public void AddContent(LayoutUIElement ui)
        {
            if (_content == null)
            {
                return;
            }

            ui.SetParent(_content);
        }
 public void SetContent(LayoutUIElement content)
 {
     _content = content;
     _content.SetParent(this);
     _content.SetAnchor(AnchorType.TopStretch);
     _content.Pivot = new Vector2(0.5f, 0);
     _content.Size  = new Vector2(100, 200);
     _content.SetIndex(0);
     RefreshContentPosition();
 }