Corrects attempt at back-to-UI final window SDI behaviour.

Maybe it'll turn out to be not what I want, but at least now it works.

ClockReceiver/VSyncPredictor.hpp

@@ -42,6 +42,10 @@ class VSyncPredictor {
 			last_vsync_ = vsync_time;
 		}
 
+		void pause() {
+			last_vsync_ = 0;
+		}
+
 		Nanos suggested_draw_time() {
 			// TODO: this is a very simple version of how this calculation
 			// should be made. It's tracking the average amount of time these

OSBindings/Qt/mainwindow.cpp

@@ -46,7 +46,7 @@ MainWindow::MainWindow(const QString &fileName) {
 	launchFile(fileName);
 }
 
-MainWindow::~MainWindow() {
+void MainWindow::deleteMachine() {
 	// Stop the timer; stopping this first ensures the machine won't attempt
 	// to write to the audioOutput while it is being shut down.
 	timer.reset();
@@ -62,21 +62,29 @@ MainWindow::~MainWindow() {
 		audioThread.stop();
 	}
 
+	machine.reset();
+}
+
+MainWindow::~MainWindow() {
+	deleteMachine();
+
 	// Store the current user selections.
 	storeSelections();
 
 	--mainWindowCount;
+	qDebug() << "Count: " << mainWindowCount;
 }
 
 void MainWindow::closeEvent(QCloseEvent *event) {
 	// SDI behaviour, which may or may not be normal (?): if the user is closing a
 	// final window, and it contains a machine, send them back to the machine picker.
 	// i.e. assume they were closing that document, not the application.
-//	if(mainWindowCount == 1 && machine) {
-//		MainWindow *const other = new MainWindow;
-//		other->setAttribute(Qt::WA_DeleteOnClose);
-//		other->show();
-//	}
+	if(mainWindowCount == 1 && machine) {
+		setVisibleWidgetSet(WidgetSet::MachinePicker);
+		deleteMachine();
+		event->ignore();
+		return;
+	}
 	QMainWindow::closeEvent(event);
 }
 
@@ -90,8 +98,6 @@ void MainWindow::init() {
 
 	createActions();
 	restoreSelections();
-
-	timer = std::make_unique<Timer>(this);
 }
 
 void MainWindow::createActions() {
@@ -280,6 +286,7 @@ void MainWindow::launchMachine() {
 			// If this is a timed machine, start up the timer.
 			const auto timedMachine = machine->timed_machine();
 			if(timedMachine) {
+				timer = std::make_unique<Timer>(this);
 				timer->startWithMachine(timedMachine, &machineMutex);
 			}
 

OSBindings/Qt/mainwindow.h

@@ -94,6 +94,8 @@ class MainWindow : public QMainWindow, public Outputs::Speaker::Speaker::Delegat
 
 		void closeEvent(QCloseEvent *event) override;
 		static inline int mainWindowCount = 0;
+
+		void deleteMachine();
 };
 
 #endif // MAINWINDOW_H

OSBindings/Qt/scantargetwidget.cpp

@@ -10,9 +10,7 @@ ScanTargetWidget::ScanTargetWidget(QWidget *parent) : QOpenGLWidget(parent) {}
 ScanTargetWidget::~ScanTargetWidget() {}
 
 void ScanTargetWidget::initializeGL() {
-	// Retain the default background colour.
-	const QColor backgroundColour = palette().color(QWidget::backgroundRole());
-	glClearColor(backgroundColour.redF(), backgroundColour.greenF(), backgroundColour.blueF(), 1.0);
+	setDefaultClearColour();
 
 	// Follow each swapped frame with an additional update.
 	connect(this, &QOpenGLWidget::frameSwapped, this, &ScanTargetWidget::vsync);
@@ -56,6 +54,8 @@ void ScanTargetWidget::paintGL() {
 }
 
 void ScanTargetWidget::vsync() {
+	if(!isConnected) return;
+
 	vsyncPredictor.announce_vsync();
 
 	const auto time_now = Time::nanos_now();
@@ -80,4 +80,12 @@ void ScanTargetWidget::stop() {
 	makeCurrent();
 	scanTarget.reset();
 	isConnected = false;
+	setDefaultClearColour();
+	vsyncPredictor.pause();
+}
+
+void ScanTargetWidget::setDefaultClearColour() {
+	// Retain the default background colour.
+	const QColor backgroundColour = palette().color(QWidget::backgroundRole());
+	glClearColor(backgroundColour.redF(), backgroundColour.greenF(), backgroundColour.blueF(), 1.0);
 }

OSBindings/Qt/scantargetwidget.h

@@ -34,6 +34,8 @@ class ScanTargetWidget : public QOpenGLWidget
 		GLuint framebuffer = 0;
 		MachineTypes::ScanProducer *producer = nullptr;
 
+		void setDefaultClearColour();
+
 	private slots:
 		void vsync();
 };