Hello Quan,

I suggest you use ui.igGridUpdating's editCellEnding event to know when a cell is edited or added, and rowDeleting event when a row is deleted.

 $("#grid1").igGrid(
  {
.....
   features:[
    {
     name:"Updating",
     editMode:"cell",
     rowDeleting: function(evt, ui){
      //enable the save button
     },
     editCellEnding: function(evt, ui){
      if(ui.update)
      {
       //enable the save button
      }
     }
    }
   ]
  }
    );

I have attached the sample to demonstrate the above.

The following is the API reference of these events;

editCellEnding event
http://igniteui.com/help/api/2016.2/ui.iggridupdating#events:editCellEnding

rowDeleting event
http://igniteui.com/help/api/2016.2/ui.iggridupdating#events:rowDeleting

Let me know if I may be of further assistance.

Thank you,
Mihoko Kamiishi