Uncheck checkbox in other rows programmatically?

I would like to implement the logic of setting the default row in the list of data by using checkbox as indicator. It functions like this: if a user check on one row this is not checked, it will check the current row and clear out the checked box. If a user click on the row that has already been checked, the checkbox will stay in check.

I have been trying to use setCellTemplate() and onCellValueChanged() to implement this, but I can't succeed in getting to set the other check box programmatically while in onCellValueChanged().

Please advise.. Thanks!!