root_layout->addWidget(button_box);
// Set tab width to 4 characters
+#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
+ expr_edit_->setTabStopDistance(util::text_width(QFontMetrics(font()), "XXXX"));
+#else
expr_edit_->setTabStopWidth(util::text_width(QFontMetrics(font()), "XXXX"));
+#endif
connect(button_box, SIGNAL(accepted()), this, SLOT(accept()));
connect(button_box, SIGNAL(rejected()), this, SLOT(reject()));