focusPrevious() {
        if (this._listWidget.length === 0) {
            return false;
        }
        const focusedIxs = this._listWidget.getFocus();
        if (focusedIxs.length === 0) {
            this._listWidget.focusLast();
            const focused = this._listWidget.getFocus()[0];
            this._listWidget.reveal(focused);
            return true;
        }
        else {
            if (focusedIxs[0] === 0) {
                this._listWidget.setFocus([]);
                return false;
            }
            else {
                this._listWidget.focusPrevious();
                const focused = this._listWidget.getFocus()[0];
                this._listWidget.reveal(focused);
                return true;
            }
        }
    }
@returns true if focus is moved to previous element