Sets the GtkTreeCellDataFunc to use for the column. This
function is used instead of the standard attributes mapping for
setting the column value, and should set the value of tree_column's
cell renderer as appropriate. func may be NULL to remove an
older one.
Sets the GtkTreeCellDataFunc to use for the column. This function is used instead of the standard attributes mapping for setting the column value, and should set the value of tree_column's cell renderer as appropriate. func may be NULL to remove an older one.