Colorizing rows in SimpleList revisited

[John McDermott <jjm jkintl com>]

I asked earlier about colorizing rows in a Gtk2::SimpleList.  Here is the 
solution I came up with:

1) add a column or columns to the data to hold the attributes of the rows 
(e.g. column number 8 for background color).  Use the SimpleList 
attribute of 'hidden'.

2) declare this method
sub Gtk2::SimpleList::set_attr {
        my ($self, $attr, $col_no) = @_;
        for(my $i = 0 ; $i < $self->get_model->get_n_columns ; $i++){  
                # how to avoid warnings on non-existant attributes???
                my $col = $self->get_column($i);
                $col->add_attribute($col->get_cell_renderers,
                         $attr=>$col_no)
                  if defined $col and defined $col->get_cell_renderers;
        }
}

3) after creating the list, configure the columns connecting the 
appropriate column and the attribute it holds.. e.g.
        $slist->set_attr( "cell-background",8); #col 8 is fg
        $slist->set_attr( "foreground",9);      #col 9 is bg
        $slist->{data}[4][8] = "green";         #change fg on row 4

The only problem is that this gives runtime warnings for cells not having 
a given attribute -- e.g. cells using the boolean renderer don't have a 
foreground color.  My question is, how do I determine whether or not a 
given renderer supports a particular attribute?

Thanks,
--john
--
John McDermott
Writer, Educator, Consultant
jjm jkintl com          http://www.jkintl.com
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