如何通过双击QDoubleSpinBox来标记整个文本？

#include <QtWidgets>

class MySpinBox : public QDoubleSpinBox
{
public:
    MySpinBox(QWidget *parent = nullptr) : QDoubleSpinBox(parent)
    {
        installEventFilter(this);
    }

    bool eventFilter(QObject *obj, QEvent *event) override
    {
        if (event->type() == QEvent::MouseButtonDblClick)
        {
            selectAll();
        }

        return QDoubleSpinBox::eventFilter(obj, event);
    }
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QWidget widget;
    QVBoxLayout layout(&widget);

    QLabel label("Double Spin Box:");
    layout.addWidget(&label);

    MySpinBox spinBox;
    layout.addWidget(&spinBox);

    widget.show();

    return app.exec();
}