Is there some way to create a cell renderer that simply
displays a value if only one value (in an array) exists, and to
display a combo box otherwise? In other words, I only want combo
boxes to appear in cells that have multiple values to choose from,
and I don't want single values to be editable.
One way to do this would be to create a cell renderer with
two view states, one showing a label and one showing a combobox,
then set currentState in the set data() accessor of the renderer
based on the incoming value.
If you're not familiar/comfortable with states, you could
achieve the same thing using a ViewStack, or just manually setting
the label and combobox to be visible/invisible as needed.