I am using CellTable to show my records but now the thing is I want show a select box when user clicks on a cell. One more thing is that select box is my own widget, not a prede
Some time ago I faced with the similar problem (tried to insert a custom widget into CellList cell), but unfortunately did not find an easy solution.
Generally, you can implement specific cell class, extending AbstractCell or ActionCell. In this case you will have to override render() method and implement your own rendering. Good example is given in AbstractCell class javadoc.