GWT java CELLTABLE MouseHover Buttoncell -

so have here cellbutton :

        column<dateiles, string> column_2 = new column<dateiles, string>(new buttoncell()) {         @override         public string getvalue(dateiles object) {             int s = object.comments.size();             string ss = string.valueof(s);             return ss;         }      };     celltable.addcolumn(column_2, "comments");     celltable.setcolumnwidth(column_2, "100px"); 

i want add buttons each cell column tooltip how possible

this.addcellpreviewhandler(new handler<tabletype>() {              @override             public void oncellpreview(final cellpreviewevent<tabletype> event) {                 int columnid = event.getcolumn();              }         });      } 

just replace tabletype object definded when instantiating table ( t of celltable<t> ) columnid can detect right column.