static void SetupImageList(SampleViewport viewport)
 {
     if (!LayoutFarm.CustomWidgets.ResImageList.HasImages)
     {
         //set imagelists
         var imgdic = new Dictionary <CustomWidgets.ImageName, Image>();
         imgdic[CustomWidgets.ImageName.CheckBoxUnChecked] = viewport.LoadImage("../../Data/imgs/arrow_close.png");
         imgdic[CustomWidgets.ImageName.CheckBoxChecked]   = viewport.LoadImage("../../Data/imgs/arrow_open.png");
         LayoutFarm.CustomWidgets.ResImageList.SetImageList(imgdic);
     }
 }