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.