Refresh the widgets from the current font

def refresh(self):
        """Refresh the widgets from the current font"""
        font = self.current_font

        # refresh btn_bold
        self.btn_bold.blockSignals(True)
        self.btn_bold.setChecked(font.weight() > 50)
        self.btn_bold.blockSignals(False)

        # refresh btn_italic
        self.btn_italic.blockSignals(True)
        self.btn_italic.setChecked(font.italic())
        self.btn_italic.blockSignals(False)

        # refresh font size
        self.spin_box.blockSignals(True)
        self.spin_box.setValue(font.pointSize())
        self.spin_box.blockSignals(False)