$(document).ready(function () {
   var spread = new GC.Spread.Sheets.Workbook(document.getElementById("ss"));
   function ContextMenu(){}
   ContextMenu.prototype = new GC.Spread.Sheets.ContextMenu.ContextMenu(spread);
   ContextMenu.prototype.onOpenMenu = function (menuData, itemsDataForShown, hitInfo, spread) {
          console.log(menuData);
          console.log(itemsDataForShown);
          console.log(hitInfo);
          console.log(spread);
          //you can change itemsDataForShown to change filter result
          //if you only want to change filter result,return false or don't return anything
          //you also can open your own context menu,if you want to do this,return true
          //return true;
   };
   var contextMenu = new ContextMenu();
   spread.contextMenu = contextMenu;
});