@Override
    public void preferenceChange(PreferenceChangeEvent event) {
        String property = event.getProperty();
        if (CommonUtils.equalObjects(event.getOldValue(), event.getNewValue())) {
            return;
        }
        switch (property) {
            case ModelPreferences.NAVIGATOR_SHOW_FOLDER_PLACEHOLDERS:
            case ModelPreferences.NAVIGATOR_SORT_ALPHABETICALLY:
            case ModelPreferences.NAVIGATOR_SORT_FOLDERS_FIRST:
            case NavigatorPreferences.NAVIGATOR_COLOR_ALL_NODES:
            case NavigatorPreferences.NAVIGATOR_GROUP_BY_DRIVER:
                tree.getViewer().refresh();
                break;
            case NavigatorPreferences.NAVIGATOR_SHOW_STATISTICS_INFO:
            case NavigatorPreferences.NAVIGATOR_SHOW_CONNECTION_HOST_NAME:
            case NavigatorPreferences.NAVIGATOR_SHOW_OBJECTS_DESCRIPTION:
            case NavigatorPreferences.NAVIGATOR_SHOW_NODE_ACTIONS:
                tree.getViewer().getTree().redraw();
                break;
        }
    }
Passing the focus request to the viewer's control.
plugins/org.jkiss.dbeaver.ui.navigator/src/org/jkiss/dbeaver/ui/navigator/database/NavigatorViewBase.java