QPanGesture is not detected on Mac

#include <QMainWindow>
#include <QGestureEvent>
#include <QPanGesture>
#include <QPinchGesture>
#include <QDebug>
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow() {
        grabGesture(Qt::PanGesture);
        grabGesture(Qt::PinchGesture);
    }
    bool event(QEvent* event) {
        if (event->type() == QEvent::Gesture) {
            QGestureEvent *gesture = static_cast<QGestureEvent*>(event);
            if (QPinchGesture *pinch = static_cast<QPinchGesture *>(
                        gesture->gesture(Qt::PinchGesture))) {
                qDebug() << "Pinch";
            }
            if (QPanGesture *pan = static_cast<QPanGesture *>(
                        gesture->gesture(Qt::PanGesture))) {
                qDebug() << "Pan";
             }
        }
        return QWidget::event(event);
    }
};