Switch to quick layout number *index*

def quick_layout_switch(self, index):
        """Switch to quick layout number *index*"""
        section = 'quick_layouts'

        try:
            settings = self.load_window_settings('layout_{}/'.format(index),
                                                 section=section)
            (hexstate, window_size, prefs_dialog_size, pos, is_maximized,
             is_fullscreen) = settings

            # The defaults layouts will always be regenerated unless there was
            # an overwrite, either by rewriting with same name, or by deleting
            # and then creating a new one
            if hexstate is None:
                # The value for hexstate shouldn't be None for a custom saved
                # layout (ie, where the index is greater than the number of
                # defaults).  See issue 6202.
                if index != 'default' and index >= self.DEFAULT_LAYOUTS:
                    QMessageBox.critical(
                            self, _("Warning"),
                            _("Error opening the custom layout.  Please close"
                              " Spyder and try again.  If the issue persists,"
                              " then you must use 'Reset to Spyder default' "
                              "from the layout menu."))
                    return
                self.setup_default_layouts(index, settings)
        except cp.NoOptionError:
            QMessageBox.critical(self, _("Warning"),
                                 _("Quick switch layout #%s has not yet "
                                   "been defined.") % str(index))
            return
            # TODO: is there any real use in calling the previous layout
            # setting?
            # self.previous_layout_settings = self.get_window_settings()
        self.set_window_settings(*settings)
        self.current_quick_layout = index

        # make sure the flags are correctly set for visible panes
        for plugin in (self.widgetlist + self.thirdparty_plugins):
            action = plugin.toggle_view_action
            action.setChecked(plugin.dockwidget.isVisible())