public boolean getCommandButtonVisibility(CommandButton btn) {
        if (btn == null) {
            throw new IllegalArgumentException();
        }

        boolean ret = true;
        switch (btn) {
            case SWITCH:
                ret = this.buttonComSwitchVisible;
                break;

            case LOCK:
                ret = this.buttonComLockVisible;
                break;

            case LOGOUT:
                ret = this.buttonComLogOutVisible;
                break;

            case PASSWORD:
                ret = this.buttonComPasswordVisible;
                break;

            case TASKMANAGER:
                ret = this.buttonComTaskmanagerVisible;
                break;

            default:
                throw new IllegalArgumentException();
        }
        return ret;
    }