The RadioButtons class is a Control subclass which represents Cocoa’s NSMatrix in “radio” mode.
A list of strings determining the radio buttons that will be present in the matrix.
By setting this attribute to something larger than 1, you can make radio buttons span over multiple columns. The number of rows will be automatically calculated from the number of items.
The cells in the array are row-ordered, that is, the first row of cells appears first in the array, followed by the second row, and so forth.
Warning. The number of items has to fit exactly in the square that is formed by the rows and columns. For example, if you have 3 columns, your number of items have to be a multiple of 3.