def set_marktype_cb(self, w, index):
        """Set type of marking."""
        self.marktype = self._mark_options[index]

        # Mark size is not used for point
        if self.marktype != 'point':
            self.w.mark_size.set_enabled(True)
        else:
            self.w.mark_size.set_enabled(False)
Set type of marking.