Drawing a combobox is one thing. Making it work like a combobox is another. If you want to hear my personal opinion then pushing comboboxes into table columns is a violation against user experience If you consider what the column contains -- it contains some VALUE. The way you change the value and the sole fact that you can change the value (or not) is meaningless while displaying that value. If you display a bunch of comboboxes in a column, you just clutter the display and you have no functional benefit over just displaying the value contained in the field. If the user wants to edit a field, he will enter edit mode and use the combo that pops up, to modify the value which afterwards will again be displayed in the column.