mtsgui: conveniently switch between tabs using Alt+Left and Alt+Right

src/mtsgui/glwidget.cpp

@@ -492,8 +492,16 @@ void GLWidget::keyPressEvent(QKeyEvent *event) {
 		case Qt::Key_PageUp:   m_context->movementScale *= 2; break;
 		case Qt::Key_PageDown: m_context->movementScale /= 2; break;
 		case Qt::Key_Left:
+			if (event->modifiers() & Qt::AltModifier) {
+				emit switchTab(-1);
+				return;
+			}
 			m_leftKeyDown = true; break;
 		case Qt::Key_Right:
+			if (event->modifiers() & Qt::AltModifier) {
+				emit switchTab(1);
+				return;
+			}
 			m_rightKeyDown = true; break;
 		case Qt::Key_Up:
 			m_upKeyDown = true; break;
@@ -520,7 +528,7 @@ void GLWidget::keyPressEvent(QKeyEvent *event) {
 			if (m_context->selectionMode == EScene) {
 				m_context->selectionMode = ENothing;
 				m_aabb.reset();
-			} else {
+			} else if (m_context->scene) {
 				m_context->selectionMode = EScene;
 				m_aabb = m_context->scene->getKDTree()->getAABB();
 			}

src/mtsgui/glwidget.h

@@ -90,6 +90,7 @@ signals:
 	void loadFileRequest(const QString &fileName);
 	void crop(int type, int x, int y, int width, int height);
 	void selectionChanged();
+	void switchTab(int rel);
 
 public slots:
 	void timerImpulse();

src/mtsgui/mainwindow.cpp

@@ -169,6 +169,7 @@ MainWindow::MainWindow(QWidget *parent) :
 	connect(ui->glView, SIGNAL(statusMessage(const QString &)), this, SLOT(onStatusMessage(const QString &)),
 		Qt::QueuedConnection);
 	connect(ui->glView, SIGNAL(selectionChanged()), this, SLOT(onSelectionChanged()));
+	connect(ui->glView, SIGNAL(switchTab(int)), this, SLOT(onSwitchTab(int)));
 
 	/* Load defaults from app settings file */
 	ui->glView->setInvertMouse(settings.value("invertMouse", false).toBool());
@@ -500,6 +501,12 @@ void MainWindow::on_actionFocusSelected_triggered() {
 	ui->glView->keyPressEvent(&event);
 }
 
+void MainWindow::onSwitchTab(int rel) {
+	int index = ui->tabBar->currentIndex() + rel;
+	if (index >= 0 && index < ui->tabBar->count())
+		ui->tabBar->setCurrentIndex(index);
+}
+
 void MainWindow::on_actionFocusAll_triggered() {
 	QKeyEvent event(QEvent::KeyPress, Qt::Key_A, Qt::NoModifier);
 	ui->glView->keyPressEvent(&event);

src/mtsgui/mainwindow.h

@@ -202,6 +202,7 @@ private slots:
 	void on_glView_crop(int type, int x=0, int y=0,
 		int width=0, int height=0);
 	void onSelectionChanged();
+	void onSwitchTab(int rel);
 
 private:
 	void exportImage(const QString &fileName);