UnityEditor.PopupWindowContent.OnOpen C# (CSharp) Method

        public virtual void OnOpen()
        {
        }

 void Init(Rect activatorRect, PopupWindowContent windowContent, PopupLocationHelper.PopupLocation[] locationPriorityOrder, ShowMode showMode)
 {
     hideFlags       = HideFlags.DontSave;
     wantsMouseMove  = true;
     m_WindowContent = windowContent;
     m_WindowContent.editorWindow = this;
     m_WindowContent.OnOpen();
     m_ActivatorRect = GUIUtility.GUIToScreenRect(activatorRect);
     ShowAsDropDown(m_ActivatorRect, m_WindowContent.GetWindowSize(), locationPriorityOrder, showMode);
 }