private void OnClickWidgetActor(WidgetActorIcon widget)
    {
        for (int i = 0; i < widgetActorIconSelecteds.Length; ++i)
        {
            var selected = widgetActorIconSelecteds [i];
            if (selected.actorId != Actor.INVALID_ID)
            {
                continue;
            }

            selected.actorImage.sprite = widget.actorImage.sprite;
            selected.actorId           = widget.actorId;

            widget.selectedMark.SetActive(true);
            break;
        }

        this.UpdateBattleButtonStatus();
    }
    private void OnClickWidgetActorPlaceHolder(WidgetActorIcon widget)
    {
        if (widget.actorId == Actor.INVALID_ID)
        {
            return;
        }

        for (int i = 0; i < widgetActorIconSelectors.Count; i++)
        {
            var selector = widgetActorIconSelectors[i];
            if (selector.actorId != widget.actorId)
            {
                continue;
            }

            selector.selectedMark.SetActive(false);
            break;
        }

        widget.actorImage.sprite = null;
        widget.actorId           = Actor.INVALID_ID;

        this.UpdateBattleButtonStatus();
    }