gtk:tree-view-column-cell-size (column area)

column -- a gtk:tree-view-column object
area -- a gdk:rectangle instance for the area a cell in the column will be allocated, or nil
xoffset -- an integer for the x offset of a cell relative to area
yoffset -- an integer for the y offset of a cell relative to area
width -- an integer for the width needed to render a cell
height -- an integer for the height needed to render a cell

Obtains the width and height needed to render the column. This is used primarily by the tree view.