Tac.PopupWindow.OnGUI C# (CSharp) Method

        void OnGUI()
        {
            if (showPopup)
            {
                GUI.skin = HighLogic.Skin;
                popupPos = Utilities.EnsureCompletelyVisible(popupPos);
                popupPos = GUILayout.Window(windowId, popupPos, DrawPopupContents, "");
            }
        }