public boolean isNavigationEvent(ColumnViewer viewer, Event event) {
		switch (event.keyCode) {
		case SWT.ARROW_UP:
		case SWT.ARROW_DOWN:
		case SWT.ARROW_LEFT:
		case SWT.ARROW_RIGHT:
		case SWT.HOME:
		case SWT.PAGE_DOWN:
		case SWT.PAGE_UP:
		case SWT.END:
			return true;
		default:
			return false;
		}
	}