Integrate standalone FSUI into Panda SDL frontend

include/panda_sdl/panda_fsui.hpp

@@ -0,0 +1,92 @@
+#pragma once
+
+#ifdef IMGUI_FRONTEND
+
+#include <SDL.h>
+
+#include <filesystem>
+#include <functional>
+#include <optional>
+#include <vector>
+
+#include "fsui/fsui.hpp"
+
+class Emulator;
+
+class PandaFsuiAdapter {
+  public:
+	enum class ClassicUiRequest {
+		None,
+		Return,
+		OpenSettings,
+	};
+
+	PandaFsuiAdapter(SDL_Window* window, Emulator& emu);
+
+	bool initialize(const fsui::FontStack& fonts);
+	void shutdown(bool clear_state);
+	void render();
+	void consumeCommands();
+
+	void setSelectorMode(bool selector_mode);
+	bool isSelectorMode() const;
+	bool hasActiveWindow() const;
+	void openPauseMenu();
+	void returnToPreviousWindow();
+	void returnToMainWindow();
+	void switchToSettings();
+
+	std::optional<std::filesystem::path> consumeLaunchPath();
+	bool consumeCloseSelector();
+	ClassicUiRequest consumeClassicUiRequest();
+
+	void setPauseCallback(std::function<void(bool)> callback);
+	void setVsyncCallback(std::function<void(bool)> callback);
+	void setExitToSelectorCallback(std::function<void()> callback);
+
+  private:
+	struct ParsedMetadata;
+	struct LanguageOption;
+
+	void syncUiStateFromConfig();
+	void persistUiState(bool reload);
+	void seedGameListPathsIfNeeded();
+	std::vector<std::filesystem::path> currentScanRoots() const;
+	bool hasSupportedExtension(const std::filesystem::path& path) const;
+	std::vector<fsui::GameEntry> buildGameList();
+	std::vector<fsui::SettingsPageDescriptor> buildSettingsPages(fsui::SettingsScope scope);
+	fsui::CurrentGameInfo buildCurrentGameInfo();
+	std::vector<fsui::MenuItemDescriptor> buildLandingItems();
+	std::vector<fsui::MenuItemDescriptor> buildStartItems();
+	std::vector<fsui::MenuItemDescriptor> buildExitItems();
+	std::vector<fsui::MenuItemDescriptor> buildPauseItems();
+	std::vector<fsui::MenuItemDescriptor> buildGameLaunchOptions(const fsui::GameEntry& entry);
+
+	std::optional<ParsedMetadata> readMetadataForPath(const std::filesystem::path& path) const;
+	fsui::GameEntry buildGameListEntry(const std::filesystem::directory_entry& entry) const;
+	std::filesystem::path defaultCoverDirectory() const;
+	std::filesystem::path findCoverPath(const std::filesystem::path& rom_path, const std::string& title_id) const;
+	std::string currentGameTitle() const;
+	std::string currentGameSubtitle() const;
+	std::string formatPercent(float value) const;
+	std::string formatInteger(int value) const;
+	std::string formatTitleId(std::uint64_t program_id) const;
+	void openFileAndLaunch();
+	void requestLaunchPath(const std::filesystem::path& path);
+	void requestClassicUi(bool open_settings);
+	void openUnsupportedPrompt(std::string title, std::string message) const;
+
+	SDL_Window* window = nullptr;
+	Emulator& emu;
+	fsui::UiContext fsuiContext;
+	fsui::UiState uiState;
+	std::vector<fsui::GameEntry> cachedGameList;
+	std::optional<std::filesystem::path> pendingLaunchPath;
+	bool closeSelectorRequested = false;
+	ClassicUiRequest pendingClassicUiRequest = ClassicUiRequest::None;
+	std::function<void(bool)> onPauseChange;
+	std::function<void(bool)> onVsyncChange;
+	std::function<void()> onExitToSelector;
+};
+
+#endif