Qt: Holdable shortcut for rewinding one frame at a time

CHANGES

@@ -19,6 +19,7 @@ Features:
  - Support varible speed (PWM) rumble
  - Ability to cap fast forward speed
  - Finer control over FPS target
+ - Holdable shortcut for rewinding one frame at a time
 Bugfixes:
  - ARM7: Fix SWI and IRQ timings
  - GBA Audio: Force audio FIFOs to 32-bit

src/platform/qt/GameController.cpp

@@ -150,6 +150,13 @@ GameController::GameController(QObject* parent)
 		controller->postLog(level, message);
 	};
 
+	connect(&m_rewindTimer, &QTimer::timeout, [this]() {
+		GBARewind(&m_threadContext, 1);
+		emit rewound(&m_threadContext);
+		emit frameAvailable(m_drawContext);
+	});
+	m_rewindTimer.setInterval(100);
+
 	m_audioThread->start(QThread::TimeCriticalPriority);
 	m_audioProcessor->moveToThread(m_audioThread);
 	connect(this, SIGNAL(gameStarted(GBAThread*)), m_audioProcessor, SLOT(start()));
@@ -443,6 +450,16 @@ void GameController::rewind(int states) {
 	emit frameAvailable(m_drawContext);
 }
 
+void GameController::startRewinding() {
+	threadInterrupt();
+	m_rewindTimer.start();
+}
+
+void GameController::stopRewinding() {
+	m_rewindTimer.stop();
+	threadContinue();
+}
+
 void GameController::keyPressed(int key) {
 	int mappedKey = 1 << key;
 	m_activeKeys |= mappedKey;

src/platform/qt/GameController.h

@@ -11,6 +11,7 @@
 #include <QObject>
 #include <QMutex>
 #include <QString>
+#include <QTimer>
 
 #include <memory>
 
@@ -108,6 +109,8 @@ public slots:
 	void frameAdvance();
 	void setRewind(bool enable, int capacity, int interval);
 	void rewind(int states = 0);
+	void startRewinding();
+	void stopRewinding();
 	void keyPressed(int key);
 	void keyReleased(int key);
 	void clearKeys();
@@ -183,6 +186,7 @@ private:
 	bool m_turbo;
 	bool m_turboForced;
 	float m_turboSpeed;
+	QTimer m_rewindTimer;
 
 	int m_stateSlot;
 

src/platform/qt/Window.cpp

@@ -800,6 +800,12 @@ void Window::setupMenu(QMenuBar* menubar) {
 	}
 	m_config->updateOption("fastForwardRatio");
 
+	m_shortcutController->addFunctions(emulationMenu, [this]() {
+		m_controller->startRewinding();
+	}, [this]() {
+		m_controller->stopRewinding();
+	}, QKeySequence("~"), tr("Rewind (held)"), "holdRewind");
+
 	QAction* rewind = new QAction(tr("Re&wind"), emulationMenu);
 	rewind->setShortcut(tr("`"));
 	connect(rewind, SIGNAL(triggered()), m_controller, SLOT(rewind()));