Bug 380742

-- Originally posted by (AT sourceforge.net): *anonymous --

-- This ticket was imported from http://sourceforge.net/p/rkward/bugs/112 on 2017-05-30 15:26:48 +0100 --
In the data editor, if one of a data frame's variables is a factor containing many levels, editing one cell results in a very big popup menu with all factor levels filling the screen. The menu doesn't show all of the levels since there are too many of them to fit on screen, and yet one cannot go out of the menu using the mouse because there's nowhere to click. All in all, this feels badly broken. ;-\)

Having many factor levels can sound silly, but that's how R imports character variables from CSV files, so that's not an uncommon scenario.

As a short-term fix, I think the popup menu shouldn't appear if there are more than 50 or 80 levels, so that the menu keeps a reasonable size. Anyway, when there are too many choices, it's an efficient solution to select a level.

The better fix would be to provide auto-completion once the user has typed enough letters that the possible choices are under 50. But hand-editing very large factors isn't probably a common use case, so maybe that's not worth it: as long as the editor doesn't do weird things, it's OK.