Qt: Ask the display, not the core, what size it should be

src/platform/qt/Display.h

@@ -55,6 +55,7 @@ public:
 	virtual int framebufferHandle() { return -1; }
 	virtual void setVideoScale(int) {}
 	virtual void setBackgroundImage(const QImage&) = 0;
+	virtual QSize contentSize() const = 0;
 
 	virtual void setVideoProxy(std::shared_ptr<VideoProxy> proxy) { m_videoProxy = proxy; }
 	std::shared_ptr<VideoProxy> videoProxy() { return m_videoProxy; }

src/platform/qt/DisplayGL.cpp

@@ -245,6 +245,8 @@ void DisplayGL::startDrawing(std::shared_ptr<CoreController> controller) {
 		show();
 		m_gl->reset();
 	}
+
+	QTimer::singleShot(8, this, &DisplayGL::updateContentSize);
 }
 
 bool DisplayGL::supportsFormat(const QSurfaceFormat& format) {
@@ -331,12 +333,14 @@ void DisplayGL::unpauseDrawing() {
 		if (!m_gl && shouldDisableUpdates()) {
 			setUpdatesEnabled(false);
 		}
+		QMetaObject::invokeMethod(this, "updateContentSize", Qt::QueuedConnection);
 	}
 }
 
 void DisplayGL::forceDraw() {
 	if (m_hasStarted) {
 		QMetaObject::invokeMethod(m_painter.get(), "forceDraw");
+		QMetaObject::invokeMethod(this, "updateContentSize", Qt::QueuedConnection);
 	}
 }
 
@@ -398,6 +402,7 @@ void DisplayGL::setVideoScale(int scale) {
 
 void DisplayGL::setBackgroundImage(const QImage& image) {
 	QMetaObject::invokeMethod(m_painter.get(), "setBackgroundImage", Q_ARG(const QImage&, image));
+	QMetaObject::invokeMethod(this, "updateContentSize", Qt::QueuedConnection);
 }
 
 void DisplayGL::resizeEvent(QResizeEvent* event) {
@@ -452,6 +457,10 @@ void DisplayGL::setupProxyThread() {
 	m_proxyThread.start();
 }
 
+void DisplayGL::updateContentSize() {
+	QMetaObject::invokeMethod(m_painter.get(), "contentSize", Qt::BlockingQueuedConnection, Q_RETURN_ARG(QSize, m_cachedContentSize));
+}
+
 int DisplayGL::framebufferHandle() {
 	return m_painter->glTex();
 }
@@ -972,6 +981,13 @@ VideoShader* PainterGL::shaders() {
 	return &m_shader;
 }
 
+QSize PainterGL::contentSize() const {
+	unsigned width, height;
+	VideoBackendGetFrameSize(m_backend, &width, &height);
+	return {static_cast<int>(width > static_cast<unsigned>(INT_MAX) ? INT_MAX : width),
+	        static_cast<int>(height > static_cast<unsigned>(INT_MAX) ? INT_MAX : height)};
+}
+
 int PainterGL::glTex() {
 #if defined(BUILD_GLES2) || defined(BUILD_GLES3)
 	if (supportsShaders()) {

src/platform/qt/DisplayGL.h

@@ -88,6 +88,7 @@ public:
 	VideoShader* shaders() override;
 	void setVideoProxy(std::shared_ptr<VideoProxy>) override;
 	int framebufferHandle() override;
+	QSize contentSize() const override { return m_cachedContentSize; }
 
 	static bool supportsFormat(const QSurfaceFormat&);
 
@@ -115,6 +116,7 @@ protected:
 
 private slots:
 	void setupProxyThread();
+	void updateContentSize();
 
 private:
 	void resizePainter();
@@ -131,6 +133,7 @@ private:
 	mGLWidget* m_gl;
 	QOffscreenSurface m_proxySurface;
 	std::unique_ptr<QOpenGLContext> m_proxyContext;
+	QSize m_cachedContentSize;
 };
 
 class PainterGL : public QObject {
@@ -182,6 +185,7 @@ public slots:
 	void setShaders(struct VDir*);
 	void clearShaders();
 	VideoShader* shaders();
+	QSize contentSize() const;
 
 signals:
 	void created();

src/platform/qt/DisplayQt.cpp

@@ -106,22 +106,18 @@ void DisplayQt::paintEvent(QPaintEvent*) {
 
 	QRect bgRect(0, 0, m_background.width(), m_background.height());
 	QRect imRect(0, 0, m_width, m_height);
-	QSize outerFrame;
+	QSize outerFrame = contentSize();
 
 	if (bgRect.width() > imRect.width()) {
 		imRect.moveLeft(bgRect.width() - imRect.width());
-		outerFrame.setWidth(bgRect.width());
 	} else {
 		bgRect.moveLeft(imRect.width() - bgRect.width());
-		outerFrame.setWidth(imRect.width());
 	}
 
 	if (bgRect.height() > imRect.height()) {
 		imRect.moveTop(bgRect.height() - imRect.height());
-		outerFrame.setHeight(bgRect.height());
 	} else {
 		bgRect.moveTop(imRect.height() - bgRect.height());
-		outerFrame.setHeight(imRect.height());
 	}
 
 	QRect full(clampSize(outerFrame, size(), isAspectRatioLocked(), isIntegerScalingLocked()));
@@ -184,3 +180,15 @@ void DisplayQt::paintEvent(QPaintEvent*) {
 		messagePainter()->paint(&painter);
 	}
 }
+
+QSize DisplayQt::contentSize() const {
+	QSize outerFrame(m_width, m_height);
+
+	if (m_background.width() > outerFrame.width()) {
+		outerFrame.setWidth(m_background.width());
+	}
+	if (m_background.height() > outerFrame.height()) {
+		outerFrame.setHeight(m_background.height());
+	}
+	return outerFrame;
+}

src/platform/qt/DisplayQt.h

@@ -22,6 +22,7 @@ public:
 	bool isDrawing() const override { return m_isDrawing; }
 	bool supportsShaders() const override { return false; }
 	VideoShader* shaders() override { return nullptr; }
+	QSize contentSize() const override;
 
 public slots:
 	void stopDrawing() override;

src/platform/qt/Window.cpp

@@ -1488,8 +1488,8 @@ void Window::setupMenu(QMenuBar* menubar) {
 			Action* setSize = m_frameSizes[i];
 			showNormal();
 			QSize size(GBA_VIDEO_HORIZONTAL_PIXELS, GBA_VIDEO_VERTICAL_PIXELS);
-			if (m_controller) {
+			if (m_display) {
-				size = m_controller->screenDimensions();
+				size = m_display->contentSize();
 			}
 			size *= i;
 			m_savedScale = i;