Qt: Add savestate load undo

CHANGES

@@ -24,6 +24,7 @@ Features:
  - Preliminary support for yanking out the game pak while a game is running
  - Thumb-drive mode by putting a file called portable.ini in the same folder
  - Configurable display driver, between software and OpenGL
+ - Undo-able savestate loading
 Bugfixes:
  - ARM7: Fix SWI and IRQ timings
  - GBA Audio: Force audio FIFOs to 32-bit

src/platform/qt/GameController.cpp

@@ -51,6 +51,8 @@ GameController::GameController(QObject* parent)
 	, m_inputController(nullptr)
 	, m_multiplayer(nullptr)
 	, m_stateSlot(1)
+	, m_backupLoadState(nullptr)
+	, m_backupSaveState(nullptr)
 {
 	m_renderer = new GBAVideoSoftwareRenderer;
 	GBAVideoSoftwareRendererCreate(m_renderer);
@@ -162,6 +164,7 @@ GameController::~GameController() {
 	GBACheatDeviceDestroy(&m_cheatDevice);
 	delete m_renderer;
 	delete[] m_drawContext;
+	delete m_backupLoadState;
 }
 
 void GameController::setMultiplayerController(MultiplayerController* controller) {
@@ -561,6 +564,10 @@ void GameController::loadState(int slot) {
 	}
 	GBARunOnThread(&m_threadContext, [](GBAThread* context) {
 		GameController* controller = static_cast<GameController*>(context->userData);
+		if (!controller->m_backupLoadState) {
+			controller->m_backupLoadState = new GBASerializedState;
+		}
+		GBASerialize(context->gba, controller->m_backupLoadState);
 		if (GBALoadState(context, context->stateDir, controller->m_stateSlot)) {
 			controller->frameAvailable(controller->m_drawContext);
 			controller->stateLoaded(context);
@@ -578,6 +585,23 @@ void GameController::saveState(int slot) {
 	});
 }
 
+void GameController::loadBackupState() {
+	if (!m_backupLoadState) {
+		return;
+	}
+
+	GBARunOnThread(&m_threadContext, [](GBAThread* context) {
+		GameController* controller = static_cast<GameController*>(context->userData);
+		if (GBADeserialize(context->gba, controller->m_backupLoadState)) {
+			GBALog(context->gba, GBA_LOG_STATUS, "Undid state load");
+			controller->frameAvailable(controller->m_drawContext);
+			controller->stateLoaded(context);
+		}
+		delete controller->m_backupLoadState;
+		controller->m_backupLoadState = nullptr;
+	});
+}
+
 void GameController::setVideoSync(bool set) {
 	m_videoSync = set;
 	if (!m_turbo) {

src/platform/qt/GameController.h

@@ -120,6 +120,7 @@ public slots:
 	void setFPSTarget(float fps);
 	void loadState(int slot = 0);
 	void saveState(int slot = 0);
+	void loadBackupState();
 	void setVideoSync(bool);
 	void setAudioSync(bool);
 	void setFrameskip(int);
@@ -192,6 +193,8 @@ private:
 	bool m_wasPaused;
 
 	int m_stateSlot;
+	GBASerializedState* m_backupLoadState;
+	GBASerializedState* m_backupSaveState; // TODO: Use this
 
 	InputController* m_inputController;
 	MultiplayerController* m_multiplayer;

src/platform/qt/Window.cpp

@@ -697,6 +697,14 @@ void Window::setupMenu(QMenuBar* menubar) {
 	m_gameActions.append(quickSave);
 	addControlledAction(quickSaveMenu, quickSave, "quickSave");
 
+	quickLoadMenu->addSeparator();
+
+	QAction* undoLoadState = new QAction(tr("Undo load state"), quickLoadMenu);
+	undoLoadState->setShortcut(tr("F11"));
+	connect(undoLoadState, SIGNAL(triggered()), m_controller, SLOT(loadBackupState()));
+	m_gameActions.append(undoLoadState);
+	addControlledAction(quickLoadMenu, undoLoadState, "undoLoadState");
+
 	quickLoadMenu->addSeparator();
 	quickSaveMenu->addSeparator();
 
@@ -961,14 +969,12 @@ void Window::setupMenu(QMenuBar* menubar) {
 
 #ifdef USE_FFMPEG
 	QAction* recordOutput = new QAction(tr("Record output..."), avMenu);
-	recordOutput->setShortcut(tr("F11"));
 	connect(recordOutput, SIGNAL(triggered()), this, SLOT(openVideoWindow()));
 	addControlledAction(avMenu, recordOutput, "recordOutput");
 #endif
 
 #ifdef USE_MAGICK
 	QAction* recordGIF = new QAction(tr("Record GIF..."), avMenu);
-	recordGIF->setShortcut(tr("Shift+F11"));
 	connect(recordGIF, SIGNAL(triggered()), this, SLOT(openGIFWindow()));
 	addControlledAction(avMenu, recordGIF, "recordGIF");
 #endif