internal override void ParseXEvent(System.IntPtr call, System.IntPtr client)
        {
            var cs = (XmHierarchyNodeStateData)Marshal.PtrToStructure(call, typeof(XmHierarchyNodeStateData));
            State = cs.state;

            Widget = Sender.AppContext.FindWidgetByHandle(cs.widget);
        }
        internal override void ParseXEvent(System.IntPtr call, System.IntPtr client)
        {
            var cs = (XmNotebookCallbackStruct)Marshal.PtrToStructure(call, typeof(XmNotebookCallbackStruct));
            Reason = ConvertReason(cs.reason);

            PageNumber = cs.page_number;
            PageWidget = (IntPtr.Zero != cs.page_widget) ? Sender.AppContext.FindWidgetByHandle(cs.page_widget) : null;

            PrevPageNumber = cs.prev_page_number;
            PrevPageWidget = (IntPtr.Zero != cs.prev_page_widget) ? Sender.AppContext.FindWidgetByHandle(cs.prev_page_widget) : null;
        }