr, bool full_resolution = true, bool apply_aspect_ratio = true);
+
 protected:
+  enum : u32
+  {
+    SETTINGS_VERSION = 2
+  };
+
+  struct OSDMessage
+  {
+    std::string text;
+    Common::Timer time;
+    float duration;
+  };
+
   CommonHostInterface();
   ~CommonHostInterface();
 
@@ -77,14 +178,10 @@ protected:
   virtual std::unique_ptr<ControllerInterface> CreateControllerInterface();
 
   virtual void OnSystemCreated() override;
-  virtual void OnSystemPaused(bool paused) override;
+  virtual void OnSystemPaused(bool paused);
   virtual void OnSystemDestroyed() override;
   virtual void OnRunningGameChanged() override;
   virtual void OnControllerTypeChanged(u32 slot) override;
-  virtual void DrawImGuiWindows() override;
-
-  virtual void SetDefaultSettings(SettingsInterface& si) override;
-  virtual void ApplySettings(SettingsInterface& si) override;
 
   virtual std::optional<HostKeyCode> GetHostKeyCode(const std::string_view key_code) const;
 
@@ -118,9 +215,70 @@ protected:
   void UpdateControllerRumble();
   void StopControllerRumble();
 
+  /// Returns the path to a save state file. Specifying an index of -1 is the "resume" save state.
+  std::string GetGameSaveStateFileName(const char* game_code, s32 slot) const;
+
+  /// Returns the path to a save state file. Specifying an index of -1 is the "resume" save state.
+  std::string GetGlobalSaveStateFileName(s32 slot) const;
+
+  /// Sets the base path for the user directory. Can be overridden by platform/frontend/command line.
+  virtual void SetUserDirectory();
+
+  /// Performs the initial load of settings. Should call CheckSettings() and LoadSettings(SettingsInterface&).
+  virtual void LoadSettings() = 0;
+
+  /// Updates logging settings.
+  virtual void UpdateLogSettings(LOGLEVEL level, const char* filter, bool log_to_console, bool log_to_debug,
+                                 bool log_to_window, bool log_to_file);
+
+  /// Returns the path of the settings file.
+  std::string GetSettingsFileName() const;
+
+  /// Returns the most recent resume save state.
+  std::string GetMostRecentResumeSaveStatePath() const;
+
+  /// Ensures the settings is valid and the correct version. If not, resets to defaults.
+  void CheckSettings(SettingsInterface& si);
+
+  /// Restores all settings to defaults.
+  virtual void SetDefaultSettings(SettingsInterface& si);
+
+  /// Loads settings to m_settings and any frontend-specific parameters.
+  virtual void LoadSettings(SettingsInterface& si);
+
+  /// Saves current settings variables to ini.
+  virtual void SaveSettings(SettingsInterface& si);
+
+  /// Checks for settings changes, std::move() the old settings away for comparing beforehand.
+  virtual void CheckForSettingsChanges(const Settings& old_settings);
+
+  /// Increases timer resolution when supported by the host OS.
+  void SetTimerResolutionIncreased(bool enabled);
+
+  void UpdateSpeedLimiterState();
+
+  void RecreateSystem() override;
+
+  virtual void DrawImGuiWindows();
+
+  void DrawFPSWindow();
+  void DrawOSDMessages();
+  void DrawDebugWindows();
+
+  std::unique_ptr<GameList> m_game_list;
+
   std::unique_ptr<ControllerInterface> m_controller_interface;
 
+  std::deque<OSDMessage> m_osd_messages;
+  std::mutex m_osd_messages_lock;
+
+  bool m_paused = false;
+  bool m_speed_limiter_temp_disabled = false;
+  bool m_speed_limiter_enabled = false;
+  bool m_timer_resolution_increased = false;
+
 private:
+  void InitializeUserDirectory();
   void RegisterGeneralHotkeys();
   void RegisterGraphicsHotkeys();
   void RegisterSaveStateHotkeys();

src/frontend-common/save_state_selector_ui.cpp

@@ -45,9 +45,9 @@ void SaveStateSelectorUI::RefreshList()
   const System* system = m_host_interface->GetSystem();
   if (system && !system->GetRunningCode().empty())
   {
-    for (s32 i = 1; i <= HostInterface::GLOBAL_SAVE_STATE_SLOTS; i++)
+    for (s32 i = 1; i <= CommonHostInterface::GLOBAL_SAVE_STATE_SLOTS; i++)
     {
-      std::optional<HostInterface::ExtendedSaveStateInfo> ssi =
+      std::optional<CommonHostInterface::ExtendedSaveStateInfo> ssi =
         m_host_interface->GetExtendedSaveStateInfo(system->GetRunningCode().c_str(), i);
 
       ListEntry li;
@@ -60,9 +60,10 @@ void SaveStateSelectorUI::RefreshList()
     }
   }
 
-  for (s32 i = 1; i <= HostInterface::GLOBAL_SAVE_STATE_SLOTS; i++)
+  for (s32 i = 1; i <= CommonHostInterface::GLOBAL_SAVE_STATE_SLOTS; i++)
   {
-    std::optional<HostInterface::ExtendedSaveStateInfo> ssi = m_host_interface->GetExtendedSaveStateInfo(nullptr, i);
+    std::optional<CommonHostInterface::ExtendedSaveStateInfo> ssi =
+      m_host_interface->GetExtendedSaveStateInfo(nullptr, i);
 
     ListEntry li;
     if (ssi)
@@ -118,7 +119,7 @@ void SaveStateSelectorUI::SelectPreviousSlot()
     (m_current_selection == 0) ? (static_cast<u32>(m_slots.size()) - 1u) : (m_current_selection - 1);
 }
 
-void SaveStateSelectorUI::InitializeListEntry(ListEntry* li, HostInterface::ExtendedSaveStateInfo* ssi)
+void SaveStateSelectorUI::InitializeListEntry(ListEntry* li, CommonHostInterface::ExtendedSaveStateInfo* ssi)
 {
   li->title = std::move(ssi->title);
   li->game_code = std::move(ssi->game_code);

src/frontend-common/save_state_selector_ui.h

@@ -48,7 +48,7 @@ private:
   };
 
   void InitializePlaceholderListEntry(ListEntry* li, s32 slot, bool global);
-  void InitializeListEntry(ListEntry* li, HostInterface::ExtendedSaveStateInfo* ssi);
+  void InitializeListEntry(ListEntry* li, CommonHostInterface::ExtendedSaveStateInfo* ssi);
 
   CommonHostInterface* m_host_interface;
   std::vector<ListEntry> m_slots;